1pod::Prima::Widget(3) User Contributed Perl Documentationpod::Prima::Widget(3)
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NAME

6       Prima::Widget - window management
7

SYNOPSIS

9          # create a widget
10          my $widget = Prima::Widget-> new(
11              size    => [ 200, 200],
12              color   => cl::Green,
13              visible => 0,
14              onPaint => sub {
15                 my ($self,$canvas) = @_;
16                 $canvas-> clear;
17                 $canvas-> text_out( "Hello world!", 10, 10);
18              },
19          );
20
21          # manipulate the widget
22          $widget-> origin( 10, 10);
23          $widget-> show;
24

DESCRIPTION

26       Prima::Widget is a descendant of Prima::Component, a class, especially
27       crafted to reflect and govern properties of a system-dependent window,
28       such as its position, hierarchy, outlook etc. Prima::Widget is mapped
29       into the screen space as a rectangular area, with distinct boundaries,
30       pointer and sometimes cursor, and a user-selectable input focus.
31

USAGE

33       Prima::Widget class and its descendants are used widely throughout the
34       toolkit, and, indeed provide almost all its user interaction and input-
35       output.  The notification system, explained in Prima::Object, is
36       employed in Prima::Widget heavily, providing the programmer with
37       unified access to the system-generated events, that occur when the user
38       moves windows, clicks the mouse, types the keyboard, etc. Descendants
39       of Prima::Widget use the internal, the direct method of overriding the
40       notifications, whereas end programs tend to use the toolkit widgets
41       equipped with anonymous subroutines ( see Prima::Object for the
42       details).
43
44       The class functionality is much more extensive comparing to the other
45       built-in classes, and therefore the explanations are grouped in several
46       topics.
47

Creation and destruction

49       The widget creation syntax is the same as for the other Prima objects:
50
51          Prima::Widget-> create(
52             name => 'Widget',
53             size => [ 20, 10],
54             onMouseClick => sub { print "click\n"; },
55             owner => $owner,
56          );
57
58       In the real life, a widget must be almost always explicitly told about
59       its owner. The owner object is either a Prima::Widget descendant, in
60       which case the widget is drawn inside its inferior, or the application
61       object, and in the latter case a widget becomes top-level. This is the
62       reason why the "insert" syntax is much more often used, as it is more
63       illustrative and is more convenient for creating several widgets in one
64       call ( see Prima::Object ).
65
66          $owner-> insert( 'Prima::Widget',
67             name => 'Widget',
68             size => [ 20, 10],
69             onMouseClick => sub { print "click\n"; },
70          );
71
72       These two examples produce identical results.
73
74       As a descendant of Prima::Component, Prima::Widget sends "Create"
75       notification when created ( more precisely, after its init stage is
76       finished. See Prima::Object for details). This notification is called
77       and processed within "create()" call. In addition, another notification
78       "Setup" is sent after the widget is created. This message is posted, so
79       it is called within "create()" but processed in the application event
80       loop. This means that the execution time of "Setup" is uncertain, as it
81       is with all posted messages; its delivery time is system-dependent, so
82       its use must be considered with care.
83
84       After a widget is created, it is usually asked to render its content,
85       provided that the widget is visible. This request is delivered by means
86       of "Paint" notification.
87
88       When the life time of a widget is over, its method "destroy()" is
89       called, often implicitly. If a widget gets destroyed because its owner
90       also does, it is guaranteed that the children widgets will be destroyed
91       first, and the owner afterwards. In such situation, widget can operate
92       with a limited functionality both on itself and its owners ( see
93       Prima::Object, Creation section ).
94

Graphic content

96       A widget can use two different ways for representing its graphic
97       content to the user. The first method is event-driven, when the "Paint"
98       notification arrives, notifying the widget that it must re-paint
99       itself.  The second is the 'direct' method, when the widget generates
100       graphic output unconditionally.
101
102   Event-driven rendering
103       A notification responsible for widget repainting is "Paint".  It
104       provides a single ( besides the widget itself ) parameter, an object,
105       where the drawing is performed. In an event-driven call, it is always
106       equals to the widget. However, if a custom mechanism should be used
107       that directly calls, for example,
108
109          $widget-> notify('Paint', $some_other_widget);
110
111       for whatever purpose, it is recommended ( not required, though ), to
112       use this parameter, not the widget itself for painting and drawing
113       calls.
114
115       The example of "Paint" callback is quite simple:
116
117          Prima::Widget-> create(
118              ...
119              onPaint => sub {
120                 my ( $self, $canvas) = @_;
121                 $canvas-> clear;
122                 $canvas-> text_out("Clicked $self->{clicked} times", 10, 10);
123              },
124              onMouseClick => sub {
125                 $_[0]-> {clicked}++;
126                 $_[0]-> repaint;
127              },
128          );
129
130       The example uses several important features of the event-driven
131       mechanism. First, no "begin_paint()"/"end_paint()" brackets are used
132       within the callback. These are called implicitly.  Second, when the
133       custom refresh of the widget's graphic content is needed, no code like
134       "notify(q(Paint))" is used - "repaint()" method is used instead.  It
135       must be noted, that the actual execution of "Paint" callbacks might or
136       might not occur inside the "repaint()" call. This behavior is governed
137       by the "::syncPaint" property.  "repaint()" marks the whole widget's
138       area to be refreshed, or invalidates the area. For the finer gradation
139       of the area that should be repainted, "invalidate_rect()" and
140       "validate_rect()" pair of functions is used. Thus,
141
142         $x-> repaint()
143
144       code is a mere alias to
145
146         $x-> invalidate_rect( 0, 0, $x-> size);
147
148       call. It must be realized, that the area, passed to "invalidate_rect()"
149       only in its ideal ( but a quite often ) execution case will be
150       pertained as a clipping rectangle when a widget executes its "Paint"
151       notification.  The user and system interactions can result in
152       exposition of other parts of a widget ( like, moving windows over a
153       widget ), and the resulting clipping rectangle can be different from
154       the one that was passed to "invalidate_rect()". Moreover, the clipping
155       rectangle can become empty as the result of these influences, and the
156       notification will not be called at all.
157
158       Invalid rectangle is presented differently inside and outside the
159       drawing mode. The first, returned by "::clipRect", employs inclusive-
160       inclusive coordinates, whereas "invalidate_rect()", "validate_rect()"
161       and "get_invalid_rect()" - inclusive-exclusive coordinates. The ideal
162       case exemplifies the above said:
163
164          $x-> onPaint( sub {
165             my @c = $_[0]-> clipRect;
166             print "clip rect:@c\n";
167          });
168          $x-> invalidate_rect( 10, 10, 20, 20);
169          ...
170          clip rect: 10 10 19 19
171
172       As noted above, "::clipRect" property is set to the clipping rectangle
173       of the widget area that is needed to be refreshed, and an event handler
174       code can take advantage of this information, increasing the efficiency
175       of the painting procedure.
176
177       Further assignments of "::clipRect" property do not make possible over-
178       painting on the screen area that lies outside the original clipping
179       region. This is also valid for all paint operations, however since the
180       original clipping rectangle is the full area of a canvas, this rule is
181       implicit and unnecessary, because whatever large the clipping rectangle
182       is, drawing and painting cannot be performed outside the physical
183       boundaries of the canvas.
184
185   Direct rendering
186       The direct rendering, contrary to the event-driven, is initiated by the
187       program, not by the system. If a programmer wishes to paint over a
188       widget immediately, then "begin_paint()" is called, and, if successful,
189       the part of the screen occupied by the widget is accessible to the
190       drawing and painting routines.
191
192       This method is useful, for example, for graphic demonstration programs,
193       that draw continuously without any input.  Another field is the screen
194       drawing, which is performed with Prima::Application class, that does
195       not have "Paint" notification. Application's graphic canvas represents
196       the whole screen, allowing over-drawing the graphic content of other
197       programs.
198
199       The event-driven rendering method adds implicit
200       "begin_paint()"/"end_paint()" brackets ( plus some system-dependent
201       actions ) and is a convenience version of the direct rendering.
202       Sometimes, however, the changes needed to be made to a widget's graphic
203       context are so insignificant, so the direct rendering method is
204       preferable, because of the cleaner and terser code. As an example might
205       serve a simple progress bar, that draws a simple colored bar.  The
206       event-driven code would be ( in short, omitting many details ) as such:
207
208          $bar = Widget-> create(
209            width => 100,
210            onPaint => sub {
211               my ( $self, $canvas) = @_;
212               $canvas-> color( cl::Blue);
213               $canvas-> bar( 0, 0, $self-> {progress}, $self-> height);
214               $canvas-> color( cl::Back);
215               $canvas-> bar( $self-> {progress}, 0, $self-> size);
216            },
217          );
218          ...
219          $bar-> {progress} += 10;
220          $bar-> repaint;
221          # or, more efficiently, ( but clumsier )
222          # $bar-> invalidate_rect( $bar->{progress}-10, 0,
223          #                 $bar->{progress}, $bar-> height);
224
225       And the direct driven:
226
227          $bar = Widget-> create( width => 100 );
228          ...
229          $bar-> begin_paint;
230          $bar-> color( cl::Blue);
231          $bar-> bar( $progress, 0, $progress + 10, $bar-> height);
232          $bar-> end_paint;
233          $progress += 10;
234
235       The pros and contras are obvious: the event-driven rendered widget
236       correctly represents the status after an eventual repaint, for example
237       when the user sweeps a window over the progress bar widget. The direct
238       method cannot be that smart, but if the status bar is an insignificant
239       part of the program, the trade-off of the functionality in favor to the
240       code simplicity might be preferred.
241
242       Both methods can be effectively disabled using the paint locking
243       mechanism. The "lock()" and "unlock()" methods can be called several
244       times, stacking the requests. This feature is useful because many
245       properties implicitly call "repaint()", and if several of these
246       properties activate in a row, the unnecessary redrawing of the widget
247       can be avoided.  The drawback is that the last "unlock()" call triggers
248       "repaint()" unconditionally.
249

Geometry

251   Basic properties
252       A widget always has its position and size determined, even if it is not
253       visible on the screen. Prima::Widget provides several properties with
254       overlapping functionality, that govern the geometry of a widget. The
255       base properties are "::origin" and "::size", and the derived are
256       "::left", "::bottom", "::right", "::top", "::width", "::height" and
257       "::rect". "::origin" and "::size" operate with two integers, "::rect"
258       with four, others with one integer value.
259
260       As the Prima toolkit coordinate space begins in the lower bottom
261       corner, the combination of "::left" and "::bottom" is same as
262       "::origin", and combination of "::left", "::bottom", "::right" and
263       "::top" - same as "::rect".
264
265       When a widget is moved or resized, correspondingly two notifications
266       occur: "Move" and "Size". The parameters to both are old and new
267       position and size. The notifications occur irrespectable to whether the
268       geometry change was issued by the program itself or by the user.
269
270   Implicit size regulations
271       Concerning the size of a widget, two additional two-integer properties
272       exist, "::sizeMin" and "::sizeMax", that constrain the extension of a
273       widget in their boundaries. The direct call that assigns values to the
274       size properties that lie outside "::sizeMin" and "::sizeMax"
275       boundaries, will fail - the widget extension will be adjusted to the
276       boundary values, not to the specified ones.
277
278       Change to widget's position and size can occur not only by an explicit
279       call to one of the geometry properties. The toolkit contains implicit
280       rules, that can move and resize a widget corresponding to the flags,
281       given to the "::growMode" property. The exact meaning of the "gm::XXX"
282       flags is not given here ( see description to "::growMode" in API
283       section ), but in short, it is possible with simple means to maintain
284       widget's size and position regarding its owner, when the latter is
285       resized. By default, and the default behavior corresponds to
286       "::growMode" 0, widget does not change neither its size nor position
287       when its owner is resized. It stays always in 'the left bottom corner'.
288       When, for example, a widget is expected to stay in 'the right bottom
289       corner', or 'the left top corner', the "gm::GrowLoX" and "gm::GrowLoY"
290       values must be used, correspondingly.  When a widget is expected to
291       cover, for example, its owner's lower part and change its width in
292       accord with the owner's, ( a horizontal scroll bar in an editor window
293       is the example), the "gm::GrowHiX" value must be used.
294
295       When this implicit size change does occur, the "::sizeMin" and
296       "::sizeMax" do take their part as well - they still do not allow the
297       widget's size to exceed their boundaries. However, this algorithm has a
298       problem, that is illustrated by the following setup. Imagine a widget
299       with size-dependent "::growMode" ( with "gm::GrowHiX" or "gm::GrowHiY"
300       bits set ) that must maintain certain relation between the owner's size
301       and its own. If the implicit size change would depend on the actual
302       widget size, derived as a result from the previous implicit size
303       action, then its size (and probably position) will be incorrect after
304       an attempt is made to change the widget's size to values outside the
305       size boundaries.
306
307       Example: child widget has width 100, growMode set to "gm::GrowHiX" and
308       sizeMin set to (95, 95). Its owner has width 200.  If the owner widget
309       changes gradually its width from 200 to 190 and then back, the
310       following width table emerges:
311
312                           Owner        Child
313         Initial state      200           100
314         Shrink             195   -5       95
315         Shrink             190   -5       95 - as it can not be less than 95.
316         Grow               195   +5      100
317         Grow               200   +5      105
318
319       That effect would exist if the differential-size algorithm would be
320       implemented, - the owner changes width by 5, and the child does the
321       same.  The situation is fixed by introducing the virtual size term.
322       The "::size" property is derived from virtual size, and as "::size"
323       cannot exceed the size boundaries, virtual size can.  It can even
324       accept the negative values. With this intermediate stage added, the
325       correct picture occurs:
326
327                           Owner        Child's       Child's
328                                        virtual width  width
329         Initial state      200           100           100
330         Shrink             195   -5       95            95
331         Shrink             190   -5       90            95
332         Grow               195   +5       95            95
333         Grow               200   +5      100           100
334
335   Geometry managers
336       The concept of geometry managers is imported from Tk, which in turn is
337       a port of Tcl-Tk. The idea behind it is that a widget size and position
338       is governed by one of the managers, which operate depending on the
339       specific options given to the widget. The selection is operated by
340       "::geometry" property, and is one of "gt::XXX" constants. The native (
341       and the default ) geometry manager is the described above grow-mode
342       algorithm ( "gt::GrowMode" ). The currently implemented Tk managers are
343       packer ( "gt::Pack" ) and placer ( "gt::Place").  Each has its own set
344       of options and methods, and their manuals are provided separately in
345       Prima::Widget::pack and Prima::Widget::place ( the manpages are also
346       imported from Tk ).
347
348       Another concept that comes along with geometry managers is the
349       'geometry request size'.  It is realized as a two-integer property
350       "::geomSize", which reflects the size deduced by some intrinsic widget
351       knowledge. The idea is that "::geomSize" it is merely a request to a
352       geometry manager, whereas the latter changes "::size" accordingly. For
353       example, a button might set its 'intrinsic' width in accord with the
354       width of text string displayed in it. If the default width for such a
355       button is not overridden, it is assigned with such a width. By default,
356       under "gt::GrowMode" geometry manager, setting "::geomSize" ( and its
357       two semi-alias properties "::geomWidth" and "::geomHeight" ) also
358       changes the actual widget size.Moreover, when the size is passed to the
359       Widget initialization code, "::size" properties are used to initialize
360       "::geomSize".  Such design minimizes the confusion between the two
361       properties, and also minimizes the direct usage of "::geomSize",
362       limiting it for selecting advisory size in widget internal code.
363
364       The geometry request size is useless under "gt::GrowMode" geometry
365       manager, but Tk managers use it extensively.
366
367   Relative coordinates
368       Another geometry issue, or rather a programming technique must be
369       mentioned - the relative coordinates. It is the well-known problem,
370       when a dialog window, developed with one font looks garbled on another
371       system with another font. The relative coordinates solve that problem;
372       the solution is to use the "::designScale" two-integer property, the
373       width and height of the font, that was used when the dialog window was
374       designed. With this property supplied, the position and size supplied
375       when a widget is actually created, are transformed in proportion
376       between the designed and the actual font metrics.
377
378       The relative coordinates can be used only when passing the geometry
379       properties values, and only before the creation stage, before a widget
380       is created, because the scaling calculations perform in
381       Prima::Widget::"profile_check_in()" method.
382
383       In order to employ the relative coordinates scheme, the owner ( or the
384       dialog ) widget must set its "::designScale" to the font metrics and
385       "::scaleChildren" property to 1.  Widgets, created with owner that
386       meets these requirements, participate in the relative coordinates
387       scheme. If a widget must be excluded from the relative geometry
388       applications, either the owner's property "::scaleChildren" must be set
389       to 0, or the widget's "::designScale" must be set to "undef".  As the
390       default "::designScale" value is "undef", no default implicit relative
391       geometry schemes are applied.
392
393       The "::designScale" property is auto-inherited; its value is copied to
394       the children widgets, unless the explicit "::designScale" was given
395       during the widget's creation. This is used when such a child widget
396       serves as an owner for some other grand-children widgets; the
397       inheritance scheme allows the grand- ( grand- etc ) children to
398       participate in the relative geometry scheme.
399
400       Note: it is advised to test such applications with the Prima::Stress
401       module, which assigns a random font as the default, so the testing
402       phase does not involve tweaking of the system settings.
403

Z-order

405       In case when two widgets overlap, one of these is drawn in full,
406       whereas the another only partly. Prima::Widget provides management of
407       the Z-axis ordering, but since Z-ordering paradigm can hardly be fit
408       into the properties scheme, the toolkit uses methods instead.
409
410       A widget can use four query methods: "first()", "last()", "next()", and
411       "prev()". These return, correspondingly, the first and the last widgets
412       in Z-order stack, and the direct neighbors of a widget ( $widget->
413       next-> prev always equals to the $widget itself, given that $widget->
414       next exists ).
415
416       The last widget is the topmost one, the one that is drawn fully.  The
417       first is the most obscured one, given that all the widgets overlap.
418
419       Z-order can also be changed at runtime ( but not during widget's
420       creation). There are three methods: "bring_to_front()", that sets the
421       widget last in the order, making it topmost, "send_to_back()", that
422       does the reverse, and "insert_behind()", that sets a widget behind the
423       another widget, passed as an argument.
424
425       Changes to Z-order trigger "ZOrderChanged" notification.
426

Parent-child relationship

428       By default, if a widget is a child to a widget or a window, it
429       maintains two features: it is clipped by its owner's boundaries and is
430       moved together as the owner widget moves, i.e. a child is inferior to
431       its parent. However, a widget without a parent still does have a valid
432       owner.  Instead of implementing parent property, the "::clipOwner"
433       property was devised. It is 1 by default, and if it is 1, then owner of
434       a widget is its parent, at the same time. However, when it is 0, many
435       things change. The widget is neither clipped nor moved together with
436       its parent. The widget become parentless, or, more strictly speaking,
437       the screen becomes its parent. Moreover, the widget's origin offset is
438       calculated then not from the owner's coordinates but from the screen,
439       and mouse events in the widget do not transgress implicitly to the
440       owner's top-level window eventual decorations.
441
442       The same results are produced if a widget is inserted in the
443       application object, which does not have screen visualization.  A widget
444       that belongs to the application object, can not reset its "::clipOwner"
445       value to 1.
446
447       The "::clipOwner" property opens a possibility for the toolkit widgets
448       to live inside other programs' windows. If the "::parentHandle" is
449       changed from its default "undef" value to a valid system window handle,
450       the widget becomes child to this window, which can belong to any
451       application residing on the same display. This option is dangerous,
452       however: normally widgets never get destroyed by no reason. A top-level
453       window is never destroyed before its "Close" notification grants the
454       destruction.  The case with "::parentHandle" is special, because a
455       widget, inserted into an alien application, must be prepared to be
456       destroyed at any moment. It is recommended to use prior knowledge about
457       such the application, and, even better, use one or another inter-
458       process communication scheme to interact with it.
459
460       A widget does not need to undertake anything special to become an
461       'owner'.  Any widget, that was set in "::owner" property on any other
462       widget, becomes an owner automatically. Its "get_widgets()" method
463       returns non-empty widget list. "get_widgets()" serves same purpose as
464       Prima::Component::"get_components()", but returns only Prima::Widget
465       descendants.
466
467       A widget can change its owner at any moment. The "::owner" property is
468       both readable and writable, and if a widget is visible during the owner
469       change, it is immediately appeared under different coordinates and
470       different clipping condition after the property change, given that its
471       "::clipOwner" is set to 1.
472

Visibility

474       A widget is created visible by default. Visible means that it is shown
475       on the screen if it is not shadowed by other widgets or windows. The
476       visibility is governed by the "::visible" property, and its two
477       convenience aliases, "show()" and "hide()".
478
479       When a widget is invisible, its geometry is not discarded; the widget
480       pertains its position and size, and is subject to all previously
481       discussed implicit sizing issues. When change to "::visible" property
482       is made, the screen is not updated immediately, but in the next event
483       loop invocation, because uncovering of the underlying area of a hidden
484       widget, and repainting of a new-shown widget both depend onto the
485       event-driven rendering functionality. If the graphic content must be
486       updated, "update_view()" must be called, but there's a problem. It is
487       obvious that if a widget is shown, the only content to be updated is
488       its own. When a widget becomes hidden, it may uncover more than one
489       widget, depending on the geometry, so it is unclear what widgets must
490       be updated.  For the practical reasons, it is enough to get one event
491       loop passed, by calling "yield()" method of the $::application object.
492       The other notifications may pass here as well, however.
493
494       There are other kinds of visibility. A widget might be visible, but one
495       of its owners might not. Or, a widget and its owners might be visible,
496       but they might be over-shadowed by the other windows. These conditions
497       are returned by "showing()" and "exposed()" functions, correspondinly.
498       These return boolean values corresponding to the condition described.
499       So, if a widget is 'exposed', it is 'showing' and 'visible';
500       "exposed()" returns always 0 if a widget is either not 'showing' or not
501       'visible'. If a widget is 'showing', then it is always 'visible'.
502       "showing()" returns always 0 if a widget is invisible.
503
504       Visibility changes trigger "Hide" and "Show" notifications.
505

Focus

507       One of the key points of any GUI is that only one window at a time can
508       possess a focus. The widget is focused, if the user's keyboard input is
509       directed to it. The toolkit adds another layer in the focusing scheme,
510       as often window managers do, highlighting the decorations of a top-
511       level window over a window with the input focus.
512
513       Prima::Widget property "::focused" governs the focused state of a
514       widget. It is sometimes too powerful to be used. Its more often
515       substitutes, "::selected" and "::current" properties provide more
516       respect to widget hierarchy.
517
518       "::selected" property sets focus to a widget if it is allowed to be
519       focused, by the usage of the "::selectable" property. With this
520       granted, the focus is passed to the widget or to the one of its (
521       grand-) children.  So to say, when 'selecting' a window with a text
522       field by clicking on a window, one does not expect the window itself to
523       be focused, but the text field. To achieve this goal and reduce
524       unnecessary coding, the "::current" property is introduced. With all
525       equal conditions, a widget that is 'current' gets precedence in getting
526       selected over widgets that are not 'current'.
527
528       De-selecting, in its turn, leaves the system in such a state when no
529       window has input focus. There are two convenience shortcuts "select()"
530       and "deselect()" defined, aliased to selected(1) and selected(0),
531       correspondingly.
532
533       As within the GUI space, there can be only one 'focused' widget, so
534       within the single widget space, there can be only one 'current' widget.
535       A widget can be marked as a current by calling "::current" ( or,
536       identically, "::currentWidget" on the owner widget ).  The
537       reassignments are performed automatically when a widget is focused.
538       The reverse is also true: if a widget is explicitly marked as
539       'current', and belongs to the widget tree with the focus in one of its
540       widgets, then the focus passed to the 'current' widget, or down to its
541       hierarchy if it is not selectable.
542
543       These relations between current widget pointer and focus allow the
544       toolkit easily implement the focusing hierarchy. The focused widget is
545       always on the top of the chain of its owner widgets, each of whose is a
546       'current' widget. If, for example, a window that contains a widget that
547       contains a focused button, become un-focused, and then user selects the
548       window again, then the button will become focused automatically.
549
550       Changes to focus produce "Enter" and "Leave" notifications.
551
552       Below discussed mouse- and keyboard- driven focusing schemes.  Note
553       that all of these work via "::selected", and do not focus the widgets
554       with "::selectable" property set to 0.
555
556   Mouse-aided focusing
557       Typically, when the user clicks the left mouse button on a widget, the
558       latter becomes focused.  One can note that not all widgets become
559       focused after the mouse click - scroll bars are the examples. Another
560       kind of behavior is the described above window with the text field -
561       clicking mouse on a window focuses a text field.
562
563       Prima::Widget has the "::selectingButtons" property, a combination of
564       mb::XXX ( mouse buttons ) flags. If the bits corresponding to the
565       buttons are set, then click of this button will automatically call
566       ::selected(1) ( not ::focused(1) ).
567
568       Another boolean property, "::firstClick" determines the behavior when
569       the mouse button action is up to focus a widget, but the widget's top-
570       level window is not active. The default value of "::firstClick" is 1,
571       but if set otherwise, the user must click twice to a widget to get it
572       focused. The property does not influence anything if the top-level
573       window was already active when the click event occured.
574
575       Due to different GUI designs, it is hardly possibly to force selection
576       of one top-level window when the click was on the another.  The window
577       manager or the OS can interfere, although this does not always happen,
578       and produces different results on different platforms. Since the
579       primary goal of the toolkit is portability, such functionality must be
580       considered with care.  Moreover, when the user selects a window by
581       clicking not on the toolkit-created widgets, but on the top-level
582       window decorations, it is not possible to discern the case from any
583       other kind of focusing.
584
585   Keyboard focusing
586       The native way to navigate between the toolkit widgets are tab- and
587       arrow- navigation. The tab ( and its reverse, shift-tab ) key
588       combinations circulate the focus between the widgets in same top-level
589       group ( but not inside the same owner widget group ). The arrow keys,
590       if the focused widget is not interested in these keystrokes, move the
591       focus in the specified direction, if it is possible. The methods that
592       provide the navigations are available and called "next_tab()" and
593       "next_positional()", correspondingly ( see API for the details).
594
595       When "next_positional()" operates with the geometry of the widgets,
596       "next_tab()" uses the "::tabStop" and "::tabOrder" properties.
597       "::tabStop", the boolean property, set to 1 by default, tells if a
598       widget is willing to participate in tab-aided focus circulation. If it
599       doesn't, "next_tab()" never uses it in its iterations.  "::tabOrder"
600       value is an integer, unique within the sibling widgets ( sharing same
601       owner ) list, and is used as simple tag when the next tab-focus
602       candidate is picked up. The default "::tabOrder" value is -1, which
603       changes automatically after widget creation to a unique value.
604

User input

606       The toolkit responds to the two basic means of the user input - the
607       keyboard and the mouse. Below described three aspects of the input
608       handling - the event-driven, the polling and the simulated input
609       issues. The event-driven input is the more or less natural way of
610       communicating with the user, so when the user presses the key or moves
611       the mouse, a system event occurs and triggers the notification in one
612       or more widgets. Polling methods provide the immediate state of the
613       input devices; the polling is rarely employed, primarily because of its
614       limited usability, and because the information it provides is passed to
615       the notification callbacks anyway.  The simulated input is little more
616       than "notify()" call with specifically crafted parameters. It interacts
617       with the system, so the emulation can gain the higher level of
618       similarity to the user actions. The simulated input functions allow the
619       notifications to be called right away, or post it, delaying the
620       notification until the next event loop invocation.
621
622   Keyboard
623       Event-driven
624           Keyboard input generates several notifications, where the most
625           important are "KeyDown" and "KeyUp". Both have almost the same list
626           of parameters ( see API ), that contain the key code, its modifiers
627           ( if any ) that were pressed and an eventual character code. The
628           algorithms that extract the meaning of the key, for example,
629           discretion between character and functional keys etc are not
630           described here. The reader is advised to look at Prima::KeySelector
631           module, which provides convenience functions for keyboard input
632           values transformations, and to the Prima::Edit and Prima::InputLine
633           modules, the classes that use extensively the keyboard input. But
634           in short, the key code is one of the "kb::XXX" ( like, kb::F10,
635           kb::Esc ) constants, and the modifier value is a combination of the
636           "km::XXX" ( km::Ctrl, km::Shift) constants. The notable exception
637           is kb::None value, which hints that the character code is of value.
638           Some other "kb::XXX"-marked keys have the character code as well,
639           and it is up to a programmer how to treat these combinations. It is
640           advised, however, to look at the key code first, and then to the
641           character code.
642
643           "KeyDown" event has also the repeat integer parameter, that shows
644           the repetitive count how many times the key was pressed.  Usually
645           it is 1, but if a widget was not able to get its portion of events
646           between the key presses, its value can be higher.  If a code
647           doesn't check for this parameter, some keyboard input may be lost.
648           If the code will be too much complicated by introducing the repeat-
649           value, one may consider setting the "::briefKeys" property to 0.
650           "::briefKeys", the boolean property, is 1 by default.  If set to 0,
651           it guarantees that the repeat value will always be 1, but with the
652           price of certain under-optimization. If the core "KeyDown"
653           processing code sees repeat value greater than 1, it simply calls
654           the notification again.
655
656           Along with these two notifications, the "TranslateAccel" event is
657           generated after "KeyDown", if the focused widget is not interested
658           in the key event. Its usage covers the needs of the other widgets
659           that are willing to read the user input, even being out of focus.
660           A notable example can be a button with a hot key, that reacts on
661           the key press when the focus is elsewhere within its top-level
662           window.  "TranslateAccel" has same parameters as "KeyDown", except
663           the REPEAT parameter.
664
665           Such out-of-focus input is also used with built-in menu keys
666           translations.  If a descendant of Prima::AbstractMenu is in the
667           reach of the widget tree hierarchy, then it is checked whether it
668           contains some hot keys that match the user input. See Prima::Menu
669           for the details. In particular, Prima::Widget has "::accelTable"
670           property, a mere slot for an object that contains a table of hot
671           keys mappings to custom subroutines.
672
673       Polling
674           The polling function for the keyboard is limited to the modifier
675           keys only. "get_shift_state()" method returns the press state of
676           the modifier keys, a combination of "km::XXX" constants.
677
678       Simulated input
679           There are two methods, corresponding to the major notifications -
680           "key_up()" and "key_down()", that accept the same parameters as the
681           "KeyUp" and "KeyDown" notifications do, plus the POST boolean flag.
682           See "API" for details.
683
684           These methods are convenience wrappers for "key_event()" method,
685           which is never used directly.
686
687   Mouse
688       Event-driven
689           Mouse notifications are send in response when the user moves the
690           mouse, or presses and releases mouse buttons.  The notifications
691           are logically grouped in two sets, the first contains "MouseDown",
692           "MouseUp", "MouseClick", and "MouseWheel", and the second -
693           "MouseMove", "MouseEnter", end "MouseLeave".
694
695           The first set deals with button actions. Pressing, de-pressing,
696           clicking ( and double-clicking ), the turn of mouse wheel
697           correspond to the four notifications. The notifications are sent
698           together with the mouse pointer coordinates, the button that was
699           touched, and the eventual modifier keys that were pressed.  In
700           addition, "MouseClick" provides the boolean flag if the click was
701           single or double, and "MouseWheel" the wheel turn amount. These
702           notifications occur when the mouse event occurs within the
703           geometrical bounds of a widget, with one notable exception, when a
704           widget is in capture mode.  If the "::capture" is set to 1, then
705           these events are sent to the widget even if the mouse pointer is
706           outside, and not sent to the widgets and windows that reside under
707           the pointer.
708
709           The second set deals with the pointer movements. When the pointer
710           passes over a widget, it receives first "MouseEnter", then series
711           of "MouseMove", and finally "MouseLeave". "MouseMove" and
712           "MouseEnter" notifications provide X,Y-coordinates and modificator
713           keys; "MouseLeave" passes no parameters.
714
715       Polling
716           The mouse input polling procedures are "get_mouse_state()" method,
717           that returns combination of "mb::XXX" constants, and the
718           "::pointerPos" two-integer property that reports the current
719           position of the mouse pointer.
720
721       Simulated input
722           There are five methods, corresponding to the mouse events -
723           "mouse_up()", "mouse_down()", "mouse_click()", "mouse_wheel()" and
724           "mouse_move()", that accept the same parameters as their event
725           counterparts do, plus the POST boolean flag. See "API" for details.
726
727           These methods are convenience wrappers for "mouse_event()" method,
728           which is never used directly.
729

Color schemes

731       Prima::Drawable deals only with such color values, that can be
732       unambiguously decomposed to their red, green and blue components.
733       Prima::Widget extends the range of the values acceptable by its color
734       properties, introducing the color schemes.  The color can be set
735       indirectly, without prior knowledge of what is its RGB value. There are
736       several constants defined in "cl::" name space, that correspond to the
737       default values of different color properties of a widget.
738
739       Prima::Widget revises the usage of "::color" and "::backColor", the
740       properties inherited from Prima::Drawable. Their values are widget's
741       'foreground' and 'background' colors, in addition to their function as
742       template values. Moreover, their dynamic change induces the repainting
743       of a widget, and they can be inherited from the owner. The inheritance
744       is governed by properties "::ownerColor" and "::ownerBackColor". While
745       these are true, changes to owner "::color" or "::backColor" copied
746       automatically to a widget. Once the widget's "::color" or "::backColor"
747       are explicitly set, the owner link breaks automatically by setting
748       "::ownerColor" or "::ownerBackColor" to 0.
749
750       In addition to these two color properties, Prima::Widget introduces six
751       others.  These are "::disabledColor", "::disabledBackColor",
752       "::hiliteColor", "::hiliteBackColor", "::light3DColor", and
753       "::dark3DColor".  The 'disabled' color pair contains the values that
754       are expected to be used as foreground and background when a widget is
755       in the disabled state ( see API, "::enabled" property ). The 'hilite'
756       values serve as the colors for representation of selection inside a
757       widget. Selection may be of any kind, and some widgets do not provide
758       any. But for those that do, the 'hilite' color values provide distinct
759       alternative colors. Examples are selections in the text widgets, or in
760       the list boxes. The last pair, "::light3DColor" and "::dark3DColor" is
761       used for drawing 3D-looking outlines of a widget. The purpose of all
762       these properties is the adequate usage of the color settings, selected
763       by the user using system-specific tools, so the program written with
764       the toolkit would look not such different, and more or less conformant
765       to the user's color preferences.
766
767       The additional "cl::" constants, mentioned above, represent these eight
768       color properties. These named correspondingly, cl::NormalText,
769       cl::Normal, cl::HiliteText, cl::Hilite, cl::DisabledText, cl::Disabled,
770       cl::Light3DColor and cl::Dark3DColor. cl::NormalText is alias to
771       cl::Fore, and cl::Normal - to cl::Back. Another constant set, "ci::"
772       can be used with the "::colorIndex" property, a multiplexer for all
773       eight color properties. "ci::" constants mimic their non-RGB "cl::"
774       counterparts, so the call "hiliteBackColor(cl::Red)" is equal to
775       "colorIndex(ci::Hilite, cl::Red)".
776
777       Mapping from these constants to the RGB color representation is used
778       with "map_color()" method. These "cl::" constants alone are sufficient
779       for acquiring the default values, but the toolkit provides wider
780       functionality than this. The "cl::" constants can be combined with the
781       "wc::" constants, that represent standard widget class.  The widget
782       class is implicitly used when single "cl::" constant is used; its value
783       is read from the "::widgetClass" property, unless one of "wc::"
784       constants is combined with the non-RGB "cl::" value. "wc::" constants
785       are described in "API"; their usage can make call of, for example,
786       "backColor( cl::Back)" on a button and on an input line result in
787       different colors, because the "cl::Back" is translated in the first
788       case into "cl::Back|wc::Button", and in another -
789       "cl::Back|wc::InputLine".
790
791       Dynamic change of the color properties result in the "ColorChanged"
792       notification.
793

Fonts

795       Prima::Widget does not change the handling of fonts - the font
796       selection inside and outside "begin_paint()"/"end_paint()" is not
797       different at all. A matter of difference is how does Prima::Widget
798       select the default font.
799
800       First, if the "::ownerFont" property is set to 1, then font of the
801       owner is copied to the widget, and is maintained all the time while the
802       property is true.  If it is not, the default font values read from the
803       system.
804
805       The default font metrics for a widget returned by "get_default_font()"
806       method, that often deals with system-dependent and user-selected
807       preferences ( see "Additional resources" ). Because a widget can host
808       an eventual Prima::Popup object, it contains "get_default_popup_font()"
809       method, that returns the default font for the popup objects. The
810       dynamic popup font settings governed, naturally, by the "::popupFont"
811       property. Prima::Window extends the functionality to
812       "get_default_menu_font()" and the "::menuFont" property.
813
814       Dynamic change of the font property results in the "FontChanged"
815       notification.
816

Additional resources

818       The resources, operated via Prima::Widget class but not that strictly
819       bound to the widget concept, are gathered in this section. The section
820       includes overview of pointer, cursor, hint, menu objects and user-
821       specified resources.
822
823   Pointer
824       The mouse pointer is the shared resource, that can change its visual
825       representation when it hovers over different kinds of widgets.  It is
826       usually a good practice for a text field, for example, set the pointer
827       icon to a jagged vertical line, or indicate a moving window with a
828       cross-arrowed pointer.
829
830       A widget can select either one of the predefined system pointers,
831       mapped by the "cr::XXX" constant set, or supply its own pointer icon of
832       an arbitrary size and color depth.
833
834       NB: Not all systems allow the colored pointer icons. System value under
835       sv::ColorPointer index containing a boolean value, whether the colored
836       icons are allowed or not.
837
838       In general, the "::pointer" property is enough for these actions.  It
839       discerns whether it has an icon or a constant passed, and sets the
840       appropriate properties. These properties are also accessible
841       separately, although their usage is not encouraged, primarily because
842       of the tangled relationship between them. These properties are:
843       "::pointerType", "::pointerIcon", and "::pointerHotSpot". See their
844       details in the "API" sections.
845
846       Another property, which is present only in Prima::Application name
847       space is called "::pointerVisible", and governs the visibility of the
848       pointer - but for all widget instances at once.
849
850   Cursor
851       The cursor is a blinking rectangular area, indicating the availability
852       of the input focus in a widget. There can be only one active cursor per
853       a GUI space, or none at all. Prima::Widget provides several cursor
854       properties: "::cursorVisible", "::cursorPos", and "::cursorSize". There
855       are also two methods, "show_cursor()" and "hide_cursor()", which are
856       not the convenience shortcuts but the functions accounting the cursor
857       hide count. If "hide_cursor()" was called three times, then
858       "show_cursor()" must be called three times as well for the cursor to
859       become visible.
860
861   Hint
862       "::hint" is a text string, that usually describes the widget's purpose
863       to the user in a brief manner. If the mouse pointer is hovered over the
864       widget longer than some timeout ( see Prima::Application::hintPause ),
865       then a label appears with the hint text, until the pointer is drawn
866       away.  The hint behavior is governed by Prima::Application, but a
867       widget can do two additional things about hint: it can enable and
868       disable it by calling "::showHint" property, and it can inherit the
869       owner's "::hint" and "::showHint" properties using "::ownerHint" and
870       "::ownerShowHint" properties. If, for example, "::ownerHint" is set to
871       1, then "::hint" value is automatically copied from the widget's owner,
872       when it changes. If, however, the widget's "::hint" or "::showHint" are
873       explicitly set, the owner link breaks automatically by setting
874       "::ownerHint" or "::ownerShowHint" to 0.
875
876       The widget can also operate the "::hintVisible" property, that shows or
877       hides the hint label immediately, if the mouse pointer is inside the
878       widget's boundaries.
879
880   Menu objects
881       The default functionality of Prima::Widget coexists with two kinds of
882       the Prima::AbstractMenu descendants - Prima::AccelTable and
883       Prima::Popup ( Prima::Window is also equipped with Prima::Menu
884       reference). The "::items" property of these objects are accessible
885       through "::accelItems" and "::popupItems", whereas the objects
886       themselves - through "::accelTable" and "::popup", correspondingly. As
887       mentioned in "User input", these objects hook the user keyboard input
888       and call the programmer-defined callback subroutine if the key stroke
889       equals to one of their table values. As for "::accelTable", its
890       function ends here. "::popup" provides access to a context pop-up menu,
891       which can be invoked by either right-clicking or pressing a system-
892       dependent key combination. As a little customization, the
893       "::popupColorIndex" and "::popupFont" properties are introduced.  (
894       "::popupColorIndex" is multiplexed to "::popupColor",
895       "::popupHiliteColor", "::popupHiliteBackColor", etc etc properties
896       exactly like the "::colorIndex" property ).
897
898       The font and color of a menu object might not always be writable
899       (Win32).
900
901       The Prima::Window class provides equivalent methods for the menu bar,
902       introducing "::menu", "::menuItems", "::menuColorIndex" ( with
903       multiplexing ) and "::menuFont" properties.
904
905   User-specified resources
906       It is considered a good idea to incorporate the user preferences into
907       the toolkit look-and-feel. Prima::Widget relies to the system-specific
908       code that tries to map these preferences as close as possible to the
909       toolkit paradigm.
910
911       Unix version employs XRDB ( X resource database ), which is the natural
912       way for the user to tell the preferences with fine granularity. Win32
913       reads the setting that the user has to set interactively, using system
914       tools. Nevertheless, the toolkit can not emulate all user settings that
915       are available on the supported platforms; it rather takes a 'least
916       common denominator', which is colors and fonts. "fetch_resource()"
917       method is capable of returning any of such settings, provided it's
918       format is font, color or a string.  The method is rarely called
919       directly.
920
921       The appealing idea of making every widget property adjustable via the
922       user-specified resources is not implemented in full.  It can be
923       accomplished up to a certain degree using "fetch_resource()" existing
924       functionality, but it is believed that calling up the method for the
925       every property for the every widget created is prohibitively expensive.
926

API

928   Properties
929       accelItems [ ITEM_LIST ]
930           Manages items of a Prima::AccelTable object associated with a
931           widget.  The ITEM_LIST format is same as
932           "Prima::AbstractMenu::items" and is described in Prima::Menu.
933
934           See also: "accelTable"
935
936       accelTable OBJECT
937           Manages a Prima::AccelTable object associated with a widget.  The
938           sole purpose of the accelTable object is to provide convenience
939           mapping of key combinations to anonymous subroutines.  Instead of
940           writing an interface specifically for Prima::Widget, the existing
941           interface of Prima::AbstractMenu was taken.
942
943           The accelTable object can be destroyed safely; its cancellation can
944           be done either via "accelTable(undef)" or "destroy()" call.
945
946           Default value: undef
947
948           See also: "accelItems"
949
950       autoEnableChildren BOOLEAN
951           If TRUE, all immediate children widgets maintain the same "enabled"
952           state as the widget. This property is useful for the group-like
953           widgets ( ComboBox, SpinEdit etc ), that employ their children for
954           visual representation.
955
956           Default value: 0
957
958       backColor COLOR
959           In widget paint state, reflects background color in the graphic
960           context.  In widget normal state, manages the basic background
961           color.  If changed, initiates "ColorChanged" notification and
962           repaints the widget.
963
964           See also: "color", "colorIndex", "ColorChanged"
965
966       bottom INTEGER
967           Maintains the lower boundary of a widget. If changed, does not
968           affect the widget height; but does so, if called in "set()"
969           together with "::top".
970
971           See also: "left", "right", "top", "origin", "rect", "growMode",
972           "Move"
973
974       briefKeys BOOLEAN
975           If 1, contracts the repetitive key press events into one
976           notification, increasing REPEAT parameter of "KeyDown" callbacks.
977           If 0, REPEAT parameter is always 1.
978
979           Default value: 1
980
981           See also: "KeyDown"
982
983       buffered BOOLEAN
984           If 1, a widget "Paint" callback draws not on the screen, but on the
985           off-screen memory instead. The memory content is copied to the
986           screen then. Used when complex drawing methods are used, or if
987           output smoothness is desired.
988
989           This behavior can not be always granted, however. If there is not
990           enough memory, then widget draws in the usual manner.
991
992           Default value: 0
993
994           See also: "Paint"
995
996       capture BOOLEAN, CLIP_OBJECT = undef
997           Manipulates capturing of the mouse events. If 1, the mouse events
998           are not passed to the widget the mouse pointer is over, but are
999           redirected to the caller widget. The call for capture might not be
1000           always granted due the race conditions between programs.
1001
1002           If CLIP_OBJECT widget is defined in set-mode call, the pointer
1003           movements are confined to CLIP_OBJECT inferior.
1004
1005           See also: "MouseDown", "MouseUp", "MouseMove", "MouseWheel",
1006           "MouseClick".
1007
1008       centered BOOLEAN
1009           A write-only property. Once set, widget is centered by X and Y axis
1010           relative to its owner.
1011
1012           See also: "x_centered", "y_centered", "growMode", "origin", "Move".
1013
1014       clipChildren BOOLEAN
1015           Affects the drawing mode when children widgets are present and
1016           obscuring the drawing area.  If set, the children widgets are
1017           automatically added to the clipping area, and drawing over them
1018           will not happen. If unset, the painting can be done over the
1019           children widgets.
1020
1021           Default: 1
1022
1023       clipOwner BOOLEAN
1024           If 1, a widget is clipped by its owner boundaries.  It is the
1025           default and expected behavior. If clipOwner is 0, a widget behaves
1026           differently: it does not clipped by the owner, it is not moved
1027           together with the parent, the origin offset is calculated not from
1028           the owner's coordinates but from the screen, and mouse events in a
1029           widget do not transgress to the top-level window decorations. In
1030           short, it itself becomes a top-level window, that, contrary to the
1031           one created from Prima::Window class, does not have any
1032           interference with system-dependent window stacking and positioning
1033           ( and any other ) policy, and is not ornamented by the window
1034           manager decorations.
1035
1036           Default value: 1
1037
1038           See "Parent-child relationship"
1039
1040           See also: "Prima::Object" owner section, "parentHandle"
1041
1042       color COLOR
1043           In widget paint state, reflects foreground color in the graphic
1044           context.  In widget normal state, manages the basic foreground
1045           color.  If changed, initiates "ColorChanged" notification and
1046           repaints the widget.
1047
1048           See also: "backColor", "colorIndex", "ColorChanged"
1049
1050       colorIndex INDEX, COLOR
1051           Manages the basic color properties indirectly, by accessing via
1052           "ci::XXX" constant. Is a complete alias for "::color",
1053           "::backColor", "::hiliteColor", "::hiliteBackColor",
1054           "::disabledColor", "::disabledBackColor", "::light3DColor", and
1055           "::dark3DColor" properties. The "ci::XXX" constants are:
1056
1057              ci::NormalText or ci::Fore
1058              ci::Normal or ci::Back
1059              ci::HiliteText
1060              ci::Hilite
1061              ci::DisabledText
1062              ci::Disabled
1063              ci::Light3DColor
1064              ci::Dark3DColor
1065
1066           The non-RGB "cl::" constants, specific to the Prima::Widget color
1067           usage are identical to their "ci::" counterparts:
1068
1069              cl::NormalText or cl::Fore
1070              cl::Normal or cl::Back
1071              cl::HiliteText
1072              cl::Hilite
1073              cl::DisabledText
1074              cl::Disabled
1075              cl::Light3DColor
1076              cl::Dark3DColor
1077
1078           See also: "color", "backColor", "ColorChanged"
1079
1080       current BOOLEAN
1081           If 1, a widget (or one of its children) is marked as the one to be
1082           focused ( or selected) when the owner widget receives "select()"
1083           call.  Within children widgets, only one or none at all can be
1084           marked as a current.
1085
1086           See also: "currentWidget", "selectable", "selected",
1087           "selectedWidget", "focused"
1088
1089       currentWidget OBJECT
1090           Points to a children widget, that is to be focused ( or selected)
1091           when the owner widget receives "select()" call.
1092
1093           See also: "current", "selectable", "selected", "selectedWidget",
1094           "focused"
1095
1096       cursorPos X_OFFSET Y_OFFSET
1097           Specifies the lower left corner of the cursor
1098
1099           See also: "cursorSize", "cursorVisible"
1100
1101       cursorSize WIDTH HEIGHT
1102           Specifies width and height of the cursor
1103
1104           See also: "cursorPos", "cursorVisible"
1105
1106       cursorVisible BOOLEAN
1107           Specifies cursor visibility flag. Default value is 0.
1108
1109           See also: "cursorSize", "cursorPos"
1110
1111       dark3DColor COLOR
1112           The color used to draw dark shades.
1113
1114           See also: "light3DColor", "colorIndex", "ColorChanged"
1115
1116       designScale X_SCALE Y_SCALE
1117           The width and height of a font, that was used when a widget (
1118           usually  a dialog or a grouping widget ) was designed.
1119
1120           See also: "scaleChildren", "width", "height", "size", "font"
1121
1122       disabledBackColor COLOR
1123           The color used to substitute "::backColor" when a widget is in its
1124           disabled state.
1125
1126           See also: "disabledColor", "colorIndex", "ColorChanged"
1127
1128       disabledColor COLOR
1129           The color used to substitute "::color" when a widget is in its
1130           disabled state.
1131
1132           See also: "disabledBackColor", "colorIndex", "ColorChanged"
1133
1134       enabled BOOLEAN
1135           Specifies if a widget can accept focus, keyboard and mouse events.
1136           Default value is 1, however, being 'enabled' does not automatically
1137           allow the widget become focused. Only the reverse is true - if
1138           enabled is 0, focusing can never happen.
1139
1140           See also: "responsive", "visible", "Enable", "Disable"
1141
1142       font %FONT
1143           Manages font context. Same syntax as in Prima::Drawable.  If
1144           changed, initiates "FontChanged" notification and repaints the
1145           widget.
1146
1147           See also: "designScale", "FontChanged", "ColorChanged"
1148
1149       geometry INTEGER
1150           Selects one of the available geometry managers. The corresponding
1151           integer constants are:
1152
1153              gt::GrowMode, gt::Default - the default grow-mode algorithm
1154              gt::Pack                  - Tk packer
1155              gt::Place                 - Tk placer
1156
1157           See "growMode", Prima::Widget::pack, Prima::Widget::place.
1158
1159       growMode MODE
1160           Specifies widget behavior, when its owner is resized or moved.
1161           MODE can be 0 ( default ) or a combination of the following
1162           constants:
1163
1164           Basic constants
1165                gm::GrowLoX      widget's left side is kept in constant
1166                                 distance from owner's right side
1167                gm::GrowLoY      widget's bottom side is kept in constant
1168                                 distance from owner's top side
1169                gm::GrowHiX      widget's right side is kept in constant
1170                                 distance from owner's right side
1171                gm::GrowHiY      widget's top side is kept in constant
1172                                 distance from owner's top side
1173                gm::XCenter      widget is kept in center on its owner's
1174                                 horizontal axis
1175                gm::YCenter      widget is kept in center on its owner's
1176                                 vertical axis
1177                gm::DontCare     widgets origin is maintained constant relative
1178                                 to the screen
1179
1180           Derived or aliased constants
1181                gm::GrowAll      gm::GrowLoX|gm::GrowLoY|gm::GrowHiX|gm::GrowHiY
1182                gm::Center       gm::XCenter|gm::YCenter
1183                gm::Client       gm::GrowHiX|gm::GrowHiY
1184                gm::Right        gm::GrowLoX|gm::GrowHiY
1185                gm::Left         gm::GrowHiY
1186                gm::Floor        gm::GrowHiX
1187
1188           See also: "Move", "origin"
1189
1190       firstClick BOOLEAN
1191           If 0, a widget bypasses first mouse click on it, if the top-level
1192           window it belongs to was not activated, so selecting such a widget
1193           it takes two mouse clicks.
1194
1195           Default value is 1
1196
1197           See also: "MouseDown", "selectable", "selected", "focused",
1198           "selectingButtons"
1199
1200       focused BOOLEAN
1201           Specifies whether a widget possesses the input focus or not.
1202           Disregards "::selectable" property on set-call.
1203
1204           See also: "selectable", "selected", "selectedWidget", "KeyDown"
1205
1206       geomWidth, geomHeight, geomSize
1207           Three properties that select geometry request size. Writing and
1208           reading to "::geomWidth" and "::geomHeight" is equivalent to
1209           "::geomSize". The properies are run-time only, and behave
1210           differently under different circumstances:
1211
1212           ·   As the properties are run-time only, they can not be set in the
1213               profile, and their initial value is fetched from "::size"
1214               property. Thus, setting the explicit size is aditionally sets
1215               the advised size in case the widget is to be used with the Tk
1216               geometry managers.
1217
1218           ·   Setting the properties under the "gt::GrowMode" geometry
1219               manager also sets the corresponding "::width", "::height", or
1220               "::size". When the properties are read, though, the real size
1221               properties are not read; the values are kept separately.
1222
1223           ·   Setting the properties under Tk geometry managers cause widgets
1224               size and position changed according to the geometry manager
1225               policy.
1226
1227       height
1228           Maintains the height of a widget.
1229
1230           See also: "width", "growMode", "Move", "Size", "get_virtual_size",
1231           "sizeMax", "sizeMin"
1232
1233       helpContext STRING
1234           A string that binds a widget, a logical part it plays with the
1235           application and an interactive help topic. STRING format is defined
1236           as POD link ( see perlpod ) - "manpage/section", where 'manpage' is
1237           the file with POD content and 'section' is the topic inside the
1238           manpage.
1239
1240           See also: "help"
1241
1242       hiliteBackColor COLOR
1243           The color used to draw alternate background areas with high
1244           contrast.
1245
1246           See also: "hiliteColor", "colorIndex", "ColorChanged"
1247
1248       hiliteColor COLOR
1249           The color used to draw alternate foreground areas with high
1250           contrast.
1251
1252           See also: "hiliteBackColor", "colorIndex", "ColorChanged"
1253
1254       hint TEXT
1255           A text, shown under mouse pointer if it is hovered over a widget
1256           longer than "Prima::Application::hintPause" timeout. The text shows
1257           only if the "::showHint" is 1.
1258
1259           See also: "hintVisible", "showHint", "ownerHint", "ownerShowHint"
1260
1261       hintVisible BOOLEAN
1262           If called in get-form, returns whether the hint label is shown or
1263           not. If in set-form, immediately turns on or off the hint label,
1264           disregarding the timeouts. It does regard the mouse pointer
1265           location, however, and does not turn on the hint label if the
1266           pointer is away.
1267
1268           See also: "hint", "showHint", "ownerHint", "ownerShowHint"
1269
1270       layered BOOLEAN
1271           If set, the widget will try to use alpha transparency available on
1272           the system.  See "Layering" in Prima::Image for more details.
1273
1274           Default: false
1275
1276           See also: "is_surface_layered"
1277
1278           Note: In Windows, mouse events will not be delivered to the layered
1279           widget if the pixel under the mouse pointer is fully transparent.
1280
1281           In X11, you need to run a composition manager, f.ex. compiz or
1282           xcompmgr.
1283
1284       left INTEGER
1285           Maintains the left boundary of a widget. If changed, does not
1286           affect the widget width; but does so, if called in "set()" together
1287           with "::right".
1288
1289           See also: "bottom", "right", "top", "origin", "rect", "growMode",
1290           "Move"
1291
1292       light3DColor COLOR
1293           The color used to draw light shades.
1294
1295           See also: "dark3DColor", "colorIndex", "ColorChanged"
1296
1297       ownerBackColor BOOLEAN
1298           If 1, the background color is synchronized with the owner's.
1299           Automatically set to 0 if "::backColor" property is explicitly set.
1300
1301           See also: "ownerColor", "backColor", "colorIndex"
1302
1303       ownerColor BOOLEAN
1304           If 1, the foreground color is synchronized with the owner's.
1305           Automatically set to 0 if "::color" property is explicitly set.
1306
1307           See also: "ownerBackColor", "color", "colorIndex"
1308
1309       ownerFont BOOLEAN
1310           If 1, the font is synchronized with the owner's.  Automatically set
1311           to 0 if "::font" property is explicitly set.
1312
1313           See also: "font", "FontChanged"
1314
1315       ownerHint BOOLEAN
1316           If 1, the hint is synchronized with the owner's.  Automatically set
1317           to 0 if "::hint" property is explicitly set.
1318
1319           See also: "hint", "showHint", "hintVisible", "ownerShowHint"
1320
1321       ownerShowHint BOOLEAN
1322           If 1, the show hint flag is synchronized with the owner's.
1323           Automatically set to 0 if "::showHint" property is explicitly set.
1324
1325           See also: "hint", "showHint", "hintVisible", "ownerHint"
1326
1327       ownerPalette BOOLEAN
1328           If 1, the palette array is synchronized with the owner's.
1329           Automatically set to 0 if "::palette" property is explicitly set.
1330
1331           See also: "palette"
1332
1333       origin X Y
1334           Maintains the left and bottom boundaries of a widget relative to
1335           its owner ( or to the screen if "::clipOwner" is set to 0 ).
1336
1337           See also: "bottom", "right", "top", "left", "rect", "growMode",
1338           "Move"
1339
1340       packInfo %OPTIONS
1341           See Prima::Widget::pack
1342
1343       palette [ @PALETTE ]
1344           Specifies array of colors, that are desired to be present into the
1345           system palette, as close to the PALETTE as possible.  This property
1346           works only if the graphic device allows palette operations. See
1347           "palette" in Prima::Drawable.
1348
1349           See also: "ownerPalette"
1350
1351       parentHandle SYSTEM_WINDOW
1352           If SYSTEM_WINDOW is a valid system-dependent window handle, then a
1353           widget becomes the child of the window specified, given the
1354           widget's "::clipOwner" is 0.  The parent window can belong to
1355           another application.
1356
1357           Default value is undef.
1358
1359           See also: "clipOwner"
1360
1361       placeInfo %OPTIONS
1362           See Prima::Widget::place
1363
1364       pointer cr::XXX or ICON
1365           Specifies the pointer icon; discerns between "cr::XXX" constants
1366           and an icon. If an icon contains a hash variable "__pointerHotSpot"
1367           with an array of two integers, these integers will be treated as
1368           the pointer hot spot. In get-mode call, this variable is
1369           automatically assigned to an icon, if the result is an icon object.
1370
1371           See also: "pointerHotSpot", "pointerIcon", "pointerType"
1372
1373       pointerHotSpot X_OFFSET Y_OFFSET
1374           Specifies the hot spot coordinates of a pointer icon, associated
1375           with a widget.
1376
1377           See also: "pointer", "pointerIcon", "pointerType"
1378
1379       pointerIcon ICON
1380           Specifies the pointer icon, associated with a widget.
1381
1382           See also: "pointerHotSpot", "pointer", "pointerType"
1383
1384       pointerPos X_OFFSET Y_OFFSET
1385           Specifies the mouse pointer coordinates relative to widget's
1386           coordinates.
1387
1388           See also: "get_mouse_state", "screen_to_client", "client_to_screen"
1389
1390       pointerType TYPE
1391           Specifies the type of the pointer, associated with the widget.
1392           TYPE can accept one constant of "cr::XXX" set:
1393
1394              cr::Default                 same pointer type as owner's
1395              cr::Arrow                   arrow pointer
1396              cr::Text                    text entry cursor-like pointer
1397              cr::Wait                    hourglass
1398              cr::Size                    general size action pointer
1399              cr::Move                    general move action pointer
1400              cr::SizeWest, cr::SizeW     right-move action pointer
1401              cr::SizeEast, cr::SizeE     left-move action pointer
1402              cr::SizeWE                  general horizontal-move action pointer
1403              cr::SizeNorth, cr::SizeN    up-move action pointer
1404              cr::SizeSouth, cr::SizeS    down-move action pointer
1405              cr::SizeNS                  general vertical-move action pointer
1406              cr::SizeNW                  up-right move action pointer
1407              cr::SizeSE                  down-left move action pointer
1408              cr::SizeNE                  up-left move action pointer
1409              cr::SizeSW                  down-right move action pointer
1410              cr::Invalid                 invalid action pointer
1411              cr::User                    user-defined icon
1412
1413           All constants except "cr::User" and "cr::Default" present a system-
1414           defined pointers, their icons and hot spot offsets. "cr::User" is a
1415           sign that an icon object was specified explicitly via
1416           "::pointerIcon" property.  "cr::Default" is a way to tell that a
1417           widget inherits its owner pointer type, no matter is it a system-
1418           defined pointer or a custom icon.
1419
1420           See also: "pointerHotSpot", "pointerIcon", "pointer"
1421
1422       popup OBJECT
1423           Manages a Prima::Popup object associated with a widget.  The
1424           purpose of the popup object is to show a context menu when the user
1425           right-clicks or selects the corresponding keyboard combination.
1426           Prima::Widget can host many children objects, Prima::Popup as well.
1427           But only the one that is set in "::popup" property will be
1428           activated automatically.
1429
1430           The popup object can be destroyed safely; its cancellation can be
1431           done either via "popup(undef)" or "destroy()" call.
1432
1433           See also: "Prima::Menu", "Popup", "Menu", "popupItems",
1434           "popupColorIndex", "popupFont"
1435
1436       popupColorIndex INDEX, COLOR
1437           Maintains eight color properties of a pop-up context menu,
1438           associated with a widget. INDEX must be one of "ci::XXX" constants
1439           ( see "::colorIndex" property ).
1440
1441           See also: "popupItems", "popupFont", "popup"
1442
1443       popupColor COLOR
1444           Basic foreground in a popup context menu color.
1445
1446           See also: "popupItems", "popupColorIndex", "popupFont", "popup"
1447
1448       popupBackColor COLOR
1449           Basic background in a popup context menu color.
1450
1451           See also: "popupItems", "popupColorIndex", "popupFont", "popup"
1452
1453       popupDark3DColor COLOR
1454           Color for drawing dark shadings in a popup context menu.
1455
1456           See also: "popupItems", "popupColorIndex", "popupFont", "popup"
1457
1458       popupDisabledColor COLOR
1459           Foreground color for disabled items in a popup context menu.
1460
1461           See also: "popupItems", "popupColorIndex", "popupFont", "popup"
1462
1463       popupDisabledBackColor COLOR
1464           Background color for disabled items in a popup context menu.
1465
1466           See also: "popupItems", "popupColorIndex", "popupFont", "popup"
1467
1468       popupFont %FONT
1469           Maintains the font of a pop-up context menu, associated with a
1470           widget.
1471
1472           See also: "popupItems", "popupColorIndex", "popup"
1473
1474       popupHiliteColor COLOR
1475           Foreground color for selected items in a popup context menu.
1476
1477           See also: "popupItems", "popupColorIndex", "popupFont", "popup"
1478
1479       popupHiliteBackColor COLOR
1480           Background color for selected items in a popup context menu.
1481
1482           See also: "popupItems", "popupColorIndex", "popupFont", "popup"
1483
1484       popupItems [ ITEM_LIST ]
1485           Manages items of a Prima::Popup object associated with a widget.
1486           The ITEM_LIST format is same as "Prima::AbstractMenu::items" and is
1487           described in Prima::Menu.
1488
1489           See also: "popup", "popupColorIndex", "popupFont"
1490
1491       popupLight3DColor COLOR
1492           Color for drawing light shadings in a popup context menu.
1493
1494           See also: "popupItems", "popupColorIndex", "popupFont", "popup"
1495
1496       rect X_LEFT_OFFSET Y_BOTTOM_OFFSET X_RIGHT_OFFSET Y_TOP_OFFSET
1497           Maintains the rectangular boundaries of a widget relative to its
1498           owner ( or to the screen if "::clipOwner" is set to 0 ).
1499
1500           See also: "bottom", "right", "top", "left", "origin", "width",
1501           "height", "size" "growMode", "Move", "Size", "get_virtual_size",
1502           "sizeMax", "sizeMin"
1503
1504       right INTEGER
1505           Maintains the right boundary of a widget. If changed, does not
1506           affect the widget width; but does so, if called in "set()" together
1507           with "::left".
1508
1509           See also: "left", "bottom", "top", "origin", "rect", "growMode",
1510           "Move"
1511
1512       scaleChildren BOOLEAN
1513           If a widget has "::scaleChildren" set to 1, then the newly-created
1514           children widgets inserted in it will be scaled corresponding to the
1515           owner's "::designScale", given that widget's "::designScale" is not
1516           "undef" and the owner's is not [0,0].
1517
1518           Default is 1.
1519
1520           See also: "designScale"
1521
1522       selectable BOOLEAN
1523           If 1, a widget can be granted focus implicitly, or by means of the
1524           user actions. "select()" regards this property, and does not focus
1525           a widget that has "::selectable" set to 0.
1526
1527           Default value is 0
1528
1529           See also: "current", "currentWidget", "selected", "selectedWidget",
1530           "focused"
1531
1532       selected BOOLEAN
1533           If called in get-mode, returns whether a widget or one of its
1534           (grand-) children is focused. If in set-mode, either simply turns
1535           the system with no-focus state ( if 0 ), or sends input focus to
1536           itself or one of the widgets tracked down by "::currentWidget"
1537           chain.
1538
1539           See also: "current", "currentWidget", "selectable",
1540           "selectedWidget", "focused"
1541
1542       selectedWidget OBJECT
1543           Points to a child widget, that has property "::selected" set to 1.
1544
1545           See also: "current", "currentWidget", "selectable", "selected",
1546           "focused"
1547
1548       selectingButtons FLAGS
1549           FLAGS is a combination of "mb::XXX" ( mouse button ) flags.  If a
1550           widget receives a click with a mouse button, that has the
1551           corresponding bit set in "::selectingButtons", then "select()" is
1552           called.
1553
1554           See also: "MouseDown", "firstClick", "selectable", "selected",
1555           "focused"
1556
1557       shape REGION
1558           Maintains the non-rectangular shape of a widget.  When setting,
1559           REGION is either a Prima::Image object, with 0 bits treated as
1560           transparent pixels, and 1 bits as opaque pixels, or a Prima::Region
1561           object.  When getting, it is either undef or a Prima::Region
1562           object.
1563
1564           Successive only if "sv::ShapeExtension" value is true.
1565
1566       showHint BOOLEAN
1567           If 1, the toolkit is allowed to show the hint label over a widget.
1568           If 0, the display of the hint is forbidden. The "::hint" property
1569           must contain non-empty string as well, if the hint label must be
1570           shown.
1571
1572           Default value is 1.
1573
1574           See also: "hint", "ownerShowHint", "hintVisible", "ownerHint"
1575
1576       size WIDTH HEIGHT
1577           Maintains the width and height of a widget.
1578
1579           See also: "width", "height" "growMode", "Move", "Size",
1580           "get_virtual_size", "sizeMax", "sizeMin"
1581
1582       sizeMax WIDTH HEIGHT
1583           Specifies the maximal size for a widget that it is allowed to
1584           accept.
1585
1586           See also: "width", "height", "size" "growMode", "Move", "Size",
1587           "get_virtual_size", "sizeMin"
1588
1589       sizeMin WIDTH HEIGHT
1590           Specifies the minimal size for a widget that it is allowed to
1591           accept.
1592
1593           See also: "width", "height", "size" "growMode", "Move", "Size",
1594           "get_virtual_size", "sizeMax"
1595
1596       syncPaint BOOLEAN
1597           If 0, the "Paint" request notifications are stacked until the event
1598           loop is called. If 1, every time the widget surface gets
1599           invalidated, the "Paint" notification is called.
1600
1601           Default value is 0.
1602
1603           See also: "invalidate_rect", "repaint", "validate_rect", "Paint"
1604
1605       tabOrder INTEGER
1606           Maintains the order in which tab- and shift-tab- key navigation
1607           algorithms select the sibling widgets. INTEGER is unique among the
1608           sibling widgets. In set mode, if INTEGER value is already taken,
1609           the occupier is assigned another unique value, but without
1610           destruction of a queue - widgets with ::tabOrder greater than of
1611           the widget, receive their new values too. Special value -1 is
1612           accepted as 'the end of list' indicator; the negative value is
1613           never returned.
1614
1615           See also: "tabStop", "next_tab", "selectable", "selected",
1616           "focused"
1617
1618       tabStop BOOLEAN
1619           Specifies whether a widget is interested in tab- and shift-tab- key
1620           navigation or not.
1621
1622           Default value is 1.
1623
1624           See also: "tabOrder", "next_tab", "selectable", "selected",
1625           "focused"
1626
1627       text TEXT
1628           A text string for generic purpose. Many Prima::Widget descendants
1629           use this property heavily - buttons, labels, input lines etc, but
1630           Prima::Widget itself does not.
1631
1632       top INTEGER
1633           Maintains the upper boundary of a widget. If changed, does not
1634           affect the widget height; but does so, if called in "set()"
1635           together with "::bottom".
1636
1637           See also: "left", "right", "bottom", "origin", "rect", "growMode",
1638           "Move"
1639
1640       transparent BOOLEAN
1641           Specifies whether the background of a widget before it starts
1642           painting is of any importance. If 1, a widget can gain certain
1643           transparency look if it does not clear the background during
1644           "Paint" event.
1645
1646           Default value is 0
1647
1648           See also: "Paint", "buffered".
1649
1650       visible BOOLEAN
1651           Specifies whether a widget is visible or not.  See "Visibility".
1652
1653           See also: "Show", "Hide", "showing", "exposed"
1654
1655       widgetClass CLASS
1656           Maintains the integer value, designating the color class that is
1657           defined by the system and is associated with Prima::Widget eight
1658           basic color properties. CLASS can be one of "wc::XXX" constants:
1659
1660              wc::Undef
1661              wc::Button
1662              wc::CheckBox
1663              wc::Combo
1664              wc::Dialog
1665              wc::Edit
1666              wc::InputLine
1667              wc::Label
1668              wc::ListBox
1669              wc::Menu
1670              wc::Popup
1671              wc::Radio
1672              wc::ScrollBar
1673              wc::Slider
1674              wc::Widget or wc::Custom
1675              wc::Window
1676              wc::Application
1677
1678           These constants are not associated with the toolkit classes; any
1679           class can use any of these constants in "::widgetClass".
1680
1681           See also: "map_color", "colorIndex"
1682
1683       widgets @WIDGETS
1684           In get-mode, returns list of immediate children widgets (identical
1685           to "get_widgets"). In set-mode accepts set of widget profiles, as
1686           "insert" does, as a list or an array. This way it is possible to
1687           create widget hierarchy in a single call.
1688
1689       width WIDTH
1690           Maintains the width of a widget.
1691
1692           See also: "height" "growMode", "Move", "Size", "get_virtual_size",
1693           "sizeMax", "sizeMin"
1694
1695       x_centered BOOLEAN
1696           A write-only property. Once set, widget is centered by the
1697           horizontal axis relative to its owner.
1698
1699           See also: "centered", "y_centered", "growMode", "origin", "Move".
1700
1701       y_centered BOOLEAN
1702           A write-only property. Once set, widget is centered by the vertical
1703           axis relative to its owner.
1704
1705           See also: "x_centered", "centered", "growMode", "origin", "Move".
1706
1707   Methods
1708       bring_to_front
1709           Sends a widget on top of all other siblings widgets
1710
1711           See also: "insert_behind", "send_to_back", "ZOrderChanged"
1712           ,"first", "next", "prev", "last"
1713
1714       can_close
1715           Sends "Close" message, and returns its boolean exit state.
1716
1717           See also: "Close", "close"
1718
1719       client_to_screen @OFFSETS
1720           Maps array of X and Y integer offsets from widget to screen
1721           coordinates.  Returns the mapped OFFSETS.
1722
1723           See also: "screen_to_client", "clipOwner"
1724
1725       close
1726           Calls "can_close()", and if successful, destroys a widget.  Returns
1727           the "can_close()" result.
1728
1729           See also: "can_close", "Close"
1730
1731       defocus
1732           Alias for focused(0) call
1733
1734           See also: "focus", "focused", "Enter", "Leave"
1735
1736       deselect
1737           Alias for selected(0) call
1738
1739           See also: "select", "selected", "Enter", "Leave"
1740
1741       exposed
1742           Returns a boolean value, indicating whether a widget is at least
1743           partly visible on the screen.  Never returns 1 if a widget has
1744           "::visible" set to 0.
1745
1746           See also: "visible", "showing", "Show", "Hide"
1747
1748       fetch_resource CLASS_NAME, NAME, CLASS_RESOURCE, RESOURCE, OWNER,
1749       RESOURCE_TYPE = fr::String
1750           Returns a system-defined scalar of resource, defined by the widget
1751           hierarchy, its class, name and owner. RESOURCE_TYPE can be one of
1752           type qualificators:
1753
1754              fr::Color  - color resource
1755              fr::Font   - font resource
1756              fs::String - text string resource
1757
1758           Such a number of the parameters is used because the method can be
1759           called before a widget is created.  CLASS_NAME is widget class
1760           string, NAME is widget name.  CLASS_RESOURCE is class of resource,
1761           and RESOURCE is the resource name.
1762
1763           For example, resources 'color' and 'disabledColor' belong to the
1764           resource class 'Foreground'.
1765
1766       first
1767           Returns the first ( from bottom ) sibling widget in Z-order.
1768
1769           See also: "last", "next", "prev"
1770
1771       focus
1772           Alias for focused(1) call
1773
1774           See also: "defocus", "focused", "Enter", "Leave"
1775
1776       hide
1777           Sets widget "::visible" to 0.
1778
1779           See also: "hide", "visible", "Show", "Hide", "showing", "exposed"
1780
1781       hide_cursor
1782           Hides the cursor. As many times "hide_cursor()" was called, as many
1783           time its counterpart "show_cursor()" must be called to reach the
1784           cursor's initial state.
1785
1786           See also: "show_cursor", "cursorVisible"
1787
1788       help
1789           Starts an interactive help viewer opened on "::helpContext" string
1790           value.
1791
1792           The string value is combined from the widget's owner
1793           "::helpContext" strings if the latter is empty or begins with a
1794           slash.  A special meaning is assigned to an empty string " " - the
1795           help() call fails when such value is found to be the section
1796           component.  This feature can be useful when a window or a dialog
1797           presents a standalone functionality in a separate module, and the
1798           documentation is related more to the module than to an embedding
1799           program. In such case, the grouping widget holds "::helpContext" as
1800           a pod manpage name with a trailing slash, and its children widgets
1801           are assigned "::helpContext" to the topics without the manpage but
1802           the leading slash instead.  If the grouping widget has an empty
1803           string " " as "::helpContext" then the help is forced to be
1804           unavailable for all the children widgets.
1805
1806           See also: "helpContext"
1807
1808       insert CLASS, %PROFILE [[ CLASS, %PROFILE], ... ]
1809           Creates one or more widgets with "owner" property set to the caller
1810           widget, and returns the list of references to the newly created
1811           widgets.
1812
1813           Has two calling formats:
1814
1815           Single widget
1816                 $parent-> insert( 'Child::Class',
1817                    name => 'child',
1818                    ....
1819                 );
1820
1821           Multiple widgets
1822                 $parent-> insert(
1823                   [
1824                      'Child::Class1',
1825                         name => 'child1',
1826                         ....
1827                   ],
1828                   [
1829                      'Child::Class2',
1830                         name => 'child2',
1831                         ....
1832                   ],
1833                 );
1834
1835       insert_behind OBJECT
1836           Sends a widget behind the OBJECT on Z-axis, given that the OBJECT
1837           is a sibling to the widget.
1838
1839           See also: "bring_to_front", "send_to_back", "ZOrderChanged"
1840           ,"first", "next", "prev", "last"
1841
1842       invalidate_rect X_LEFT_OFFSET Y_BOTTOM_OFFSET X_RIGHT_OFFSET
1843       Y_TOP_OFFSET
1844           Marks the rectangular area of a widget as 'invalid', so re-painting
1845           of the area happens. See "Graphic content".
1846
1847           See also: "validate_rect", "get_invalid_rect", "repaint", "Paint",
1848           "syncPaint", "update_view"
1849
1850       is_surface_layered
1851           Returns true if both the widget and it's top-most parent are
1852           layered.  If the widget itself is top-most, i.e. a window, a non-
1853           clipOwner widget, or a child to application, then is the same as
1854           "layered".
1855
1856           See also: layered
1857
1858       key_down CODE, KEY = kb::NoKey, MOD = 0, REPEAT = 1, POST = 0
1859           The method sends or posts ( POST flag ) simulated "KeyDown" event
1860           to the system. CODE, KEY, MOD and REPEAT are the parameters to be
1861           passed to the notification callbacks.
1862
1863           See also: "key_up", "key_event", "KeyDown"
1864
1865       key_event COMMAND, CODE, KEY = kb::NoKey, MOD = 0, REPEAT = 1, POST = 0
1866           The method sends or posts ( POST flag ) simulated keyboard event to
1867           the system. CODE, KEY, MOD and REPEAT are the parameters to be
1868           passed to an eventual "KeyDown" or "KeyUp" notifications.  COMMAND
1869           is allowed to be either "cm::KeyDown" or "cm::KeyUp".
1870
1871           See also: "key_down", "key_up", "KeyDown", "KeyUp"
1872
1873       key_up CODE, KEY = kb::NoKey, MOD = 0, POST = 0
1874           The method sends or posts ( POST flag ) simulated "KeyUp" event to
1875           the system. CODE, KEY and MOD are the parameters to be passed to
1876           the notification callbacks.
1877
1878           See also: "key_down", "key_event", "KeyUp"
1879
1880       last
1881           Returns the last ( the topmost ) sibling widget in Z-order.
1882
1883           See also: "first", "next", "prev"
1884
1885       lock
1886           Turns off the ability of a widget to re-paint itself.  As many
1887           times "lock()" was called, as may times its counterpart, "unlock()"
1888           must be called to enable re-painting again.  Returns a boolean
1889           success flag.
1890
1891           See also: "unlock", "repaint", "Paint", "get_locked"
1892
1893       map_color COLOR
1894           Transforms "cl::XXX" and "ci::XXX" combinations into RGB color
1895           representation and returns the result. If COLOR is already in RGB
1896           format, no changes are made.
1897
1898           See also: "colorIndex"
1899
1900       mouse_click BUTTON = mb::Left, MOD = 0, X = 0, Y = 0, DBL_CLICK = 0,
1901       POST = 0
1902           The method sends or posts ( POST flag ) simulated "MouseClick"
1903           event to the system. BUTTON, MOD, X, Y, and DBL_CLICK are the
1904           parameters to be passed to the notification callbacks.
1905
1906           See also: "MouseDown", "MouseUp", "MouseWheel", "MouseMove",
1907           "MouseEnter", "MouseLeave"
1908
1909       mouse_down BUTTON = mb::Left, MOD = 0, X = 0, Y = 0, POST = 0
1910           The method sends or posts ( POST flag ) simulated "MouseDown" event
1911           to the system. BUTTON, MOD, X, and Y are the parameters to be
1912           passed to the notification callbacks.
1913
1914           See also: "MouseUp", "MouseWheel", "MouseClick", "MouseMove",
1915           "MouseEnter", "MouseLeave"
1916
1917       mouse_enter MOD = 0, X = 0, Y = 0, POST = 0
1918           The method sends or posts ( POST flag ) simulated "MouseEnter"
1919           event to the system. MOD, X, and Y are the parameters to be passed
1920           to the notification callbacks.
1921
1922           See also: "MouseDown", "MouseUp", "MouseWheel", "MouseClick",
1923           "MouseMove", "MouseLeave"
1924
1925       mouse_event COMMAND = cm::MouseDown, BUTTON = mb::Left, MOD = 0, X = 0,
1926       Y = 0, DBL_CLICK = 0, POST = 0
1927           The method sends or posts ( POST flag ) simulated mouse event to
1928           the system. BUTTON, MOD, X, Y and DBL_CLICK are the parameters to
1929           be passed to an eventual mouse notifications.  COMMAND is allowed
1930           to be one of "cm::MouseDown", "cm::MouseUp", "cm::MouseWheel",
1931           "cm::MouseClick", "cm::MouseMove", "cm::MouseEnter",
1932           "cm::MouseLeave" constants.
1933
1934           See also: "mouse_down", "mouse_up", "mouse_wheel", "mouse_click",
1935           "mouse_move", "mouse_enter", "mouse_leave", "MouseDown", "MouseUp",
1936           "MouseWheel", "MouseClick", "MouseMove", "MouseEnter", "MouseLeave"
1937
1938       mouse_leave
1939           The method sends or posts ( POST flag ) simulated "MouseLeave"
1940           event to the system.
1941
1942           See also: "MouseDown", "MouseUp", "MouseWheel", "MouseClick",
1943           "MouseMove", "MouseEnter", "MouseLeave"
1944
1945       mouse_move MOD = 0, X = 0, Y = 0, POST = 0
1946           The method sends or posts ( POST flag ) simulated "MouseMove" event
1947           to the system. MOD, X, and Y are the parameters to be passed to the
1948           notification callbacks.
1949
1950           See also: "MouseDown", "MouseUp", "MouseWheel", "MouseClick",
1951           "MouseEnter", "MouseLeave"
1952
1953       mouse_up BUTTON = mb::Left, MOD = 0, X = 0, Y = 0, POST = 0
1954           The method sends or posts ( POST flag ) simulated "MouseUp" event
1955           to the system. BUTTON, MOD, X, and Y are the parameters to be
1956           passed to the notification callbacks.
1957
1958           See also: "MouseDown", "MouseWheel", "MouseClick", "MouseMove",
1959           "MouseEnter", "MouseLeave"
1960
1961       mouse_wheel MOD = 0, X = 0, Y = 0, INCR = 0, POST = 0
1962           The method sends or posts ( POST flag ) simulated "MouseUp" event
1963           to the system. MOD, X, Y and INCR are the parameters to be passed
1964           to the notification callbacks.
1965
1966           See also: "MouseDown", "MouseUp", "MouseClick", "MouseMove",
1967           "MouseEnter", "MouseLeave"
1968
1969       next
1970           Returns the neighbor sibling widget, next ( above ) in Z-order.  If
1971           none found, undef is returned.
1972
1973           See also: "first", "last", "prev"
1974
1975       next_tab FORWARD = 1
1976           Returns the next widget in the sorted by "::tabOrder" list of
1977           sibling widgets. FORWARD is a boolean lookup direction flag.  If
1978           none found, the first ( or the last, depending on FORWARD flag )
1979           widget is returned. Only widgets with "::tabStop" set to 1
1980           participate.
1981
1982           Also used by the internal keyboard navigation code.
1983
1984           See also: "next_positional", "tabOrder", "tabStop", "selectable"
1985
1986       next_positional DELTA_X DELTA_Y
1987           Returns a sibling, (grand-)child of a sibling or (grand-)child
1988           widget, that matched best the direction specified by DELTA_X and
1989           DELTA_Y.  At one time, only one of these parameters can be zero;
1990           another parameter must be either 1 or -1.
1991
1992           Also used by the internal keyboard navigation code.
1993
1994           See also: "next_tab", "origin"
1995
1996       pack, packForget, packSlaves
1997           See Prima::Widget::pack
1998
1999       place, placeForget, placeSlaves
2000           See Prima::Widget::place
2001
2002       prev
2003           Returns the neighbor sibling widget, previous ( below ) in Z-order.
2004           If none found, undef is returned.
2005
2006           See also: "first", "last", "next"
2007
2008       repaint
2009           Marks the whole widget area as 'invalid', so re-painting of the
2010           area happens. See "Graphic content".
2011
2012           See also: "validate_rect", "get_invalid_rect", "invalidate_rect",
2013           "Paint", "update_view", "syncPaint"
2014
2015       rect_bevel $CANVAS, @RECT, %OPTIONS
2016           Draws a rectangular area, similar to produced by "rect3d" over
2017           @RECT that is 4-integer coordinates of the area, but implicitly
2018           using widget's "light3DColor" and "dark3DColor" properties' values.
2019           The following options are recognized:
2020
2021           fill COLOR
2022               If set, the area is filled with COLOR, ortherwise is left
2023               intact.
2024
2025           width INTEGER
2026               Width of the border in pixels
2027
2028           concave BOOLEAN
2029               If 1, draw a concave area, bulged otherwise
2030
2031       responsive
2032           Returns a boolean flag, indicating whether a widget and its owners
2033           have all "::enabled" 1 or not. Useful for fast check if a widget
2034           should respond to the user actions.
2035
2036           See also: "enabled"
2037
2038       screen_to_client @OFFSETS
2039           Maps array of X and Y integer offsets from screen to widget
2040           coordinates.  Returns the mapped OFFSETS.
2041
2042           See also: "client_to_screen"
2043
2044       scroll DELTA_X DELTA_Y %OPTIONS
2045           Scrolls the graphic context area by DELTA_X and DELTA_Y pixels.
2046           OPTIONS is hash, that contains optional parameters to the scrolling
2047           procedure:
2048
2049           clipRect [X1, Y1, X2, Y2]
2050               The clipping area is confined by X1, Y1, X2, Y2 rectangular
2051               area.  If not specified, the clipping area covers the whole
2052               widget.  Only the bits, covered by clipRect are affected.  Bits
2053               scrolled from the outside of the rectangle to the inside are
2054               painted; bits scrolled from the inside of the rectangle to the
2055               outside are not painted.
2056
2057           confineRect [X1, Y1, X2, Y2]
2058               The scrolling area is confined by X1, Y1, X2, Y2 rectangular
2059               area.  If not specified, the scrolling area covers the whole
2060               widget.
2061
2062           withChildren BOOLEAN
2063               If 1, the scrolling performs with the eventual children widgets
2064               change their positions to DELTA_X and DELTA_Y as well.
2065
2066           Cannot be used inside paint state.
2067
2068           See also: "Paint", "get_invalid_rect"
2069
2070       select
2071           Alias for selected(1) call
2072
2073           See also: "deselect", "selected", "Enter", "Leave"
2074
2075       send_to_back
2076           Sends a widget at bottom of all other siblings widgets
2077
2078           See also: "insert_behind", "bring_to_front", "ZOrderChanged"
2079           ,"first", "next", "prev", "last"
2080
2081       show
2082           Sets widget "::visible" to 1.
2083
2084           See also: "hide", "visible", "Show", "Hide", "showing", "exposed"
2085
2086       show_cursor
2087           Shows the cursor. As many times "hide_cursor()" was called, as many
2088           time its counterpart "show_cursor()" must be called to reach the
2089           cursor's initial state.
2090
2091           See also: "hide_cursor", "cursorVisible"
2092
2093       showing
2094           Returns a boolean value, indicating whether the widget and its
2095           owners have all "::visible" 1 or not.
2096
2097       unlock
2098           Turns on the ability of a widget to re-paint itself.  As many times
2099           "lock()" was called, as may times its counterpart, "unlock()" must
2100           be called to enable re-painting again.  When last "unlock()" is
2101           called, an implicit "repaint()" call is made.  Returns a boolean
2102           success flag.
2103
2104           See also: "lock", "repaint", "Paint", "get_locked"
2105
2106       update_view
2107           If any parts of a widget were marked as 'invalid' by either
2108           "invalidate_rect()" or "repaint()" calls or the exposure caused by
2109           window movements ( or any other), then "Paint" notification is
2110           immediately called.  If no parts are invalid, no action is
2111           performed.  If a widget has "::syncPaint" set to 1, "update_view()"
2112           is always a no-operation call.
2113
2114           See also: "invalidate_rect", "get_invalid_rect", "repaint",
2115           "Paint", "syncPaint", "update_view"
2116
2117       validate_rect X_LEFT_OFFSET Y_BOTTOM_OFFSET X_RIGHT_OFFSET Y_TOP_OFFSET
2118           Reverses the effect of "invalidate_rect()", restoring the original,
2119           'valid' state of widget area covered by the rectangular area
2120           passed. If a widget with previously invalid areas was wholly
2121           validated by this method, no "Paint" notifications occur.
2122
2123           See also: "invalidate_rect", "get_invalid_rect", "repaint",
2124           "Paint", "syncPaint", "update_view"
2125
2126   Get-methods
2127       get_default_font
2128           Returns the default font for a Prima::Widget class.
2129
2130           See also: "font"
2131
2132       get_default_popup_font
2133           Returns the default font for a Prima::Popup class.
2134
2135           See also: "font"
2136
2137       get_invalid_rect
2138           Returns the result of successive calls "invalidate_rect()",
2139           "validate_rect()" and "repaint()", as a rectangular area ( four
2140           integers ) that cover all invalid regions in a widget.  If none
2141           found, (0,0,0,0) is returned.
2142
2143           See also: "validate_rect", "invalidate_rect", "repaint", "Paint",
2144           "syncPaint", "update_view"
2145
2146       get_handle
2147           Returns a system handle for a widget
2148
2149           See also: "get_parent_handle", "Window::get_client_handle"
2150
2151       get_locked
2152           Returns 1 if a widget is in "lock()" - initiated repaint-blocked
2153           state.
2154
2155           See also: "lock", "unlock"
2156
2157       get_mouse_state
2158           Returns a combination of "mb::XXX" constants, reflecting the
2159           currently pressed mouse buttons.
2160
2161           See also: "pointerPos", "get_shift_state"
2162
2163       get_parent
2164           Returns the owner widget that clips the widget boundaries, or
2165           application object if a widget is top-level.
2166
2167           See also: "clipOwner"
2168
2169       get_parent_handle
2170           Returns a system handle for a parent of a widget, a window that
2171           belongs to another program. Returns 0 if the widget's owner and
2172           parent are in the same application and process space.
2173
2174           See also: "get_handle", "clipOwner"
2175
2176       get_pointer_size
2177           Returns two integers, width and height of a icon, that the system
2178           accepts as valid for a pointer.  If the icon is supplied that is
2179           more or less than these values, it is truncated or padded with
2180           transparency bits, but is not stretched.  Can be called with class
2181           syntax.
2182
2183       get_shift_state
2184           Returns a combination of "km::XXX" constants, reflecting the
2185           currently pressed keyboard modificator buttons.
2186
2187           See also: "get_shift_state"
2188
2189       get_virtual_size
2190           Returns virtual width and height of a widget.  See "Geometry",
2191           Implicit size regulations.
2192
2193           See also: "width", "height", "size" "growMode", "Move", "Size",
2194           "sizeMax", "sizeMin"
2195
2196       get_widgets
2197           Returns list of children widgets.
2198
2199   Events
2200       Change
2201           Generic notification, used for Prima::Widget descendants;
2202           Prima::Widget itself neither calls not uses the event.  Designed to
2203           be called when an arbitrary major state of a widget is changed.
2204
2205       Click
2206           Generic notification, used for Prima::Widget descendants;
2207           Prima::Widget itself neither calls not uses the event.  Designed to
2208           be called when an arbitrary major action for a widget is called.
2209
2210       Close
2211           Triggered by "can_close()" and "close()" functions.  If the event
2212           flag is cleared during execution, these functions fail.
2213
2214           See also: "close", "can_close"
2215
2216       ColorChanged INDEX
2217           Called when one of widget's color properties is changed, either by
2218           direct property change or by the system. INDEX is one of "ci::XXX"
2219           constants.
2220
2221           See also: "colorIndex"
2222
2223       Disable
2224           Triggered by a successive enabled(0) call
2225
2226           See also: "Enable", "enabled", "responsive"
2227
2228       DragDrop X Y
2229           Design in progress. Supposed to be triggered when a drag-and-drop
2230           session started by the widget.  X and Y are mouse pointer
2231           coordinates on the session start.
2232
2233           See also: "DragOver", "EndDrag"
2234
2235       DragOver X Y STATE
2236           Design in progress. Supposed to be called when a mouse pointer is
2237           passed over a widget during a drag-and-drop session.  X and Y are
2238           mouse pointer coordinates, identical to "MouseMove" X Y parameters.
2239           STATE value is undefined.
2240
2241           See also: "DragDrop", "EndDrag"
2242
2243       Enable
2244           Triggered by a successive enabled(1) call
2245
2246           See also: "Disable", "enabled", "responsive"
2247
2248       EndDrag X Y
2249           Design in progress. Supposed to be called when a drag-and-drop
2250           session is finished successfully over a widget. X and Y are mouse
2251           pointer coordinates on the session end.
2252
2253           See also: "DragDrop", "DragOver"
2254
2255       Enter
2256           Called when a widget receives the input focus.
2257
2258           See also: "Leave", "focused", "selected"
2259
2260       FontChanged
2261           Called when a widget font is changed either by direct property
2262           change or by the system.
2263
2264           See also: "font", "ColorChanged"
2265
2266       Hide
2267           Triggered by a successive visible(0) call
2268
2269           See also: "Show", "visible", "showing", "exposed"
2270
2271       Hint SHOW_FLAG
2272           Called when the hint label is about to show or hide, depending on
2273           SHOW_FLAG. The hint show or hide action fails, if the event flag is
2274           cleared during execution.
2275
2276           See also: "showHint", "ownerShowHint", "hintVisible", "ownerHint"
2277
2278       KeyDown CODE, KEY, MOD, REPEAT
2279           Sent to the focused widget when the user presses a key.  CODE
2280           contains an eventual character code, KEY is one of "kb::XXX"
2281           constants, MOD is a combination of the modificator keys pressed
2282           when the event occurred ( "km::XXX" ). REPEAT is how many times the
2283           key was pressed; usually it is 1.  ( see "::briefKeys" ).
2284
2285           The valid "km::" constants are:
2286
2287              km::Shift
2288              km::Ctrl
2289              km::Alt
2290              km::KeyPad
2291              km::DeadKey
2292              km::Unicode
2293
2294           The valid "kb::" constants are grouped in several sets.  Some codes
2295           are aliased, like, "kb::PgDn" and "kb::PageDown".
2296
2297           Modificator keys
2298                  kb::ShiftL   kb::ShiftR   kb::CtrlL      kb::CtrlR
2299                  kb::AltL     kb::AltR     kb::MetaL      kb::MetaR
2300                  kb::SuperL   kb::SuperR   kb::HyperL     kb::HyperR
2301                  kb::CapsLock kb::NumLock  kb::ScrollLock kb::ShiftLock
2302
2303           Keys with character code defined
2304                  kb::Backspace  kb::Tab    kb::Linefeed   kb::Enter
2305                  kb::Return     kb::Escape kb::Esc        kb::Space
2306
2307           Function keys
2308                  kb::F1 .. kb::F30
2309                  kb::L1 .. kb::L10
2310                  kb::R1 .. kb::R10
2311
2312           Other
2313                  kb::Clear    kb::Pause   kb::SysRq  kb::SysReq
2314                  kb::Delete   kb::Home    kb::Left   kb::Up
2315                  kb::Right    kb::Down    kb::PgUp   kb::Prior
2316                  kb::PageUp   kb::PgDn    kb::Next   kb::PageDown
2317                  kb::End      kb::Begin   kb::Select kb::Print
2318                  kb::PrintScr kb::Execute kb::Insert kb::Undo
2319                  kb::Redo     kb::Menu    kb::Find   kb::Cancel
2320                  kb::Help     kb::Break   kb::BackTab
2321
2322           See also: "KeyUp", "briefKeys", "key_down", "help", "popup",
2323           "tabOrder", "tabStop", "accelTable"
2324
2325       KeyUp CODE, KEY, MOD
2326           Sent to the focused widget when the user releases a key.  CODE
2327           contains an eventual character code, KEY is one of "kb::XXX"
2328           constants, MOD is a combination of the modificator keys pressed
2329           when the event occurred ( "km::XXX" ).
2330
2331           See also: "KeyDown", "key_up"
2332
2333       Leave
2334           Called when the input focus is removed from a widget
2335
2336           See also: "Enter", "focused", "selected"
2337
2338       Menu MENU VAR_NAME
2339           Called before the user-navigated menu ( pop-up or pull-down ) is
2340           about to show another level of submenu on the screen. MENU is
2341           Prima::AbstractMenu descendant, that children to a widget, and
2342           VAR_NAME is the name of the menu item that is about to be shown.
2343
2344           Used for making changes in the menu structures dynamically.
2345
2346           See also: "popupItems"
2347
2348       MouseClick BUTTON, MOD, X, Y, DOUBLE_CLICK
2349           Called when a mouse click ( button is pressed, and then released
2350           within system-defined interval of time ) is happened in the widget
2351           area. BUTTON is one of "mb::XXX" constants, MOD is a combination of
2352           "km::XXX" constants, reflecting pressed modificator keys during the
2353           event, X and Y are the mouse pointer coordinates. DOUBLE_CLICK is a
2354           boolean flag, set to 1 if it was a double click, 0 if a single.
2355
2356           "mb::XXX" constants are:
2357
2358              mb::b1 or mb::Left
2359              mb::b2 or mb::Middle
2360              mb::b3 or mb::Right
2361              mb::b4
2362              mb::b5
2363              mb::b6
2364              mb::b7
2365              mb::b8
2366
2367           See also: "MouseDown", "MouseUp", "MouseWheel", "MouseMove",
2368           "MouseEnter", "MouseLeave"
2369
2370       MouseDown BUTTON, MOD, X, Y
2371           Occurs when the user presses mouse button on a widget.  BUTTON is
2372           one of "mb::XXX" constants, MOD is a combination of "km::XXX"
2373           constants, reflecting the pressed modificator keys during the
2374           event, X and Y are the mouse pointer coordinates.
2375
2376           See also: "MouseUp", "MouseClick", "MouseWheel", "MouseMove",
2377           "MouseEnter", "MouseLeave"
2378
2379       MouseEnter MOD, X, Y
2380           Occurs when the mouse pointer is entered the area occupied by a
2381           widget ( without mouse button pressed ).  MOD is a combination of
2382           "km::XXX" constants, reflecting the pressed modificator keys during
2383           the event, X and Y are the mouse pointer coordinates.
2384
2385           See also: "MouseDown", "MouseUp", "MouseClick", "MouseWheel",
2386           "MouseMove", "MouseLeave"
2387
2388       MouseLeave
2389           Occurs when the mouse pointer is driven off the area occupied by a
2390           widget ( without mouse button pressed ).
2391
2392           See also: "MouseDown", "MouseUp", "MouseClick", "MouseWheel",
2393           "MouseMove", "MouseEnter"
2394
2395       MouseMove MOD, X, Y
2396           Occurs when the mouse pointer is transported over a widget.  MOD is
2397           a combination of  "km::XXX" constants, reflecting the pressed
2398           modificator keys during the event, X and Y are the mouse pointer
2399           coordinates.
2400
2401           See also: "MouseDown", "MouseUp", "MouseClick", "MouseWheel",
2402           "MouseEnter", "MouseLeave"
2403
2404       MouseUp BUTTON, MOD, X, Y
2405           Occurs when the user depresses mouse button on a widget.  BUTTON is
2406           one of "mb::XXX" constants, MOD is a combination of "km::XXX"
2407           constants, reflecting the pressed modificator keys during the
2408           event, X and Y are the mouse pointer coordinates.
2409
2410           See also: "MouseDown", "MouseClick", "MouseWheel", "MouseMove",
2411           "MouseEnter", "MouseLeave"
2412
2413       MouseWheel MOD, X, Y, INCR
2414           Occurs when the user rotates mouse wheel on a widget.  MOD is a
2415           combination of "km::XXX" constants, reflecting the pressed
2416           modificator keys during the event, INCR is the wheel movement,
2417           scaled by 120.  +120 is a step upwards, or -120 downwards.  For
2418           wheels which are discrete button clicks INCR is +/-120 but other
2419           devices may give other amounts.  A widget should scroll by INCR/120
2420           many units, or partial unit, for whatever its unit of movement
2421           might be, such as lines of text, slider ticks, etc.
2422
2423           A widget might like to vary its unit move according to the MOD
2424           keys.  For example "Prima::SpinEdit" has a "step" and "pageStep"
2425           and moves by "pageStep" when "km::Ctrl" is held down (see
2426           Prima::Sliders).
2427
2428           See also: "MouseDown", "MouseUp", "MouseClick", "MouseMove",
2429           "MouseEnter", "MouseLeave"
2430
2431       Move OLD_X, OLD_Y, NEW_X, NEW_Y
2432           Triggered when widget changes its position relative to its parent,
2433           either by Prima::Widget methods or by the user.  OLD_X and OLD_Y
2434           are the old coordinates of a widget, NEW_X and NEW_Y are the new
2435           ones.
2436
2437           See also: "Size", "origin", "growMode", "centered", "clipOwner"
2438
2439       Paint CANVAS
2440           Caused when the system calls for the refresh of a graphic context,
2441           associated with a widget. CANVAS is the widget itself, however its
2442           usage instead of widget is recommended ( see "Graphic content" ).
2443
2444           See also: "repaint", "syncPaint", "get_invalid_rect", "scroll",
2445           "colorIndex", "font"
2446
2447       Popup BY_MOUSE, X, Y
2448           Called by the system when the user presses a key or mouse
2449           combination defined for a context pop-up menu execution.  By
2450           default executes the associated Prima::Popup object, if it is
2451           present. If the event flag is cleared during the execution of
2452           callbacks, the pop-up menu is not shown.
2453
2454           See also: "popup"
2455
2456       Setup
2457           This message is posted right after "Create" notification, and comes
2458           first from the event loop. Prima::Widget does not use it.
2459
2460       Show
2461           Triggered by a successive visible(1) call
2462
2463           See also: "Show", "visible", "showing", "exposed"
2464
2465       Size OLD_WIDTH, OLD_HEIGHT, NEW_WIDTH, NEW_HEIGHT
2466           Triggered when widget changes its size, either by Prima::Widget
2467           methods or by the user.  OLD_WIDTH and OLD_HEIGHT are the old
2468           extensions of a widget, NEW_WIDTH and NEW_HEIGHT are the new ones.
2469
2470           See also: "Move", "origin", "size", "growMode", "sizeMax",
2471           "sizeMin", "rect", "clipOwner"
2472
2473       SysHandle
2474           Same as in "Component", but introduces the following "Widget"
2475           properties can trigger it:
2476
2477           clipOwner, syncPaint, layered, transparent
2478
2479           This event will be only needed when the system handle (that can be
2480           acquired by "get_handle" ) is needed.
2481
2482       TranslateAccel CODE, KEY, MOD
2483           A distributed "KeyDown" event. Traverses all the object tree that
2484           the widget which received original "KeyDown" event belongs to. Once
2485           the event flag is cleared, the iteration stops.
2486
2487           Used for tracking keyboard events by out-of-focus widgets.
2488
2489           See also: "KeyDown"
2490
2491       ZOrderChanged
2492           Triggered when a widget changes its stacking order, or Z-order
2493           among its siblings, either by Prima::Widget methods or by the user.
2494
2495           See also: "bring_to_front", "insert_behind", "send_to_back"
2496

AUTHOR

2498       Dmitry Karasik, <dmitry@karasik.eu.org>.
2499

SEE ALSO

2501       Prima, Prima::Object, Prima::Drawable.
2502
2503
2504
2505perl v5.28.0                      2017-05-15             pod::Prima::Widget(3)
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