1XmDisplay(library call) XmDisplay(library call)
2
6 XmDisplay — The Display widget class
7
9 #include <Xm/Display.h>
10
12 The XmDisplay object is used by the Motif widgets to store information
13 that is specific to a display. It also allows the toolkit to access
14 certain information on widget hierarchies that would otherwise be
15 unavailable. Each client has one XmDisplay object for each display it
16 accesses.
17 An XmDisplay object is automatically created when the application cre‐
19 ates the first shell on a display (usually accomplished by a call to
20 XtAppInitialize or XtAppCreateShell). It is not necessary to create an
21 XmDisplay object by any other means. An application can use the func‐
22 tion XmGetXmDisplay to obtain the widget ID of the XmDisplay object for
23 a given display.
24 An application cannot supply initial values for XmDisplay resources as
26 arguments to a call to any function that creates widgets. The applica‐
27 tion or user can supply initial values in a resource file. After cre‐
28 ating the first shell on the display, the application can use
29 XmGetXmDisplay to obtain the widget ID of the XmDisplay object and then
30 call XtSetValues to set the XmDisplay resources.
31 XmDisplay resources specify the drag protocol style for a client par‐
33 ticipating in drag and drop transactions. The two basic protocol types
34 are preregister and dynamic. When a preregister protocol is used, the
35 toolkit handles any communication between the initiator and receiver
36 clients and displays the appropriate drag-over and drag-under visual
37 effects. A client registers its drop sites in advance and this informa‐
38 tion is stored in a property for each top-level window. When the drag
39 pointer enters a top-level window, the drop site information is read by
40 the initiator. A dynamic protocol allows the source and destination
41 clients to dynamically communicate drag and drop state information
42 between each other, and to update their respective visuals accordingly.
43 The toolkit provides drop site information as the pointer passes over
44 any given drop site. In this mode, a receiver can supply a procedure
45 to generate its own drag-under effects.
46 Classes
48 Display inherits behavior and resources from Core, Composite, Shell,
49 WMShell, VendorShell, TopLevelShell, and ApplicationShell classes.
50 The class pointer is xmDisplayClass.
52 The class name is XmDisplay.
54 New Resources
56 The following table defines a set of widget resources used by the pro‐
57 grammer to specify data. The programmer can also set the resource val‐
58 ues for the inherited classes to set attributes for this widget. To
59 reference a resource by name or by class in a .Xdefaults file, remove
60 the XmN or XmC prefix and use the remaining letters. To specify one of
61 the defined values for a resource in a .Xdefaults file, remove the Xm
62 prefix and use the remaining letters (in either lowercase or uppercase,
63 but include any underscores between words). The codes in the access
64 column indicate if the given resource can be set at creation time (C),
65 set by using XtSetValues (S), retrieved by using XtGetValues (G), or is
66 not applicable (N/A).
67 ┌─────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
69 │ │ XmDisplay Resourc│e Set │ │ │
70 │Name │ Class │ Type │ Default │ Access │
71 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
72 │XmNdefaultButtonEmphasis │ XmCDefaultButtonEmphasis │ XtEnum │ XmEXTERNAL_HIGHLIGHT │ C │
73 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
74 │XmNdefaultVirtualBindings │ XmCDefaultVirtualBindings │ String │ dynamic │ C │
75 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
76 │XmNdragInitiatorProtocolStyle │ XmCDragInitiatorProtocolStyle │ unsigned char │ XmDRAG_PREFER_RECEIVER │ CG │
77 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
78 │XmNdragReceiverProtocolStyle │ XmCDragReceiverProtocolStyle │ unsigned char │ XmDRAG_PREFER_DYNAMIC │ CG │
79 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
80 │XmNdragStartCallback │ XmCCallback │ XtCallbackList │ NULL │ C │
81 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
82 │XmNenableBtn1Transfer │ XmCEnableBtn1Transfer │ XtEnum │ XmOFF │ C │
83 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
84 │XmNenableButtonTab │ XmCEnableButtonTab │ Boolean │ False │ C │
85 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
86 │XmNenableDragIcon │ XmCEnableDragIcon │ Boolean │ False │ C │
87 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
88 │XmNenableEtchedInMenu │ XmCEnableEtchedInMenu │ Boolean │ False │ C │
89 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
90 │XmNenableToggleColor │ XmCEnableToggleColor │ Boolean │ False │ C │
91 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
92 │XmNenableToggleVisual │ XmCEnableToggleVisual │ Boolean │ False │ C │
93 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
94 │XmNenableUnselectableDrag │ XmCEnableUnselectableDrag │ Boolean │ True │ C │
95 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
96 │XmNenableWarp │ XmCEnableWarp │ XtEnum │ True │ CSG │
97 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
98 │XmNmotifVersion │ XmCMotifVersion │ int │ XmVERSION │ CSG │
99 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
100 │XmNnoFontCallback │ XmCCallback │ XtCallbackList │ NULL │ C │
101 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
102 │XmNnoRenditionCallback │ XmCCallback │ XtCallbackList │ NULL │ C │
103 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
104 │XmNuserData │ XmCUserData │ XtPointer │ NULL │ CSG │
105 ├──────────────────────────────┼───────────────────────────────┼────────────────┼────────────────────────┼────────┤
106 └──────────────────────────────┴───────────────────────────────┴────────────────┴────────────────────────┴────────┘
107 XmNdefaultButtonEmphasis
108 Specifies whether to change the look of the PushButton widget
109 and gadget that have the XmNshowAsDefault resource set. When
110 the PushButton is the default, it has an etched out button
111 which is enclosed with another etched in border. The XmNde‐
112 faultButtonEmphasis has the follow possible values, which
113 affect the location cursor:
114 XmINTERNAL_HIGHLIGHT
116 Causes the location cursor to appear in between the
117 two etched borders to minimize the space required.
118 XmEXTERNAL_HIGHLIGHT
120 Causes the PushButton to draw the location cursor
121 outside the second border.
122 XmNdefaultVirtualBindings
124 Specifies the default virtual bindings for the display. Fol‐
125 lowing is an example of a specification for the defaultVirtu‐
126 alBindings resource in a resource file:
127 *defaultVirtualBindings: \
129 osfBackSpace: <Key>BackSpace \n\
130 osfInsert: <Key>InsertChar \n\
131 osfDelete: <Key>DeleteChar \n\
132 ...
133 osfLeft: <Key>left, Ctrl<Key>H
134 XmNdragInitiatorProtocolStyle
136 Specifies the drag and drop protocol requirements or prefer‐
137 ence when the client is an initiator. The possible values are
138 XmDRAG_PREREGISTER
140 As an initiator, this client does not use the
141 dynamic protocol and can only arrange visual
142 effects with receivers who provide preregistered
143 information.
144 XmDRAG_DYNAMIC
146 As an initiator, this client does not make use of
147 any preregistered drop site information made avail‐
148 able by other clients, and can only arrange visual
149 effects with receivers who use the dynamic proto‐
150 col.
151 XmDRAG_NONE
153 Specifies that drag and drop is disabled for this
154 client.
155 XmDRAG_DROP_ONLY
157 As an initiator, this client does not use either
158 the preregistered drop site information or the
159 dynamic protocol. It supports dragging, and any
160 time the cursor is over a client that supports drag
161 and drop, valid feedback is provided. There are no
162 other visual effects.
163 XmDRAG_PREFER_DYNAMIC
165 As an initiator, this client can support both the
166 preregister and dynamic protocols, but prefers to
167 use dynamic protocols whenever possible in order to
168 provide high-quality drag-under feedback.
169 XmDRAG_PREFER_PREREGISTER
171 As an initiator, this client can support both the
172 preregister and dynamic protocols, but prefers to
173 use the preregister protocol whenever possible in
174 order to accommodate performance needs or to pro‐
175 vide consistent drag-over feedback.
176 XmDRAG_PREFER_RECEIVER
178 Indicates that this client can support both prereg‐
179 ister and dynamic protocols, but will defer to the
180 preference of the receiver client. This value is
181 valid only for the XmNdragInitiatorProtocolStyle
182 resource, and is its default value.
183 XmNdragReceiverProtocolStyle
185 Specifies the drag and drop protocol requirements or prefer‐
186 ence when this client is a receiver. The values are
187 XmDRAG_PREREGISTER
189 As a receiver, this client preregisters drop site
190 information and does not use the dynamic protocol.
191 It can only arrange visual effects with initiators
192 who make use of the preregistered information.
193 XmDRAG_DYNAMIC
195 As a receiver, this client uses the dynamic proto‐
196 col and does not preregister drop site information.
197 It can only arrange visual effects with initiators
198 who use the dynamic protocol.
199 XmDRAG_NONE
201 Specifies that drag and drop is disabled for this
202 client.
203 XmDRAG_DROP_ONLY
205 As a receiver, this client neither uses the dynamic
206 protocol nor preregisters drop site information. It
207 supports dropping, and when dragging over this
208 client, valid feedback is always provided, but
209 there are no other visual effects.
210 XmDRAG_PREFER_DYNAMIC
212 As a receiver, this client can support both the
213 preregister and dynamic protocols, but prefers to
214 use the dynamic protocol whenever possible in order
215 to provide high-quality drag-under feedback.
216 XmDRAG_PREFER_PREREGISTER
218 As a receiver, this client can support both the
219 preregister and dynamic protocols, but prefers to
220 use the preregister protocol whenever possible in
221 order to accommodate performance needs.
222 The default value of this resource is dependent on the capa‐
224 bilities of the display. If the display supports the shape
225 extension, allowing the dynamic protocol to use arbitrarily
226 sized drag cursors, the default of this resource is
227 XmDRAG_PREFER_DYNAMIC, otherwise the default is XmDRAG_PRE‐
228 FER_PREREGISTER.
229 The actual protocol used between an initiator and a receiver
231 is based on the protocol style of the receiver and initiator.
232 The decision matrix is described in the following table.
233 ┌───────────────┬──────────────────────────────────────────────┐
235 │Drag Initiator │ │ │ │ │
236 │ │ Drag Receiver Protocol Style │ │ │ │
237 ├───────────────┼──────────────────────────────┼───┼───┼───────┤
238 ├───────────────┼──────────────────────────────┼───┼───┼───────┤
239 ├───────────────┼──────────────────────────────┼───┼───┼───────┤
240 ├───────────────┼──────────────────────────────┼───┼───┼───────┤
241 ├───────────────┼──────────────────────────────┼───┼───┼───────┤
242 ├───────────────┼──────────────────────────────┼───┼───┼───────┤
243 └───────────────┴──────────────────────────────┴───┴───┴───────┘
244 The value XmDRAG_NONE does not appear in the matrix. When
245 specified for either the initiator or receiver side,
246 XmDRAG_NONE implies that drag and drop transactions are not
247 supported. A value of XmDRAG_DROP_ONLY (Drop Only) results
248 when an initiator and receiver cannot compromise protocol
249 styles, that is, one client requires dynamic mode while the
250 other can only support preregister mode, or if either explic‐
251 itly has specified XmDRAG_DROP_ONLY.
252 XmNdragStartCallback
254 Specifies the list of callbacks that are invoked when the
255 XmDragStart function is called. The type of structure whose
256 address is passed to this callback is XmDragStartCallback‐
257 Struct. The callback reason is XmCR_DRAG_START.
258 XmNenableBtn1Transfer
260 Specifies if selection and transfer actions are integrated on
261 Btn1 and extend actions are activated on Btn2. This resource
262 can take the following values:
263 XmOFF Disables integration and selection activation on
265 Btn1.
266 XmBUTTON2_TRANSFER
268 Enables integration and selection activation on
269 Btn1 and transfer on Btn2.
270 XmBUTTON2_ADJUST
272 Enables integration and selection activation on
273 Btn1 and adjust on Btn2.
274 This resource affects the actions of Text, TextField, List,
276 and Container.
277 XmNenableButtonTab
279 Specifies if the action for the <Tab> key (KNextField and
280 KPrevField actions) is to be modified. A value of True modi‐
281 fies the key to move as an arrow key until the boundary of a
282 tab group is reached. Then, at the boundary of the tab group,
283 KNextField and KPrevField will move to the next or previous
284 tab group, respectively. A value of False does not cause mod‐
285 ification.
286 XmNenableDragIcon
288 Specifies which set of icons are to be used for system
289 default cursors during drag and drop operations. A value of
290 False specifies that earlier versions of Motif release icons
291 are used, a value of True specifies that alternate icons are
292 used. This resource affects both the 16x16 and the 32x32
293 icons that the system defaults for each of the Screen objects
294 associated with this display.
295 XmNenableEtchedInMenu
297 Specifies the shadowing of the button widgets and gadgets in
298 menus when the control is activated. A value of True causes
299 the selected menu to be drawn with the shadow etched in; this
300 shadow style is consistent with the selected appearance of
301 other button widgets outside of menus. A value of False
302 causes the selected menu to be draw with the shadow etched
303 out. This resource affects the actions of PushButton, Toggle‐
304 Button, and CascadeButton widgets and gadgets when they are
305 children of Menu.
306 When this resource is set, the background of a button in a
308 menu uses the XmNselectColor (derived from the XmNselect‐
309 Pixel) when armed as a default. A PushButton uses the XmNarm‐
310 Color if it is defined. A ToggleButton uses the XmNselect‐
311 Color if XmNindicatorOn is False and XmNfillOnSelect is True.
312 XmNenableToggleColor
314 Specifies how to determine the default value of the XmNse‐
315 lectColor resource of ToggleButton and ToggleButtonGadget. A
316 value of True causes the default value of XmNselectColor to
317 be set to the value of XmNhighlightColor. A value of False
318 causes the default value of XmNselectColor to be set to the
319 value of XmNbackground. This resource only affects the
320 appearance of ToggleButton widgets and gadgets that are in
321 XmONE_OF_MANY or XmONE_OF_MANY_ROUND mode. In addition,
322 XmNenableToggleColor only influences the default value of
323 XmNselectColor. That is, if the user or application sets a
324 value for XmNselectColor, then XmNenableToggleColor is
325 ignored.
326 XmNenableToggleVisual
328 Specifies the visual appearance of the ToggleButton widget
329 and/or gadget. This resource affects the default value of the
330 ToggleButton[Gadget] XmNindicatorType and XmNindicatorOn
331 resources. When the ToggleButton is in a RadioBox, a value of
332 True causes the XmONE_OF_MANY_ROUND (a shadowed circle) to be
333 the default. Otherwise, when this resource is True, the Tog‐
334 gleButton XmNindicatorOn resource causes a default of
335 XmN_OF_MANY, which will be a shadowed square with a check
336 mark (check box).
337 A value of False causes the following:
339 XmONE_OF_MANY
341 Is a shadowed diamond.
342 XmN_OF_MANY
344 Is a shadowed square.
345 XmNenableUnselectableDrag
347 Specifies whether or not it is possible to drag from Label
348 and Scale. A value of True enables the drag; a value of
349 False disables it.
350 XmNenableWarp
352 Specifies if an application is allowed to warp the pointer
353 from the user. A value of True enables warping, a value of
354 False does not.
355 XmNmotifVersion
357 Specifies the current version of Motif that the current
358 implementation is supposed to behave like. By default, this
359 resource gets its value from release values in Xm.h.
360 XmNnoFontCallback
362 This callback is called whenever a rendition attempts to load
363 a font or fontset and fails. This can happen on creation if
364 the font is specified as XmLOAD_IMMEDIATE or when an attempt
365 is made to render an XmString using a font specified as
366 XmLOAD_DEFERRED. An application can have this callback
367 attempt to remedy this problem by calling XmRenditionUpdate
368 on the input rendition to provide a font for the widget to
369 use. This may be done by either providing an an alternative
370 font name to be loaded using the XmNfontName and XmNfontType
371 resources or with an already loaded font using the XmNfont
372 resource. The callback reason is XmCR_NO_FONT. This callback
373 uses the XmDisplayCallbackStruct structure.
374 XmNnoRenditionCallback
376 This callback is called whenever an attempt is made to render
377 a segment with a RENDITION tag which does not match any ren‐
378 ditions in a given render table. The callback reason is
379 XmCR_NO_RENDITION. This callback uses the XmDisplayCallback‐
380 Struct structure.
381 An application can have this callback attempt to remedy this
383 problem by creating a new rendition with the given tag and
384 adding it to render_table.
385 The XmNnoRenditionCallback should deallocate the render table
387 passed in in the render_table field of the callback struc‐
388 ture. Note that the table will automatically be deallocated
389 if the XmRenderTableAddRenditions function is called on it.
390 The callback should NOT deallocate the modified render table
391 that is passed back to Motif in the render_table field. If
392 the application wishes to manipulate this render table fur‐
393 ther, it should make a copy with the XmRenderTableCopy func‐
394 tion before returning from the callback.
395 XmNuserData
397 Specifies a client data pointer for applications. An inter‐
398 nally unused resource.
399 Inherited Resources
401 All of the superclass resources inherited by XmDisplay are designated
402 N/A (not applicable).
403 Callback Information
405 A pointer to the following structure is passed to the XmNdragStartCall‐
406 back callback:
407 typedef struct
409 {
410 int reason;
411 XEvent *event;
412 Widget timeStamp;
413 Boolean doit;
414 }XmDragStartCallbackStruct;
415 reason Indicates why the callback was invoked
417 event Points to the XEvent that triggered the callback
419 widget Indicates the ID of the widget from which the drag was initi‐
421 ated.
422 doit Is an IN/OUT member that allows the callback to determine
424 whether to continue with the drag or cancel. Setting doit to
425 False will cancel the drag. The default value is NULL.
426 A pointer to the following structure is passed to the XmNnoFontCallback
428 and XmNnoRenditionCallback callbacks:
429 typedef struct
431 {
432 int reason;
433 XEvent *event;
434 XmRendition rendition;
435 char *font_name;
436 XmRenderTable render_table;
437 XmStringTag tag;
438 }XmDisplayCallbackStruct;
439 reason Indicates why the callback was invoked.
441 event Points to the XEvent that triggered the callback. It can be
443 NULL.
444 rendition Specifies the rendition with the missing font.
446 font_name Specifies the name of the font or font set which could not be
448 loaded.
449 render_table
451 Specifies the render table with the missing rendition.
452 tag Specifies the tag of the missing rendition.
454 The following table describes the reasons for which the individual
456 callback structure fields are valid.
457 ┌──────────────────┬──────────────────────┐
459 │Reason │ Valid Fields │
460 ├──────────────────┼──────────────────────┤
461 │XmCR_NO_FONT │ rendition, font_name │
462 ├──────────────────┼──────────────────────┤
463 │XmCR_NO_RENDITION │ render_table, tag │
464 ├──────────────────┼──────────────────────┤
465 └──────────────────┴──────────────────────┘
467 ApplicationShell(3), Composite(3), Core(3), TopLevelShell(3), Vendor‐
468 Shell(3), WMShell(3), XmGetXmDisplay(3), and XmScreen(3).
469 XmDisplay(library call)