1wxScrolledWindow(3) Erlang Module Definition wxScrolledWindow(3)
2
6 wxScrolledWindow - The wxScrolled (not implemented in wx) class manages
7 scrolling for its client area, transforming the coordinates according
8 to the scrollbar positions, and setting the scroll positions, thumb
9 sizes and ranges according to the area in view.
10
12 There are two commonly used (but not the only possible!) specializa‐
13 tions of this class:
14 Note: See wxScrolled::Create() (not implemented in wx) if you want to
16 use wxScrolled (not implemented in wx) with a custom class.
17 Starting from version 2.4 of wxWidgets, there are several ways to use a
19 ?wxScrolledWindow (and now wxScrolled (not implemented in wx)). In par‐
20 ticular, there are three ways to set the size of the scrolling area:
21 One way is to set the scrollbars directly using a call to setScroll‐
23 bars/6. This is the way it used to be in any previous version of wxWid‐
24 gets and it will be kept for backwards compatibility.
25 An additional method of manual control, which requires a little less
27 computation of your own, is to set the total size of the scrolling area
28 by calling either wxWindow:setVirtualSize/3, or wxWindow:fitInside/1,
29 and setting the scrolling increments for it by calling setScrollRate/3.
30 Scrolling in some orientation is enabled by setting a non-zero incre‐
31 ment for it.
32 The most automatic and newest way is to simply let sizers determine the
34 scrolling area. This is now the default when you set an interior sizer
35 into a wxScrolled (not implemented in wx) with wxWindow:setSizer/3. The
36 scrolling area will be set to the size requested by the sizer and the
37 scrollbars will be assigned for each orientation according to the need
38 for them and the scrolling increment set by setScrollRate/3. As above,
39 scrolling is only enabled in orientations with a non-zero increment.
40 You can influence the minimum size of the scrolled area controlled by a
41 sizer by calling wxWindow::SetVirtualSizeHints(). (Calling setScroll‐
42 bars/6 has analogous effects in wxWidgets 2.4 - in later versions it
43 may not continue to override the sizer.)
44 Note that if maximum size hints are still supported by wxWin‐
46 dow::SetVirtualSizeHints(), use them at your own dire risk. They may or
47 may not have been removed for 2.4, but it really only makes sense to
48 set minimum size hints here. We should probably replace wxWin‐
49 dow::SetVirtualSizeHints() with wxWindow::SetMinVirtualSize() or simi‐
50 lar and remove it entirely in future.
51 As with all windows, an application can draw onto a wxScrolled (not im‐
53 plemented in wx) using a device context.
54 You have the option of handling the OnPaint handler or overriding the
56 wxScrolled::OnDraw() (not implemented in wx) function, which is passed
57 a pre-scrolled device context (prepared by doPrepareDC/2).
58 If you don't wish to calculate your own scrolling, you must call doPre‐
60 pareDC/2 when not drawing from within OnDraw() (not implemented in wx),
61 to set the device origin for the device context according to the cur‐
62 rent scroll position.
63 A wxScrolled (not implemented in wx) will normally scroll itself and
65 therefore its child windows as well. It might however be desired to
66 scroll a different window than itself: e.g. when designing a spread‐
67 sheet, you will normally only have to scroll the (usually white) cell
68 area, whereas the (usually grey) label area will scroll very differ‐
69 ently. For this special purpose, you can call setTargetWindow/2 which
70 means that pressing the scrollbars will scroll a different window.
71 Note that the underlying system knows nothing about scrolling coordi‐
73 nates, so that all system functions (mouse events, expose events, re‐
74 fresh calls etc) as well as the position of subwindows are relative to
75 the "physical" origin of the scrolled window. If the user insert a
76 child window at position (10,10) and scrolls the window down 100 pixels
77 (moving the child window out of the visible area), the child window
78 will report a position of (10,-90).
79 Styles
81 This class supports the following styles:
83 Note: Don't confuse wxScrollWinEvents generated by this class with
85 wxScrollEvent objects generated by wxScrollBar and wxSlider.
86 Remark: Use wxScrolled (not implemented in wx) for applications where
88 the user scrolls by a fixed amount, and where a 'page' can be inter‐
89 preted to be the current visible portion of the window. For more so‐
90 phisticated applications, use the wxScrolled (not implemented in wx)
91 implementation as a guide to build your own scroll behaviour or use
92 wxVScrolledWindow (not implemented in wx) or its variants.
93 Since: The wxScrolled (not implemented in wx) template exists since
95 version 2.9.0. In older versions, only ?wxScrolledWindow (equivalent of
96 wxScrolled<wxPanel>) was available.
97 See: wxScrollBar, wxClientDC, wxPaintDC, wxVScrolledWindow (not imple‐
99 mented in wx), wxHScrolledWindow (not implemented in wx), wxHVScrolled‐
100 Window (not implemented in wx)
101 This class is derived (and can use functions) from: wxPanel wxWindow
103 wxEvtHandler
104 wxWidgets docs: wxScrolledWindow
106
108 Event types emitted from this class: scrollwin_top, scrollwin_bottom,
109 scrollwin_lineup, scrollwin_linedown, scrollwin_pageup, scrollwin_page‐
110 down, scrollwin_thumbtrack, scrollwin_thumbrelease
111
113 wxScrolledWindow() = wx:wx_object()
114
116 new() -> wxScrolledWindow()
117 Default constructor.
119 new(Parent) -> wxScrolledWindow()
121 Types:
123 Parent = wxWindow:wxWindow()
125 new(Parent, Options :: [Option]) -> wxScrolledWindow()
127 Types:
129 Parent = wxWindow:wxWindow()
131 Option =
132 {winid, integer()} |
133 {pos, {X :: integer(), Y :: integer()}} |
134 {size, {W :: integer(), H :: integer()}} |
135 {style, integer()}
136 Constructor.
138 Remark: The window is initially created without visible scroll‐
140 bars. Call setScrollbars/6 to specify how big the virtual window
141 size should be.
142 calcScrolledPosition(This, Pt) -> {X :: integer(), Y :: integer()}
144 Types:
146 This = wxScrolledWindow()
148 Pt = {X :: integer(), Y :: integer()}
149 calcScrolledPosition(This, X, Y) ->
151 {Xx :: integer(), Yy :: integer()}
152 Types:
154 This = wxScrolledWindow()
156 X = Y = integer()
157 Translates the logical coordinates to the device ones.
159 For example, if a window is scrolled 10 pixels to the bottom,
161 the device coordinates of the origin are (0, 0) (as always), but
162 the logical coordinates are (0, 10) and so the call to Calc‐
163 ScrolledPosition(0, 10, xx, yy) will return 0 in yy.
164 See: calcUnscrolledPosition/3
166 calcUnscrolledPosition(This, Pt) ->
168 {X :: integer(), Y :: integer()}
169 Types:
171 This = wxScrolledWindow()
173 Pt = {X :: integer(), Y :: integer()}
174 calcUnscrolledPosition(This, X, Y) ->
176 {Xx :: integer(), Yy :: integer()}
177 Types:
179 This = wxScrolledWindow()
181 X = Y = integer()
182 Translates the device coordinates to the logical ones.
184 For example, if a window is scrolled 10 pixels to the bottom,
186 the device coordinates of the origin are (0, 0) (as always), but
187 the logical coordinates are (0, 10) and so the call to CalcUn‐
188 scrolledPosition(0, 0, xx, yy) will return 10 in yy.
189 See: calcScrolledPosition/3
191 enableScrolling(This, XScrolling, YScrolling) -> ok
193 Types:
195 This = wxScrolledWindow()
197 XScrolling = YScrolling = boolean()
198 Enable or disable use of wxWindow:scrollWindow/4 for scrolling.
200 By default, when a scrolled window is logically scrolled, wxWin‐
202 dow:scrollWindow/4 is called on the underlying window which
203 scrolls the window contents and only invalidates the part of the
204 window newly brought into view. If false is passed as an argu‐
205 ment, then this "physical scrolling" is disabled and the window
206 is entirely invalidated whenever it is scrolled by calling
207 wxWindow:refresh/2.
208 It should be rarely necessary to disable physical scrolling, so
210 this method shouldn't be called in normal circumstances.
211 getScrollPixelsPerUnit(This) ->
213 {XUnit :: integer(), YUnit :: integer()}
214 Types:
216 This = wxScrolledWindow()
218 Get the number of pixels per scroll unit (line), in each direc‐
220 tion, as set by setScrollbars/6.
221 A value of zero indicates no scrolling in that direction.
223 See: setScrollbars/6, wxWindow:getVirtualSize/1
225 getViewStart(This) -> {X :: integer(), Y :: integer()}
227 Types:
229 This = wxScrolledWindow()
231 This is a simple overload of GetViewStart(int*,int*); see that
233 function for more info.
234 doPrepareDC(This, Dc) -> ok
236 Types:
238 This = wxScrolledWindow()
240 Dc = wxDC:wxDC()
241 Call this function to prepare the device context for drawing a
243 scrolled image.
244 It sets the device origin according to the current scroll posi‐
246 tion. doPrepareDC/2 is called automatically within the default
247 wxEVT_PAINT event handler, so your OnDraw() (not implemented in
248 wx) override will be passed an already 'pre-scrolled' device
249 context. However, if you wish to draw from outside of OnDraw()
250 (not implemented in wx) (e.g. from your own wxEVT_PAINT han‐
251 dler), you must call this function yourself.
252 For example:
254 Notice that the function sets the origin by moving it relatively
256 to the current origin position, so you shouldn't change the ori‐
257 gin before calling doPrepareDC/2 or, if you do, reset it to (0,
258 0) later. If you call doPrepareDC/2 immediately after device
259 context creation, as in the example above, this problem doesn't
260 arise, of course, so it is customary to do it like this.
261 prepareDC(This, Dc) -> ok
263 Types:
265 This = wxScrolledWindow()
267 Dc = wxDC:wxDC()
268 This function is for backwards compatibility only and simply
270 calls doPrepareDC/2 now.
271 Notice that it is not called by the default paint event handle
273 (doPrepareDC/2 is), so overriding this method in your derived
274 class is useless.
275 scroll(This, Pt) -> ok
277 Types:
279 This = wxScrolledWindow()
281 Pt = {X :: integer(), Y :: integer()}
282 This is an overload of scroll/3; see that function for more
284 info.
285 scroll(This, X, Y) -> ok
287 Types:
289 This = wxScrolledWindow()
291 X = Y = integer()
292 Scrolls a window so the view start is at the given point.
294 Remark: The positions are in scroll units, not pixels, so to
296 convert to pixels you will have to multiply by the number of
297 pixels per scroll increment. If either parameter is ?wxDefault‐
298 Coord (-1), that position will be ignored (no change in that di‐
299 rection).
300 See: setScrollbars/6, getScrollPixelsPerUnit/1
302 setScrollbars(This, PixelsPerUnitX, PixelsPerUnitY, NoUnitsX,
304 NoUnitsY) ->
305 ok
306 Types:
308 This = wxScrolledWindow()
310 PixelsPerUnitX = PixelsPerUnitY = NoUnitsX = NoUnitsY = inte‐
311 ger()
312 setScrollbars(This, PixelsPerUnitX, PixelsPerUnitY, NoUnitsX,
314 NoUnitsY,
315 Options :: [Option]) ->
316 ok
317 Types:
319 This = wxScrolledWindow()
321 PixelsPerUnitX = PixelsPerUnitY = NoUnitsX = NoUnitsY = inte‐
322 ger()
323 Option =
324 {xPos, integer()} | {yPos, integer()} | {noRefresh, bool‐
325 ean()}
326 Sets up vertical and/or horizontal scrollbars.
328 The first pair of parameters give the number of pixels per
330 'scroll step', i.e. amount moved when the up or down scroll ar‐
331 rows are pressed. The second pair gives the length of scrollbar
332 in scroll steps, which sets the size of the virtual window.
333 xPos and yPos optionally specify a position to scroll to immedi‐
335 ately.
336 For example, the following gives a window horizontal and verti‐
338 cal scrollbars with 20 pixels per scroll step, and a size of 50
339 steps (1000 pixels) in each direction:
340 wxScrolled (not implemented in wx) manages the page size itself,
342 using the current client window size as the page size.
343 Note that for more sophisticated scrolling applications, for ex‐
345 ample where scroll steps may be variable according to the posi‐
346 tion in the document, it will be necessary to derive a new class
347 from wxWindow, overriding OnSize() and adjusting the scrollbars
348 appropriately.
349 See: wxWindow:setVirtualSize/3
351 setScrollRate(This, Xstep, Ystep) -> ok
353 Types:
355 This = wxScrolledWindow()
357 Xstep = Ystep = integer()
358 Set the horizontal and vertical scrolling increment only.
360 See the pixelsPerUnit parameter in setScrollbars/6.
362 setTargetWindow(This, Window) -> ok
364 Types:
366 This = wxScrolledWindow()
368 Window = wxWindow:wxWindow()
369 Call this function to tell wxScrolled (not implemented in wx) to
371 perform the actual scrolling on a different window (and not on
372 itself).
373 This method is useful when only a part of the window should be
375 scrolled. A typical example is a control consisting of a fixed
376 header and the scrollable contents window: the scrollbars are
377 attached to the main window itself, hence it, and not the con‐
378 tents window must be derived from wxScrolled (not implemented in
379 wx), but only the contents window scrolls when the scrollbars
380 are used. To implement such setup, you need to call this method
381 with the contents window as argument.
382 Notice that if this method is used, GetSizeAvailableForScroll‐
384 Target() (not implemented in wx) method must be overridden.
385 destroy(This :: wxScrolledWindow()) -> ok
387 Destroys the object.
389wxWidgets team. wx 2.2.1 wxScrolledWindow(3)