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1 /////////////////////////////////////////////////////////////////////////////
2 // Name: scrolwin.h
3 // Purpose: interface of wxScrolled template
4 // Author: wxWidgets team
5 // RCS-ID: $Id$
6 // Licence: wxWindows licence
7 /////////////////////////////////////////////////////////////////////////////
8
9 /**
10 Possible values for the second argument of wxScrolled::ShowScrollbars().
11 */
12 enum wxScrollbarVisibility
13 {
14 wxSHOW_SB_NEVER = -1, ///< Never show the scrollbar at all.
15 wxSHOW_SB_DEFAULT, ///< Show scrollbar only if it is needed.
16 wxSHOW_SB_ALWAYS ///< Always show scrollbar, even if not needed.
17 };
18
19 /**
20
21 The wxScrolled class manages scrolling for its client area, transforming
22 the coordinates according to the scrollbar positions, and setting the
23 scroll positions, thumb sizes and ranges according to the area in view.
24
25 There are two commonly used (but not the only possible!) specializations of
26 this class:
27
28 - ::wxScrolledWindow, aka wxScrolled<wxPanel>, is equivalent to
29 ::wxScrolledWindow from earlier versions. Derived from wxPanel, it shares
30 wxPanel's behaviour with regard to TAB traversal and focus handling. Use
31 this if the scrolled window will have child controls.
32
33 - ::wxScrolledCanvas, aka wxScrolled<wxWindow>, derives from wxWindow and
34 so doesn't handle children specially. This is suitable e.g. for
35 implementing scrollable controls such as tree or list controls.
36
37 Starting from version 2.4 of wxWidgets, there are several ways to use a
38 ::wxScrolledWindow (and now wxScrolled). In particular, there are
39 three ways to set the size of the scrolling area:
40
41 One way is to set the scrollbars directly using a call to SetScrollbars().
42 This is the way it used to be in any previous version of wxWidgets and it
43 will be kept for backwards compatibility.
44
45 An additional method of manual control, which requires a little less
46 computation of your own, is to set the total size of the scrolling area by
47 calling either wxWindow::SetVirtualSize(), or wxWindow::FitInside(), and
48 setting the scrolling increments for it by calling SetScrollRate().
49 Scrolling in some orientation is enabled by setting a non-zero increment
50 for it.
51
52 The most automatic and newest way is to simply let sizers determine the
53 scrolling area. This is now the default when you set an interior sizer into
54 a wxScrolled with wxWindow::SetSizer(). The scrolling area will be
55 set to the size requested by the sizer and the scrollbars will be assigned
56 for each orientation according to the need for them and the scrolling
57 increment set by SetScrollRate(). As above, scrolling is only enabled in
58 orientations with a non-zero increment. You can influence the minimum size
59 of the scrolled area controlled by a sizer by calling
60 wxWindow::SetVirtualSizeHints(). (Calling SetScrollbars() has analogous
61 effects in wxWidgets 2.4 -- in later versions it may not continue to
62 override the sizer.)
63
64 Note that if maximum size hints are still supported by
65 wxWindow::SetVirtualSizeHints(), use them at your own dire risk. They may
66 or may not have been removed for 2.4, but it really only makes sense to set
67 minimum size hints here. We should probably replace
68 wxWindow::SetVirtualSizeHints() with wxWindow::SetMinVirtualSize() or
69 similar and remove it entirely in future.
70
71 @todo review docs for this class replacing SetVirtualSizeHints() with
72 SetMinClientSize().
73
74 As with all windows, an application can draw onto a wxScrolled using a
75 @ref overview_dc "device context".
76
77 You have the option of handling the OnPaint handler or overriding the
78 wxScrolled::OnDraw() function, which is passed a pre-scrolled device
79 context (prepared by wxScrolled::DoPrepareDC()).
80
81 If you don't wish to calculate your own scrolling, you must call
82 DoPrepareDC() when not drawing from within OnDraw(), to set the device
83 origin for the device context according to the current scroll position.
84
85 A wxScrolled will normally scroll itself and therefore its child windows
86 as well. It might however be desired to scroll a different window than
87 itself: e.g. when designing a spreadsheet, you will normally only have to
88 scroll the (usually white) cell area, whereas the (usually grey) label area
89 will scroll very differently. For this special purpose, you can call
90 SetTargetWindow() which means that pressing the scrollbars will scroll a
91 different window.
92
93 Note that the underlying system knows nothing about scrolling coordinates,
94 so that all system functions (mouse events, expose events, refresh calls
95 etc) as well as the position of subwindows are relative to the "physical"
96 origin of the scrolled window. If the user insert a child window at
97 position (10,10) and scrolls the window down 100 pixels (moving the child
98 window out of the visible area), the child window will report a position
99 of (10,-90).
100
101 @beginStyleTable
102 @style{wxHSCROLL}
103 If this style is specified and ::wxVSCROLL isn't, the window will be
104 scrollable only in horizontal direction (by default, i.e. if neither
105 this style nor ::wxVSCROLL is specified, it scrolls in both
106 directions).
107 @style{wxVSCROLL}
108 If this style is specified and ::wxHSCROLL isn't, the window will be
109 scrollable only in vertical direction (by default, i.e. if neither
110 this style nor ::wxHSCROLL is specified, it scrolls in both
111 directions).
112 @style{wxALWAYS_SHOW_SB}
113 Since wxWidgets 2.9.5, specifying this style makes the window always
114 show its scrollbars, even if they are not used. See ShowScrollbars().
115 @style{wxRETAINED}
116 Uses a backing pixmap to speed refreshes. Motif only.
117 @endStyleTable
118
119
120 @beginEventEmissionTable{wxScrollWinEvent}
121 @event{EVT_SCROLLWIN(func)}
122 Process all scroll events.
123 @event{EVT_SCROLLWIN_TOP(func)}
124 Process @c wxEVT_SCROLLWIN_TOP scroll-to-top events.
125 @event{EVT_SCROLLWIN_BOTTOM(func)}
126 Process @c wxEVT_SCROLLWIN_BOTTOM scroll-to-bottom events.
127 @event{EVT_SCROLLWIN_LINEUP(func)}
128 Process @c wxEVT_SCROLLWIN_LINEUP line up events.
129 @event{EVT_SCROLLWIN_LINEDOWN(func)}
130 Process @c wxEVT_SCROLLWIN_LINEDOWN line down events.
131 @event{EVT_SCROLLWIN_PAGEUP(func)}
132 Process @c wxEVT_SCROLLWIN_PAGEUP page up events.
133 @event{EVT_SCROLLWIN_PAGEDOWN(func)}
134 Process @c wxEVT_SCROLLWIN_PAGEDOWN page down events.
135 @event{EVT_SCROLLWIN_THUMBTRACK(func)}
136 Process @c wxEVT_SCROLLWIN_THUMBTRACK thumbtrack events
137 (frequent events sent as the user drags the thumbtrack).
138 @event{EVT_SCROLLWIN_THUMBRELEASE(func)}
139 Process @c wxEVT_SCROLLWIN_THUMBRELEASE thumb release events.
140 @endEventTable
141
142 @note
143 Don't confuse wxScrollWinEvents generated by this class with
144 wxScrollEvent objects generated by wxScrollBar and wxSlider.
145
146
147 @remarks
148 Use wxScrolled for applications where the user scrolls by a fixed amount,
149 and where a 'page' can be interpreted to be the current visible portion of
150 the window. For more sophisticated applications, use the wxScrolled
151 implementation as a guide to build your own scroll behaviour or use
152 wxVScrolledWindow or its variants.
153
154 @since The wxScrolled template exists since version 2.9.0. In older versions,
155 only ::wxScrolledWindow (equivalent of wxScrolled<wxPanel>) was
156 available.
157
158 @library{wxcore}
159 @category{miscwnd}
160
161 @see wxScrollBar, wxClientDC, wxPaintDC,
162 wxVScrolledWindow, wxHScrolledWindow, wxHVScrolledWindow,
163 */
164 template<class T>
165 class wxScrolled : public T
166 {
167 public:
168 /// Default constructor.
169 wxScrolled();
170
171 /**
172 Constructor.
173
174 @param parent
175 Parent window.
176 @param id
177 Window identifier. The value @c wxID_ANY indicates a default value.
178 @param pos
179 Window position. If a position of ::wxDefaultPosition is specified
180 then a default position is chosen.
181 @param size
182 Window size. If a size of ::wxDefaultSize is specified then the
183 window is sized appropriately.
184 @param style
185 Window style. See wxScrolled.
186 @param name
187 Window name.
188
189 @remarks The window is initially created without visible scrollbars.
190 Call SetScrollbars() to specify how big the virtual window
191 size should be.
192 */
193 wxScrolled(wxWindow* parent, wxWindowID id = -1,
194 const wxPoint& pos = wxDefaultPosition,
195 const wxSize& size = wxDefaultSize,
196 long style = wxHSCROLL | wxVSCROLL,
197 const wxString& name = "scrolledWindow");
198
199 /**
200 Translates the logical coordinates to the device ones. For example, if
201 a window is scrolled 10 pixels to the bottom, the device coordinates of
202 the origin are (0, 0) (as always), but the logical coordinates are (0,
203 10) and so the call to CalcScrolledPosition(0, 10, xx, yy) will return
204 0 in yy.
205
206 @beginWxPerlOnly
207 In wxPerl this method takes two parameters and returns a
208 2-element list (xx, yy).
209 @endWxPerlOnly
210
211 @see CalcUnscrolledPosition()
212 */
213 void CalcScrolledPosition(int x, int y, int* xx, int* yy) const;
214 wxPoint CalcScrolledPosition(const wxPoint& pt) const;
215
216 /**
217 Translates the device coordinates to the logical ones. For example, if
218 a window is scrolled 10 pixels to the bottom, the device coordinates of
219 the origin are (0, 0) (as always), but the logical coordinates are (0,
220 10) and so the call to CalcUnscrolledPosition(0, 0, xx, yy) will return
221 10 in yy.
222
223 @beginWxPerlOnly
224 In wxPerl this method takes two parameters and returns a
225 2-element list (xx, yy).
226 @endWxPerlOnly
227
228 @see CalcScrolledPosition()
229 */
230 void CalcUnscrolledPosition(int x, int y, int* xx, int* yy) const;
231 wxPoint CalcUnscrolledPosition(const wxPoint& pt) const;
232
233 /**
234 Creates the window for two-step construction. Derived classes
235 should call or replace this function. See wxScrolled::wxScrolled()
236 for details.
237 */
238 bool Create(wxWindow* parent, wxWindowID id = -1,
239 const wxPoint& pos = wxDefaultPosition,
240 const wxSize& size = wxDefaultSize,
241 long style = wxHSCROLL | wxVSCROLL,
242 const wxString& name = "scrolledWindow");
243
244 /**
245 Disable use of keyboard keys for scrolling.
246
247 By default cursor movement keys (including Home, End, Page Up and Down)
248 are used to scroll the window appropriately. If the derived class uses
249 these keys for something else, e.g. changing the currently selected
250 item, this function can be used to disable this behaviour as it's not
251 only not necessary then but can actually be actively harmful if another
252 object forwards a keyboard event corresponding to one of the above keys
253 to us using ProcessWindowEvent() because the event will always be
254 processed which can be undesirable.
255
256 @since 2.9.1
257 */
258 void DisableKeyboardScrolling();
259
260 /**
261 Call this function to prepare the device context for drawing a scrolled
262 image.
263
264 It sets the device origin according to the current scroll position.
265 DoPrepareDC() is called automatically within the default @c wxEVT_PAINT
266 event handler, so your OnDraw() override will be passed an already
267 'pre-scrolled' device context. However, if you wish to draw from
268 outside of OnDraw() (e.g. from your own @c wxEVT_PAINT handler), you
269 must call this function yourself.
270
271 For example:
272 @code
273 void MyWindow::OnEvent(wxMouseEvent& event)
274 {
275 wxClientDC dc(this);
276 DoPrepareDC(dc);
277
278 dc.SetPen(*wxBLACK_PEN);
279 float x, y;
280 event.Position(&x, &y);
281 if (xpos > -1 && ypos > -1 && event.Dragging())
282 {
283 dc.DrawLine(xpos, ypos, x, y);
284 }
285 xpos = x;
286 ypos = y;
287 }
288 @endcode
289
290 Notice that the function sets the origin by moving it relatively to the
291 current origin position, so you shouldn't change the origin before
292 calling DoPrepareDC() or, if you do, reset it to (0, 0) later. If you
293 call DoPrepareDC() immediately after device context creation, as in the
294 example above, this problem doesn't arise, of course, so it is
295 customary to do it like this.
296 */
297 void DoPrepareDC(wxDC& dc);
298
299 /**
300 Enable or disable use of wxWindow::ScrollWindow() for scrolling.
301
302 By default, when a scrolled window is logically scrolled,
303 wxWindow::ScrollWindow() is called on the underlying window which
304 scrolls the window contents and only invalidates the part of the window
305 newly brought into view. If @false is passed as an argument, then this
306 "physical scrolling" is disabled and the window is entirely invalidated
307 whenever it is scrolled by calling wxWindow::Refresh().
308
309 It should be rarely necessary to disable physical scrolling, so this
310 method shouldn't be called in normal circumstances.
311
312 @param xScrolling
313 If @true, enables physical scrolling in the x direction.
314 @param yScrolling
315 If @true, enables physical scrolling in the y direction.
316 */
317 void EnableScrolling(bool xScrolling, bool yScrolling);
318
319 /**
320 Set the scrollbar visibility.
321
322 By default the scrollbar in the corresponding direction is only shown
323 if it is needed, i.e. if the virtual size of the scrolled window in
324 this direction is greater than the current physical window size. Using
325 this function the scrollbar visibility can be changed to be:
326 - wxSHOW_SB_ALWAYS: To always show the scrollbar, even if it is
327 not needed currently (wxALWAYS_SHOW_SB style can be used during
328 the window creation to achieve the same effect but it applies
329 in both directions).
330 - wxSHOW_SB_NEVER: To never show the scrollbar at all. In this case
331 the program should presumably provide some other way for the
332 user to scroll the window.
333 - wxSHOW_SB_DEFAULT: To restore the default behaviour described
334 above.
335
336 @param horz
337 The desired visibility for the horizontal scrollbar.
338 @param vert
339 The desired visibility for the vertical scrollbar.
340
341 @since 2.9.0
342 */
343 void ShowScrollbars(wxScrollbarVisibility horz, wxScrollbarVisibility vert);
344
345 /**
346 Get the number of pixels per scroll unit (line), in each direction, as
347 set by SetScrollbars(). A value of zero indicates no scrolling in that
348 direction.
349
350 @param xUnit
351 Receives the number of pixels per horizontal unit.
352 @param yUnit
353 Receives the number of pixels per vertical unit.
354
355 @beginWxPerlOnly
356 In wxPerl this method takes no parameters and returns a
357 2-element list (xUnit, yUnit).
358 @endWxPerlOnly
359
360 @see SetScrollbars(), GetVirtualSize()
361 */
362 void GetScrollPixelsPerUnit(int* xUnit, int* yUnit) const;
363
364 /**
365 Get the position at which the visible portion of the window starts.
366
367 @param x
368 Receives the first visible x position in scroll units.
369 @param y
370 Receives the first visible y position in scroll units.
371
372 @remarks
373 If either of the scrollbars is not at the home position, @a x
374 and/or @a y will be greater than zero.
375 Combined with wxWindow::GetClientSize(), the application can use this
376 function to efficiently redraw only the visible portion of the window.
377 The positions are in logical scroll units, not pixels, so to convert
378 to pixels you will have to multiply by the number of pixels per scroll
379 increment.
380
381 @beginWxPerlOnly
382 In wxPerl this method takes no parameters and returns a
383 2-element list (x, y).
384 @endWxPerlOnly
385
386 @see SetScrollbars(), Scroll()
387 */
388 void GetViewStart(int* x, int* y) const;
389
390 /**
391 This is a simple overload of GetViewStart(int*,int*); see that function
392 for more info.
393 */
394 wxPoint GetViewStart() const;
395
396 /**
397 Gets the size in device units of the scrollable window area (as
398 opposed to the client size, which is the area of the window currently
399 visible).
400
401 @param x
402 Receives the length of the scrollable window, in pixels.
403 @param y
404 Receives the height of the scrollable window, in pixels.
405
406 @remarks Use wxDC::DeviceToLogicalX() and wxDC::DeviceToLogicalY() to
407 translate these units to logical units.
408
409 @beginWxPerlOnly
410 In wxPerl this method takes no parameters and returns a
411 2-element list (xUnit, yUnit).
412 @endWxPerlOnly
413
414 @see SetScrollbars(), GetScrollPixelsPerUnit()
415 */
416 void GetVirtualSize(int* x, int* y) const;
417
418 /**
419 Motif only: @true if the window has a backing bitmap.
420 */
421 bool IsRetained() const;
422
423 /**
424 Called by the default paint event handler to allow the application to
425 define painting behaviour without having to worry about calling
426 DoPrepareDC().
427
428 Instead of overriding this function you may also just process the paint
429 event in the derived class as usual, but then you will have to call
430 DoPrepareDC() yourself.
431 */
432 virtual void OnDraw(wxDC& dc);
433
434 /**
435 This function is for backwards compatibility only and simply calls
436 DoPrepareDC() now. Notice that it is not called by the default paint
437 event handle (DoPrepareDC() is), so overriding this method in your
438 derived class is useless.
439 */
440 void PrepareDC(wxDC& dc);
441
442 /**
443 Scrolls a window so the view start is at the given point.
444
445 @param x
446 The x position to scroll to, in scroll units.
447 @param y
448 The y position to scroll to, in scroll units.
449
450 @remarks The positions are in scroll units, not pixels, so to convert to
451 pixels you will have to multiply by the number of
452 pixels per scroll increment. If either parameter is
453 ::wxDefaultCoord (-1), that position will be ignored (no change
454 in that direction).
455
456 @see SetScrollbars(), GetScrollPixelsPerUnit()
457 */
458 void Scroll(int x, int y);
459
460 /**
461 This is an overload of Scroll(int,int); see that function for more info.
462 */
463 void Scroll(const wxPoint& pt);
464
465 /**
466 Set the horizontal and vertical scrolling increment only. See the
467 pixelsPerUnit parameter in SetScrollbars().
468 */
469 void SetScrollRate(int xstep, int ystep);
470
471 /**
472 Sets up vertical and/or horizontal scrollbars.
473
474 The first pair of parameters give the number of pixels per 'scroll
475 step', i.e. amount moved when the up or down scroll arrows are pressed.
476 The second pair gives the length of scrollbar in scroll steps, which
477 sets the size of the virtual window.
478
479 @a xPos and @a yPos optionally specify a position to scroll to
480 immediately.
481
482 For example, the following gives a window horizontal and vertical
483 scrollbars with 20 pixels per scroll step, and a size of 50 steps (1000
484 pixels) in each direction:
485 @code
486 window->SetScrollbars(20, 20, 50, 50);
487 @endcode
488
489 wxScrolled manages the page size itself, using the current client
490 window size as the page size.
491
492 Note that for more sophisticated scrolling applications, for example
493 where scroll steps may be variable according to the position in the
494 document, it will be necessary to derive a new class from wxWindow,
495 overriding OnSize() and adjusting the scrollbars appropriately.
496
497 @param pixelsPerUnitX
498 Pixels per scroll unit in the horizontal direction.
499 @param pixelsPerUnitY
500 Pixels per scroll unit in the vertical direction.
501 @param noUnitsX
502 Number of units in the horizontal direction.
503 @param noUnitsY
504 Number of units in the vertical direction.
505 @param xPos
506 Position to initialize the scrollbars in the horizontal direction,
507 in scroll units.
508 @param yPos
509 Position to initialize the scrollbars in the vertical direction, in
510 scroll units.
511 @param noRefresh
512 Will not refresh window if @true.
513
514 @see wxWindow::SetVirtualSize()
515 */
516 void SetScrollbars(int pixelsPerUnitX, int pixelsPerUnitY,
517 int noUnitsX,
518 int noUnitsY,
519 int xPos = 0,
520 int yPos = 0,
521 bool noRefresh = false);
522
523 /**
524 Call this function to tell wxScrolled to perform the actual scrolling
525 on a different window (and not on itself).
526
527 This method is useful when only a part of the window should be
528 scrolled. A typical example is a control consisting of a fixed header
529 and the scrollable contents window: the scrollbars are attached to the
530 main window itself, hence it, and not the contents window must be
531 derived from wxScrolled, but only the contents window scrolls when the
532 scrollbars are used. To implement such setup, you need to call this
533 method with the contents window as argument.
534
535 Notice that if this method is used, GetSizeAvailableForScrollTarget()
536 method must be overridden.
537 */
538 void SetTargetWindow(wxWindow *window);
539 wxWindow *GetTargetWindow() const;
540
541
542 void SetTargetRect(const wxRect& rect);
543 wxRect GetTargetRect() const;
544
545 int GetScrollPageSize(int orient) const;
546 void SetScrollPageSize(int orient, int pageSize);
547 int GetScrollLines( int orient ) const;
548 void SetScale(double xs, double ys);
549 double GetScaleX() const;
550 double GetScaleY() const;
551
552 virtual void AdjustScrollbars();
553
554 /**
555 Are we generating the autoscroll events?
556 */
557 bool IsAutoScrolling() const;
558
559 /**
560 Stop generating the scroll events when mouse is held outside the
561 window.
562 */
563 void StopAutoScrolling();
564
565 /**
566 This method can be overridden in a derived class to forbid sending the
567 auto scroll events - note that unlike StopAutoScrolling() it doesn't
568 stop the timer, so it will be called repeatedly and will typically
569 return different values depending on the current mouse position
570
571 The base class version just returns true.
572 */
573 virtual bool SendAutoScrollEvents(wxScrollWinEvent& event) const;
574
575
576 protected:
577 /**
578 Function which must be overridden to implement the size available for
579 the scroll target for the given size of the main window.
580
581 This method must be overridden if SetTargetWindow() is used (it is
582 never called otherwise). The implementation should decrease the @a size
583 to account for the size of the non-scrollable parts of the main window
584 and return only the size available for the scrollable window itself.
585 E.g. in the example given in SetTargetWindow() documentation the
586 function would subtract the height of the header window from the
587 vertical component of @a size.
588 */
589 virtual wxSize GetSizeAvailableForScrollTarget(const wxSize& size);
590 };
591
592
593 /**
594 Scrolled window derived from wxPanel.
595
596 See wxScrolled for a detailed description.
597
598 @note Note that because this class derives from wxPanel, it shares its
599 behaviour with regard to TAB traversal and focus handling (in
600 particular, it forwards focus to its children). If you don't want
601 this behaviour, use ::wxScrolledCanvas instead.
602
603 @note ::wxScrolledWindow is an alias for wxScrolled<wxPanel> since version
604 2.9.0. In older versions, it was a standalone class.
605
606 @library{wxcore}
607 @category{miscwnd}
608
609 @see wxScrolled, ::wxScrolledCanvas
610 */
611 typedef wxScrolled<wxPanel> wxScrolledWindow;
612
613 /**
614 Alias for wxScrolled<wxWindow>. Scrolled window that doesn't have children
615 and so doesn't need or want special handling of TAB traversal.
616
617 @since 2.9.0
618
619 @library{wxcore}
620 @category{miscwnd}
621
622 @see wxScrolled, ::wxScrolledWindow
623 */
624 typedef wxScrolled<wxWindow> wxScrolledCanvas;