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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 */
12enum 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{wxRETAINED}
103 Uses a backing pixmap to speed refreshes. Motif only.
104 @endStyleTable
105
106
107 @beginEventEmissionTable{wxScrollWinEvent}
108 @event{EVT_SCROLLWIN(func)}
109 Process all scroll events.
110 @event{EVT_SCROLLWIN_TOP(func)}
111 Process @c wxEVT_SCROLLWIN_TOP scroll-to-top events.
112 @event{EVT_SCROLLWIN_BOTTOM(func)}
113 Process @c wxEVT_SCROLLWIN_BOTTOM scroll-to-bottom events.
114 @event{EVT_SCROLLWIN_LINEUP(func)}
115 Process @c wxEVT_SCROLLWIN_LINEUP line up events.
116 @event{EVT_SCROLLWIN_LINEDOWN(func)}
117 Process @c wxEVT_SCROLLWIN_LINEDOWN line down events.
118 @event{EVT_SCROLLWIN_PAGEUP(func)}
119 Process @c wxEVT_SCROLLWIN_PAGEUP page up events.
120 @event{EVT_SCROLLWIN_PAGEDOWN(func)}
121 Process @c wxEVT_SCROLLWIN_PAGEDOWN page down events.
122 @event{EVT_SCROLLWIN_THUMBTRACK(func)}
123 Process @c wxEVT_SCROLLWIN_THUMBTRACK thumbtrack events
124 (frequent events sent as the user drags the thumbtrack).
125 @event{EVT_SCROLLWIN_THUMBRELEASE(func)}
126 Process @c wxEVT_SCROLLWIN_THUMBRELEASE thumb release events.
127 @endEventTable
128
129 @note
130 Don't confuse wxScrollWinEvents generated by this class with
131 wxScrollEvent objects generated by wxScrollBar and wxSlider.
132
133
134 @remarks
135 Use wxScrolled for applications where the user scrolls by a fixed amount,
136 and where a 'page' can be interpreted to be the current visible portion of
137 the window. For more sophisticated applications, use the wxScrolled
138 implementation as a guide to build your own scroll behaviour or use
139 wxVScrolledWindow or its variants.
140
141 @since The wxScrolled template exists since version 2.9.0. In older versions,
142 only ::wxScrolledWindow (equivalent of wxScrolled<wxPanel>) was
143 available.
144
145 @library{wxcore}
146 @category{miscwnd}
147
148 @see wxScrollBar, wxClientDC, wxPaintDC,
149 wxVScrolledWindow, wxHScrolledWindow, wxHVScrolledWindow,
150*/
151template<class T>
152class wxScrolled : public T
153{
154public:
155 /// Default constructor.
156 wxScrolled();
157
158 /**
159 Constructor.
160
161 @param parent
162 Parent window.
163 @param id
164 Window identifier. The value @c wxID_ANY indicates a default value.
165 @param pos
166 Window position. If a position of ::wxDefaultPosition is specified
167 then a default position is chosen.
168 @param size
169 Window size. If a size of ::wxDefaultSize is specified then the
170 window is sized appropriately.
171 @param style
172 Window style. See wxScrolled.
173 @param name
174 Window name.
175
176 @remarks The window is initially created without visible scrollbars.
177 Call SetScrollbars() to specify how big the virtual window
178 size should be.
179 */
180 wxScrolled(wxWindow* parent, wxWindowID id = -1,
181 const wxPoint& pos = wxDefaultPosition,
182 const wxSize& size = wxDefaultSize,
183 long style = wxHSCROLL | wxVSCROLL,
184 const wxString& name = "scrolledWindow");
185
186
187 /**
188 Translates the logical coordinates to the device ones. For example, if
189 a window is scrolled 10 pixels to the bottom, the device coordinates of
190 the origin are (0, 0) (as always), but the logical coordinates are (0,
191 10) and so the call to CalcScrolledPosition(0, 10, xx, yy) will return
192 0 in yy.
193
194 @beginWxPerlOnly
195 In wxPerl this method takes two parameters and returns a
196 2-element list (xx, yy).
197 @endWxPerlOnly
198
199 @see CalcUnscrolledPosition()
200 */
201 void CalcScrolledPosition(int x, int y, int* xx, int* yy) const;
202
203 /**
204 Translates the device coordinates to the logical ones. For example, if
205 a window is scrolled 10 pixels to the bottom, the device coordinates of
206 the origin are (0, 0) (as always), but the logical coordinates are (0,
207 10) and so the call to CalcUnscrolledPosition(0, 0, xx, yy) will return
208 10 in yy.
209
210 @beginWxPerlOnly
211 In wxPerl this method takes two parameters and returns a
212 2-element list (xx, yy).
213 @endWxPerlOnly
214
215 @see CalcScrolledPosition()
216 */
217 void CalcUnscrolledPosition(int x, int y, int* xx, int* yy) const;
218
219 /**
220 Creates the window for two-step construction. Derived classes
221 should call or replace this function. See wxScrolled::wxScrolled()
222 for details.
223 */
224 bool Create(wxWindow* parent, wxWindowID id = -1,
225 const wxPoint& pos = wxDefaultPosition,
226 const wxSize& size = wxDefaultSize,
227 long style = wxHSCROLL | wxVSCROLL,
228 const wxString& name = "scrolledWindow");
229
230 /**
231 Disable use of keyboard keys for scrolling.
232
233 By default cursor movement keys (including Home, End, Page Up and Down)
234 are used to scroll the window appropriately. If the derived class uses
235 these keys for something else, e.g. changing the currently selected
236 item, this function can be used to disable this behaviour as it's not
237 only not necessary then but can actually be actively harmful if another
238 object forwards a keyboard event corresponding to one of the above keys
239 to us using ProcessWindowEvent() because the event will always be
240 processed which can be undesirable.
241
242 @since 2.9.1
243 */
244 void DisableKeyboardScrolling();
245
246 /**
247 Call this function to prepare the device context for drawing a scrolled
248 image.
249
250 It sets the device origin according to the current scroll position.
251 DoPrepareDC() is called automatically within the default @c wxEVT_PAINT
252 event handler, so your OnDraw() override will be passed an already
253 'pre-scrolled' device context. However, if you wish to draw from
254 outside of OnDraw() (e.g. from your own @c wxEVT_PAINT handler), you
255 must call this function yourself.
256
257 For example:
258 @code
259 void MyWindow::OnEvent(wxMouseEvent& event)
260 {
261 wxClientDC dc(this);
262 DoPrepareDC(dc);
263
264 dc.SetPen(*wxBLACK_PEN);
265 float x, y;
266 event.Position(&x, &y);
267 if (xpos > -1 && ypos > -1 && event.Dragging())
268 {
269 dc.DrawLine(xpos, ypos, x, y);
270 }
271 xpos = x;
272 ypos = y;
273 }
274 @endcode
275
276 Notice that the function sets the origin by moving it relatively to the
277 current origin position, so you shouldn't change the origin before
278 calling DoPrepareDC() or, if you do, reset it to (0, 0) later. If you
279 call DoPrepareDC() immediately after device context creation, as in the
280 example above, this problem doesn't arise, of course, so it is
281 customary to do it like this.
282 */
283 void DoPrepareDC(wxDC& dc);
284
285 /**
286 Enable or disable physical scrolling in the given direction. Physical
287 scrolling is the physical transfer of bits up or down the
288 screen when a scroll event occurs. If the application scrolls by a
289 variable amount (e.g. if there are different font sizes) then physical
290 scrolling will not work, and you should switch it off. Note that you
291 will have to reposition child windows yourself, if physical scrolling
292 is disabled.
293
294 @param xScrolling
295 If @true, enables physical scrolling in the x direction.
296 @param yScrolling
297 If @true, enables physical scrolling in the y direction.
298
299 @remarks Physical scrolling may not be available on all platforms. Where
300 it is available, it is enabled by default.
301 */
302 void EnableScrolling(bool xScrolling, bool yScrolling);
303
304 /**
305 Set the scrollbar visibility.
306
307 By default the scrollbar in the corresponding direction is only shown
308 if it is needed, i.e. if the virtual size of the scrolled window in
309 this direction is greater than the current physical window size. Using
310 this function the scrollbar visibility can be changed to be:
311 - wxSHOW_SB_ALWAYS: To always show the scrollbar, even if it is
312 not needed currently (wxALWAYS_SHOW_SB style can be used during
313 the window creation to achieve the same effect but it applies
314 in both directions).
315 - wxSHOW_SB_NEVER: To never show the scrollbar at all. In this case
316 the program should presumably provide some other way for the
317 user to scroll the window.
318 - wxSHOW_SB_DEFAULT: To restore the default behaviour described
319 above.
320
321 @param horz
322 The desired visibility for the horizontal scrollbar.
323 @param vert
324 The desired visibility for the vertical scrollbar.
325
326 @since 2.9.0
327 */
328 void ShowScrollbars(wxScrollbarVisibility horz, wxScrollbarVisibility vert);
329
330 /**
331 Get the number of pixels per scroll unit (line), in each direction, as
332 set by SetScrollbars(). A value of zero indicates no scrolling in that
333 direction.
334
335 @param xUnit
336 Receives the number of pixels per horizontal unit.
337 @param yUnit
338 Receives the number of pixels per vertical unit.
339
340 @beginWxPerlOnly
341 In wxPerl this method takes no parameters and returns a
342 2-element list (xUnit, yUnit).
343 @endWxPerlOnly
344
345 @see SetScrollbars(), GetVirtualSize()
346 */
347 void GetScrollPixelsPerUnit(int* xUnit, int* yUnit) const;
348
349 /**
350 Get the position at which the visible portion of the window starts.
351
352 @param x
353 Receives the first visible x position in scroll units.
354 @param y
355 Receives the first visible y position in scroll units.
356
357 @remarks
358 If either of the scrollbars is not at the home position, @a x
359 and/or @a y will be greater than zero.
360 Combined with wxWindow::GetClientSize(), the application can use this
361 function to efficiently redraw only the visible portion of the window.
362 The positions are in logical scroll units, not pixels, so to convert
363 to pixels you will have to multiply by the number of pixels per scroll
364 increment.
365
366 @beginWxPerlOnly
367 In wxPerl this method takes no parameters and returns a
368 2-element list (x, y).
369 @endWxPerlOnly
370
371 @see SetScrollbars(), Scroll()
372 */
373 void GetViewStart(int* x, int* y) const;
374
375 /**
376 This is a simple overload of GetViewStart(int*,int*); see that function
377 for more info.
378 */
379 wxPoint GetViewStart() const;
380
381 /**
382 Gets the size in device units of the scrollable window area (as
383 opposed to the client size, which is the area of the window currently
384 visible).
385
386 @param x
387 Receives the length of the scrollable window, in pixels.
388 @param y
389 Receives the height of the scrollable window, in pixels.
390
391 @remarks Use wxDC::DeviceToLogicalX() and wxDC::DeviceToLogicalY() to
392 translate these units to logical units.
393
394 @beginWxPerlOnly
395 In wxPerl this method takes no parameters and returns a
396 2-element list (xUnit, yUnit).
397 @endWxPerlOnly
398
399 @see SetScrollbars(), GetScrollPixelsPerUnit()
400 */
401 void GetVirtualSize(int* x, int* y) const;
402
403 /**
404 Motif only: @true if the window has a backing bitmap.
405 */
406 bool IsRetained() const;
407
408 /**
409 Called by the default paint event handler to allow the application to
410 define painting behaviour without having to worry about calling
411 DoPrepareDC().
412
413 Instead of overriding this function you may also just process the paint
414 event in the derived class as usual, but then you will have to call
415 DoPrepareDC() yourself.
416 */
417 virtual void OnDraw(wxDC& dc);
418
419 /**
420 This function is for backwards compatibility only and simply calls
421 DoPrepareDC() now. Notice that it is not called by the default paint
422 event handle (DoPrepareDC() is), so overriding this method in your
423 derived class is useless.
424 */
425 void PrepareDC(wxDC& dc);
426
427 /**
428 Scrolls a window so the view start is at the given point.
429
430 @param x
431 The x position to scroll to, in scroll units.
432 @param y
433 The y position to scroll to, in scroll units.
434
435 @remarks The positions are in scroll units, not pixels, so to convert to
436 pixels you will have to multiply by the number of
437 pixels per scroll increment. If either parameter is
438 ::wxDefaultCoord (-1), that position will be ignored (no change
439 in that direction).
440
441 @see SetScrollbars(), GetScrollPixelsPerUnit()
442 */
443 void Scroll(int x, int y);
444
445 /**
446 This is an overload of Scroll(int,int); see that function for more info.
447 */
448 void Scroll(const wxPoint& pt);
449
450 /**
451 Set the horizontal and vertical scrolling increment only. See the
452 pixelsPerUnit parameter in SetScrollbars().
453 */
454 void SetScrollRate(int xstep, int ystep);
455
456 /**
457 Sets up vertical and/or horizontal scrollbars.
458
459 The first pair of parameters give the number of pixels per 'scroll
460 step', i.e. amount moved when the up or down scroll arrows are pressed.
461 The second pair gives the length of scrollbar in scroll steps, which
462 sets the size of the virtual window.
463
464 @a xPos and @a yPos optionally specify a position to scroll to
465 immediately.
466
467 For example, the following gives a window horizontal and vertical
468 scrollbars with 20 pixels per scroll step, and a size of 50 steps (1000
469 pixels) in each direction:
470 @code
471 window->SetScrollbars(20, 20, 50, 50);
472 @endcode
473
474 wxScrolled manages the page size itself, using the current client
475 window size as the page size.
476
477 Note that for more sophisticated scrolling applications, for example
478 where scroll steps may be variable according to the position in the
479 document, it will be necessary to derive a new class from wxWindow,
480 overriding OnSize() and adjusting the scrollbars appropriately.
481
482 @param pixelsPerUnitX
483 Pixels per scroll unit in the horizontal direction.
484 @param pixelsPerUnitY
485 Pixels per scroll unit in the vertical direction.
486 @param noUnitsX
487 Number of units in the horizontal direction.
488 @param noUnitsY
489 Number of units in the vertical direction.
490 @param xPos
491 Position to initialize the scrollbars in the horizontal direction,
492 in scroll units.
493 @param yPos
494 Position to initialize the scrollbars in the vertical direction, in
495 scroll units.
496 @param noRefresh
497 Will not refresh window if @true.
498
499 @see wxWindow::SetVirtualSize()
500 */
501 void SetScrollbars(int pixelsPerUnitX, int pixelsPerUnitY,
502 int noUnitsX,
503 int noUnitsY,
504 int xPos = 0,
505 int yPos = 0,
506 bool noRefresh = false);
507
508 /**
509 Call this function to tell wxScrolled to perform the actual scrolling
510 on a different window (and not on itself).
511
512 This method is useful when only a part of the window should be
513 scrolled. A typical example is a control consisting of a fixed header
514 and the scrollable contents window: the scrollbars are attached to the
515 main window itself, hence it, and not the contents window must be
516 derived from wxScrolled, but only the contents window scrolls when the
517 scrollbars are used. To implement such setup, you need to call this
518 method with the contents window as argument.
519
520 Notice that if this method is used, GetSizeAvailableForScrollTarget()
521 method must be overridden.
522 */
523 void SetTargetWindow(wxWindow *window);
524 wxWindow *GetTargetWindow() const;
525
526
527 void SetTargetRect(const wxRect& rect);
528 wxRect GetTargetRect() const;
529
530 int GetScrollPageSize(int orient) const;
531 void SetScrollPageSize(int orient, int pageSize);
532 int GetScrollLines( int orient ) const;
533 void SetScale(double xs, double ys);
534 double GetScaleX() const;
535 double GetScaleY() const;
536
537 virtual void AdjustScrollbars();
538
539 /**
540 Are we generating the autoscroll events?
541 */
542 bool IsAutoScrolling() const;
543
544 /**
545 Stop generating the scroll events when mouse is held outside the
546 window.
547 */
548 void StopAutoScrolling();
549
550 /**
551 This method can be overridden in a derived class to forbid sending the
552 auto scroll events - note that unlike StopAutoScrolling() it doesn't
553 stop the timer, so it will be called repeatedly and will typically
554 return different values depending on the current mouse position
555
556 The base class version just returns true.
557 */
558 virtual bool SendAutoScrollEvents(wxScrollWinEvent& event) const;
559
560
561protected:
562 /**
563 Function which must be overridden to implement the size available for
564 the scroll target for the given size of the main window.
565
566 This method must be overridden if SetTargetWindow() is used (it is
567 never called otherwise). The implementation should decrease the @a size
568 to account for the size of the non-scrollable parts of the main window
569 and return only the size available for the scrollable window itself.
570 E.g. in the example given in SetTargetWindow() documentation the
571 function would subtract the height of the header window from the
572 vertical component of @a size.
573 */
574 virtual wxSize GetSizeAvailableForScrollTarget(const wxSize& size);
575};
576
577
578/**
579 Scrolled window derived from wxPanel.
580
581 See wxScrolled for a detailed description.
582
583 @note Note that because this class derives from wxPanel, it shares its
584 behaviour with regard to TAB traversal and focus handling (in
585 particular, it forwards focus to its children). If you don't want
586 this behaviour, use ::wxScrolledCanvas instead.
587
588 @note ::wxScrolledWindow is an alias for wxScrolled<wxPanel> since version
589 2.9.0. In older versions, it was a standalone class.
590
591 @library{wxcore}
592 @category{miscwnd}
593
594 @see wxScrolled, ::wxScrolledCanvas
595*/
596typedef wxScrolled<wxPanel> wxScrolledWindow;
597
598/**
599 Alias for wxScrolled<wxWindow>. Scrolled window that doesn't have children
600 and so doesn't need or want special handling of TAB traversal.
601
602 @since 2.9.0
603
604 @library{wxcore}
605 @category{miscwnd}
606
607 @see wxScrolled, ::wxScrolledWindow
608*/
609typedef wxScrolled<wxWindow> wxScrolledCanvas;