1 /////////////////////////////////////////////////////////////////////////////
3 // Purpose: interface of wxScrolled template
4 // Author: wxWidgets team
5 // Licence: wxWindows licence
6 /////////////////////////////////////////////////////////////////////////////
9 Possible values for the second argument of wxScrolled::ShowScrollbars().
11 enum wxScrollbarVisibility
13 wxSHOW_SB_NEVER
= -1, ///< Never show the scrollbar at all.
14 wxSHOW_SB_DEFAULT
, ///< Show scrollbar only if it is needed.
15 wxSHOW_SB_ALWAYS
///< Always show scrollbar, even if not needed.
20 The wxScrolled class manages scrolling for its client area, transforming
21 the coordinates according to the scrollbar positions, and setting the
22 scroll positions, thumb sizes and ranges according to the area in view.
24 There are two commonly used (but not the only possible!) specializations of
27 - ::wxScrolledWindow, aka wxScrolled<wxPanel>, is equivalent to
28 ::wxScrolledWindow from earlier versions. Derived from wxPanel, it shares
29 wxPanel's behaviour with regard to TAB traversal and focus handling. Use
30 this if the scrolled window will have child controls.
32 - ::wxScrolledCanvas, aka wxScrolled<wxWindow>, derives from wxWindow and
33 so doesn't handle children specially. This is suitable e.g. for
34 implementing scrollable controls such as tree or list controls.
36 Starting from version 2.4 of wxWidgets, there are several ways to use a
37 ::wxScrolledWindow (and now wxScrolled). In particular, there are
38 three ways to set the size of the scrolling area:
40 One way is to set the scrollbars directly using a call to SetScrollbars().
41 This is the way it used to be in any previous version of wxWidgets and it
42 will be kept for backwards compatibility.
44 An additional method of manual control, which requires a little less
45 computation of your own, is to set the total size of the scrolling area by
46 calling either wxWindow::SetVirtualSize(), or wxWindow::FitInside(), and
47 setting the scrolling increments for it by calling SetScrollRate().
48 Scrolling in some orientation is enabled by setting a non-zero increment
51 The most automatic and newest way is to simply let sizers determine the
52 scrolling area. This is now the default when you set an interior sizer into
53 a wxScrolled with wxWindow::SetSizer(). The scrolling area will be
54 set to the size requested by the sizer and the scrollbars will be assigned
55 for each orientation according to the need for them and the scrolling
56 increment set by SetScrollRate(). As above, scrolling is only enabled in
57 orientations with a non-zero increment. You can influence the minimum size
58 of the scrolled area controlled by a sizer by calling
59 wxWindow::SetVirtualSizeHints(). (Calling SetScrollbars() has analogous
60 effects in wxWidgets 2.4 -- in later versions it may not continue to
63 Note that if maximum size hints are still supported by
64 wxWindow::SetVirtualSizeHints(), use them at your own dire risk. They may
65 or may not have been removed for 2.4, but it really only makes sense to set
66 minimum size hints here. We should probably replace
67 wxWindow::SetVirtualSizeHints() with wxWindow::SetMinVirtualSize() or
68 similar and remove it entirely in future.
70 @todo review docs for this class replacing SetVirtualSizeHints() with
73 As with all windows, an application can draw onto a wxScrolled using a
74 @ref overview_dc "device context".
76 You have the option of handling the OnPaint handler or overriding the
77 wxScrolled::OnDraw() function, which is passed a pre-scrolled device
78 context (prepared by wxScrolled::DoPrepareDC()).
80 If you don't wish to calculate your own scrolling, you must call
81 DoPrepareDC() when not drawing from within OnDraw(), to set the device
82 origin for the device context according to the current scroll position.
84 A wxScrolled will normally scroll itself and therefore its child windows
85 as well. It might however be desired to scroll a different window than
86 itself: e.g. when designing a spreadsheet, you will normally only have to
87 scroll the (usually white) cell area, whereas the (usually grey) label area
88 will scroll very differently. For this special purpose, you can call
89 SetTargetWindow() which means that pressing the scrollbars will scroll a
92 Note that the underlying system knows nothing about scrolling coordinates,
93 so that all system functions (mouse events, expose events, refresh calls
94 etc) as well as the position of subwindows are relative to the "physical"
95 origin of the scrolled window. If the user insert a child window at
96 position (10,10) and scrolls the window down 100 pixels (moving the child
97 window out of the visible area), the child window will report a position
102 If this style is specified and ::wxVSCROLL isn't, the window will be
103 scrollable only in horizontal direction (by default, i.e. if neither
104 this style nor ::wxVSCROLL is specified, it scrolls in both
107 If this style is specified and ::wxHSCROLL isn't, the window will be
108 scrollable only in vertical direction (by default, i.e. if neither
109 this style nor ::wxHSCROLL is specified, it scrolls in both
111 @style{wxALWAYS_SHOW_SB}
112 Since wxWidgets 2.9.5, specifying this style makes the window always
113 show its scrollbars, even if they are not used. See ShowScrollbars().
115 Uses a backing pixmap to speed refreshes. Motif only.
119 @beginEventEmissionTable{wxScrollWinEvent}
120 @event{EVT_SCROLLWIN(func)}
121 Process all scroll events.
122 @event{EVT_SCROLLWIN_TOP(func)}
123 Process @c wxEVT_SCROLLWIN_TOP scroll-to-top events.
124 @event{EVT_SCROLLWIN_BOTTOM(func)}
125 Process @c wxEVT_SCROLLWIN_BOTTOM scroll-to-bottom events.
126 @event{EVT_SCROLLWIN_LINEUP(func)}
127 Process @c wxEVT_SCROLLWIN_LINEUP line up events.
128 @event{EVT_SCROLLWIN_LINEDOWN(func)}
129 Process @c wxEVT_SCROLLWIN_LINEDOWN line down events.
130 @event{EVT_SCROLLWIN_PAGEUP(func)}
131 Process @c wxEVT_SCROLLWIN_PAGEUP page up events.
132 @event{EVT_SCROLLWIN_PAGEDOWN(func)}
133 Process @c wxEVT_SCROLLWIN_PAGEDOWN page down events.
134 @event{EVT_SCROLLWIN_THUMBTRACK(func)}
135 Process @c wxEVT_SCROLLWIN_THUMBTRACK thumbtrack events
136 (frequent events sent as the user drags the thumbtrack).
137 @event{EVT_SCROLLWIN_THUMBRELEASE(func)}
138 Process @c wxEVT_SCROLLWIN_THUMBRELEASE thumb release events.
142 Don't confuse wxScrollWinEvents generated by this class with
143 wxScrollEvent objects generated by wxScrollBar and wxSlider.
147 Use wxScrolled for applications where the user scrolls by a fixed amount,
148 and where a 'page' can be interpreted to be the current visible portion of
149 the window. For more sophisticated applications, use the wxScrolled
150 implementation as a guide to build your own scroll behaviour or use
151 wxVScrolledWindow or its variants.
153 @since The wxScrolled template exists since version 2.9.0. In older versions,
154 only ::wxScrolledWindow (equivalent of wxScrolled<wxPanel>) was
160 @see wxScrollBar, wxClientDC, wxPaintDC,
161 wxVScrolledWindow, wxHScrolledWindow, wxHVScrolledWindow,
164 class wxScrolled
: public T
167 /// Default constructor.
176 Window identifier. The value @c wxID_ANY indicates a default value.
178 Window position. If a position of ::wxDefaultPosition is specified
179 then a default position is chosen.
181 Window size. If a size of ::wxDefaultSize is specified then the
182 window is sized appropriately.
184 Window style. See wxScrolled.
188 @remarks The window is initially created without visible scrollbars.
189 Call SetScrollbars() to specify how big the virtual window
192 wxScrolled(wxWindow
* parent
, wxWindowID id
= -1,
193 const wxPoint
& pos
= wxDefaultPosition
,
194 const wxSize
& size
= wxDefaultSize
,
195 long style
= wxHSCROLL
| wxVSCROLL
,
196 const wxString
& name
= "scrolledWindow");
199 Translates the logical coordinates to the device ones. For example, if
200 a window is scrolled 10 pixels to the bottom, the device coordinates of
201 the origin are (0, 0) (as always), but the logical coordinates are (0,
202 10) and so the call to CalcScrolledPosition(0, 10, xx, yy) will return
206 In wxPerl this method takes two parameters and returns a
207 2-element list (xx, yy).
210 @see CalcUnscrolledPosition()
212 void CalcScrolledPosition(int x
, int y
, int* xx
, int* yy
) const;
213 wxPoint
CalcScrolledPosition(const wxPoint
& pt
) const;
216 Translates the device coordinates to the logical ones. For example, if
217 a window is scrolled 10 pixels to the bottom, the device coordinates of
218 the origin are (0, 0) (as always), but the logical coordinates are (0,
219 10) and so the call to CalcUnscrolledPosition(0, 0, xx, yy) will return
223 In wxPerl this method takes two parameters and returns a
224 2-element list (xx, yy).
227 @see CalcScrolledPosition()
229 void CalcUnscrolledPosition(int x
, int y
, int* xx
, int* yy
) const;
230 wxPoint
CalcUnscrolledPosition(const wxPoint
& pt
) const;
233 Creates the window for two-step construction. Derived classes
234 should call or replace this function. See wxScrolled::wxScrolled()
237 bool Create(wxWindow
* parent
, wxWindowID id
= -1,
238 const wxPoint
& pos
= wxDefaultPosition
,
239 const wxSize
& size
= wxDefaultSize
,
240 long style
= wxHSCROLL
| wxVSCROLL
,
241 const wxString
& name
= "scrolledWindow");
244 Disable use of keyboard keys for scrolling.
246 By default cursor movement keys (including Home, End, Page Up and Down)
247 are used to scroll the window appropriately. If the derived class uses
248 these keys for something else, e.g. changing the currently selected
249 item, this function can be used to disable this behaviour as it's not
250 only not necessary then but can actually be actively harmful if another
251 object forwards a keyboard event corresponding to one of the above keys
252 to us using ProcessWindowEvent() because the event will always be
253 processed which can be undesirable.
257 void DisableKeyboardScrolling();
260 Call this function to prepare the device context for drawing a scrolled
263 It sets the device origin according to the current scroll position.
264 DoPrepareDC() is called automatically within the default @c wxEVT_PAINT
265 event handler, so your OnDraw() override will be passed an already
266 'pre-scrolled' device context. However, if you wish to draw from
267 outside of OnDraw() (e.g. from your own @c wxEVT_PAINT handler), you
268 must call this function yourself.
272 void MyWindow::OnEvent(wxMouseEvent& event)
277 dc.SetPen(*wxBLACK_PEN);
279 event.Position(&x, &y);
280 if (xpos > -1 && ypos > -1 && event.Dragging())
282 dc.DrawLine(xpos, ypos, x, y);
289 Notice that the function sets the origin by moving it relatively to the
290 current origin position, so you shouldn't change the origin before
291 calling DoPrepareDC() or, if you do, reset it to (0, 0) later. If you
292 call DoPrepareDC() immediately after device context creation, as in the
293 example above, this problem doesn't arise, of course, so it is
294 customary to do it like this.
296 void DoPrepareDC(wxDC
& dc
);
299 Enable or disable use of wxWindow::ScrollWindow() for scrolling.
301 By default, when a scrolled window is logically scrolled,
302 wxWindow::ScrollWindow() is called on the underlying window which
303 scrolls the window contents and only invalidates the part of the window
304 newly brought into view. If @false is passed as an argument, then this
305 "physical scrolling" is disabled and the window is entirely invalidated
306 whenever it is scrolled by calling wxWindow::Refresh().
308 It should be rarely necessary to disable physical scrolling, so this
309 method shouldn't be called in normal circumstances.
312 If @true, enables physical scrolling in the x direction.
314 If @true, enables physical scrolling in the y direction.
316 void EnableScrolling(bool xScrolling
, bool yScrolling
);
319 Set the scrollbar visibility.
321 By default the scrollbar in the corresponding direction is only shown
322 if it is needed, i.e. if the virtual size of the scrolled window in
323 this direction is greater than the current physical window size. Using
324 this function the scrollbar visibility can be changed to be:
325 - wxSHOW_SB_ALWAYS: To always show the scrollbar, even if it is
326 not needed currently (wxALWAYS_SHOW_SB style can be used during
327 the window creation to achieve the same effect but it applies
329 - wxSHOW_SB_NEVER: To never show the scrollbar at all. In this case
330 the program should presumably provide some other way for the
331 user to scroll the window.
332 - wxSHOW_SB_DEFAULT: To restore the default behaviour described
336 The desired visibility for the horizontal scrollbar.
338 The desired visibility for the vertical scrollbar.
342 void ShowScrollbars(wxScrollbarVisibility horz
, wxScrollbarVisibility vert
);
345 Get the number of pixels per scroll unit (line), in each direction, as
346 set by SetScrollbars(). A value of zero indicates no scrolling in that
350 Receives the number of pixels per horizontal unit.
352 Receives the number of pixels per vertical unit.
355 In wxPerl this method takes no parameters and returns a
356 2-element list (xUnit, yUnit).
359 @see SetScrollbars(), GetVirtualSize()
361 void GetScrollPixelsPerUnit(int* xUnit
, int* yUnit
) const;
364 Get the position at which the visible portion of the window starts.
367 Receives the first visible x position in scroll units.
369 Receives the first visible y position in scroll units.
372 If either of the scrollbars is not at the home position, @a x
373 and/or @a y will be greater than zero.
374 Combined with wxWindow::GetClientSize(), the application can use this
375 function to efficiently redraw only the visible portion of the window.
376 The positions are in logical scroll units, not pixels, so to convert
377 to pixels you will have to multiply by the number of pixels per scroll
381 In wxPerl this method takes no parameters and returns a
382 2-element list (x, y).
385 @see SetScrollbars(), Scroll()
387 void GetViewStart(int* x
, int* y
) const;
390 This is a simple overload of GetViewStart(int*,int*); see that function
393 wxPoint
GetViewStart() const;
396 Gets the size in device units of the scrollable window area (as
397 opposed to the client size, which is the area of the window currently
401 Receives the length of the scrollable window, in pixels.
403 Receives the height of the scrollable window, in pixels.
405 @remarks Use wxDC::DeviceToLogicalX() and wxDC::DeviceToLogicalY() to
406 translate these units to logical units.
409 In wxPerl this method takes no parameters and returns a
410 2-element list (xUnit, yUnit).
413 @see SetScrollbars(), GetScrollPixelsPerUnit()
415 void GetVirtualSize(int* x
, int* y
) const;
418 Motif only: @true if the window has a backing bitmap.
420 bool IsRetained() const;
423 Called by the default paint event handler to allow the application to
424 define painting behaviour without having to worry about calling
427 Instead of overriding this function you may also just process the paint
428 event in the derived class as usual, but then you will have to call
429 DoPrepareDC() yourself.
431 virtual void OnDraw(wxDC
& dc
);
434 This function is for backwards compatibility only and simply calls
435 DoPrepareDC() now. Notice that it is not called by the default paint
436 event handle (DoPrepareDC() is), so overriding this method in your
437 derived class is useless.
439 void PrepareDC(wxDC
& dc
);
442 Scrolls a window so the view start is at the given point.
445 The x position to scroll to, in scroll units.
447 The y position to scroll to, in scroll units.
449 @remarks The positions are in scroll units, not pixels, so to convert to
450 pixels you will have to multiply by the number of
451 pixels per scroll increment. If either parameter is
452 ::wxDefaultCoord (-1), that position will be ignored (no change
455 @see SetScrollbars(), GetScrollPixelsPerUnit()
457 void Scroll(int x
, int y
);
460 This is an overload of Scroll(int,int); see that function for more info.
462 void Scroll(const wxPoint
& pt
);
465 Set the horizontal and vertical scrolling increment only. See the
466 pixelsPerUnit parameter in SetScrollbars().
468 void SetScrollRate(int xstep
, int ystep
);
471 Sets up vertical and/or horizontal scrollbars.
473 The first pair of parameters give the number of pixels per 'scroll
474 step', i.e. amount moved when the up or down scroll arrows are pressed.
475 The second pair gives the length of scrollbar in scroll steps, which
476 sets the size of the virtual window.
478 @a xPos and @a yPos optionally specify a position to scroll to
481 For example, the following gives a window horizontal and vertical
482 scrollbars with 20 pixels per scroll step, and a size of 50 steps (1000
483 pixels) in each direction:
485 window->SetScrollbars(20, 20, 50, 50);
488 wxScrolled manages the page size itself, using the current client
489 window size as the page size.
491 Note that for more sophisticated scrolling applications, for example
492 where scroll steps may be variable according to the position in the
493 document, it will be necessary to derive a new class from wxWindow,
494 overriding OnSize() and adjusting the scrollbars appropriately.
496 @param pixelsPerUnitX
497 Pixels per scroll unit in the horizontal direction.
498 @param pixelsPerUnitY
499 Pixels per scroll unit in the vertical direction.
501 Number of units in the horizontal direction.
503 Number of units in the vertical direction.
505 Position to initialize the scrollbars in the horizontal direction,
508 Position to initialize the scrollbars in the vertical direction, in
511 Will not refresh window if @true.
513 @see wxWindow::SetVirtualSize()
515 void SetScrollbars(int pixelsPerUnitX
, int pixelsPerUnitY
,
520 bool noRefresh
= false);
523 Call this function to tell wxScrolled to perform the actual scrolling
524 on a different window (and not on itself).
526 This method is useful when only a part of the window should be
527 scrolled. A typical example is a control consisting of a fixed header
528 and the scrollable contents window: the scrollbars are attached to the
529 main window itself, hence it, and not the contents window must be
530 derived from wxScrolled, but only the contents window scrolls when the
531 scrollbars are used. To implement such setup, you need to call this
532 method with the contents window as argument.
534 Notice that if this method is used, GetSizeAvailableForScrollTarget()
535 method must be overridden.
537 void SetTargetWindow(wxWindow
*window
);
538 wxWindow
*GetTargetWindow() const;
541 void SetTargetRect(const wxRect
& rect
);
542 wxRect
GetTargetRect() const;
544 int GetScrollPageSize(int orient
) const;
545 void SetScrollPageSize(int orient
, int pageSize
);
546 int GetScrollLines( int orient
) const;
547 void SetScale(double xs
, double ys
);
548 double GetScaleX() const;
549 double GetScaleY() const;
551 virtual void AdjustScrollbars();
554 Are we generating the autoscroll events?
556 bool IsAutoScrolling() const;
559 Stop generating the scroll events when mouse is held outside the
562 void StopAutoScrolling();
565 This method can be overridden in a derived class to forbid sending the
566 auto scroll events - note that unlike StopAutoScrolling() it doesn't
567 stop the timer, so it will be called repeatedly and will typically
568 return different values depending on the current mouse position
570 The base class version just returns true.
572 virtual bool SendAutoScrollEvents(wxScrollWinEvent
& event
) const;
577 Function which must be overridden to implement the size available for
578 the scroll target for the given size of the main window.
580 This method must be overridden if SetTargetWindow() is used (it is
581 never called otherwise). The implementation should decrease the @a size
582 to account for the size of the non-scrollable parts of the main window
583 and return only the size available for the scrollable window itself.
584 E.g. in the example given in SetTargetWindow() documentation the
585 function would subtract the height of the header window from the
586 vertical component of @a size.
588 virtual wxSize
GetSizeAvailableForScrollTarget(const wxSize
& size
);
593 Scrolled window derived from wxPanel.
595 See wxScrolled for a detailed description.
597 @note Note that because this class derives from wxPanel, it shares its
598 behaviour with regard to TAB traversal and focus handling (in
599 particular, it forwards focus to its children). If you don't want
600 this behaviour, use ::wxScrolledCanvas instead.
602 @note ::wxScrolledWindow is an alias for wxScrolled<wxPanel> since version
603 2.9.0. In older versions, it was a standalone class.
608 @see wxScrolled, ::wxScrolledCanvas
610 typedef wxScrolled
<wxPanel
> wxScrolledWindow
;
613 Alias for wxScrolled<wxWindow>. Scrolled window that doesn't have children
614 and so doesn't need or want special handling of TAB traversal.
621 @see wxScrolled, ::wxScrolledWindow
623 typedef wxScrolled
<wxWindow
> wxScrolledCanvas
;