[wxWidgets.git] / interface / scrolwin.h

/////////////////////////////////////////////////////////////////////////////
// Name:        scrolwin.h
// Purpose:     documentation for wxScrolledWindow class
// Author:      wxWidgets team
// RCS-ID:      $Id$
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

/**
    @class wxScrolledWindow
    @wxheader{scrolwin.h}
    
    The wxScrolledWindow class manages scrolling for its client area, transforming
    the coordinates according to the scrollbar positions, and setting the
    scroll positions, thumb sizes and ranges according to the area in view.
    
    Starting from version 2.4 of wxWidgets, there are several ways to use a
    wxScrolledWindow. In particular, there are now three ways to set the
    size of the scrolling area:
    
    One way is to set the scrollbars directly using a call to
    wxScrolledWindow::SetScrollbars.
    This is the way it used to be in any previous version of wxWidgets
    and it will be kept for backwards compatibility.
    
    An additional method of manual control, which requires a little less
    computation of your own, is to set the total size of the scrolling area by
    calling either wxWindow::SetVirtualSize,
    or wxWindow::FitInside, and setting the
    scrolling increments for it by calling 
    wxScrolledWindow::SetScrollRate.
    Scrolling in some orientation is enabled by setting a non-zero increment
    for it.
    
    The most automatic and newest way is to simply let sizers determine the
    scrolling area. This is now the default when you set an interior sizer
    into a wxScrolledWindow with wxWindow::SetSizer.
    The scrolling area will be set to the size requested by the sizer and
    the scrollbars will be assigned for each orientation according to the need
    for them and the scrolling increment set by 
    wxScrolledWindow::SetScrollRate.
    As above, scrolling is only enabled in orientations with a non-zero
    increment.  You can influence the minimum size of the scrolled area
    controlled by a sizer by calling
    wxWindow::SetVirtualSizeHints.
    (calling wxScrolledWindow::SetScrollbars
     has analogous effects in wxWidgets 2.4 -- in later versions it may not continue
     to override the sizer)
    
    Note:  if Maximum size hints are still supported by SetVirtualSizeHints, use
    them at your own dire risk.  They may or may not have been removed for 2.4,
    but it really only makes sense to set minimum size hints here.  We should
    probably replace SetVirtualSizeHints with SetMinVirtualSize or similar
    and remove it entirely in future.
    
    As with all windows, an application can draw onto a wxScrolledWindow using
    a @ref overview_dcoverview "device context".
    
    You have the option of handling the OnPaint handler
    or overriding the wxScrolledWindow::OnDraw function, which is
    passed a pre-scrolled device context (prepared by 
    wxScrolledWindow::DoPrepareDC).
    
    If you don't wish to calculate your own scrolling, you must call DoPrepareDC
    when not drawing from
    within OnDraw, to set the device origin for the device context according to the
    current
    scroll position.
    
    A wxScrolledWindow will normally scroll itself and therefore its child windows
    as well. It
    might however be desired to scroll a different window than itself: e.g. when
    designing a
    spreadsheet, you will normally only have to scroll the (usually white) cell
    area, whereas the
    (usually grey) label area will scroll very differently. For this special
    purpose, you can
    call wxScrolledWindow::SetTargetWindow which means that pressing
    the scrollbars will scroll a different window.
    
    Note that the underlying system knows nothing about scrolling coordinates, so
    that all system
    functions (mouse events, expose events, refresh calls etc) as well as the
    position of subwindows
    are relative to the "physical" origin of the scrolled window. If the user
    insert a child window at
    position (10,10) and scrolls the window down 100 pixels (moving the child
    window out of the visible
    area), the child window will report a position of (10,-90).
    
    @beginStyleTable
    @style{wxRETAINED}:
           Uses a backing pixmap to speed refreshes. Motif only.
    @endStyleTable
    
    @library{wxcore}
    @category{miscwnd}
    
    @seealso
    wxScrollBar, wxClientDC, wxPaintDC, wxVScrolledWindow
*/
class wxScrolledWindow : public wxPanel
{
public:
    //@{
    /**
        Constructor.
        
        @param parent 
        Parent window.
        
        @param id 
        Window identifier. The value wxID_ANY indicates a default value.
        
        @param pos 
        Window position. If a position of (-1, -1) is specified then a default position
        is chosen.
        
        @param size 
        Window size. If a size of (-1, -1) is specified then the window is sized
        appropriately.
        
        @param style 
        Window style. See wxScrolledWindow.
        
        @param name 
        Window name.
        
        @remarks The window is initially created without visible scrollbars. Call
                   SetScrollbars() to specify how big
                   the virtual window size should be.
    */
    wxScrolledWindow();
        wxScrolledWindow(wxWindow* parent, wxWindowID id = -1,
                         const wxPoint& pos = wxDefaultPosition,
                         const wxSize& size = wxDefaultSize,
                         long style = wxHSCROLL |  wxVSCROLL,
                         const wxString& name = "scrolledWindow");
    //@}

    /**
        Destructor.
    */
    ~wxScrolledWindow();

    /**
        Translates the logical coordinates to the device ones. For example, if a window
        is
        scrolled 10 pixels to the bottom, the device coordinates of the origin are (0,
        0)
        (as always), but the logical coordinates are (0, 10) and so the call to
        CalcScrolledPosition(0, 10, xx, yy) will return 0 in yy.
        
        @sa CalcUnscrolledPosition()
    */
    void CalcScrolledPosition(int x, int y, int * xx, int * yy);

    /**
        Translates the device coordinates to the logical ones. For example, if a window
        is
        scrolled 10 pixels to the bottom, the device coordinates of the origin are (0,
        0)
        (as always), but the logical coordinates are (0, 10) and so the call to
        CalcUnscrolledPosition(0, 0, xx, yy) will return 10 in yy.
        
        @sa CalcScrolledPosition()
    */
    void CalcUnscrolledPosition(int x, int y, int * xx, int * yy);

    /**
        Creates the window for two-step construction. Derived classes
        should call or replace this function. See wxScrolledWindow()
        for details.
    */
    bool Create(wxWindow* parent, wxWindowID id = -1,
                const wxPoint& pos = wxDefaultPosition,
                const wxSize& size = wxDefaultSize,
                long style = wxHSCROLL |  wxVSCROLL,
                const wxString& name = "scrolledWindow");

    /**
        Call this function to prepare the device context for drawing a scrolled image.
        It
        sets the device origin according to the current scroll position.
        
        DoPrepareDC is called automatically within the default OnPaint() event
        handler, so your OnDraw() override
        will be passed a 'pre-scrolled' device context. However, if you wish to draw
        from
        outside of OnDraw (via OnPaint), or you wish to implement OnPaint yourself, you
        must
        call this function yourself. For example:
    */
    void DoPrepareDC(wxDC& dc);

    /**
        Enable or disable physical scrolling in the given direction. Physical
        scrolling is the physical transfer of bits up or down the
        screen when a scroll event occurs. If the application scrolls by a
        variable amount (e.g. if there are different font sizes) then physical
        scrolling will not work, and you should switch it off. Note that you
        will have to reposition child windows yourself, if physical scrolling
        is disabled.
        
        @param xScrolling 
        If @true, enables physical scrolling in the x direction.
        
        @param yScrolling 
        If @true, enables physical scrolling in the y direction.
        
        @remarks Physical scrolling may not be available on all platforms. Where
                   it is available, it is enabled by default.
    */
    void EnableScrolling(bool xScrolling, bool yScrolling);

    /**
        Get the number of pixels per scroll unit (line), in each direction, as set
        by SetScrollbars(). A value of zero indicates no
        scrolling in that direction.
        
        @param xUnit 
        Receives the number of pixels per horizontal unit.
        
        @param yUnit 
        Receives the number of pixels per vertical unit.
        
        @sa SetScrollbars(), GetVirtualSize()
    */
    void GetScrollPixelsPerUnit(int* xUnit, int* yUnit);

    /**
        Get the position at which the visible portion of the window starts.
        
        @param x 
        Receives the first visible x position in scroll units.
        
        @param y 
        Receives the first visible y position in scroll units.
        
        @remarks If either of the scrollbars is not at the home position, x
                   and/or y will be greater than zero.  Combined with
                   wxWindow::GetClientSize, the application can use this
                   function to efficiently redraw only the visible
                   portion of the window.  The positions are in logical
                   scroll units, not pixels, so to convert to pixels you
                   will have to multiply by the number of pixels per
                   scroll increment.
        
        @sa SetScrollbars()
    */
    void GetViewStart(int* x, int* y);

    /**
        Gets the size in device units of the scrollable window area (as
        opposed to the client size, which is the area of the window currently
        visible).
        
        @param x 
        Receives the length of the scrollable window, in pixels.
        
        @param y 
        Receives the height of the scrollable window, in pixels.
        
        @remarks Use wxDC::DeviceToLogicalX and wxDC::DeviceToLogicalY to
                   translate these units to logical units.
        
        @sa SetScrollbars(), GetScrollPixelsPerUnit()
    */
    void GetVirtualSize(int* x, int* y);

    /**
        Motif only: @true if the window has a backing bitmap.
    */
    bool IsRetained();

    /**
        Called by the default paint event handler to allow the application to define
        painting behaviour without having to worry about calling 
        DoPrepareDC().
        
        Instead of overriding this function you may also just process the paint event
        in the derived class as usual, but then you will have to call DoPrepareDC()
        yourself.
    */
    virtual void OnDraw(wxDC& dc);

    /**
        This function is for backwards compatibility only and simply calls 
        DoPrepareDC() now. Notice that it is 
        not called by the default paint event handle (DoPrepareDC() is), so
        overriding this method in your derived class is useless.
    */
    void PrepareDC(wxDC& dc);

    /**
        Scrolls a window so the view start is at the given point.
        
        @param x 
        The x position to scroll to, in scroll units.
        
        @param y 
        The y position to scroll to, in scroll units.
        
        @remarks The positions are in scroll units, not pixels, so to convert to
                   pixels you will have to multiply by the number of
                   pixels per scroll increment. If either parameter is
                   -1, that position will be ignored (no change in that
                   direction).
        
        @sa SetScrollbars(), GetScrollPixelsPerUnit()
    */
    void Scroll(int x, int y);

    /**
        Set the horizontal and vertical scrolling increment only. See the pixelsPerUnit
        parameter in SetScrollbars.
    */
    void SetScrollRate(int xstep, int ystep);

    /**
        Sets up vertical and/or horizontal scrollbars.
        
        @param pixelsPerUnitX 
        Pixels per scroll unit in the horizontal direction.
        
        @param pixelsPerUnitY 
        Pixels per scroll unit in the vertical direction.
        
        @param noUnitsX 
        Number of units in the horizontal direction.
        
        @param noUnitsY 
        Number of units in the vertical direction.
        
        @param xPos 
        Position to initialize the scrollbars in the horizontal direction, in scroll
        units.
        
        @param yPos 
        Position to initialize the scrollbars in the vertical direction, in scroll
        units.
        
        @param noRefresh 
        Will not refresh window if @true.
        
        @remarks The first pair of parameters give the number of pixels per
                   'scroll step', i.e. amount moved when the up or down
                   scroll arrows are pressed. The second pair gives the
                   length of scrollbar in scroll steps, which sets the
                   size of the virtual window.
        
        @sa wxWindow::SetVirtualSize
    */
    void SetScrollbars(int pixelsPerUnitX, int pixelsPerUnitY,
                       int noUnitsX,
                       int noUnitsY,
                       int xPos = 0,
                       int yPos = 0,
                       bool noRefresh = @false);

    /**
        Call this function to tell wxScrolledWindow to perform the actual scrolling on
        a different window (and not on itself).
    */
    void SetTargetWindow(wxWindow* window);
};
Commit	Line	Data
23324ae1 FM	1	/////////////////////////////////////////////////////////////////////////////
	2	// Name: scrolwin.h
	3	// Purpose: documentation for wxScrolledWindow class
	4	// Author: wxWidgets team
	5	// RCS-ID: $Id$
	6	// Licence: wxWindows license
	7	/////////////////////////////////////////////////////////////////////////////
	8
	9	/**
	10	@class wxScrolledWindow
	11	@wxheader{scrolwin.h}
	12
	13	The wxScrolledWindow class manages scrolling for its client area, transforming
	14	the coordinates according to the scrollbar positions, and setting the
	15	scroll positions, thumb sizes and ranges according to the area in view.
	16
	17	Starting from version 2.4 of wxWidgets, there are several ways to use a
	18	wxScrolledWindow. In particular, there are now three ways to set the
	19	size of the scrolling area:
	20
	21	One way is to set the scrollbars directly using a call to
	22	wxScrolledWindow::SetScrollbars.
	23	This is the way it used to be in any previous version of wxWidgets
	24	and it will be kept for backwards compatibility.
	25
	26	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 by
	28	calling either wxWindow::SetVirtualSize,
	29	or wxWindow::FitInside, and setting the
	30	scrolling increments for it by calling
	31	wxScrolledWindow::SetScrollRate.
	32	Scrolling in some orientation is enabled by setting a non-zero increment
	33	for it.
	34
	35	The most automatic and newest way is to simply let sizers determine the
	36	scrolling area. This is now the default when you set an interior sizer
	37	into a wxScrolledWindow with wxWindow::SetSizer.
	38	The scrolling area will be set to the size requested by the sizer and
	39	the scrollbars will be assigned for each orientation according to the need
	40	for them and the scrolling increment set by
	41	wxScrolledWindow::SetScrollRate.
	42	As above, scrolling is only enabled in orientations with a non-zero
	43	increment. You can influence the minimum size of the scrolled area
	44	controlled by a sizer by calling
	45	wxWindow::SetVirtualSizeHints.
	46	(calling wxScrolledWindow::SetScrollbars
	47	has analogous effects in wxWidgets 2.4 -- in later versions it may not continue
	48	to override the sizer)
	49
	50	Note: if Maximum size hints are still supported by SetVirtualSizeHints, use
	51	them at your own dire risk. They may or may not have been removed for 2.4,
	52	but it really only makes sense to set minimum size hints here. We should
	53	probably replace SetVirtualSizeHints with SetMinVirtualSize or similar
	54	and remove it entirely in future.
	55
	56	As with all windows, an application can draw onto a wxScrolledWindow using
	57	a @ref overview_dcoverview "device context".
	58
	59	You have the option of handling the OnPaint handler
	60	or overriding the wxScrolledWindow::OnDraw function, which is
	61	passed a pre-scrolled device context (prepared by
	62	wxScrolledWindow::DoPrepareDC).
	63
	64	If you don't wish to calculate your own scrolling, you must call DoPrepareDC
65	when not drawing from
66	within OnDraw, to set the device origin for the device context according to the
67	current
68	scroll position.
69
70	A wxScrolledWindow will normally scroll itself and therefore its child windows
71	as well. It
72	might however be desired to scroll a different window than itself: e.g. when
73	designing a
74	spreadsheet, you will normally only have to scroll the (usually white) cell
75	area, whereas the
76	(usually grey) label area will scroll very differently. For this special
77	purpose, you can
78	call wxScrolledWindow::SetTargetWindow which means that pressing
79	the scrollbars will scroll a different window.
80
81	Note that the underlying system knows nothing about scrolling coordinates, so
82	that all system
83	functions (mouse events, expose events, refresh calls etc) as well as the
84	position of subwindows
85	are relative to the "physical" origin of the scrolled window. If the user
86	insert a child window at
87	position (10,10) and scrolls the window down 100 pixels (moving the child
88	window out of the visible
89	area), the child window will report a position of (10,-90).
90
91	@beginStyleTable
92	@style{wxRETAINED}:
93	Uses a backing pixmap to speed refreshes. Motif only.
94	@endStyleTable
95
96	@library{wxcore}
97	@category{miscwnd}
98
99	@seealso
100	wxScrollBar, wxClientDC, wxPaintDC, wxVScrolledWindow
101	*/
102	class wxScrolledWindow : public wxPanel
103	{
104	public:
105	//@{
106	/**
107	Constructor.
108
109	@param parent
110	Parent window.
111
112	@param id
113	Window identifier. The value wxID_ANY indicates a default value.
114
115	@param pos
116	Window position. If a position of (-1, -1) is specified then a default position
117	is chosen.
118
119	@param size
120	Window size. If a size of (-1, -1) is specified then the window is sized
121	appropriately.
122
123	@param style
124	Window style. See wxScrolledWindow.
125
126	@param name
127	Window name.
128
129	@remarks The window is initially created without visible scrollbars. Call
130	SetScrollbars() to specify how big
131	the virtual window size should be.
132	*/
133	wxScrolledWindow();
134	wxScrolledWindow(wxWindow* parent, wxWindowID id = -1,
135	const wxPoint& pos = wxDefaultPosition,
136	const wxSize& size = wxDefaultSize,
137	long style = wxHSCROLL \| wxVSCROLL,
138	const wxString& name = "scrolledWindow");
139	//@}
140
141	/**
142	Destructor.
143	*/
144	~wxScrolledWindow();
145
146	/**
147	Translates the logical coordinates to the device ones. For example, if a window
148	is
149	scrolled 10 pixels to the bottom, the device coordinates of the origin are (0,
150	0)
151	(as always), but the logical coordinates are (0, 10) and so the call to
152	CalcScrolledPosition(0, 10, xx, yy) will return 0 in yy.
153
154	@sa CalcUnscrolledPosition()
155	*/
156	void CalcScrolledPosition(int x, int y, int * xx, int * yy);
157
158	/**
159	Translates the device coordinates to the logical ones. For example, if a window
160	is
161	scrolled 10 pixels to the bottom, the device coordinates of the origin are (0,
162	0)
163	(as always), but the logical coordinates are (0, 10) and so the call to
164	CalcUnscrolledPosition(0, 0, xx, yy) will return 10 in yy.
165
166	@sa CalcScrolledPosition()
167	*/
168	void CalcUnscrolledPosition(int x, int y, int * xx, int * yy);
169
170	/**
171	Creates the window for two-step construction. Derived classes
172	should call or replace this function. See wxScrolledWindow()
173	for details.
174	*/
175	bool Create(wxWindow* parent, wxWindowID id = -1,
176	const wxPoint& pos = wxDefaultPosition,
177	const wxSize& size = wxDefaultSize,
178	long style = wxHSCROLL \| wxVSCROLL,
179	const wxString& name = "scrolledWindow");
180
181	/**
182	Call this function to prepare the device context for drawing a scrolled image.
183	It
184	sets the device origin according to the current scroll position.
185
186	DoPrepareDC is called automatically within the default OnPaint() event
187	handler, so your OnDraw() override
188	will be passed a 'pre-scrolled' device context. However, if you wish to draw
189	from
190	outside of OnDraw (via OnPaint), or you wish to implement OnPaint yourself, you
191	must
192	call this function yourself. For example:
193	*/
194	void DoPrepareDC(wxDC& dc);
195
196	/**
197	Enable or disable physical scrolling in the given direction. Physical
198	scrolling is the physical transfer of bits up or down the
199	screen when a scroll event occurs. If the application scrolls by a
200	variable amount (e.g. if there are different font sizes) then physical
201	scrolling will not work, and you should switch it off. Note that you
202	will have to reposition child windows yourself, if physical scrolling
203	is disabled.
204
205	@param xScrolling
206	If @true, enables physical scrolling in the x direction.
207
208	@param yScrolling
209	If @true, enables physical scrolling in the y direction.
210
211	@remarks Physical scrolling may not be available on all platforms. Where
212	it is available, it is enabled by default.
213	*/
214	void EnableScrolling(bool xScrolling, bool yScrolling);
215
216	/**
217	Get the number of pixels per scroll unit (line), in each direction, as set
218	by SetScrollbars(). A value of zero indicates no
219	scrolling in that direction.
220
221	@param xUnit
222	Receives the number of pixels per horizontal unit.
223
224	@param yUnit
225	Receives the number of pixels per vertical unit.
226
227	@sa SetScrollbars(), GetVirtualSize()
228	*/
229	void GetScrollPixelsPerUnit(int* xUnit, int* yUnit);
230
231	/**
232	Get the position at which the visible portion of the window starts.
233
234	@param x
235	Receives the first visible x position in scroll units.
236
237	@param y
238	Receives the first visible y position in scroll units.
239
240	@remarks If either of the scrollbars is not at the home position, x
241	and/or y will be greater than zero. Combined with
242	wxWindow::GetClientSize, the application can use this
243	function to efficiently redraw only the visible
244	portion of the window. The positions are in logical
245	scroll units, not pixels, so to convert to pixels you
246	will have to multiply by the number of pixels per
247	scroll increment.
248
249	@sa SetScrollbars()
250	*/
251	void GetViewStart(int* x, int* y);
252
253	/**
254	Gets the size in device units of the scrollable window area (as
255	opposed to the client size, which is the area of the window currently
256	visible).
257
258	@param x
259	Receives the length of the scrollable window, in pixels.
260
261	@param y
262	Receives the height of the scrollable window, in pixels.
263
264	@remarks Use wxDC::DeviceToLogicalX and wxDC::DeviceToLogicalY to
265	translate these units to logical units.
266
267	@sa SetScrollbars(), GetScrollPixelsPerUnit()
268	*/
269	void GetVirtualSize(int* x, int* y);
270
271	/**
272	Motif only: @true if the window has a backing bitmap.
273	*/
274	bool IsRetained();
275
276	/**
277	Called by the default paint event handler to allow the application to define
278	painting behaviour without having to worry about calling
279	DoPrepareDC().
280
281	Instead of overriding this function you may also just process the paint event
282	in the derived class as usual, but then you will have to call DoPrepareDC()
283	yourself.
284	*/
285	virtual void OnDraw(wxDC& dc);
286
287	/**
288	This function is for backwards compatibility only and simply calls
289	DoPrepareDC() now. Notice that it is
290	not called by the default paint event handle (DoPrepareDC() is), so
291	overriding this method in your derived class is useless.
292	*/
293	void PrepareDC(wxDC& dc);
294
295	/**
296	Scrolls a window so the view start is at the given point.
297
298	@param x
299	The x position to scroll to, in scroll units.
300
301	@param y
302	The y position to scroll to, in scroll units.
303
304	@remarks The positions are in scroll units, not pixels, so to convert to
305	pixels you will have to multiply by the number of
306	pixels per scroll increment. If either parameter is
307	-1, that position will be ignored (no change in that
308	direction).
309
310	@sa SetScrollbars(), GetScrollPixelsPerUnit()
311	*/
312	void Scroll(int x, int y);
313
314	/**
315	Set the horizontal and vertical scrolling increment only. See the pixelsPerUnit
316	parameter in SetScrollbars.
317	*/
318	void SetScrollRate(int xstep, int ystep);
319
320	/**
321	Sets up vertical and/or horizontal scrollbars.
322
323	@param pixelsPerUnitX
324	Pixels per scroll unit in the horizontal direction.
325
326	@param pixelsPerUnitY
327	Pixels per scroll unit in the vertical direction.
328
329	@param noUnitsX
330	Number of units in the horizontal direction.
331
332	@param noUnitsY
333	Number of units in the vertical direction.
334
335	@param xPos
336	Position to initialize the scrollbars in the horizontal direction, in scroll
337	units.
338
339	@param yPos
340	Position to initialize the scrollbars in the vertical direction, in scroll
341	units.
342
343	@param noRefresh
344	Will not refresh window if @true.
345
346	@remarks The first pair of parameters give the number of pixels per
347	'scroll step', i.e. amount moved when the up or down
348	scroll arrows are pressed. The second pair gives the
349	length of scrollbar in scroll steps, which sets the
350	size of the virtual window.
351
352	@sa wxWindow::SetVirtualSize
353	*/
354	void SetScrollbars(int pixelsPerUnitX, int pixelsPerUnitY,
355	int noUnitsX,
356	int noUnitsY,
357	int xPos = 0,
358	int yPos = 0,
359	bool noRefresh = @false);
360
361	/**
362	Call this function to tell wxScrolledWindow to perform the actual scrolling on
363	a different window (and not on itself).
364	*/
365	void SetTargetWindow(wxWindow* window);
366	};