Fixed a severe crash bug

[wxWidgets.git] / include / wx / vscroll.h

diff --git a/include/wx/vscroll.h b/include/wx/vscroll.h
index 5f4f2cb0a625b9945aa060b7c24487b0090a5ab4..bfb1b252afbbb279117a63fdee431520ae235874 100644 (file)
--- a/include/wx/vscroll.h
+++ b/include/wx/vscroll.h
@@ -1,133 +1,629 @@
 /////////////////////////////////////////////////////////////////////////////
 // Name:        include/wx/vscroll.h
 /////////////////////////////////////////////////////////////////////////////
 // Name:        include/wx/vscroll.h

-// Purpose:     wxVScrolledWindow: generalization of wxScrolledWindow
+// Purpose:     Variable scrolled windows (wx[V/H/HV]ScrolledWindow)

 // Author:      Vadim Zeitlin
 // Author:      Vadim Zeitlin

-// Modified by:
+// Modified by: Brad Anderson, Bryan Petty

 // Created:     30.05.03
 // RCS-ID:      $Id$
 // Created:     30.05.03
 // RCS-ID:      $Id$

-// Copyright:   (c) 2003 Vadim Zeitlin <vadim@wxwindows.org>
+// Copyright:   (c) 2003 Vadim Zeitlin <vadim@wxwidgets.org>

 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 #ifndef _WX_VSCROLL_H_
 #define _WX_VSCROLL_H_
 
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 #ifndef _WX_VSCROLL_H_
 #define _WX_VSCROLL_H_
 

-#include "wx/panel.h"           // base class
-
-// ----------------------------------------------------------------------------
-// wxVScrolledWindow
-// ----------------------------------------------------------------------------
-
-/*
-   In the name of this class, "V" may stand for "variable" because it can be
-   used for scrolling lines of variable heights; "virtual" because it is not
-   necessary to know the heights of all lines in advance -- only those which
-   are shown on the screen need to be measured; or, even, "vertical" because
-   this class only supports scrolling in one direction currently (this could
-   and probably will change in the future however).
-
-   In any case, this is a generalization of the wxScrolledWindow class which
-   can be only used when all lines have the same height. It lacks some other
-   wxScrolledWindow features however, notably it currently lacks support for
-   horizontal scrolling; it can't scroll another window nor only a rectangle
-   of the window and not its entire client area.
- */
-class WXDLLEXPORT wxVScrolledWindow : public wxPanel
+#include "wx/panel.h"
+#include "wx/position.h"
+
+class WXDLLIMPEXP_FWD_CORE wxVarScrollHelperEvtHandler;
+
+
+// Using the same techniques as the wxScrolledWindow class      |
+// hierarchy, the wx[V/H/HV]ScrolledWindow classes are slightly |
+// more complex (compare with the diagram outlined in           |
+// scrolwin.h) for the purpose of reducing code duplication     |
+// through the use of mix-in classes.                           |
+//                                                              |
+//                  wxVarScrollHelperBase                       |
+//                   /                 \                        |
+//                  /                   \                       |
+//                 V                     V                      |
+//  wxVarHScrollHelper                 wxVarVScrollHelper       |
+//       |          \                   /           |           |
+//       |           \                 /            |           |
+//       |            V               V             |           |
+//       |           wxVarHVScrollHelper            |           |
+//       |                      |                   |           |
+//       |                      |                   V           |
+//       |         wxPanel      |    wxVarVScrollLegacyAdaptor  |
+//       |         /  \  \      |                   |           |
+//       |        /    \  `-----|----------.        |           |
+//       |       /      \       |           \       |           |
+//       |      /        \      |            \      |           |
+//       V     V          \     |             V     V           |
+//  wxHScrolledWindow      \    |        wxVScrolledWindow      |
+//                          V   V                               |
+//                    wxHVScrolledWindow                        |
+//                                                              |
+//                                                              |
+//   Border added to suppress GCC multi-line comment warnings ->|
+
+
+// ===========================================================================
+// wxVarScrollHelperBase
+// ===========================================================================
+
+// Provides all base common scroll calculations needed for either orientation,
+// automatic scrollbar functionality, saved scroll positions, functionality
+// for changing the target window to be scrolled, as well as defining all
+// required virtual functions that need to be implemented for any orientation
+// specific work.
+
+class WXDLLIMPEXP_CORE wxVarScrollHelperBase

 {
 public:
     // constructors and such
     // ---------------------
 
 {
 public:
     // constructors and such
     // ---------------------
 

-    // default ctor, you must call Create() later
-    wxVScrolledWindow() { Init(); }
+    wxVarScrollHelperBase(wxWindow *winToScroll);
+    virtual ~wxVarScrollHelperBase();

 
 

-    // normal ctor, no need to call Create() after this one
+    // operations
+    // ----------
+
+    // with physical scrolling on, the device origin is changed properly when
+    // a wxPaintDC is prepared, children are actually moved and laid out
+    // properly, and the contents of the window (pixels) are actually moved
+    void EnablePhysicalScrolling(bool scrolling = true)
+        { m_physicalScrolling = scrolling; }
+
+    // wxNOT_FOUND if none, i.e. if it is below the last item
+    int VirtualHitTest(wxCoord coord) const;
+
+    // recalculate all our parameters and redisplay all units
+    virtual void RefreshAll();
+
+    // accessors
+    // ---------
+
+    // get the first currently visible unit
+    size_t GetVisibleBegin() const { return m_unitFirst; }
+
+    // get the last currently visible unit
+    size_t GetVisibleEnd() const
+        { return m_unitFirst + m_nUnitsVisible; }
+
+    // is this unit currently visible?
+    bool IsVisible(size_t unit) const
+        { return unit >= m_unitFirst && unit < GetVisibleEnd(); }
+
+    // translate between scrolled and unscrolled coordinates
+    int CalcScrolledPosition(int coord) const
+        {  return DoCalcScrolledPosition(coord); }
+    int CalcUnscrolledPosition(int coord) const
+        {  return DoCalcUnscrolledPosition(coord); }
+
+    virtual int DoCalcScrolledPosition(int coord) const;
+    virtual int DoCalcUnscrolledPosition(int coord) const;
+
+    // update the thumb size shown by the scrollbar
+    virtual void UpdateScrollbar();
+    void RemoveScrollbar();
+
+    // Normally the wxScrolledWindow will scroll itself, but in some rare
+    // occasions you might want it to scroll [part of] another window (e.g. a
+    // child of it in order to scroll only a portion the area between the
+    // scrollbars (spreadsheet: only cell area will move).
+    virtual void SetTargetWindow(wxWindow *target);
+    virtual wxWindow *GetTargetWindow() const { return m_targetWindow; }
+
+    // Override this function to draw the graphic (or just process EVT_PAINT)
+    //virtual void OnDraw(wxDC& WXUNUSED(dc)) { }
+
+    // change the DC origin according to the scroll position. To properly
+    // forward calls to wxWindow::Layout use WX_FORWARD_TO_SCROLL_HELPER()
+    // derived class
+    virtual void DoPrepareDC(wxDC& dc);
+
+    // the methods to be called from the window event handlers
+    void HandleOnScroll(wxScrollWinEvent& event);
+    void HandleOnSize(wxSizeEvent& event);
+#if wxUSE_MOUSEWHEEL
+    void HandleOnMouseWheel(wxMouseEvent& event);
+#endif // wxUSE_MOUSEWHEEL
+
+    // these functions must be overidden in the derived class to return
+    // orientation specific data (e.g. the width for vertically scrolling
+    // derivatives in the case of GetOrientationTargetSize())
+    virtual int GetOrientationTargetSize() const = 0;
+    virtual int GetNonOrientationTargetSize() const = 0;
+    virtual wxOrientation GetOrientation() const = 0;
+
+protected:
+    // all *Unit* functions are protected to be exposed by
+    // wxVarScrollHelperBase implementations (with appropriate names)
+
+    // get the number of units this window contains (previously set by
+    // SetUnitCount())
+    size_t GetUnitCount() const { return m_unitMax; }
+
+    // set the number of units the helper contains: the derived class must
+    // provide the sizes for all units with indices up to the one given here
+    // in its OnGetUnitSize()
+    void SetUnitCount(size_t count);
+
+    // redraw the specified unit
+    virtual void RefreshUnit(size_t unit);
+
+    // redraw all units in the specified range (inclusive)
+    virtual void RefreshUnits(size_t from, size_t to);
+
+    // scroll to the specified unit: it will become the first visible unit in
+    // the window

     //
     //

-    // note that wxVSCROLL is always automatically added to our style, there is
-    // no need to specify it explicitly
-    wxVScrolledWindow(wxWindow *parent,
-                      wxWindowID id = wxID_ANY,
-                      const wxPoint& pos = wxDefaultPosition,
-                      const wxSize& size = wxDefaultSize,
-                      long style = 0,
-                      const wxString& name = wxPanelNameStr)
+    // return true if we scrolled the window, false if nothing was done
+    bool DoScrollToUnit(size_t unit);
+
+    // scroll by the specified number of units/pages
+    virtual bool DoScrollUnits(int units);
+    virtual bool DoScrollPages(int pages);
+
+    // this function must be overridden in the derived class and it should
+    // return the size of the given unit in pixels
+    virtual wxCoord OnGetUnitSize(size_t n) const = 0;
+
+    // this function doesn't have to be overridden but it may be useful to do
+    // it if calculating the units' sizes is a relatively expensive operation
+    // as it gives the user code a possibility to calculate several of them at
+    // once
+    //
+    // OnGetUnitsSizeHint() is normally called just before OnGetUnitSize() but
+    // you shouldn't rely on the latter being called for all units in the
+    // interval specified here. It is also possible that OnGetUnitHeight() will
+    // be called for the units outside of this interval, so this is really just
+    // a hint, not a promise.
+    //
+    // finally note that unitMin is inclusive, while unitMax is exclusive, as
+    // usual
+    virtual void OnGetUnitsSizeHint(size_t WXUNUSED(unitMin),
+                                    size_t WXUNUSED(unitMax)) const
+        { }
+
+    // when the number of units changes, we try to estimate the total size
+    // of all units which is a rather expensive operation in terms of unit
+    // access, so if the user code may estimate the average size
+    // better/faster than we do, it should override this function to implement
+    // its own logic
+    //
+    // this function should return the best guess for the total size it may
+    // make
+    virtual wxCoord EstimateTotalSize() const { return DoEstimateTotalSize(); }
+
+    wxCoord DoEstimateTotalSize() const;
+
+    // find the index of the unit we need to show to fit the specified unit on
+    // the opposite side either fully or partially (depending on fullyVisible)
+    size_t FindFirstVisibleFromLast(size_t last,
+                                    bool fullyVisible = false) const;
+
+    // get the total size of the units between unitMin (inclusive) and
+    // unitMax (exclusive)
+    wxCoord GetUnitsSize(size_t unitMin, size_t unitMax) const;
+
+    // get the offset of the first visible unit
+    wxCoord GetScrollOffset() const
+        { return GetUnitsSize(0, GetVisibleBegin()); }
+
+    // get the size of the target window
+    wxSize GetTargetSize() const { return m_targetWindow->GetClientSize(); }
+
+    void GetTargetSize(int *w, int *h)

     {
     {

-        Init();
+        wxSize size = GetTargetSize();
+        if ( w )
+            *w = size.x;
+        if ( h )
+            *h = size.y;
+    }

 
 

-        (void)Create(parent, id, pos, size, style, name);
+    // calculate the new scroll position based on scroll event type
+    size_t GetNewScrollPosition(wxScrollWinEvent& event) const;
+
+    // replacement implementation of wxWindow::Layout virtual method.  To
+    // properly forward calls to wxWindow::Layout use
+    // WX_FORWARD_TO_SCROLL_HELPER() derived class
+    bool ScrollLayout();
+
+#ifdef __WXMAC__
+    // queue mac window update after handling scroll event
+    virtual void UpdateMacScrollWindow() = 0;
+#endif // __WXMAC__
+
+    // change the target window
+    void DoSetTargetWindow(wxWindow *target);
+
+    // delete the event handler we installed
+    void DeleteEvtHandler();
+
+    // helper function abstracting the orientation test: with vertical
+    // orientation, it assigns the first value to x and the second one to y,
+    // with horizontal orientation it reverses them, i.e. the first value is
+    // assigned to y and the second one to x
+    void AssignOrient(wxCoord& x, wxCoord& y, wxCoord first, wxCoord second);
+
+    // similar to "oriented assignment" above but does "oriented increment":
+    // for vertical orientation, y is incremented by the given value and x if
+    // left unchanged, for horizontal orientation x is incremented
+    void IncOrient(wxCoord& x, wxCoord& y, wxCoord inc);
+
+private:
+
+    // the window that receives the scroll events and the window to actually
+    // scroll, respectively
+    wxWindow    *m_win,
+                *m_targetWindow;
+
+    // the total number of (logical) units
+    size_t m_unitMax;
+
+    // the total (estimated) size
+    wxCoord m_sizeTotal;
+
+    // the first currently visible unit
+    size_t m_unitFirst;
+
+    // the number of currently visible units (including the last, possibly only
+    // partly, visible one)
+    size_t m_nUnitsVisible;
+
+    // accumulated mouse wheel rotation
+#if wxUSE_MOUSEWHEEL
+    int m_sumWheelRotation;
+#endif
+
+    // do child scrolling (used in DoPrepareDC())
+    bool m_physicalScrolling;
+
+    // handler injected into target window to forward some useful events to us
+    wxVarScrollHelperEvtHandler *m_handler;
+};
+
+
+
+// ===========================================================================
+// wxVarVScrollHelper
+// ===========================================================================
+
+// Provides public API functions targeted for vertical-specific scrolling,
+// wrapping the functionality of wxVarScrollHelperBase.
+
+class WXDLLIMPEXP_CORE wxVarVScrollHelper : public wxVarScrollHelperBase
+{
+public:
+    // constructors and such
+    // ---------------------
+
+    // ctor must be given the associated window
+    wxVarVScrollHelper(wxWindow *winToScroll)
+        : wxVarScrollHelperBase(winToScroll)
+    {

     }
 
     }
 

-    // same as the previous ctor but returns status code: true if ok
-    //
-    // just as with the ctor above, wxVSCROLL style is always used, there is no
-    // need to specify it
-    bool Create(wxWindow *parent,
-                wxWindowID id = wxID_ANY,
-                const wxPoint& pos = wxDefaultPosition,
-                const wxSize& size = wxDefaultSize,
-                long style = 0,
-                const wxString& name = wxPanelNameStr)
+    // operators
+
+    void SetRowCount(size_t rowCount) { SetUnitCount(rowCount); }
+    bool ScrollToRow(size_t row) { return DoScrollToUnit(row); }
+
+    virtual bool ScrollRows(int rows)
+        { return DoScrollUnits(rows); }
+    virtual bool ScrollRowPages(int pages)
+        { return DoScrollPages(pages); }
+
+    virtual void RefreshRow(size_t row)
+        { RefreshUnit(row); }
+    virtual void RefreshRows(size_t from, size_t to)
+        { RefreshUnits(from, to); }
+
+    // accessors
+
+    size_t GetRowCount() const                  { return GetUnitCount(); }
+    size_t GetVisibleRowsBegin() const          { return GetVisibleBegin(); }
+    size_t GetVisibleRowsEnd() const            { return GetVisibleEnd(); }
+    bool IsRowVisible(size_t row) const         { return IsVisible(row); }
+
+    virtual int GetOrientationTargetSize() const
+        { return GetTargetWindow()->GetClientSize().y; }
+    virtual int GetNonOrientationTargetSize() const
+        { return GetTargetWindow()->GetClientSize().x; }
+    virtual wxOrientation GetOrientation() const { return wxVERTICAL; }
+
+protected:
+    // this function must be overridden in the derived class and it should
+    // return the size of the given row in pixels
+    virtual wxCoord OnGetRowHeight(size_t n) const = 0;
+    wxCoord OnGetUnitSize(size_t n) const       { return OnGetRowHeight(n); }
+
+    virtual void OnGetRowsHeightHint(size_t WXUNUSED(rowMin),
+                                     size_t WXUNUSED(rowMax)) const { }
+
+    // forward calls to OnGetRowsHeightHint()
+    virtual void OnGetUnitsSizeHint(size_t unitMin, size_t unitMax) const
+        { OnGetRowsHeightHint(unitMin, unitMax); }
+
+    // again, if not overridden, it will fall back on default method
+    virtual wxCoord EstimateTotalHeight() const
+        { return DoEstimateTotalSize(); }
+
+    // forward calls to EstimateTotalHeight()
+    virtual wxCoord EstimateTotalSize() const { return EstimateTotalHeight(); }
+
+    wxCoord GetRowsHeight(size_t rowMin, size_t rowMax) const
+        { return GetUnitsSize(rowMin, rowMax); }
+};
+
+
+
+// ===========================================================================
+// wxVarHScrollHelper
+// ===========================================================================
+
+// Provides public API functions targeted for horizontal-specific scrolling,
+// wrapping the functionality of wxVarScrollHelperBase.
+
+class WXDLLIMPEXP_CORE wxVarHScrollHelper : public wxVarScrollHelperBase
+{
+public:
+    // constructors and such
+    // ---------------------
+
+    // ctor must be given the associated window
+    wxVarHScrollHelper(wxWindow *winToScroll)
+        : wxVarScrollHelperBase(winToScroll)

     {
     {

-        return wxPanel::Create(parent, id, pos, size, style | wxVSCROLL, name);

     }
 
     }
 

+    // operators

 
 

-    // operations
-    // ----------
+    void SetColumnCount(size_t columnCount)
+        { SetUnitCount(columnCount); }

 
 

-    // set the number of lines the window contains: the derived class must
-    // provide the heights for all lines with indices up to the one given here
-    // in its OnGetLineHeight()
-    void SetLineCount(size_t count);
+    bool ScrollToColumn(size_t column)
+        { return DoScrollToUnit(column); }
+    virtual bool ScrollColumns(int columns)
+        { return DoScrollUnits(columns); }
+    virtual bool ScrollColumnPages(int pages)
+        { return DoScrollPages(pages); }

 
 

-    // scroll to the specified line: it will become the first visible line in
-    // the window
+    virtual void RefreshColumn(size_t column)
+        { RefreshUnit(column); }
+    virtual void RefreshColumns(size_t from, size_t to)
+        { RefreshUnits(from, to); }
+
+    // accessors
+
+    size_t GetColumnCount() const
+        { return GetUnitCount(); }
+    size_t GetVisibleColumnsBegin() const
+        { return GetVisibleBegin(); }
+    size_t GetVisibleColumnsEnd() const
+        { return GetVisibleEnd(); }
+    bool IsColumnVisible(size_t column) const
+        { return IsVisible(column); }
+
+
+    virtual int GetOrientationTargetSize() const
+        { return GetTargetWindow()->GetClientSize().x; }
+    virtual int GetNonOrientationTargetSize() const
+        { return GetTargetWindow()->GetClientSize().y; }
+    virtual wxOrientation GetOrientation() const   { return wxHORIZONTAL; }
+
+protected:
+    // this function must be overridden in the derived class and it should
+    // return the size of the given column in pixels
+    virtual wxCoord OnGetColumnWidth(size_t n) const = 0;
+    wxCoord OnGetUnitSize(size_t n) const { return OnGetColumnWidth(n); }
+
+    virtual void OnGetColumnsWidthHint(size_t WXUNUSED(columnMin),
+                                        size_t WXUNUSED(columnMax)) const
+        { }
+
+    // forward calls to OnGetColumnsWidthHint()
+    virtual void OnGetUnitsSizeHint(size_t unitMin, size_t unitMax) const
+        { OnGetColumnsWidthHint(unitMin, unitMax); }
+
+    // again, if not overridden, it will fall back on default method
+    virtual wxCoord EstimateTotalWidth() const { return DoEstimateTotalSize(); }
+
+    // forward calls to EstimateTotalWidth()
+    virtual wxCoord EstimateTotalSize() const { return EstimateTotalWidth(); }
+
+    wxCoord GetColumnsWidth(size_t columnMin, size_t columnMax) const
+        { return GetUnitsSize(columnMin, columnMax); }
+};
+
+
+
+// ===========================================================================
+// wxVarHVScrollHelper
+// ===========================================================================
+
+// Provides public API functions targeted at functions with similar names in
+// both wxVScrollHelper and wxHScrollHelper so class scope doesn't need to be
+// specified (since we are using multiple inheritance). It also provides
+// functions to make changing values for both orientations at the same time
+// easier.
+
+class WXDLLIMPEXP_CORE wxVarHVScrollHelper : public wxVarVScrollHelper,
+                                        public wxVarHScrollHelper
+{
+public:
+    // constructors and such
+    // ---------------------
+
+    // ctor must be given the associated window
+    wxVarHVScrollHelper(wxWindow *winToScroll)
+        : wxVarVScrollHelper(winToScroll), wxVarHScrollHelper(winToScroll) { }
+
+    // operators
+    // ---------
+
+    // set the number of units the window contains for each axis: the derived
+    // class must provide the widths and heights for all units with indices up
+    // to each of the one given here in its OnGetColumnWidth() and
+    // OnGetRowHeight()
+    void SetRowColumnCount(size_t rowCount, size_t columnCount);
+
+
+    // with physical scrolling on, the device origin is changed properly when
+    // a wxPaintDC is prepared, children are actually moved and laid out
+    // properly, and the contents of the window (pixels) are actually moved
+    void EnablePhysicalScrolling(bool vscrolling = true, bool hscrolling = true)
+    {
+        wxVarVScrollHelper::EnablePhysicalScrolling(vscrolling);
+        wxVarHScrollHelper::EnablePhysicalScrolling(hscrolling);
+    }
+
+    // scroll to the specified row/column: it will become the first visible
+    // cell in the window

     //
     // return true if we scrolled the window, false if nothing was done
     //
     // return true if we scrolled the window, false if nothing was done

-    bool ScrollToLine(size_t line);
+    bool ScrollToRowColumn(size_t row, size_t column);
+    bool ScrollToRowColumn(const wxPosition &pos)
+        { return ScrollToRowColumn(pos.GetRow(), pos.GetColumn()); }
+
+    // redraw the specified cell
+    virtual void RefreshRowColumn(size_t row, size_t column);
+    virtual void RefreshRowColumn(const wxPosition &pos)
+        { RefreshRowColumn(pos.GetRow(), pos.GetColumn()); }
+
+    // redraw the specified regions (inclusive).  If the target window for
+    // both orientations is the same the rectangle of cells is refreshed; if
+    // the target windows differ the entire client size opposite the
+    // orientation direction is refreshed between the specified limits
+    virtual void RefreshRowsColumns(size_t fromRow, size_t toRow,
+                                    size_t fromColumn, size_t toColumn);
+    virtual void RefreshRowsColumns(const wxPosition& from,
+                                    const wxPosition& to)
+    {
+        RefreshRowsColumns(from.GetRow(), to.GetRow(),
+                          from.GetColumn(), to.GetColumn());
+    }

 
 

-    // scroll by the specified number of lines/pages
-    virtual bool ScrollLines(int lines);
-    virtual bool ScrollPages(int pages);
+    // locate the virtual position from the given device coordinates
+    wxPosition VirtualHitTest(wxCoord x, wxCoord y) const;
+    wxPosition VirtualHitTest(const wxPoint &pos) const
+        { return VirtualHitTest(pos.x, pos.y); }

 
 

-    // redraw the specified line
-    void RefreshLine(size_t line);
+    // change the DC origin according to the scroll position. To properly
+    // forward calls to wxWindow::Layout use WX_FORWARD_TO_SCROLL_HELPER()
+    // derived class. We use this version to call both base classes'
+    // DoPrepareDC()
+    virtual void DoPrepareDC(wxDC& dc);

 
 

-    // redraw all lines in the specified range (inclusive)
-    void RefreshLines(size_t from, size_t to);
+    // replacement implementation of wxWindow::Layout virtual method.  To
+    // properly forward calls to wxWindow::Layout use
+    // WX_FORWARD_TO_SCROLL_HELPER() derived class. We use this version to
+    // call both base classes' ScrollLayout()
+    bool ScrollLayout();
+
+    // accessors
+    // ---------

 
 

-    // return the item at the specified (in physical coordinates) position or.
+    // get the number of units this window contains (previously set by
+    // Set[Column/Row/RowColumn/Unit]Count())
+    wxSize GetRowColumnCount() const;

 
 

-    // wxNOT_FOUND if none, i.e. if it is below the last item
-    int HitTest(wxCoord x, wxCoord y) const;
-    int HitTest(const wxPoint& pt) const { return HitTest(pt.x, pt.y); }
+    // get the first currently visible units
+    wxPosition GetVisibleBegin() const;
+    wxPosition GetVisibleEnd() const;
+
+    // is this cell currently visible?
+    bool IsVisible(size_t row, size_t column) const;
+    bool IsVisible(const wxPosition &pos) const
+        { return IsVisible(pos.GetRow(), pos.GetColumn()); }
+};

 
 

-    // recalculate all our parameters and redisplay all lines
-    virtual void RefreshAll();

 
 
 
 

+#if WXWIN_COMPATIBILITY_2_8
+
+// ===========================================================================
+// wxVarVScrollLegacyAdaptor
+// ===========================================================================
+
+// Provides backwards compatible API for applications originally built using
+// wxVScrolledWindow in 2.6 or 2.8. Originally, wxVScrolledWindow referred
+// to scrolling "lines". We use "units" in wxVarScrollHelperBase to avoid
+// implying any orientation (since the functions are used for both horizontal
+// and vertical scrolling in derived classes). And in the new
+// wxVScrolledWindow and wxHScrolledWindow classes, we refer to them as
+// "rows" and "columns", respectively. This is to help clear some confusion
+// in not only those classes, but also in wxHVScrolledWindow where functions
+// are inherited from both.
+
+class WXDLLIMPEXP_CORE wxVarVScrollLegacyAdaptor : public wxVarVScrollHelper
+{
+public:
+    // constructors and such
+    // ---------------------
+    wxVarVScrollLegacyAdaptor(wxWindow *winToScroll)
+        : wxVarVScrollHelper(winToScroll)
+    {
+    }
+

     // accessors
     // ---------
 
     // accessors
     // ---------
 

-    // get the number of lines this window contains (previously set by
-    // SetLineCount())
-    size_t GetLineCount() const { return m_lineMax; }
-
-    // get the first currently visible line
-    size_t GetFirstVisibleLine() const { return m_lineFirst; }
+    // this is the same as GetVisibleRowsBegin(), exists to match
+    // GetLastVisibleLine() and for backwards compatibility only
+    wxDEPRECATED( size_t GetFirstVisibleLine() const );

 
     // get the last currently visible line
 
     // get the last currently visible line

-    size_t GetLastVisibleLine() const { return m_lineFirst + m_nVisible - 1; }
+    //
+    // this function is unsafe as it returns (size_t)-1 (i.e. a huge positive
+    // number) if the control is empty, use GetVisibleRowsEnd() instead, this
+    // one is kept for backwards compatibility
+    wxDEPRECATED( size_t GetLastVisibleLine() const );
+
+    // "line" to "unit" compatibility functions
+    // ----------------------------------------
+
+    // get the number of lines this window contains (set by SetLineCount())
+    wxDEPRECATED( size_t GetLineCount() const );
+
+    // set the number of lines the helper contains: the derived class must
+    // provide the sizes for all lines with indices up to the one given here
+    // in its OnGetLineHeight()
+    wxDEPRECATED( void SetLineCount(size_t count) );
+
+    // redraw the specified line
+    wxDEPRECATED( virtual void RefreshLine(size_t line) );
+
+    // redraw all lines in the specified range (inclusive)
+    wxDEPRECATED( virtual void RefreshLines(size_t from, size_t to) );

 
 

-    // is this line currently visible?
-    bool IsVisible(size_t line) const
-        { return line >= m_lineFirst && line <= GetLastVisibleLine(); }
+    // scroll to the specified line: it will become the first visible line in
+    // the window
+    //
+    // return true if we scrolled the window, false if nothing was done
+    wxDEPRECATED( bool ScrollToLine(size_t line) );

 
 

+    // scroll by the specified number of lines/pages
+    wxDEPRECATED( virtual bool ScrollLines(int lines) );
+    wxDEPRECATED( virtual bool ScrollPages(int pages) );

 
 protected:
 
 protected:

+    // unless the code has been updated to override OnGetRowHeight() instead,

     // this function must be overridden in the derived class and it should
     // this function must be overridden in the derived class and it should

-    // return the height of the given line in pixels
-    virtual wxCoord OnGetLineHeight(size_t n) const = 0;
+    // return the height of the given row in pixels
+    wxDEPRECATED_BUT_USED_INTERNALLY(
+        virtual wxCoord OnGetLineHeight(size_t n) const );
+
+    // forwards the calls from base class pure virtual function to pure virtual
+    // OnGetLineHeight instead (backwards compatible name)
+    // note that we don't need to forward OnGetUnitSize() as it is already
+    // forwarded to OnGetRowHeight() in wxVarVScrollHelper
+    virtual wxCoord OnGetRowHeight(size_t n) const;

 
     // this function doesn't have to be overridden but it may be useful to do
     // it if calculating the lines heights is a relatively expensive operation
 
     // this function doesn't have to be overridden but it may be useful to do
     // it if calculating the lines heights is a relatively expensive operation


@@ -142,54 +638,238 @@ protected:
     //
     // finally note that lineMin is inclusive, while lineMax is exclusive, as
     // usual
     //
     // finally note that lineMin is inclusive, while lineMax is exclusive, as
     // usual

-    virtual void OnGetLinesHint(size_t lineMin, size_t lineMax) const { }
+    wxDEPRECATED_BUT_USED_INTERNALLY( virtual void OnGetLinesHint(
+        size_t lineMin, size_t lineMax) const );

 
 

-    // when the number of lines changes, we try to estimate the total height
-    // of all lines which is a rather expensive operation in terms of lines
-    // access, so if the user code may estimate the average height
-    // better/faster than we do, it should override this function to implement
-    // its own logic
+    // forwards the calls from base class pure virtual function to pure virtual
+    // OnGetLinesHint instead (backwards compatible name)
+    void OnGetRowsHeightHint(size_t rowMin, size_t rowMax) const;
+};
+
+#else // !WXWIN_COMPATIBILITY_2_8
+
+// shortcut to avoid checking compatibility modes later
+// remove this and all references to wxVarVScrollLegacyAdaptor once
+// wxWidgets 2.6 and 2.8 compatibility is removed
+typedef wxVarVScrollHelper wxVarVScrollLegacyAdaptor;
+
+#endif // WXWIN_COMPATIBILITY_2_8/!WXWIN_COMPATIBILITY_2_8
+
+
+// this macro must be used in declaration of wxVarScrollHelperBase-derived
+// classes
+#define WX_FORWARD_TO_VAR_SCROLL_HELPER()                                     \
+public:                                                                       \
+    virtual void PrepareDC(wxDC& dc) { DoPrepareDC(dc); }                     \
+    virtual bool Layout() { return ScrollLayout(); }
+
+
+
+// ===========================================================================
+// wxVScrolledWindow
+// ===========================================================================
+
+// In the name of this class, "V" may stand for "variable" because it can be
+// used for scrolling rows of variable heights; "virtual", because it is not
+// necessary to know the heights of all rows in advance -- only those which
+// are shown on the screen need to be measured; or even "vertical", because
+// this class only supports scrolling vertically.
+
+// In any case, this is a generalization of the wxScrolledWindow class which
+// can be only used when all rows have the same heights. It lacks some other
+// wxScrolledWindow features however, notably it can't scroll only a rectangle
+// of the window and not its entire client area.
+
+class WXDLLIMPEXP_CORE wxVScrolledWindow : public wxPanel,
+                                      public wxVarVScrollLegacyAdaptor
+{
+public:
+    // constructors and such
+    // ---------------------
+
+    // default ctor, you must call Create() later
+    wxVScrolledWindow() : wxVarVScrollLegacyAdaptor(this) { }
+
+    // normal ctor, no need to call Create() after this one

     //
     //

-    // this function should return the best guess for the total height it may
-    // make
-    virtual wxCoord EstimateTotalHeight() const;
+    // note that wxVSCROLL is always automatically added to our style, there is
+    // no need to specify it explicitly
+    wxVScrolledWindow(wxWindow *parent,
+                      wxWindowID id = wxID_ANY,
+                      const wxPoint& pos = wxDefaultPosition,
+                      const wxSize& size = wxDefaultSize,
+                      long style = 0,
+                      const wxString& name = wxPanelNameStr)
+    : wxVarVScrollLegacyAdaptor(this)
+    {
+        (void)Create(parent, id, pos, size, style, name);
+    }
+
+    // same as the previous ctor but returns status code: true if ok
+    //
+    // just as with the ctor above, wxVSCROLL style is always used, there is no
+    // need to specify it
+    bool Create(wxWindow *parent,
+                wxWindowID id = wxID_ANY,
+                const wxPoint& pos = wxDefaultPosition,
+                const wxSize& size = wxDefaultSize,
+                long style = 0,
+                const wxString& name = wxPanelNameStr)
+    {
+        return wxPanel::Create(parent, id, pos, size, style | wxVSCROLL, name);
+    }

 
 

+#if WXWIN_COMPATIBILITY_2_8
+    // Make sure we prefer our version of HitTest rather than wxWindow's
+    // These functions should no longer be masked in favor of VirtualHitTest()
+    int HitTest(wxCoord WXUNUSED(x), wxCoord y) const
+        { return wxVarVScrollHelper::VirtualHitTest(y); }
+    int HitTest(const wxPoint& pt) const
+        { return HitTest(pt.x, pt.y); }
+#endif // WXWIN_COMPATIBILITY_2_8

 
 

-    // the event handlers
-    void OnSize(wxSizeEvent& event);
-    void OnScroll(wxScrollWinEvent& event);
+    WX_FORWARD_TO_VAR_SCROLL_HELPER()

 
 

-    // find the index of the line we need to show at the top of the window such
-    // that the last (fully or partially) visible line is the given one
-    size_t FindFirstFromBottom(size_t lineLast, bool fullyVisible = false);
+#ifdef __WXMAC__
+protected:
+    virtual void UpdateMacScrollWindow() { Update(); }
+#endif // __WXMAC__

 
 

-    // get the total height of the lines between lineMin (inclusive) and
-    // lineMax (exclusive)
-    wxCoord GetLinesHeight(size_t lineMin, size_t lineMax) const;
+private:
+    wxDECLARE_NO_COPY_CLASS(wxVScrolledWindow);
+    DECLARE_ABSTRACT_CLASS(wxVScrolledWindow)
+};

 
 

-    // update the thumb size shown by the scrollbar
-    void UpdateScrollbar();
+
+
+// ===========================================================================
+// wxHScrolledWindow
+// ===========================================================================
+
+// In the name of this class, "H" stands for "horizontal" because it can be
+// used for scrolling columns of variable widths. It is not necessary to know
+// the widths of all columns in advance -- only those which are shown on the
+// screen need to be measured.
+
+// This is a generalization of the wxScrolledWindow class which can be only
+// used when all columns have the same width. It lacks some other
+// wxScrolledWindow features however, notably it can't scroll only a rectangle
+// of the window and not its entire client area.
+
+class WXDLLIMPEXP_CORE wxHScrolledWindow : public wxPanel,
+                                      public wxVarHScrollHelper
+{
+public:
+    // constructors and such
+    // ---------------------
+
+    // default ctor, you must call Create() later
+    wxHScrolledWindow() : wxVarHScrollHelper(this) { }
+
+    // normal ctor, no need to call Create() after this one
+    //
+    // note that wxHSCROLL is always automatically added to our style, there is
+    // no need to specify it explicitly
+    wxHScrolledWindow(wxWindow *parent,
+                      wxWindowID id = wxID_ANY,
+                      const wxPoint& pos = wxDefaultPosition,
+                      const wxSize& size = wxDefaultSize,
+                      long style = 0,
+                      const wxString& name = wxPanelNameStr)
+        : wxVarHScrollHelper(this)
+    {
+        (void)Create(parent, id, pos, size, style, name);
+    }
+
+    // same as the previous ctor but returns status code: true if ok
+    //
+    // just as with the ctor above, wxHSCROLL style is always used, there is no
+    // need to specify it
+    bool Create(wxWindow *parent,
+                wxWindowID id = wxID_ANY,
+                const wxPoint& pos = wxDefaultPosition,
+                const wxSize& size = wxDefaultSize,
+                long style = 0,
+                const wxString& name = wxPanelNameStr)
+    {
+        return wxPanel::Create(parent, id, pos, size, style | wxHSCROLL, name);
+    }
+
+    WX_FORWARD_TO_VAR_SCROLL_HELPER()
+
+#ifdef __WXMAC__
+protected:
+    virtual void UpdateMacScrollWindow() { Update(); }
+#endif // __WXMAC__

 
 private:
 
 private:

-    // common part of all ctors
-    void Init();
+    wxDECLARE_NO_COPY_CLASS(wxHScrolledWindow);
+    DECLARE_ABSTRACT_CLASS(wxHScrolledWindow)
+};

 
 
 
 

-    // the total number of (logical) lines
-    size_t m_lineMax;

 
 

-    // the total (estimated) height
-    wxCoord m_heightTotal;
+// ===========================================================================
+// wxHVScrolledWindow
+// ===========================================================================

 
 

-    // the first currently visible line
-    size_t m_lineFirst;
+// This window inherits all functionality of both vertical and horizontal
+// scrolled windows automatically handling everything needed to scroll both
+// axis simultaneously.

 
 

-    // the number of currently visible lines (including the last, possibly only
-    // partly, visible one)
-    size_t m_nVisible;
+class WXDLLIMPEXP_CORE wxHVScrolledWindow : public wxPanel,
+                                       public wxVarHVScrollHelper
+{
+public:
+    // constructors and such
+    // ---------------------
+
+    // default ctor, you must call Create() later
+    wxHVScrolledWindow()
+        : wxPanel(),
+          wxVarHVScrollHelper(this) { }

 
 

+    // normal ctor, no need to call Create() after this one
+    //
+    // note that wxVSCROLL and wxHSCROLL are always automatically added to our
+    // style, there is no need to specify them explicitly
+    wxHVScrolledWindow(wxWindow *parent,
+                       wxWindowID id = wxID_ANY,
+                       const wxPoint& pos = wxDefaultPosition,
+                       const wxSize& size = wxDefaultSize,
+                       long style = 0,
+                       const wxString& name = wxPanelNameStr)
+        : wxPanel(),
+          wxVarHVScrollHelper(this)
+    {
+        (void)Create(parent, id, pos, size, style, name);
+    }
+
+    // same as the previous ctor but returns status code: true if ok
+    //
+    // just as with the ctor above, wxVSCROLL and wxHSCROLL styles are always
+    // used, there is no need to specify them
+    bool Create(wxWindow *parent,
+                wxWindowID id = wxID_ANY,
+                const wxPoint& pos = wxDefaultPosition,
+                const wxSize& size = wxDefaultSize,
+                long style = 0,
+                const wxString& name = wxPanelNameStr)
+    {
+        return wxPanel::Create(parent, id, pos, size,
+                               style | wxVSCROLL | wxHSCROLL, name);
+    }
+
+    WX_FORWARD_TO_VAR_SCROLL_HELPER()

 
 

-    DECLARE_EVENT_TABLE()
+#ifdef __WXMAC__
+protected:
+    virtual void UpdateMacScrollWindow() { Update(); }
+#endif // __WXMAC__
+
+private:
+    wxDECLARE_NO_COPY_CLASS(wxHVScrolledWindow);
+    DECLARE_ABSTRACT_CLASS(wxHVScrolledWindow)

 };
 
 #endif // _WX_VSCROLL_H_
 };
 
 #endif // _WX_VSCROLL_H_