Fix crash in wxDC::GetMultiLineTextExtent() after last commit.

[wxWidgets.git] / src / gtk / scrolwin.cpp

diff --git a/src/gtk/scrolwin.cpp b/src/gtk/scrolwin.cpp
index bf6a8921e8cc62a7b48c857f053302fd4fa7e07c..2ce5843e923bf46d3e762bf595ff1f128e55f196 100644 (file)
--- a/src/gtk/scrolwin.cpp
+++ b/src/gtk/scrolwin.cpp
@@ -1,26 +1,15 @@
 /////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////

-// Name:        gtk/scrolwin.cpp
+// Name:        src/gtk/scrolwin.cpp

 // Purpose:     wxScrolledWindow implementation
 // Purpose:     wxScrolledWindow implementation

-// Author:      Julian Smart
-// Modified by:
+// Author:      Robert Roebling
+// Modified by: Ron Lee
+//              Vadim Zeitlin: removed 90% of duplicated common code

 // Created:     01/02/97
 // RCS-ID:      $Id$
 // Created:     01/02/97
 // RCS-ID:      $Id$

-// Copyright:   (c) Julian Smart and Markus Holzem
-// Licence:     wxWindows license
+// Copyright:   (c) Robert Roebling
+// Licence:     wxWindows licence

 /////////////////////////////////////////////////////////////////////////////
 
 /////////////////////////////////////////////////////////////////////////////
 

-// ============================================================================
-// declarations
-// ============================================================================
-
-// ----------------------------------------------------------------------------
-// headers
-// ----------------------------------------------------------------------------
-
-#ifdef __GNUG__
-    #pragma implementation "scrolwin.h"
-#endif
-

 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 


@@ -28,750 +17,178 @@
     #pragma hdrstop
 #endif
 
     #pragma hdrstop
 #endif
 

-#include "wx/utils.h"
-#include "wx/dcclient.h"
-
-#include "wx/gtk/scrolwin.h"
-#include "wx/panel.h"
+#include "wx/scrolwin.h"

 
 #include <gtk/gtk.h>
 
 #include <gtk/gtk.h>

-#include "wx/gtk/win_gtk.h"
+#include "wx/gtk/private/gtk2-compat.h"

 
 // ----------------------------------------------------------------------------
 
 // ----------------------------------------------------------------------------

-// event tables
+// wxScrollHelper implementation

 // ----------------------------------------------------------------------------
 
 // ----------------------------------------------------------------------------
 

-BEGIN_EVENT_TABLE(wxScrolledWindow, wxPanel)
-    EVT_SCROLLWIN(wxScrolledWindow::OnScroll)
-    EVT_SIZE(wxScrolledWindow::OnSize)
-    EVT_PAINT(wxScrolledWindow::OnPaint)
-    EVT_CHAR(wxScrolledWindow::OnChar)
-END_EVENT_TABLE()
-
-IMPLEMENT_DYNAMIC_CLASS(wxScrolledWindow, wxPanel)
-
-// ============================================================================
-// implementation
-// ============================================================================
-
-//-----------------------------------------------------------------------------
-// data
-//-----------------------------------------------------------------------------
-
-extern bool       g_blockEventsOnDrag;
-
-//-----------------------------------------------------------------------------
-// idle system
-//-----------------------------------------------------------------------------
-
-extern void wxapp_install_idle_handler();
-extern bool g_isIdle;
-
-//-----------------------------------------------------------------------------
-// "value_changed" from m_vAdjust
-//-----------------------------------------------------------------------------
-
-static void gtk_scrolled_window_vscroll_callback( GtkAdjustment *adjust, wxScrolledWindow *win )
+void wxScrollHelper::SetScrollbars(int pixelsPerUnitX, int pixelsPerUnitY,
+                                   int noUnitsX, int noUnitsY,
+                                   int xPos, int yPos,
+                                   bool noRefresh)

 {
 {

-    if (g_isIdle)
-        wxapp_install_idle_handler();
-
-    if (g_blockEventsOnDrag) return;
-
-    if (!win->m_hasVMT) return;
+    // prevent programmatic position changes from causing scroll events
+    m_win->SetScrollPos(wxHORIZONTAL, xPos);
+    m_win->SetScrollPos(wxVERTICAL, yPos);

 
 

-    win->GtkVScroll( adjust->value );
+    base_type::SetScrollbars(
+        pixelsPerUnitX, pixelsPerUnitY, noUnitsX, noUnitsY, xPos, yPos, noRefresh);

 }
 
 }
 

-//-----------------------------------------------------------------------------
-// "value_changed" from m_hAdjust
-//-----------------------------------------------------------------------------
-
-static void gtk_scrolled_window_hscroll_callback( GtkAdjustment *adjust, wxScrolledWindow *win )
+void wxScrollHelper::DoAdjustScrollbar(GtkRange* range,
+                                       int pixelsPerLine,
+                                       int winSize,
+                                       int virtSize,
+                                       int *pos,
+                                       int *lines,
+                                       int *linesPerPage)

 {
 {

-    if (g_isIdle)
-        wxapp_install_idle_handler();
-
-    if (g_blockEventsOnDrag) return;
-    if (!win->m_hasVMT) return;
-
-    win->GtkHScroll( adjust->value );
-}
-
-//-----------------------------------------------------------------------------
-// InsertChild for wxScrolledWindow
-//-----------------------------------------------------------------------------
-
-static void wxInsertChildInScrolledWindow( wxWindow* parent, wxWindow* child )
-{
-    // The window might have been scrolled already, do we
-    // have to adapt the position.
-    GtkPizza *pizza = GTK_PIZZA(parent->m_wxwindow);
-    child->m_x += pizza->xoffset;
-    child->m_y += pizza->yoffset;
-
-    gtk_pizza_put( GTK_PIZZA(parent->m_wxwindow),
-                     GTK_WIDGET(child->m_widget),
-                     child->m_x,
-                     child->m_y,
-                     child->m_width,
-                     child->m_height );
-}
-
-// ----------------------------------------------------------------------------
-// wxScrolledWindow creation
-// ----------------------------------------------------------------------------
-
-void wxScrolledWindow::Init()
-{
-    m_xScrollPixelsPerLine = 0;
-    m_yScrollPixelsPerLine = 0;
-    m_xScrollingEnabled = TRUE;
-    m_yScrollingEnabled = TRUE;
-    m_xScrollPosition = 0;
-    m_yScrollPosition = 0;
-    m_xScrollLines = 0;
-    m_yScrollLines = 0;
-    m_xScrollLinesPerPage = 0;
-    m_yScrollLinesPerPage = 0;
-    m_targetWindow = (wxWindow*) NULL;
-    m_scaleX = 1.0;
-    m_scaleY = 1.0;
-    m_hasScrolling = TRUE;
-}
-
-bool wxScrolledWindow::Create(wxWindow *parent,
-                              wxWindowID id,
-                              const wxPoint& pos,
-                              const wxSize& size,
-                              long style,
-                              const wxString& name)
-{
-    Init();
-
-    if (!PreCreation( parent, pos, size ) ||
-        !CreateBase( parent, id, pos, size, style, wxDefaultValidator, name ))
-    {
-        wxFAIL_MSG( wxT("wxWindow creation failed") );
-        return FALSE;
-    }
-
-    m_insertCallback = wxInsertChildInScrolledWindow;
-    
-    m_targetWindow = this;
-
-    m_widget = gtk_scrolled_window_new( (GtkAdjustment *) NULL, (GtkAdjustment *) NULL );
-    GTK_WIDGET_UNSET_FLAGS( m_widget, GTK_CAN_FOCUS );
-
-    GtkScrolledWindow *scrolledWindow = GTK_SCROLLED_WINDOW(m_widget);
-
-    GtkScrolledWindowClass *scroll_class = GTK_SCROLLED_WINDOW_CLASS( GTK_OBJECT_GET_CLASS(m_widget) );
-    scroll_class->scrollbar_spacing = 0;
-
-    gtk_scrolled_window_set_policy( scrolledWindow, GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC );
-
-    m_hAdjust = gtk_range_get_adjustment( GTK_RANGE(scrolledWindow->hscrollbar) );
-    m_vAdjust = gtk_range_get_adjustment( GTK_RANGE(scrolledWindow->vscrollbar) );
-
-    m_wxwindow = gtk_pizza_new();
-
-    gtk_container_add( GTK_CONTAINER(m_widget), m_wxwindow );
-
-    GtkPizza *pizza = GTK_PIZZA(m_wxwindow);
+    if (!range)
+        return;

 
 

-    if (HasFlag(wxRAISED_BORDER))
-    {
-        gtk_pizza_set_shadow_type( pizza, GTK_MYSHADOW_OUT );
-    }
-    else if (HasFlag(wxSUNKEN_BORDER))
+    int upper;
+    int page_size;
+    if (pixelsPerLine > 0 && winSize > 0 && winSize < virtSize)

     {
     {

-        gtk_pizza_set_shadow_type( pizza, GTK_MYSHADOW_IN );
-    }
-    else if (HasFlag(wxSIMPLE_BORDER))
-    {
-        gtk_pizza_set_shadow_type( pizza, GTK_MYSHADOW_THIN );
+        upper = (virtSize + pixelsPerLine - 1) / pixelsPerLine;
+        page_size = winSize / pixelsPerLine;
+        *lines = upper;
+        *linesPerPage = page_size;

     }
     else
     {
     }
     else
     {

-        gtk_pizza_set_shadow_type( pizza, GTK_MYSHADOW_NONE );
+        // GtkRange won't allow upper == lower, so for disabled state use [0,1]
+        //   with a page size of 1. This will also clamp position to 0.
+        upper = 1;
+        page_size = 1;
+        *lines = 0;
+        *linesPerPage = 0;

     }
 
     }
 

-    GTK_WIDGET_SET_FLAGS( m_wxwindow, GTK_CAN_FOCUS );
-    m_acceptsFocus = TRUE;
-
-    // I _really_ don't want scrollbars in the beginning
-    m_vAdjust->lower = 0.0;
-    m_vAdjust->upper = 1.0;
-    m_vAdjust->value = 0.0;
-    m_vAdjust->step_increment = 1.0;
-    m_vAdjust->page_increment = 1.0;
-    gtk_signal_emit_by_name( GTK_OBJECT(m_vAdjust), "changed" );
-    m_hAdjust->lower = 0.0;
-    m_hAdjust->upper = 1.0;
-    m_hAdjust->value = 0.0;
-    m_hAdjust->step_increment = 1.0;
-    m_hAdjust->page_increment = 1.0;
-    gtk_signal_emit_by_name( GTK_OBJECT(m_hAdjust), "changed" );
+    gtk_range_set_increments(range, 1, page_size);
+    gtk_adjustment_set_page_size(gtk_range_get_adjustment(range), page_size);
+    gtk_range_set_range(range, 0, upper);

 
 

-    // Handlers for new scrollbar values
-    GtkVConnectEvent();
-    GtkHConnectEvent();
-
-    gtk_widget_show( m_wxwindow );
-
-    if (m_parent)
-        m_parent->DoAddChild( this );
-
-    PostCreation();
-
-    Show( TRUE );
-
-    return TRUE;
+    // ensure that the scroll position is always in valid range
+    if (*pos > *lines)
+        *pos = *lines;

 }
 
 }
 

-// ----------------------------------------------------------------------------
-// setting scrolling parameters
-// ----------------------------------------------------------------------------
-
-/*
- * pixelsPerUnitX/pixelsPerUnitY: number of pixels per unit (e.g. pixels per text line)
- * noUnitsX/noUnitsY:        : no. units per scrollbar
- */
-void wxScrolledWindow::SetScrollbars (int pixelsPerUnitX, int pixelsPerUnitY,
-               int noUnitsX, int noUnitsY,
-               int xPos, int yPos, bool noRefresh )
+void wxScrollHelper::AdjustScrollbars()

 {
 {

-    m_xScrollPixelsPerLine = pixelsPerUnitX;
-    m_yScrollPixelsPerLine = pixelsPerUnitY;
-    m_xScrollPosition = xPos;
-    m_yScrollPosition = yPos;
-    m_xScrollLines = noUnitsX;
-    m_yScrollLines = noUnitsY;
-    
-    m_hAdjust->lower = 0.0;
-    m_hAdjust->upper = noUnitsX;
-    m_hAdjust->value = xPos;
-    m_hAdjust->step_increment = 1.0;
-    m_hAdjust->page_increment = 2.0;
-
-    m_vAdjust->lower = 0.0;
-    m_vAdjust->upper = noUnitsY;
-    m_vAdjust->value = yPos;
-    m_vAdjust->step_increment = 1.0;
-    m_vAdjust->page_increment = 2.0;
-    
-    AdjustScrollbars();
-}
+    int vw, vh;
+    m_targetWindow->GetVirtualSize(&vw, &vh);

 
 

-void wxScrolledWindow::AdjustScrollbars()
-{

     int w, h;
     int w, h;

-    m_targetWindow->GetClientSize( &w, &h );
-    
-    if (m_xScrollPixelsPerLine == 0)
-        m_hAdjust->page_size = 1.0;
-    else
-        m_hAdjust->page_size = (w / m_xScrollPixelsPerLine);
-        
-    if (m_yScrollPixelsPerLine == 0)
-        m_vAdjust->page_size = 1.0;
-    else
-        m_vAdjust->page_size = (h / m_yScrollPixelsPerLine);
-    
-    m_xScrollLinesPerPage = (int)(m_hAdjust->page_size + 0.5);
-    m_yScrollLinesPerPage = (int)(m_vAdjust->page_size + 0.5);
-    
-    gtk_signal_emit_by_name( GTK_OBJECT(m_vAdjust), "changed" );
-    gtk_signal_emit_by_name( GTK_OBJECT(m_hAdjust), "changed" );
-}
-
-// ----------------------------------------------------------------------------
-// target window handling
-// ----------------------------------------------------------------------------
-
-void wxScrolledWindow::SetTargetWindow( wxWindow *target )
-{
-    wxASSERT_MSG( target, wxT("target window must not be NULL") );
-    m_targetWindow = target;
-}
-
-wxWindow *wxScrolledWindow::GetTargetWindow()
-{
-    return m_targetWindow;
-}
-
-// Override this function if you don't want to have wxScrolledWindow
-// automatically change the origin according to the scroll position.
-void wxScrolledWindow::PrepareDC(wxDC& dc)
-{
-    dc.SetDeviceOrigin( -m_xScrollPosition * m_xScrollPixelsPerLine,
-                        -m_yScrollPosition * m_yScrollPixelsPerLine );
-}
-
-void wxScrolledWindow::GetScrollPixelsPerUnit (int *x_unit, int *y_unit) const
-{
-    if ( x_unit )
-        *x_unit = m_xScrollPixelsPerLine;
-    if ( y_unit )
-        *y_unit = m_yScrollPixelsPerLine;
-}
-
-int wxScrolledWindow::GetScrollPageSize(int orient) const
-{
-    if ( orient == wxHORIZONTAL )
-        return m_xScrollLinesPerPage;
-    else
-        return m_yScrollLinesPerPage;
-}
-
-void wxScrolledWindow::SetScrollPageSize(int orient, int pageSize)
-{
-    if ( orient == wxHORIZONTAL )
-        m_xScrollLinesPerPage = pageSize;
-    else
-        m_yScrollLinesPerPage = pageSize;
-}
-
-void wxScrolledWindow::OnScroll(wxScrollWinEvent& event)
-{
-    int orient = event.GetOrientation();
-
-    int nScrollInc = CalcScrollInc(event);
-    if (nScrollInc == 0) return;
-
-    if (orient == wxHORIZONTAL)
-    {
-        int newPos = m_xScrollPosition + nScrollInc;
-        SetScrollPos(wxHORIZONTAL, newPos, TRUE );
-    }
-    else
-    {
-        int newPos = m_yScrollPosition + nScrollInc;
-        SetScrollPos(wxVERTICAL, newPos, TRUE );
-    }
-
-    if (orient == wxHORIZONTAL)
-    {
-        m_xScrollPosition += nScrollInc;
-    }
-    else
+    const wxSize availSize = GetSizeAvailableForScrollTarget(
+        m_win->GetSize() - m_win->GetWindowBorderSize());
+    if ( availSize.x >= vw && availSize.y >= vh )

     {
     {

-        m_yScrollPosition += nScrollInc;
-    }
+        w = availSize.x;
+        h = availSize.y;

 
 

-    if (orient == wxHORIZONTAL)
-    {
-       if (m_xScrollingEnabled)
-            m_targetWindow->ScrollWindow(-m_xScrollPixelsPerLine * nScrollInc, 0, (const wxRect *) NULL);
-       else
-            m_targetWindow->Refresh();
-    }
-    else
-    {
-        if (m_yScrollingEnabled)
-            m_targetWindow->ScrollWindow(0, -m_yScrollPixelsPerLine * nScrollInc, (const wxRect *) NULL);
-        else
-            m_targetWindow->Refresh();
-    }
-}
+        // we know that the scrollbars will be removed
+        DoAdjustHScrollbar(w, vw);
+        DoAdjustVScrollbar(h, vh);

 
 

-void wxScrolledWindow::Scroll( int x_pos, int y_pos )
-{
-    if (!m_targetWindow)

         return;
         return;

-
-    if (((x_pos == -1) || (x_pos == m_xScrollPosition)) &&
-        ((y_pos == -1) || (y_pos == m_yScrollPosition))) return;
-
-    if ((x_pos != -1) && (m_xScrollPixelsPerLine))
-    {
-        int max = (int)(m_hAdjust->upper - m_hAdjust->page_size + 0.5);
-        if (max < 0) max = 0;
-        if (x_pos > max) x_pos = max;
-        if (x_pos < 0) x_pos = 0;
-            
-        int old_x = m_xScrollPosition;
-        m_xScrollPosition = x_pos;
-        m_hAdjust->value = x_pos;
-        
-        m_targetWindow->ScrollWindow( (old_x-m_xScrollPosition)*m_xScrollPixelsPerLine, 0 );
-        
-        // Just update the scrollbar, don't send any wxWindows event
-        GtkHDisconnectEvent();
-        gtk_signal_emit_by_name( GTK_OBJECT(m_hAdjust), "value_changed" );
-        GtkHConnectEvent();
-    }
-    
-    if ((y_pos != -1) && (m_yScrollPixelsPerLine))
-    {
-        int max = (int)(m_vAdjust->upper - m_vAdjust->page_size + 0.5);
-        if (max < 0) max = 0;
-        if (y_pos > max) y_pos = max;
-        if (y_pos < 0) y_pos = 0;
-            
-        int old_y = m_yScrollPosition;
-        m_yScrollPosition = y_pos;
-        m_vAdjust->value = y_pos;
-        
-        m_targetWindow->ScrollWindow( 0, (old_y-m_yScrollPosition)*m_yScrollPixelsPerLine );
-        
-        // Just update the scrollbar, don't send any wxWindows event
-        GtkVDisconnectEvent();
-        gtk_signal_emit_by_name( GTK_OBJECT(m_vAdjust), "value_changed" );
-        GtkVConnectEvent();

     }
     }

-}
-
-void wxScrolledWindow::GtkVScroll( float value )
-{
-    if (!m_targetWindow)
-        return;

 
 

-    if (m_yScrollPixelsPerLine == 0)
-        return;
-    
-    int y_pos = (int)(value+0.5);
-    
-    if (y_pos == m_yScrollPosition)
-        return;
-    
-    GtkScrolledWindow *scrolledWindow = GTK_SCROLLED_WINDOW(m_widget);
-    GtkRange *range = GTK_RANGE(scrolledWindow->vscrollbar);
-    
-    wxEventType command = wxEVT_SCROLLWIN_THUMBTRACK;
-    if      (range->scroll_type == GTK_SCROLL_STEP_BACKWARD) command = wxEVT_SCROLLWIN_LINEUP;
-    else if (range->scroll_type == GTK_SCROLL_STEP_FORWARD)  command = wxEVT_SCROLLWIN_LINEDOWN;
-    else if (range->scroll_type == GTK_SCROLL_PAGE_BACKWARD) command = wxEVT_SCROLLWIN_PAGEUP;
-    else if (range->scroll_type == GTK_SCROLL_PAGE_FORWARD)  command = wxEVT_SCROLLWIN_PAGEDOWN;
-
-    wxScrollWinEvent event( command, y_pos, wxVERTICAL );
-    event.SetEventObject( this );
-    GetEventHandler()->ProcessEvent( event );
-}
+    m_targetWindow->GetClientSize(&w, NULL);
+    DoAdjustHScrollbar(w, vw);

 
 

-void wxScrolledWindow::GtkHScroll( float value )
-{
-    if (!m_targetWindow)
-        return;
-        
-    if (m_xScrollPixelsPerLine == 0)
-        return;
-    
-    int x_pos = (int)(value+0.5);
-
-    if (x_pos == m_xScrollPosition)
-        return;
+    m_targetWindow->GetClientSize(NULL, &h);
+    DoAdjustVScrollbar(h, vh);

 
 

-    GtkScrolledWindow *scrolledWindow = GTK_SCROLLED_WINDOW(m_widget);
-    GtkRange *range = GTK_RANGE(scrolledWindow->hscrollbar);
-    
-    wxEventType command = wxEVT_SCROLLWIN_THUMBTRACK;
-    if      (range->scroll_type == GTK_SCROLL_STEP_BACKWARD) command = wxEVT_SCROLLWIN_LINEUP;
-    else if (range->scroll_type == GTK_SCROLL_STEP_FORWARD)  command = wxEVT_SCROLLWIN_LINEDOWN;
-    else if (range->scroll_type == GTK_SCROLL_PAGE_BACKWARD) command = wxEVT_SCROLLWIN_PAGEUP;
-    else if (range->scroll_type == GTK_SCROLL_PAGE_FORWARD)  command = wxEVT_SCROLLWIN_PAGEDOWN;
-
-    wxScrollWinEvent event( command, x_pos, wxHORIZONTAL );
-    event.SetEventObject( this );
-    GetEventHandler()->ProcessEvent( event );
-}
-
-void wxScrolledWindow::EnableScrolling (bool x_scroll, bool y_scroll)
-{
-    m_xScrollingEnabled = x_scroll;
-    m_yScrollingEnabled = y_scroll;
-}
-
-void wxScrolledWindow::GetVirtualSize (int *x, int *y) const
-{
-    if ( x )
-        *x = m_xScrollPixelsPerLine * m_xScrollLines;
-    if ( y )
-        *y = m_yScrollPixelsPerLine * m_yScrollLines;
-}
-
-// Where the current view starts from
-void wxScrolledWindow::GetViewStart (int *x, int *y) const
-{
-    if ( x )
-        *x = m_xScrollPosition;
-    if ( y )
-        *y = m_yScrollPosition;
-}
-
-void wxScrolledWindow::CalcScrolledPosition(int x, int y, int *xx, int *yy) const
-{
-    if ( xx )
-        *xx = x - m_xScrollPosition * m_xScrollPixelsPerLine;
-    if ( yy )
-        *yy = y - m_yScrollPosition * m_yScrollPixelsPerLine;
-}
-
-void wxScrolledWindow::CalcUnscrolledPosition(int x, int y, int *xx, int *yy) const
-{
-    if ( xx )
-        *xx = x + m_xScrollPosition * m_xScrollPixelsPerLine;
-    if ( yy )
-        *yy = y + m_yScrollPosition * m_yScrollPixelsPerLine;
-}
-
-int wxScrolledWindow::CalcScrollInc(wxScrollWinEvent& event)
-{
-    int pos = event.GetPosition();
-    int orient = event.GetOrientation();
-
-    int nScrollInc = 0;
-    if (event.GetEventType() == wxEVT_SCROLLWIN_TOP)
-    {
-            if (orient == wxHORIZONTAL)
-                nScrollInc = - m_xScrollPosition;
-            else
-                nScrollInc = - m_yScrollPosition;
-    } else
-    if (event.GetEventType() == wxEVT_SCROLLWIN_BOTTOM)
-    {
-            if (orient == wxHORIZONTAL)
-                nScrollInc = m_xScrollLines - m_xScrollPosition;
-            else
-                nScrollInc = m_yScrollLines - m_yScrollPosition;
-    } else
-    if (event.GetEventType() == wxEVT_SCROLLWIN_LINEUP)
-    {
-            nScrollInc = -1;
-    } else
-    if (event.GetEventType() == wxEVT_SCROLLWIN_LINEDOWN)
+    const int w_old = w;
+    m_targetWindow->GetClientSize(&w, NULL);
+    if ( w != w_old )

     {
     {

-            nScrollInc = 1;
-    } else
-    if (event.GetEventType() == wxEVT_SCROLLWIN_PAGEUP)
-    {
-            if (orient == wxHORIZONTAL)
-                nScrollInc = -GetScrollPageSize(wxHORIZONTAL);
-            else
-                nScrollInc = -GetScrollPageSize(wxVERTICAL);
-    } else
-    if (event.GetEventType() == wxEVT_SCROLLWIN_PAGEDOWN)
-    {
-            if (orient == wxHORIZONTAL)
-                nScrollInc = GetScrollPageSize(wxHORIZONTAL);
-            else
-                nScrollInc = GetScrollPageSize(wxVERTICAL);
-    } else
-    if ((event.GetEventType() == wxEVT_SCROLLWIN_THUMBTRACK) ||
-        (event.GetEventType() == wxEVT_SCROLLWIN_THUMBRELEASE))
-    {
-            if (orient == wxHORIZONTAL)
-                nScrollInc = pos - m_xScrollPosition;
-            else
-                nScrollInc = pos - m_yScrollPosition;
-    }
+        // It is necessary to repeat the calculations in this case to avoid an
+        // observed infinite series of size events, involving alternating
+        // changes in visibility of the scrollbars.
+        // At this point, GTK+ has already queued a resize, which will cause
+        // AdjustScrollbars() to be called again. If the scrollbar visibility
+        // is not correct before then, yet another resize will occur, possibly
+        // leading to an unending series if the sizes are just right.
+        DoAdjustHScrollbar(w, vw);

 
 

-    if (orient == wxHORIZONTAL)
-    {
-        if (m_xScrollPixelsPerLine > 0)
-        {
-            int max = (int)(m_hAdjust->upper - m_hAdjust->page_size + 0.5);
-            if (max < 0) max = 0;
-
-            if ( (m_xScrollPosition + nScrollInc) < 0 )
-                nScrollInc = -m_xScrollPosition; // As -ve as we can go
-            else if ( (m_xScrollPosition + nScrollInc) > max )
-                nScrollInc = max - m_xScrollPosition; // As +ve as we can go
-        }
-        else
-            m_targetWindow->Refresh();
-    }
-    else
-    {
-        if (m_yScrollPixelsPerLine > 0)
-        {
-            int max = (int)(m_vAdjust->upper - m_vAdjust->page_size + 0.5);
-            if (max < 0) max = 0;
-
-            if ( (m_yScrollPosition + nScrollInc) < 0 )
-                nScrollInc = -m_yScrollPosition; // As -ve as we can go
-            else if ( (m_yScrollPosition + nScrollInc) > max )
-                nScrollInc = max - m_yScrollPosition; // As +ve as we can go
-        }
-        else
-            m_targetWindow->Refresh();
+        m_targetWindow->GetClientSize(NULL, &h);
+        DoAdjustVScrollbar(h, vh);

     }
     }

-
-    return nScrollInc;

 }
 
 }
 

-void wxScrolledWindow::SetScrollPos( int orient, int pos, bool WXUNUSED(refresh) )
+void wxScrollHelper::DoScrollOneDir(int orient,
+                                    int pos,
+                                    int pixelsPerLine,
+                                    int *posOld)

 {
 {

-    wxCHECK_RET( m_widget != NULL, wxT("invalid window") );
-
-    wxCHECK_RET( m_wxwindow != NULL, wxT("window needs client area for scrolling") );
-
-    if (orient == wxHORIZONTAL)
+    if ( pos != -1 && pos != *posOld && pixelsPerLine )

     {
     {

-        int max = (int)(m_hAdjust->upper - m_hAdjust->page_size + 0.5);
-        if (max < 0) max = 0;
-        
-        if (pos > max) pos = 0;
-        if (pos < 0) pos = 0;
-        
-        if (pos == (int)(m_hAdjust->value+0.5)) return;
-        m_hAdjust->value = pos;
-    }
-    else
-    {
-        int max = (int)(m_vAdjust->upper - m_vAdjust->page_size + 0.5);
-        if (max < 0) max = 0;
-        
-        if (pos > max) pos = 0;
-        if (pos < 0) pos = 0;
-        
-        if (pos == (int)(m_vAdjust->value+0.5)) return;
-        m_vAdjust->value = pos;
-    }
-
-    if (m_wxwindow->window)
-    {
-        if (orient == wxHORIZONTAL)
-        {
-            // Just update the scrollbar, don't send any wxWindows event
-            GtkHDisconnectEvent();
-            gtk_signal_emit_by_name( GTK_OBJECT(m_hAdjust), "value_changed" );
-            GtkHConnectEvent();
-        }
-        else
-        {
-            // Just update the scrollbar, don't send any wxWindows event
-            GtkVDisconnectEvent();
-            gtk_signal_emit_by_name( GTK_OBJECT(m_vAdjust), "value_changed" );
-            GtkVConnectEvent();
-        }
-    }
-}
+        m_win->SetScrollPos(orient, pos);
+        pos = m_win->GetScrollPos(orient);

 
 

-void wxScrolledWindow::GtkVConnectEvent()
-{
-    gtk_signal_connect( GTK_OBJECT(m_vAdjust), "value_changed",
-          (GtkSignalFunc) gtk_scrolled_window_vscroll_callback, (gpointer) this );
-}
+        int diff = (*posOld - pos)*pixelsPerLine;
+        m_targetWindow->ScrollWindow(orient == wxHORIZONTAL ? diff : 0,
+                                     orient == wxHORIZONTAL ? 0 : diff);

 
 

-void wxScrolledWindow::GtkHConnectEvent()
-{
-    gtk_signal_connect( GTK_OBJECT(m_hAdjust), "value_changed",
-          (GtkSignalFunc) gtk_scrolled_window_hscroll_callback, (gpointer) this );
+        *posOld = pos;
+    }

 }
 
 }
 

-void wxScrolledWindow::GtkHDisconnectEvent()
+void wxScrollHelper::DoScroll( int x_pos, int y_pos )

 {
 {

-    gtk_signal_disconnect_by_func( GTK_OBJECT(m_hAdjust),
-        (GtkSignalFunc) gtk_scrolled_window_hscroll_callback, (gpointer) this );
-}
+    wxCHECK_RET( m_targetWindow != 0, wxT("No target window") );

 
 

-void wxScrolledWindow::GtkVDisconnectEvent()
-{
-    gtk_signal_disconnect_by_func( GTK_OBJECT(m_vAdjust),
-        (GtkSignalFunc) gtk_scrolled_window_vscroll_callback, (gpointer) this );
+    DoScrollOneDir(wxHORIZONTAL, x_pos, m_xScrollPixelsPerLine, &m_xScrollPosition);
+    DoScrollOneDir(wxVERTICAL, y_pos, m_yScrollPixelsPerLine, &m_yScrollPosition);

 }
 
 // ----------------------------------------------------------------------------
 }
 
 // ----------------------------------------------------------------------------

-// event handlers
+// scrollbars visibility

 // ----------------------------------------------------------------------------
 
 // ----------------------------------------------------------------------------
 

-// Default OnSize resets scrollbars, if any
-void wxScrolledWindow::OnSize(wxSizeEvent& WXUNUSED(event))
+namespace

 {
 {

-#if wxUSE_CONSTRAINTS
-    if (GetAutoLayout())
-        Layout();
-#endif
-
-    AdjustScrollbars();
-}
-
-// This calls OnDraw, having adjusted the origin according to the current
-// scroll position
-void wxScrolledWindow::OnPaint(wxPaintEvent& WXUNUSED(event))
-{
-    wxPaintDC dc(this);
-    PrepareDC(dc);
-
-    OnDraw(dc);
-}

 
 

-// kbd handling: notice that we use OnChar() and not OnKeyDown() for
-// compatibility here - if we used OnKeyDown(), the programs which process
-// arrows themselves in their OnChar() would never get the message and like
-// this they always have the priority
-void wxScrolledWindow::OnChar(wxKeyEvent& event)
+GtkPolicyType GtkPolicyFromWX(wxScrollbarVisibility visibility)

 {
 {

-    int stx, sty,       // view origin
-        szx, szy,       // view size (total)
-        clix, cliy;     // view size (on screen)
-
-    ViewStart(&stx, &sty);
-    GetClientSize(&clix, &cliy);
-    GetVirtualSize(&szx, &szy);
-
-    if( m_xScrollPixelsPerLine )
-    {
-        clix /= m_xScrollPixelsPerLine;
-        szx /= m_xScrollPixelsPerLine;
-    }
-    else
-    {
-        clix = 0;
-        szx = -1;
-    }
-    if( m_yScrollPixelsPerLine )
-    {
-        cliy /= m_yScrollPixelsPerLine;
-        szy /= m_yScrollPixelsPerLine;
-    }
-    else
-    {
-        cliy = 0;
-        szy = -1;
-    }
-
-    int dsty;
-    switch ( event.KeyCode() )
+    GtkPolicyType policy;
+    switch ( visibility )

     {
     {

-        case WXK_PAGEUP:
-        case WXK_PRIOR:
-            dsty = sty - (5 * cliy / 6);
-            Scroll(-1, (dsty == -1) ? 0 : dsty);
+        case wxSHOW_SB_NEVER:
+            policy = GTK_POLICY_NEVER;

             break;
 
             break;
 

-        case WXK_PAGEDOWN:
-        case WXK_NEXT:
-            Scroll(-1, sty + (5 * cliy / 6));
+        case wxSHOW_SB_DEFAULT:
+            policy = GTK_POLICY_AUTOMATIC;

             break;
 
             break;
 

-        case WXK_HOME:
-            Scroll(0, event.ControlDown() ? 0 : -1);
-            break;
-
-        case WXK_END:
-            Scroll(szx - clix, event.ControlDown() ? szy - cliy : -1);
-            break;
+        default:
+            wxFAIL_MSG( wxS("unknown scrollbar visibility") );
+            // fall through

 
 

-        case WXK_UP:
-            Scroll(-1, sty - 1);
+        case wxSHOW_SB_ALWAYS:
+            policy = GTK_POLICY_ALWAYS;

             break;
             break;

+    }

 
 

-        case WXK_DOWN:
-            Scroll(-1, sty + 1);
-            break;
+    return policy;
+}

 
 

-        case WXK_LEFT:
-            Scroll(stx - 1, -1);
-            break;
+} // anonymous namespace

 
 

-        case WXK_RIGHT:
-            Scroll(stx + 1, -1);
-            break;
+void wxScrollHelper::DoShowScrollbars(wxScrollbarVisibility horz,
+                                      wxScrollbarVisibility vert)
+{
+    GtkScrolledWindow * const scrolled = GTK_SCROLLED_WINDOW(m_win->m_widget);
+    wxCHECK_RET( scrolled, "window must be created" );

 
 

-        default:
-            // not for us
-            event.Skip();
-    }
+    gtk_scrolled_window_set_policy(scrolled,
+                                   GtkPolicyFromWX(horz),
+                                   GtkPolicyFromWX(vert));

 }
 }