workaround for MGL's weirdness: won't render rectangles of w=1 or h=1

[wxWidgets.git] / src / generic / scrlwing.cpp

diff --git a/src/generic/scrlwing.cpp b/src/generic/scrlwing.cpp
index 18a963a16eac8725937c2c42a91ea1d1aa6b34e3..cf4792b5fc5a76a6cbc465aa55b43b13706b3369 100644 (file)
--- a/src/generic/scrlwing.cpp
+++ b/src/generic/scrlwing.cpp
@@ -384,15 +384,22 @@ void wxScrollHelper::SetScrollbars(int pixelsPerUnitX,
 }
 
 // ----------------------------------------------------------------------------
-// target window handling
+// [target] window handling
 // ----------------------------------------------------------------------------
 
 void wxScrollHelper::DeleteEvtHandler()
 {
-    // FIXME: we should search for m_handler in the handler list
-    if ( m_targetWindow )
+    // search for m_handler in the handler list
+    if ( m_win && m_handler )
     {
-        m_targetWindow->PopEventHandler(TRUE /* Delete old event handler*/);
+        if ( m_win->RemoveEventHandler(m_handler) )
+        {
+            delete m_handler;
+        }
+        //else: something is very wrong, so better [maybe] leak memory than
+        //      risk a crash because of double deletion
+
+        m_handler = NULL;
     }
 }
 
@@ -402,6 +409,7 @@ void wxScrollHelper::SetWindow(wxWindow *win)
 
     m_win = win;
 
+    // by default, the associated window is also the target window
     DoSetTargetWindow(win);
 }
 
@@ -410,20 +418,25 @@ void wxScrollHelper::DoSetTargetWindow(wxWindow *target)
     m_targetWindow = target;
 
     // install the event handler which will intercept the events we're
-    // interested in
-    m_handler = new wxScrollHelperEvtHandler(this);
-    m_targetWindow->PushEventHandler(m_handler);
+    // interested in (but only do it for our real window, not the target window
+    // which we scroll - we don't need to hijack its events)
+    if ( m_targetWindow == m_win )
+    {
+        // if we already have a handler, delete it first
+        DeleteEvtHandler();
+
+        m_handler = new wxScrollHelperEvtHandler(this);
+        m_targetWindow->PushEventHandler(m_handler);
+    }
 }
 
-void wxScrollHelper::SetTargetWindow( wxWindow *target )
+void wxScrollHelper::SetTargetWindow(wxWindow *target)
 {
     wxCHECK_RET( target, wxT("target window must not be NULL") );
 
     if ( target == m_targetWindow )
         return;
 
-    DeleteEvtHandler();
-
     DoSetTargetWindow(target);
 }
 
@@ -451,12 +464,12 @@ void wxScrollHelper::HandleOnScroll(wxScrollWinEvent& event)
     if (orient == wxHORIZONTAL)
     {
         m_xScrollPosition += nScrollInc;
-        m_targetWindow->SetScrollPos(wxHORIZONTAL, m_xScrollPosition);
+        m_win->SetScrollPos(wxHORIZONTAL, m_xScrollPosition);
     }
     else
     {
         m_yScrollPosition += nScrollInc;
-        m_targetWindow->SetScrollPos(wxVERTICAL, m_yScrollPosition);
+        m_win->SetScrollPos(wxVERTICAL, m_yScrollPosition);
     }
 
     bool needsRefresh = FALSE;
@@ -621,14 +634,14 @@ void wxScrollHelper::AdjustScrollbars()
         m_xScrollPosition = wxMin( m_xScrollLines-noPagePositions, m_xScrollPosition);
         m_xScrollPosition = wxMax( 0, m_xScrollPosition );
 
-        m_targetWindow->SetScrollbar(wxHORIZONTAL, m_xScrollPosition, noPagePositions, m_xScrollLines);
+        m_win->SetScrollbar(wxHORIZONTAL, m_xScrollPosition, noPagePositions, m_xScrollLines);
         // The amount by which we scroll when paging
         SetScrollPageSize(wxHORIZONTAL, noPagePositions);
     }
     else
     {
         m_xScrollPosition = 0;
-        m_targetWindow->SetScrollbar (wxHORIZONTAL, 0, 0, 0, FALSE);
+        m_win->SetScrollbar (wxHORIZONTAL, 0, 0, 0, FALSE);
     }
 
     if (m_yScrollLines > 0)
@@ -645,14 +658,14 @@ void wxScrollHelper::AdjustScrollbars()
         m_yScrollPosition = wxMin( m_yScrollLines-noPagePositions, m_yScrollPosition );
         m_yScrollPosition = wxMax( 0, m_yScrollPosition );
 
-        m_targetWindow->SetScrollbar(wxVERTICAL, m_yScrollPosition, noPagePositions, m_yScrollLines);
+        m_win->SetScrollbar(wxVERTICAL, m_yScrollPosition, noPagePositions, m_yScrollLines);
         // The amount by which we scroll when paging
         SetScrollPageSize(wxVERTICAL, noPagePositions);
     }
     else
     {
         m_yScrollPosition = 0;
-        m_targetWindow->SetScrollbar (wxVERTICAL, 0, 0, 0, FALSE);
+        m_win->SetScrollbar (wxVERTICAL, 0, 0, 0, FALSE);
     }
 
     if (oldXScroll != m_xScrollPosition)
@@ -744,7 +757,7 @@ void wxScrollHelper::Scroll( int x_pos, int y_pos )
         m_xScrollPosition = wxMax( 0, m_xScrollPosition );
 
         if (old_x != m_xScrollPosition) {
-            m_targetWindow->SetScrollPos( wxHORIZONTAL, m_xScrollPosition );
+            m_win->SetScrollPos( wxHORIZONTAL, m_xScrollPosition );
             m_targetWindow->ScrollWindow( (old_x-m_xScrollPosition)*m_xScrollPixelsPerLine, 0,
                                           GetRect() );
         }
@@ -765,7 +778,7 @@ void wxScrollHelper::Scroll( int x_pos, int y_pos )
         m_yScrollPosition = wxMax( 0, m_yScrollPosition );
 
         if (old_y != m_yScrollPosition) {
-            m_targetWindow->SetScrollPos( wxVERTICAL, m_yScrollPosition );
+            m_win->SetScrollPos( wxVERTICAL, m_yScrollPosition );
             m_targetWindow->ScrollWindow( 0, (old_y-m_yScrollPosition)*m_yScrollPixelsPerLine,
                                           GetRect() );
         }
@@ -824,8 +837,8 @@ void wxScrollHelper::CalcUnscrolledPosition(int x, int y, int *xx, int *yy) cons
 void wxScrollHelper::HandleOnSize(wxSizeEvent& WXUNUSED(event))
 {
 #if wxUSE_CONSTRAINTS
-    if ( m_targetWindow->GetAutoLayout() )
-        m_targetWindow->Layout();
+    if ( m_win->GetAutoLayout() )
+        m_win->Layout();
 #endif
 
     AdjustScrollbars();
@@ -835,7 +848,8 @@ void wxScrollHelper::HandleOnSize(wxSizeEvent& WXUNUSED(event))
 // scroll position
 void wxScrollHelper::HandleOnPaint(wxPaintEvent& WXUNUSED(event))
 {
-    wxPaintDC dc(m_targetWindow);
+    // don't use m_targetWindow here, this is always called for ourselves
+    wxPaintDC dc(m_win);
     DoPrepareDC(dc);
 
     OnDraw(dc);