Fix bug in wxSplitterWindow not handling the event state correct in case of sash pos changing or resize.

samples/splitter/splitter.cpp

@@ -129,7 +129,7 @@ private:
     wxSplitterWindow* m_splitter;
     wxWindow *m_replacewindow;
     int m_sashPos;
-    bool m_lockSash:1;
+    bool m_lockSash;
 
     wxDECLARE_EVENT_TABLE();
     wxDECLARE_NO_COPY_CLASS(MyFrame);
@@ -277,7 +277,7 @@ MyFrame::MyFrame()
     splitMenu->Append(SPLIT_SETGRAVITY,
                       "Set &gravity\tCtrl-G",
                       "Set gravity of sash");
-    splitMenu->Append(SPLIT_LOCKSASH,
+    splitMenu->AppendCheckItem(SPLIT_LOCKSASH,
                       "Toggle sash &lock on resize\tCtrl-R",
                       "Keep the sash in a fixed position while resizing");
     splitMenu->AppendSeparator();
@@ -550,8 +550,6 @@ void MySplitterWindow::OnPositionChanged(wxSplitterEvent& event)
     // new position. If the sash is not locked, this has no effect but
     // doesn't hurt either.
     m_frame->SetSashPos(event.GetSashPosition());
-
-    event.Skip();
 }
 
 void MySplitterWindow::OnPositionResize(wxSplitterEvent &event)
@@ -560,17 +558,19 @@ void MySplitterWindow::OnPositionResize(wxSplitterEvent &event)
     // if it is not locked. Otherwise we hold it at the position
     // the user specified by manually dragging.
     if (m_frame->IsSashLocked())
+    {
+        // We set the last known position to keep the sash in place.
+        // For this particular example we could also simply use
+        // event.Veto()
+        // as well and it would have the same effect.
         event.SetSashPosition(m_frame->GetSashPos());
-
-    event.Skip();
+    }
 }
 
 void MySplitterWindow::OnPositionChanging(wxSplitterEvent& event)
 {
     wxLogStatus(m_frame, "Position is changing, now = %d (or %d)",
                 event.GetSashPosition(), GetSashPosition());
-
-    event.Skip();
 }
 
 void MySplitterWindow::OnDClick(wxSplitterEvent& event)
@@ -579,6 +579,7 @@ void MySplitterWindow::OnDClick(wxSplitterEvent& event)
     m_frame->SetStatusText("Splitter double clicked", 1);
 #endif // wxUSE_STATUSBAR
 
+    // Let the splitter window handle the event as well.
     event.Skip();
 }
 
@@ -588,6 +589,7 @@ void MySplitterWindow::OnUnsplitEvent(wxSplitterEvent& event)
     m_frame->SetStatusText("Splitter unsplit", 1);
 #endif // wxUSE_STATUSBAR
 
+    // Let the splitter window handle the event as well.
     event.Skip();
 }
 

src/generic/splitter.cpp

@@ -488,19 +488,22 @@ void wxSplitterWindow::OnSize(wxSizeEvent& event)
             update.m_data.resize.oldSize = old_size;
             update.m_data.resize.newSize = size;
 
-            if (!DoSendEvent(update))
+            if (DoSendEvent(update))
             {
-                // the event handler vetoed the change
-                newPosition = -1;
-            }
-            else
-            {
-                // If the user set the sashposition to -1
-                // we keep the already calculated value,
-                // otherwise the user provided the new position.
-                int userPos = update.GetSashPosition();
-                if (userPos != -1)
-                    newPosition = userPos;
+                if (update.IsAllowed())
+                {
+                    // If the user set the sashposition to -1
+                    // we keep the already calculated value, otherwise
+                    // the user provided the new position.
+                    int userPos = update.GetSashPosition();
+                    if (userPos != -1)
+                        newPosition = userPos;
+                }
+                else
+                {
+                    // the event handler vetoed the change
+                    newPosition = -1;
+                }
             }
 
             // Also check if the second window became too small.
@@ -925,7 +928,7 @@ void wxSplitterWindow::UpdateSize()
 
 bool wxSplitterWindow::DoSendEvent(wxSplitterEvent& event)
 {
-    return !GetEventHandler()->ProcessEvent(event) || event.IsAllowed();
+    return GetEventHandler()->ProcessEvent(event);
 }
 
 wxSize wxSplitterWindow::DoGetBestSize() const
@@ -1032,15 +1035,18 @@ int wxSplitterWindow::OnSashPositionChanging(int newSashPosition)
     wxSplitterEvent event(wxEVT_SPLITTER_SASH_POS_CHANGING, this);
     event.m_data.resize.pos = newSashPosition;
 
-    if ( !DoSendEvent(event) )
+    if (DoSendEvent(event))
     {
-        // the event handler vetoed the change
-        newSashPosition = -1;
-    }
-    else
-    {
-        // it could have been changed by it
-        newSashPosition = event.GetSashPosition();
+        if (event.IsAllowed())
+        {
+            // it could have been changed by it
+            newSashPosition = event.GetSashPosition();
+        }
+        else
+        {
+            // the event handler vetoed the change
+            newSashPosition = -1;
+        }
     }
 
     return newSashPosition;