private void StartDrag(CrownDockSplitter splitter)
{
_activeSplitter = splitter;
Cursor.Current = _activeSplitter.ResizeCursor;
_initialContact = Cursor.Position;
_isDragging = true;
_activeSplitter.ShowOverlay();
_dragTimer.Start();
}
private void CheckCursor()
{
if (_isDragging)
{
return;
}
CrownDockSplitter hotSplitter = HotSplitter();
if (hotSplitter != null)
{
Cursor.Current = hotSplitter.ResizeCursor;
}
}
public bool PreFilterMessage(ref Message m)
{
// We only care about mouse events
if (!(m.Msg == (int)WM.MOUSEMOVE || m.Msg == (int)WM.LBUTTONDOWN || m.Msg == (int)WM.LBUTTONUP || m.Msg == (int)WM.LBUTTONDBLCLK || m.Msg == (int)WM.RBUTTONDOWN || m.Msg == (int)WM.RBUTTONUP || m.Msg == (int)WM.RBUTTONDBLCLK))
{
return(false);
}
// Stop drag.
if (m.Msg == (int)WM.LBUTTONUP)
{
if (_isDragging)
{
StopDrag();
return(true);
}
}
// Exit out early if we're simply releasing a non-splitter drag over the area
if (m.Msg == (int)WM.LBUTTONUP && !_isDragging)
{
return(false);
}
// Force cursor if already dragging.
if (_isDragging)
{
Cursor.Current = _activeSplitter.ResizeCursor;
}
// Return out early if we're dragging something that's not a splitter.
if (m.Msg == (int)WM.MOUSEMOVE && !_isDragging && _dockPanel.MouseButtonState != MouseButtons.None)
{
return(false);
}
// Try and create a control from the message handle.
Control control = Control.FromHandle(m.HWnd);
// Exit out if we didn't manage to create a control.
if (control == null)
{
return(false);
}
// Exit out if the control is not the dock panel or a child control.
if (!(control == _dockPanel || _dockPanel.Contains(control)))
{
return(false);
}
// Update the mouse cursor
CheckCursor();
// Start drag.
if (m.Msg == (int)WM.LBUTTONDOWN)
{
CrownDockSplitter hotSplitter = HotSplitter();
if (hotSplitter != null)
{
StartDrag(hotSplitter);
return(true);
}
}
// Stop events passing through if we're hovering over a splitter
if (HotSplitter() != null)
{
return(true);
}
// Stop all events from going through if we're dragging a splitter.
if (_isDragging)
{
return(true);
}
return(false);
}
