protected override void DestroyWindowCore(HandleRef hwnd)
{
PInvoke.DestroyWindow(hwnd.Handle);
}
protected override IntPtr WndProc(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
handled = false;
switch (msg)
{
case PInvoke.WM_NCHITTEST: // Activate mouse events
handled = true;
return(new IntPtr(PInvoke.HTCLIENT));
case PInvoke.WM_PAINT:
PInvoke.PAINTSTRUCT pStruct;
PInvoke.BeginPaint(hWnd, out pStruct);
this.Render();
PInvoke.EndPaint(hWnd, ref pStruct);
handled = true;
return(IntPtr.Zero);
case PInvoke.WM_MOUSEMOVE:
if ((PInvoke.GetKeyState(PInvoke.VK_LBUTTON) & 0x80) == 0)
{
_isDragging = false;
}
if (_isDragging)
{
PInvoke.SetCursor(_cursorGrabbing);
var offsetX = (int)((_dragStartPos.X - PInvoke.LOWORD(lParam)) / _scale);
var offsetY = (int)((_dragStartPos.Y - PInvoke.HIWORD(lParam)) / _scale);
if (_dragFirstVisiblePos.X + offsetX < 0)
{
FirstVisiblePos.X = 0;
}
else if (_dragFirstVisiblePos.X + offsetX + RealVisibleWidth > RealWidth)
{
FirstVisiblePos.X = (int)(RealWidth - RealVisibleWidth);
}
else
{
FirstVisiblePos.X = _dragFirstVisiblePos.X + offsetX;
}
if (_dragFirstVisiblePos.Y + offsetY < 0)
{
FirstVisiblePos.Y = 0;
}
else if (_dragFirstVisiblePos.Y + offsetY + RealVisibleHeight > RealHeight)
{
FirstVisiblePos.Y = (int)(RealHeight - RealVisibleHeight);
}
else
{
FirstVisiblePos.Y = _dragFirstVisiblePos.Y + offsetY;
}
StaticLoader.Mediator.NotifyColleagues(MediatorMessages.ResizeImageScrollBar);
handled = true;
}
return(IntPtr.Zero);
case PInvoke.WM_LBUTTONDOWN:
PInvoke.SetCursor(_cursorGrabbing);
_dragStartPos.X = PInvoke.LOWORD(lParam);
_dragStartPos.Y = PInvoke.HIWORD(lParam);
_dragFirstVisiblePos = FirstVisiblePos;
_isDragging = true;
handled = true;
return(IntPtr.Zero);
case PInvoke.WM_LBUTTONUP:
_isDragging = false;
handled = true;
return(IntPtr.Zero);
}
return(IntPtr.Zero);
}
