protected override void WndProc(ref Message message) {
switch (message.Msg) {
case WM_COMMAND: {
// need to dispatch the message for the context menu
if (message.LParam == IntPtr.Zero)
commandDispatch.Invoke(null, new object[] {
message.WParam.ToInt32() & 0xFFFF });
} break;
case WM_NCHITTEST: {
message.Result = (IntPtr)HitResult.Caption;
if (HitTest != null) {
Point p = new Point(
Macros.GET_X_LPARAM(message.LParam) - location.X,
Macros.GET_Y_LPARAM(message.LParam) - location.Y
);
HitTestEventArgs e = new HitTestEventArgs(p, HitResult.Caption);
HitTest(this, e);
message.Result = (IntPtr)e.HitResult;
}
} break;
case WM_NCLBUTTONDBLCLK: {
if (MouseDoubleClick != null) {
MouseDoubleClick(this, new MouseEventArgs(MouseButtons.Left, 2,
Macros.GET_X_LPARAM(message.LParam) - location.X,
Macros.GET_Y_LPARAM(message.LParam) - location.Y, 0));
}
message.Result = IntPtr.Zero;
} break;
case WM_NCRBUTTONDOWN: {
message.Result = IntPtr.Zero;
} break;
case WM_NCRBUTTONUP: {
if (contextMenu != null)
ShowContextMenu(new Point(
Macros.GET_X_LPARAM(message.LParam),
Macros.GET_Y_LPARAM(message.LParam)
));
message.Result = IntPtr.Zero;
} break;
case WM_WINDOWPOSCHANGING: {
WindowPos wp = (WindowPos)Marshal.PtrToStructure(
message.LParam, typeof(WindowPos));
if (!lockPositionAndSize) {
// prevent the window from leaving the screen
if ((wp.flags & SWP_NOMOVE) == 0) {
Rectangle rect = Screen.GetWorkingArea(
new Rectangle(wp.x, wp.y, wp.cx, wp.cy));
const int margin = 16;
wp.x = Math.Max(wp.x, rect.Left - wp.cx + margin);
wp.x = Math.Min(wp.x, rect.Right - margin);
wp.y = Math.Max(wp.y, rect.Top - wp.cy + margin);
wp.y = Math.Min(wp.y, rect.Bottom - margin);
}
// update location and fire event
if ((wp.flags & SWP_NOMOVE) == 0) {
if (location.X != wp.x || location.Y != wp.y) {
location = new Point(wp.x, wp.y);
if (LocationChanged != null)
LocationChanged(this, EventArgs.Empty);
}
}
// update size and fire event
if ((wp.flags & SWP_NOSIZE) == 0) {
if (size.Width != wp.cx || size.Height != wp.cy) {
size = new Size(wp.cx, wp.cy);
if (SizeChanged != null)
SizeChanged(this, EventArgs.Empty);
}
}
// update the size of the layered window
if ((wp.flags & SWP_NOSIZE) == 0) {
NativeMethods.UpdateLayeredWindow(Handle, IntPtr.Zero,
IntPtr.Zero, ref size, IntPtr.Zero, IntPtr.Zero, 0,
IntPtr.Zero, 0);
}
// update the position of the layered window
if ((wp.flags & SWP_NOMOVE) == 0) {
NativeMethods.SetWindowPos(Handle, IntPtr.Zero,
location.X, location.Y, 0, 0, SWP_NOSIZE | SWP_NOACTIVATE |
SWP_NOZORDER | SWP_NOSENDCHANGING);
}
}
// do not forward any move or size messages
wp.flags |= SWP_NOSIZE | SWP_NOMOVE;
// suppress any frame changed events
wp.flags &= ~SWP_FRAMECHANGED;
Marshal.StructureToPtr(wp, message.LParam, false);
message.Result = IntPtr.Zero;
} break;
default: {
base.WndProc(ref message);
} break;
}
}
