private unsafe void SetTopmostState(bool isTop)
{
isTop &= this.AllowTopMost;
// Don’t apply state if it’s the same as incoming state
if (this.appliedTopMost.HasValue && this.appliedTopMost == isTop)
{
return;
}
if (this.Child is null)
{
return;
}
var hwndSource = PresentationSource.FromVisual(this.Child) as HwndSource;
if (hwndSource is null)
{
return;
}
var hwnd = new HWND(hwndSource.Handle);
RECT rect;
if (!PInvoke.GetWindowRect(hwnd, &rect))
{
return;
}
//Debug.WriteLine("setting z-order " + isTop);
const SET_WINDOW_POS_FLAGS SWP_TOPMOST = SET_WINDOW_POS_FLAGS.SWP_NOACTIVATE | SET_WINDOW_POS_FLAGS.SWP_NOOWNERZORDER | SET_WINDOW_POS_FLAGS.SWP_NOSIZE | SET_WINDOW_POS_FLAGS.SWP_NOMOVE | SET_WINDOW_POS_FLAGS.SWP_NOREDRAW | SET_WINDOW_POS_FLAGS.SWP_NOSENDCHANGING;
var left = rect.left;
var top = rect.top;
var width = rect.GetWidth();
var height = rect.GetHeight();
if (isTop)
{
PInvoke.SetWindowPos(hwnd, HWND_TOPMOST, left, top, width, height, SWP_TOPMOST);
}
else
{
// Z-Order would only get refreshed/reflected if clicking the
// the titlebar (as opposed to other parts of the external
// window) unless I first set the popup to HWND_BOTTOM
// then HWND_TOP before HWND_NOTOPMOST
PInvoke.SetWindowPos(hwnd, HWND_BOTTOM, left, top, width, height, SWP_TOPMOST);
PInvoke.SetWindowPos(hwnd, HWND_TOP, left, top, width, height, SWP_TOPMOST);
PInvoke.SetWindowPos(hwnd, HWND_NOTOPMOST, left, top, width, height, SWP_TOPMOST);
}
this.appliedTopMost = isTop;
}
private static void HideWindowIcon(IntPtr handle)
{
const SET_WINDOW_POS_FLAGS refreshFrameFlags = SET_WINDOW_POS_FLAGS.SWP_NOMOVE |
SET_WINDOW_POS_FLAGS.SWP_NOSIZE |
SET_WINDOW_POS_FLAGS.SWP_NOZORDER |
SET_WINDOW_POS_FLAGS.SWP_FRAMECHANGED;
var style = (WINDOW_EX_STYLE)GetWindowLong((HWND)handle, WINDOW_LONG_PTR_INDEX.GWL_EXSTYLE);
style |= WINDOW_EX_STYLE.WS_EX_DLGMODALFRAME;
SetWindowLong((HWND)handle, WINDOW_LONG_PTR_INDEX.GWL_EXSTYLE, (int)style);
SetWindowPos((HWND)handle, (HWND)IntPtr.Zero, 0, 0, 0, 0, refreshFrameFlags);
SendMessage((HWND)handle, WM_SETICON, 0, 0);
SendMessage((HWND)handle, WM_SETICON, 1, 0);
}