private static bool _ExtendGlassFrameInternal(Window window, Thickness margin)
{
Assert.IsNotNull(window);
Assert.IsTrue(window.CheckAccess());
// Expect that this might be called on OSes other than Vista.
if (!Utility.IsOSVistaOrNewer)
{
// Not an error. Just not on Vista so we're not going to get glass.
return(false);
}
IntPtr hwnd = new WindowInteropHelper(window).Handle;
if (IntPtr.Zero == hwnd)
{
throw new InvalidOperationException("Window must be shown before extending glass.");
}
HwndSource hwndSource = HwndSource.FromHwnd(hwnd);
bool isGlassEnabled = NativeMethods.DwmIsCompositionEnabled();
if (!isGlassEnabled)
{
window.Background = SystemColors.WindowBrush;
hwndSource.CompositionTarget.BackgroundColor = SystemColors.WindowColor;
}
else
{
// Apply the transparent background to both the Window and the HWND
window.Background = Brushes.Transparent;
hwndSource.CompositionTarget.BackgroundColor = Colors.Transparent;
// Thickness is going to be DIPs, need to convert to system coordinates.
Point deviceTopLeft = DpiHelper.LogicalPixelsToDevice(new Point(margin.Left, margin.Top));
Point deviceBottomRight = DpiHelper.LogicalPixelsToDevice(new Point(margin.Right, margin.Bottom));
var dwmMargin = new MARGINS
{
// err on the side of pushing in glass an extra pixel.
cxLeftWidth = (int)Math.Ceiling(deviceTopLeft.X),
cxRightWidth = (int)Math.Ceiling(deviceBottomRight.X),
cyTopHeight = (int)Math.Ceiling(deviceTopLeft.Y),
cyBottomHeight = (int)Math.Ceiling(deviceBottomRight.Y),
};
NativeMethods.DwmExtendFrameIntoClientArea(hwnd, ref dwmMargin);
}
// Even if glass isn't currently enabled, add the hook so we can appropriately respond
// if that changes.
bool addHook = !_extendedWindows.ContainsKey(hwnd);
if (addHook)
{
HwndSourceHook hook = delegate(IntPtr innerHwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
if (WM.DWMCOMPOSITIONCHANGED == (WM)msg)
{
_ExtendGlassFrameInternal(window, margin);
handled = false;
}
return(IntPtr.Zero);
};
_extendedWindows.Add(hwnd, hook);
hwndSource.AddHook(hook);
window.Closing += _OnExtendedWindowClosing;
}
return(isGlassEnabled);
}
private void _InitializeCaptionHeight()
{
Point ptCaption = new Point(0, NativeMethods.GetSystemMetrics(SM.CYCAPTION));
WindowCaptionHeight = DpiHelper.DevicePixelsToLogical(ptCaption).Y;
}