private static void HideDropShadow(CustomChrome window)
{
var dropShadowEffect = window.Effect as DropShadowEffect;
if (dropShadowEffect != null)
{
// By making the effect nearly invisible but yet still enough
// visible this hack allow to "hide" the drop shadow but still
// be able to show the resizing handles when AllowTransparency
// is set to "true"
if (window.ResizeMode != ResizeMode.NoResize &&
window.ResizeMode != ResizeMode.CanMinimize)
{
// To "disable" drop shadow effet, we must use an opacity > 0
// otherwise the resizing border will not work (default is 1)
// 0.05 was tested to be visible "enough" to make it work
dropShadowEffect.Opacity = 1;// 0.05;
// Force a blur radius to allow resizing handle to work
// When the drop shadow opacity is nearly 0, the blur radius
// also shrink, a value of 10 seems to be large enough
dropShadowEffect.BlurRadius = 10;
}
else
{
dropShadowEffect.Opacity = 1;
dropShadowEffect.BlurRadius = 10;
}
}
}
/// <summary>
/// Create and show (if enabled) the drop shadow effect
/// around the window border
/// </summary>
/// <param name="window"></param>
/// <remarks>
/// We need to always create the drop shadow effect
/// even if not enabled to be able to support resizing
/// </remarks>
private static void ShowDropShadow(CustomChrome window)
{
var dropShadowEffect = window.Effect as DropShadowEffect;
if (dropShadowEffect == null)
{
window.Effect = CreateDropShadowEffect(
window.DropShadowColor,
window.DropShadowOpacity,
window.DropShadowBlurRadius);
}
else
{
dropShadowEffect.Color = window.DropShadowColor;
dropShadowEffect.Opacity = window.DropShadowOpacity;
dropShadowEffect.BlurRadius = Math.Max(window.DropShadowBlurRadius, 2);
}
// Set the border to make the effect visible when window
// cannot resize or can only minimize
if (window.ResizeMode == ResizeMode.NoResize ||
window.ResizeMode == ResizeMode.CanMinimize)
{
double borderWidth = GetResizeBorderWidth(window);
window.BorderThickness = new Thickness(borderWidth);
}
if (!window.EnableDropShadow)
{
HideDropShadow(window);
}
}
/// <summary>
/// Get the highest value between the current resize border width and
/// the drop shadow blur radius
/// </summary>
/// <param name="window"></param>
/// <returns>
/// The highest value between the resize border width and the drop shadown blur radius
/// </returns>
private static double GetResizeBorderWidth(CustomChrome window)
{
// Override the resize border width if the blur radius is higher
double borderWidth = Math.Max(window.ResizeBorderWidth,
window.DropShadowBlurRadius);
// Guard against lower than default resize width
return(borderWidth > DependencyPropertyDefault.ResizeBorderWidth ?
borderWidth : DependencyPropertyDefault.ResizeBorderWidth);
}
private static void SetCustomWindow(CustomChrome window)
{
window.WindowStyle = WindowStyle.None;
window.BorderBrush = Brushes.Transparent;
window.AllowsTransparency = true;
window.SnapsToDevicePixels = true;
//TextOptions.SetTextFormattingMode(window, TextFormattingMode.Display);
//RenderOptions.SetBitmapScalingMode(window, BitmapScalingMode.HighQuality);
}
private static IntPtr WindowHookProc(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
CustomChrome window = GetWindow(hWnd) as CustomChrome;
switch (msg)
{
// Toggle the DropShadowEffect when window is snapped or maximized
case WM_SIZE:
{
int resizing = (int)wParam;
if (resizing == SIZE_RESTORED)
{
MonitorArea monitorArea = GetMonitorArea(hWnd);
if (monitorArea != null)
{
// LOWORD
int width = ((int)lParam & 0x0000ffff);
// HIWORD
int height = (int)((int)lParam & 0xffff0000) >> 16;
// Detect if window was snapped to screen side of current monitor
// or if spanning width on multiple monitors (to avoid unsnapping)
if (height == monitorArea.Work.Height ||
width >= SystemParameters.VirtualScreenWidth)
{
window.IsSnapped = true;
UpdateResizeBorder(window, monitorArea, window.Left, window.Left + width);
}
else
{
window.IsSnapped = false;
ShowDropShadow(window);
EnableResizeBorder(window);
}
}
}
else if (resizing == SIZE_MAXIMIZED)
{
// Required when maximized from dragging window
DisableResizeBorder(window);
}
}
break;
// To handle proper resizing of the custom window
case WM_GETMINMAXINFO:
{
MonitorArea monitorArea = GetMonitorArea(hWnd);
if (monitorArea != null)
{
MINMAXINFO mmi = (MINMAXINFO)Marshal.PtrToStructure(lParam, typeof(MINMAXINFO));
mmi.ptMaxPosition.x = monitorArea.Offset.x;
mmi.ptMaxPosition.y = monitorArea.Offset.y;
mmi.ptMaxSize.x = monitorArea.Work.Width;
mmi.ptMaxSize.y = monitorArea.Work.Height;
// To support minimum window size
mmi.ptMinTrackSize.x = (int)window.MinWidth;
mmi.ptMinTrackSize.y = (int)window.MinHeight;
Marshal.StructureToPtr(mmi, lParam, true);
handled = true;
}
}
break;
// To activate/deactivate border resize handles from window position
case WM_WINDOWPOSCHANGED:
{
WINDOWPOS windowPos = (WINDOWPOS)Marshal.PtrToStructure(lParam, typeof(WINDOWPOS));
// When window is snapped and position changes
if ((windowPos.flags & SWP_NOMOVE) != SWP_NOMOVE)
{
if (window.IsSnapped)
{
MonitorArea monitorArea = GetMonitorArea(hWnd);
if (monitorArea != null)
{
UpdateResizeBorder(window, monitorArea, windowPos.x, windowPos.x + windowPos.cx);
}
}
}
}
break;
}
return(IntPtr.Zero);
}