public DecoratorWindow()
{
DecoratorRoot = new DecoratorWindowRoot {
Background = null
};
_onAutoResizeHandler = OnAutoResize;
_dpiChangedHandler = OnDpiChanged;
_messageFilterHook = MessageFilter;
}
private static void BuildWindow(
object psh, int x, int y, Visual placementTarget,
bool transparent, HwndSourceHook hook, AutoResizedEventHandler handler,
HwndDpiChangedEventHandler dpiChangedHandler)
{
bool isChildPopup = (bool)pshIsChildPopupProperty.GetValue(psh) !;
Debug.Assert(!isChildPopup || (isChildPopup && !transparent), "Child popups cannot be transparent");
transparent = transparent && !isChildPopup;
Visual mainTreeVisual = placementTarget;
if (isChildPopup)
{
// If the popup is nested inside other popups, get out into the main tree
// before querying for the presentation source.
mainTreeVisual = FindMainTreeVisual(placementTarget);
}
// get visual's PresentationSource
var hwndSource = GetPresentationSource(mainTreeVisual) as HwndSource;
// get parent handle
IntPtr parent = IntPtr.Zero;
if (hwndSource != null)
{
parent = GetHandle(hwndSource);
}
int classStyle = 0;
int style = NativeMethods.WS_CLIPSIBLINGS;
int styleEx = NativeMethods.WS_EX_TOOLWINDOW | NativeMethods.WS_EX_NOACTIVATE;
if (isChildPopup)
{
// The popup was created in an environment where it should
// be a child window, not a popup window.
style |= NativeMethods.WS_CHILD;
}
else
{
style |= NativeMethods.WS_POPUP;
styleEx |= NativeMethods.WS_EX_TOPMOST;
}
// set window parameters
var param = new HwndSourceParameters(string.Empty);
param.WindowClassStyle = classStyle;
param.WindowStyle = style;
param.ExtendedWindowStyle = styleEx;
param.SetPosition(x, y);
(hook.Target as PopupEx)?.CreateParams(ref param);
if (isChildPopup)
{
if (parent != IntPtr.Zero)
{
param.ParentWindow = parent;
}
}
else
{
param.UsesPerPixelOpacity = transparent;
if (parent != IntPtr.Zero && ConnectedToForegroundWindow(parent))
{
param.ParentWindow = parent;
}
}
// create popup's window object
var newWindow = new HwndSource(param);
// add hook to the popup's window
newWindow.AddHook(hook);
// initialize the private critical window object
pshWindowField.SetValue(psh, securityCriticalDataClassOfWindowCtor.Invoke(
new object[] { newWindow }));
// Set background color
var hwndTarget = newWindow.CompositionTarget;
hwndTarget.BackgroundColor = transparent ? Colors.Transparent : Colors.Black;
// add AddAutoResizedEventHandler event handler
newWindow.AutoResized += handler;
newWindow.DpiChanged += dpiChangedHandler;
}