/// <summary>
/// Set the IsSubmenuOpen property value at the right time.
/// </summary>
private static object CoerceIsSubmenuOpen(DependencyObject element, object value)
{
SplitButton splitButton = element as SplitButton;
if ((bool)value)
{
if (!splitButton.IsLoaded)
{
splitButton.Loaded += delegate(object sender, RoutedEventArgs args)
{
splitButton.CoerceValue(IsSubmenuOpenProperty);
};
return(BooleanBoxes.FalseBox);
}
}
return((bool)value && splitButton.HasItems);
}
private static void OnIsSubmenuOpenChanged(DependencyObject sender, DependencyPropertyChangedEventArgs args)
{
SplitButton splitButton = sender as SplitButton;
if ((bool)args.NewValue)
{
openSplitButton = splitButton;
// Handle keyboard events as long as the popup is displayed
var window = Window.GetWindow(splitButton);
window.PreviewKeyDown += OnPreviewKeyDown;
if (Mouse.Captured != splitButton)
{
Mouse.Capture(splitButton, CaptureMode.SubTree);
Mouse.AddLostMouseCaptureHandler(splitButton, OnLostMouseCapture);
}
}
else
{
// Remove popup keyboard handler
var window = Window.GetWindow(splitButton);
window.PreviewKeyDown -= OnPreviewKeyDown;
openSplitButton = null;
if (Mouse.Captured == splitButton)
{
Mouse.Capture(null);
}
if (splitButton.IsKeyboardFocused)
{
splitButton.Focus();
}
}
}
private static void OnIsSubmenuOpenChanged(DependencyObject sender, DependencyPropertyChangedEventArgs args)
{
SplitButton splitButton = sender as SplitButton;
if ((bool)args.NewValue)
{
openSplitButton = splitButton;
// Handle keyboard events as long as the popup is displayed
var window = Window.GetWindow(splitButton);
window.PreviewKeyDown += OnPreviewKeyDown;
if (Mouse.Captured != splitButton)
{
Mouse.Capture(splitButton, CaptureMode.SubTree);
Mouse.AddLostMouseCaptureHandler(splitButton, OnLostMouseCapture);
}
}
else
{
// Remove popup keyboard handler
var window = Window.GetWindow(splitButton);
window.PreviewKeyDown -= OnPreviewKeyDown;
openSplitButton = null;
if (Mouse.Captured == splitButton)
{
Mouse.Capture(null);
}
if (splitButton.IsKeyboardFocused)
{
splitButton.Focus();
}
}
}