// When visibility is changed, set the default focus
void OnVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
{
if (!(bool)e.NewValue)
{
return;
}
var popupControl = VisualHelpers.FindChild <ContentControl>(this, "PopupContentControl");
Dispatcher.BeginInvoke(DispatcherPriority.Render,
new Action(delegate
{
// Verify object really is visible because sometimes it's not once we switch to Render
if (!GetIsPopupVisible(this))
{
return;
}
if (lastFocusControl != null && lastFocusControl.Focusable)
{
lastFocusControl.Focus();
}
else
{
lastFocusControl = VisualHelpers.FindChild <UIElement>(popupControl, "PART_DefaultFocusControl");
// If we can find the part named PART_DefaultFocusControl, set focus to it
if (lastFocusControl != null && lastFocusControl.Focusable)
{
lastFocusControl.Focus();
}
else
{
lastFocusControl = VisualHelpers.FindFirstFocusableChild(popupControl);
// If no DefaultFocusControl found, try and set focus to the first focusable element found in popup
if (lastFocusControl != null)
{
lastFocusControl.Focus();
}
else
{
// Just give the Popup UserControl focus so it can handle keyboard input
popupControl.Focus();
}
}
}
}
)
);
}
// Run storyboard when IsPopupVisible property changes to true
void OnIsPopupVisibleChanged()
{
var isShown = GetIsPopupVisible(this);
if (isShown && !isLoading)
{
var panel = VisualHelpers.FindChild <FrameworkElement>(this, "PopupPanelContent");
if (panel != null)
{
// Run Storyboard
var animation = (Storyboard)panel.FindResource("ShowEditPanelStoryboard");
animation.Begin();
}
}
// When hiding popup, clear the LastFocusControl
if (!isShown)
{
lastFocusControl = null;
}
}
// Keyboard Events
void OnPreviewKeyDown(object sender, KeyEventArgs e)
{
var popup = VisualHelpers.FindAncester <PopupPanel>((DependencyObject)sender);
var cmd = GetPopupEscapeKeyCommand(popup);
switch (e.Key)
{
case Key.Escape:
if (cmd != null && cmd.CanExecute(null))
{
cmd.Execute(null);
e.Handled = true;
}
else
{
// By default the Escape Key closes the popup when pressed
var expression = GetBindingExpression(IsPopupVisibleProperty);
if (expression != null)
{
var dataType = expression.DataItem.GetType();
dataType.GetProperties().Single(x => x.Name == expression.ParentBinding.Path.Path)
.SetValue(expression.DataItem, false, null);
}
}
break;
case Key.Enter:
// Don't want to run Enter command if focus is in a TextBox with AcceptsReturn = True
if (
!(e.KeyboardDevice.FocusedElement is TextBox && ((TextBox)e.KeyboardDevice.FocusedElement).AcceptsReturn) &&
cmd != null && cmd.CanExecute(null))
{
cmd.Execute(null);
e.Handled = true;
}
break;
}
}
static object CoercePopupParent(DependencyObject obj, object value)
{
// If PopupParent is null, return the Window object
return(value ?? VisualHelpers.FindAncester <Window>(obj));
}