private static void OnShowingKeyTipChanged(DependencyObject element, DependencyPropertyChangedEventArgs e)
{
if ((bool)e.NewValue)
{
UIElement uie = RibbonHelper.GetContainingUIElement(element);
if (uie != null &&
uie.Visibility != Visibility.Visible)
{
// revert the value if the element is not visible
element.SetValue(ShowingKeyTipProperty, false);
return;
}
// Raise the ActivatingKeyTip event.
ActivatingKeyTipEventArgs activatingEventArgs = new ActivatingKeyTipEventArgs();
IInputElement inputElement = element as IInputElement;
if (inputElement != null)
{
inputElement.RaiseEvent(activatingEventArgs);
}
// KeyTips could have been dismissed due to one
// of the event handler, hence check again.
KeyTipService current = Current;
if (current.State != KeyTipState.None)
{
if (activatingEventArgs.KeyTipVisibility == Visibility.Visible)
{
// Create the keytip and add it as the adorner.
UIElement adornedElement = RibbonHelper.GetContainingUIElement(activatingEventArgs.PlacementTarget == null ? element : activatingEventArgs.PlacementTarget);
if (adornedElement != null && adornedElement.IsVisible)
{
bool isScrollAdornerLayer = false;
AdornerLayer adornerLayer = GetAdornerLayer(adornedElement, out isScrollAdornerLayer);
if (adornerLayer != null)
{
KeyTipAdorner adorner = new KeyTipAdorner(adornedElement,
activatingEventArgs.PlacementTarget,
activatingEventArgs.KeyTipHorizontalPlacement,
activatingEventArgs.KeyTipVerticalPlacement,
activatingEventArgs.KeyTipHorizontalOffset,
activatingEventArgs.KeyTipVerticalOffset,
activatingEventArgs.Handled ? null : activatingEventArgs.OwnerRibbonGroup);
LinkKeyTipControlToAdorner(adorner, element);
adornerLayer.Add(adorner);
element.SetValue(KeyTipAdornerProperty, adorner);
element.SetValue(KeyTipAdornerHolderProperty, adornedElement);
// Begin invode an operation to nudge all the keytips into the
// adorner layer boundary unless the layer belongs to a scroll viewer.
if (!isScrollAdornerLayer)
{
current.EnqueueAdornerLayerForPlacementProcessing(adornerLayer);
}
}
}
}
if (activatingEventArgs.KeyTipVisibility != Visibility.Collapsed)
{
// add the element to currentActiveKeyTipElement list.
current._currentActiveKeyTipElements.Add(element);
}
else
{
// Revert the value if it is asked by event handlers
// (i.e, by setting KeyTipVisibility to collapsed.
element.SetValue(ShowingKeyTipProperty, false);
}
}
else
{
// Revert the value if we already dismissed keytips.
element.SetValue(ShowingKeyTipProperty, false);
}
}
else
{
// Remove keytip from adorner.
KeyTipAdorner adorner = (KeyTipAdorner)element.GetValue(KeyTipAdornerProperty);
UIElement adornedElement = (UIElement)element.GetValue(KeyTipAdornerHolderProperty);
if (adornedElement != null && adorner != null)
{
UnlinkKeyTipControlFromAdorner(adorner);
bool isScrollAdornerLayer = false;
AdornerLayer adornerLayer = GetAdornerLayer(adornedElement, out isScrollAdornerLayer);
if (adornerLayer != null)
{
adornerLayer.Remove(adorner);
}
}
element.ClearValue(KeyTipAdornerProperty);
element.ClearValue(KeyTipAdornerHolderProperty);
}
}
private static void UnlinkKeyTipControlFromAdorner(KeyTipAdorner adorner)
{
KeyTipControl keyTipControl = adorner.KeyTipControl;
adorner.UnlinkKeyTipControl();
if (keyTipControl != null)
{
// Save the unlinked KeyTipControl to cache for reuse.
KeyTipService current = Current;
if (current._cachedKeyTipControls == null)
{
current._cachedKeyTipControls = new List<KeyTipControl>();
}
current._cachedKeyTipControls.Add(keyTipControl);
}
}
private static void LinkKeyTipControlToAdorner(KeyTipAdorner adorner, DependencyObject keyTipElement)
{
KeyTipService current = Current;
KeyTipControl keyTipControl = null;
if (current._cachedKeyTipControls != null &&
current._cachedKeyTipControls.Count > 0)
{
// Retrieve a KeyTipControl from cache for reuse.
int count = current._cachedKeyTipControls.Count;
keyTipControl = current._cachedKeyTipControls[count - 1];
current._cachedKeyTipControls.RemoveAt(count - 1);
}
if (keyTipControl == null)
{
keyTipControl = new KeyTipControl();
}
adorner.LinkKeyTipControl(keyTipElement, keyTipControl);
}
