/// <summary>
/// Called when a storyboard finishes.
/// </summary>
/// <param name="sender">The AccordionItem that finished a storyboard.</param>
/// <param name="e">The <see cref="System.EventArgs"/> instance containing
/// the event data.</param>
/// <remarks>AccordionItem is required to make this call.</remarks>
private void OnStoryboardFinished(object sender, EventArgs e)
{
_isBusyWithAction = false;
if (ParentAccordion != null)
{
ParentAccordion.OnActionFinish(this);
}
}
/// <summary>
/// Starts an action, such as resize, collapse or expand.
/// </summary>
internal virtual void StartAction()
{
if (ScheduledAction == AccordionAction.None)
{
throw new InvalidOperationException(Properties.Resources.AccordionItem_StartAction_InvalidCall);
}
Action layoutAction;
switch (ScheduledAction)
{
case AccordionAction.Collapse:
layoutAction = () =>
{
VisualStateManager.GoToState(this, VisualStates.StateExpanded, false);
// We only want to notify the parent that this action is finished when we are done with
// the state transition. In SL this is done through OnStoryboardFinished, but the same code
// in WPF would result in a corrupted state because OnStoryboardFinished gets called more frequently than expected.
// In the WPF case, we make the scheduled action synchornous to ensure the transition is properly done.
#if SILVERLIGHT
VisualStateManager.GoToState(this, VisualStates.StateCollapsed, true);
#else
if (VisualStateManager.GoToState(this, VisualStates.StateCollapsed, true))
{
ParentAccordion.OnActionFinish(this);
}
#endif
};
break;
case AccordionAction.Expand:
layoutAction = () =>
{
VisualStateManager.GoToState(this, VisualStates.StateCollapsed, false);
#if SILVERLIGHT
VisualStateManager.GoToState(this, VisualStates.StateExpanded, true);
#else
if (VisualStateManager.GoToState(this, VisualStates.StateExpanded, true))
{
ParentAccordion.OnActionFinish(this);
}
#endif
};
break;
case AccordionAction.Resize:
layoutAction = () =>
{
// trigger ExpandedState to run again, by quickly moving to collapsed.
// the effect is not noticeable because no layout pass is done.
VisualStateManager.GoToState(this, VisualStates.StateExpanded, false);
VisualStateManager.GoToState(this, VisualStates.StateCollapsed, false);
#if SILVERLIGHT
VisualStateManager.GoToState(this, VisualStates.StateExpanded, true);
#else
if (VisualStateManager.GoToState(this, VisualStates.StateExpanded, true))
{
ParentAccordion.OnActionFinish(this);
}
#endif
};
break;
default:
{
string message = string.Format(
CultureInfo.InvariantCulture,
Properties.Resources.AccordionItem_StartAction_InvalidAction,
ScheduledAction);
throw new NotSupportedException(message);
}
}
ScheduledAction = AccordionAction.None;
layoutAction();
}
