/// <summary>
/// Removes the current Accordion from the collection of selected
/// items.
/// </summary>
/// <remarks>
/// This API supports the .NET Framework infrastructure and is not
/// intended to be used directly from your code.
/// </remarks>
void ISelectionItemProvider.RemoveFromSelection()
{
AccordionItem owner = OwnerAccordionItem;
Accordion parent = owner.ParentAccordion;
if (parent == null)
{
throw new InvalidOperationException("System.Windows.Controls.Properties.Resources.Automation_OperationCannotBePerformed");
}
parent.SelectedItems.Remove(owner);
}
/// <summary>
/// Expands the AccordionItem.
/// </summary>
/// <remarks>
/// This API supports the .NET Framework infrastructure and is not
/// intended to be used directly from your code.
/// </remarks>
void IExpandCollapseProvider.Expand()
{
if (!IsEnabled())
{
throw new ElementNotEnabledException();
}
AccordionItem owner = OwnerAccordionItem;
if (owner.IsLocked)
{
throw new InvalidOperationException("System.Windows.Controls.Properties.Resources.Automation_OperationCannotBePerformed");
}
owner.IsSelected = true;
}
/// <summary>
/// ExpandDirectionProperty PropertyChangedCallback call back static
/// function.
/// This function validates the new value before calling virtual function
/// OnExpandDirectionChanged.
/// </summary>
/// <param name="d">Expander object whose ExpandDirection property is
/// changed.</param>
/// <param name="e">DependencyPropertyChangedEventArgs which contains
/// the old and new values.</param>
private static void OnExpandDirectionPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
AccordionItem ctrl = (AccordionItem)d;
ExpandDirection oldValue = (ExpandDirection)e.OldValue;
ExpandDirection newValue = (ExpandDirection)e.NewValue;
if (!ctrl._allowedToWriteExpandDirection)
{
// revert to old value
ctrl.ExpandDirection = oldValue;
string message = string.Format(
CultureInfo.InvariantCulture,
"Properties.Resources.AccordionItem_InvalidWriteToExpandDirection",
newValue);
throw new InvalidOperationException(message);
}
// invalid value. This check is not of great importance anymore since
// the previous check should catch all invalid sets.
if (newValue != ExpandDirection.Down &&
newValue != ExpandDirection.Left &&
newValue != ExpandDirection.Right &&
newValue != ExpandDirection.Up)
{
// revert to old value
ctrl.ExpandDirection = oldValue;
string message = string.Format(
CultureInfo.InvariantCulture,
"Properties.Resources.Expander_OnExpandDirectionPropertyChanged_InvalidValue",
newValue);
throw new ArgumentException(message, "e");
}
if (ctrl.ExpandSite != null)
{
// Jump to correct percentage after a direction change
ctrl.ExpandSite.Percentage = ctrl.IsSelected ? 1 : 0;
}
ctrl.UpdateVisualState(true);
}
/// <summary>
/// Retrieves a UI Automation provider for each child element that is
/// selected.
/// </summary>
/// <returns>An array of UI Automation providers.</returns>
/// <remarks>
/// This API supports the .NET Framework infrastructure and is not
/// intended to be used directly from your code.
/// </remarks>
public IRawElementProviderSimple[] GetSelection()
{
Accordion owner = OwnerAccordion;
List <IRawElementProviderSimple> selection = new List <IRawElementProviderSimple>(owner.SelectedIndices.Count);
foreach (int index in owner.SelectedIndices)
{
AccordionItem item = owner.ItemContainerGenerator.ContainerFromIndex(index) as AccordionItem;
if (item != null)
{
AutomationPeer peer = FromElement(item);
if (peer != null)
{
selection.Add(ProviderFromPeer(peer));
}
}
}
return(selection.ToArray());
}
/// <summary>
/// SelectedProperty PropertyChangedCallback static function.
/// </summary>
/// <param name="d">Expander object whose Expanded property is changed.</param>
/// <param name="e">DependencyPropertyChangedEventArgs which contains the
/// old and new values.</param>
private static void OnIsSelectedPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
AccordionItem ctrl = (AccordionItem)d;
bool isSelected = (bool)e.NewValue;
// Not allowed to change the IsSelected state when locked.
if (ctrl.IsLocked && ctrl._isSelectedNestedLevel == 0)
{
ctrl._isSelectedNestedLevel++;
ctrl.SetValue(IsSelectedProperty, e.OldValue);
ctrl._isSelectedNestedLevel--;
throw new InvalidOperationException("Properties.Resources.AccordionItem_OnIsSelectedPropertyChanged_InvalidChange");
}
if (ctrl._isSelectedNestedLevel == 0)
{
Accordion parent = ctrl.ParentAccordion;
if (parent != null)
{
if (isSelected)
{
parent.OnAccordionItemSelected(ctrl);
}
else
{
parent.OnAccordionItemUnselected(ctrl);
}
}
if (isSelected)
{
ctrl.OnSelected();
}
else
{
ctrl.OnUnselected();
}
}
}
protected override IList <AutomationPeer> GetChildrenCore()
{
Accordion owner = OwnerAccordion;
ItemCollection items = owner.Items;
if (items.Count <= 0)
{
return(null);
}
List <AutomationPeer> peers = new List <AutomationPeer>(items.Count);
for (int i = 0; i < items.Count; i++)
{
AccordionItem element = owner.ItemContainerGenerator.ContainerFromIndex(i) as AccordionItem;
if (element != null)
{
peers.Add(FromElement(element) ?? CreatePeerForElement(element));
}
}
return(peers);
}
/// <summary>
/// ContentTargetSizeProperty property changed handler.
/// </summary>
/// <param name="d">AccordionItem that changed its ContentTargetSize.</param>
/// <param name="e">Event arguments.</param>
private static void OnContentTargetSizePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
AccordionItem source = (AccordionItem)d;
Size targetSize = (Size)e.NewValue;
if (!source._allowedToWriteContentTargetSize)
{
// revert to old value
source.ContentTargetSize = (Size)e.OldValue;
throw new InvalidOperationException("Properties.Resources.AccordionItem_InvalidWriteToContentTargetSize");
}
// Pass the value to the expandSite
// This is done explicitly so an animation action can be scheduled
// deterministicly.
ExpandableContentControl expandSite = source.ExpandSite;
if (expandSite != null && !expandSite.TargetSize.Equals(targetSize))
{
expandSite.TargetSize = targetSize;
if (source.IsSelected)
{
if (source.ParentAccordion != null && source.ParentAccordion.IsResizing)
{
// if the accordion is resizing, this item should snap immediately
expandSite.Percentage = 1;
}
else
{
// otherwise schedule the resize
source.Schedule(AccordionAction.Resize);
}
}
}
}
/// <summary>
/// Initializes a new instance of the AccordionAutomationPeer class.
/// </summary>
/// <param name="owner">
/// The Accordion that is associated with this
/// AccordionAutomationPeer.
/// </param>
public AccordionItemAutomationPeer(AccordionItem owner)
: base(owner)
{
}
/// <summary>
/// ExpandableContentControlStyleProperty property changed handler.
/// </summary>
/// <param name="d">AccordionItem that changed its ExpandableContentControlStyle.</param>
/// <param name="e">Event arguments.</param>
private static void OnExpandableContentControlStylePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
AccordionItem source = (AccordionItem)d;
source.OnExpandableContentControlStyleChanged(e.OldValue as Style, e.NewValue as Style);
}
/// <summary>
/// AccordionButtonStyleProperty property changed handler.
/// </summary>
/// <param name="d">AccordionItem that changed its AccordionButtonStyle.</param>
/// <param name="e">Event arguments.</param>
private static void OnAccordionButtonStylePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
AccordionItem source = (AccordionItem)d;
source.OnAccordionButtonStyleChanged(e.OldValue as Style, e.NewValue as Style);
}
/// <summary>
/// Initializes a new instance of the AccordionAutomationPeer class.
/// </summary>
/// <param name="owner">
/// The Accordion that is associated with this
/// AccordionAutomationPeer.
/// </param>
public AccordionItemAutomationPeer(AccordionItem owner)
: base(owner)
{
}
/// <summary>
/// Starts the next action in the list, in a particular order.
/// </summary>
/// <remarks>An AccordionItem is should always signal that it is
/// finished with an action.</remarks>
private void StartNextAction()
{
if (_currentActioningItem != null)
{
return;
}
// First do collapses, then resizes and finally expands.
AccordionItem next = _scheduledActions.FirstOrDefault(item => item.ScheduledAction == AccordionAction.Collapse);
if (next == null)
{
next = _scheduledActions.FirstOrDefault(item => item.ScheduledAction == AccordionAction.Resize);
}
if (next == null)
{
next = _scheduledActions.FirstOrDefault(item => item.ScheduledAction == AccordionAction.Expand);
}
if (next != null)
{
_currentActioningItem = next;
_scheduledActions.Remove(next);
next.StartAction();
}
}
/// <summary>
/// Signals the finish of an action by an item.
/// </summary>
/// <param name="item">The AccordionItem that finishes an action.</param>
/// <remarks>An AccordionItem should always signal a finish, for this call
/// will start the next scheduled action.</remarks>
internal virtual void OnActionFinish(AccordionItem item)
{
if (SelectionSequence == SelectionSequence.CollapseBeforeExpand)
{
lock (this)
{
if (!_currentActioningItem.Equals(item))
{
throw new InvalidOperationException("Properties.Resources.Accordion_OnActionFinish_InvalidFinish");
}
_currentActioningItem = null;
StartNextAction();
}
}
}
/// <summary>
/// Allows an AccordionItem to signal the need for a visual action
/// (resize, collapse, expand).
/// </summary>
/// <param name="item">The AccordionItem that signals for a schedule.</param>
/// <param name="action">The action it is scheduling for.</param>
/// <returns>True if the item is allowed to proceed without scheduling,
/// false if the item needs to wait for a signal to execute the action.</returns>
internal async virtual Task<bool> ScheduleAction(AccordionItem item, AccordionAction action)
{
if (SelectionSequence == SelectionSequence.CollapseBeforeExpand)
{
lock (this)
{
if (!_scheduledActions.Contains(item))
{
_scheduledActions.Add(item);
}
}
if (_currentActioningItem == null)
{
await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, StartNextAction);
}
return false;
}
else
{
return true;
}
}
internal void OnHeaderSizeChange(AccordionItem item)
{
LayoutChildren();
}
/// <summary>
/// Called when an AccordionItem selected.
/// </summary>
/// <param name="accordionItem">The accordion item that was selected.</param>
internal void OnAccordionItemSelected(AccordionItem accordionItem)
{
SelectItem(ItemContainerGenerator.IndexFromContainer(accordionItem));
}
