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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System.Collections;
using System.Windows.Automation.Provider;
using System.Windows.Controls;
using System.Windows.Data;
using MS.Internal.Data;
namespace System.Windows.Automation.Peers
{
///
public class GroupItemAutomationPeer : FrameworkElementAutomationPeer
{
///
public GroupItemAutomationPeer(GroupItem owner): base(owner)
{
}
///
override protected string GetClassNameCore()
{
return "GroupItem";
}
/// <summary>
/// Gets the position of this GroupItem within a set.
/// </summary>
/// <remarks>
/// Gets the CollectionViewGroupInternal linked to this groupItem via ItemForItemContainerProperty,
/// this collection describes the elements belonging to this GroupItem, we need the collection this
/// GroupItem belongs to, so we look one level up using Parent.
/// </remarks>
override protected int GetPositionInSetCore()
{
int positionInSet = base.GetPositionInSetCore();
if (positionInSet == AutomationProperties.AutomationPositionInSetDefault)
{
GroupItem groupItem = (GroupItem)Owner;
CollectionViewGroupInternal group = groupItem.GetValue(ItemContainerGenerator.ItemForItemContainerProperty) as CollectionViewGroupInternal;
if (group != null)
{
CollectionViewGroup parent = group.Parent;
if (parent != null)
{
positionInSet = parent.Items.IndexOf(group) + 1;
}
}
}
return positionInSet;
}
/// <summary>
/// Gets the size of a set that contains this GroupItem.
/// </summary>
/// <remarks>
/// Gets the CollectionViewGroupInternal linked to this groupItem via ItemForItemContainerProperty,
/// this collection describes the elements belonging to this GroupItem, we need the collection this
/// GroupItem belongs to, so we look one level up using Parent.
/// </remarks>
override protected int GetSizeOfSetCore()
{
int sizeOfSet = base.GetSizeOfSetCore();
if (sizeOfSet == AutomationProperties.AutomationSizeOfSetDefault)
{
GroupItem groupItem = (GroupItem)Owner;
CollectionViewGroupInternal group = groupItem.GetValue(ItemContainerGenerator.ItemForItemContainerProperty) as CollectionViewGroupInternal;
if (group != null)
{
CollectionViewGroup parent = group.Parent;
if (parent != null)
{
sizeOfSet = parent.Items.Count;
}
}
}
return sizeOfSet;
}
///
override protected AutomationControlType GetAutomationControlTypeCore()
{
return AutomationControlType.Group;
}
///
override public object GetPattern(PatternInterface patternInterface)
{
if(patternInterface == PatternInterface.ExpandCollapse)
{
GroupItem groupItem = (GroupItem)Owner;
if(groupItem.Expander != null)
{
AutomationPeer expanderPeer = UIElementAutomationPeer.CreatePeerForElement(groupItem.Expander);
if(expanderPeer != null && expanderPeer is IExpandCollapseProvider)
{
expanderPeer.EventsSource = this;
return (IExpandCollapseProvider)expanderPeer;
}
}
}
return base.GetPattern(patternInterface);
}
///
protected override List<AutomationPeer> GetChildrenCore()
{
GroupItem owner = (GroupItem)Owner;
ItemsControl itemsControl = ItemsControl.ItemsControlFromItemContainer(Owner);
if (itemsControl != null)
{
ItemsControlAutomationPeer itemsControlAP = itemsControl.CreateAutomationPeer() as ItemsControlAutomationPeer;
if (itemsControlAP != null)
{
List<AutomationPeer> children = new List<AutomationPeer>();
bool useNetFx472CompatibleAccessibilityFeatures = AccessibilitySwitches.UseNetFx472CompatibleAccessibilityFeatures;
if (!useNetFx472CompatibleAccessibilityFeatures && owner.Expander != null)
{
_expanderPeer = UIElementAutomationPeer.CreatePeerForElement(owner.Expander);
if (_expanderPeer != null)
{
_expanderPeer.EventsSource = this;
// Call GetChildren so the Expander's toggle button updates its EventsSource as well
_expanderPeer.GetChildren();
}
}
Panel itemsHost = owner.ItemsHost;
if (itemsHost == null)
{
if (_expanderPeer == null)
{
return null;
}
else
{
children.Add(_expanderPeer);
return children;
}
}
IList childItems = itemsHost.Children;
ItemPeersStorage<ItemAutomationPeer> addedChildren = new ItemPeersStorage<ItemAutomationPeer>();
foreach (UIElement child in childItems)
{
if (!((MS.Internal.Controls.IGeneratorHost)itemsControl).IsItemItsOwnContainer(child))
{
UIElementAutomationPeer peer = child.CreateAutomationPeer() as UIElementAutomationPeer;
if (peer != null)
{
children.Add(peer);
if (useNetFx472CompatibleAccessibilityFeatures)
{
//
// The AncestorsInvalid check is meant so that we do this call to invalidate the
// GroupItemPeers containing the realized item peers only when we arrive here from an
// UpdateSubtree call because that call does not otherwise descend into parts of the tree
// that have their children invalid as an optimization.
//
if (itemsControlAP.RecentlyRealizedPeers.Count > 0 && this.AncestorsInvalid)
{
GroupItemAutomationPeer groupItemPeer = peer as GroupItemAutomationPeer;
if (groupItemPeer != null)
{
groupItemPeer.InvalidateGroupItemPeersContainingRecentlyRealizedPeers(itemsControlAP.RecentlyRealizedPeers);
}
}
}
else
{
//
// The AncestorsInvalid check is meant so that we do this call to invalidate the
// GroupItemPeers only when we arrive here from an
// UpdateSubtree call because that call does not otherwise descend into parts of the tree
// that have their children invalid as an optimization.
//
if (this.AncestorsInvalid)
{
GroupItemAutomationPeer groupItemPeer = peer as GroupItemAutomationPeer;
if (groupItemPeer != null)
{
// invalidate all GroupItemAP children, so
// that the top-level ItemsControlAP's
// ItemPeers collection is repopulated.
groupItemPeer.AncestorsInvalid = true;
groupItemPeer.ChildrenValid = true;
}
}
}
}
}
else
{
object item = itemsControl.ItemContainerGenerator.ItemFromContainer(child);
// ItemFromContainer can return {UnsetValue} if we're in a re-entrant
// call while the generator is in the midst of unhooking the container.
// Ignore such children.
if (item == DependencyProperty.UnsetValue)
{
continue;
}
// try to reuse old peer if it exists either in Current AT or in WeakRefStorage of Peers being sent to Client
ItemAutomationPeer peer = useNetFx472CompatibleAccessibilityFeatures
? itemsControlAP.ItemPeers[item]
: itemsControlAP.ReusablePeerFor(item);
peer = itemsControlAP.ReusePeerForItem(peer, item);
if (peer != null)
{
if (useNetFx472CompatibleAccessibilityFeatures)
{
//
// We have now connected the realized peer to its actual parent. Hence the cache can be cleared
//
int realizedPeerIndex = itemsControlAP.RecentlyRealizedPeers.IndexOf(peer);
if (realizedPeerIndex >= 0)
{
itemsControlAP.RecentlyRealizedPeers.RemoveAt(realizedPeerIndex);
}
}
}
else
{
peer = itemsControlAP.CreateItemAutomationPeerInternal(item);
}
//perform hookup so the events sourced from wrapper peer are fired as if from the data item
if (peer != null)
{
AutomationPeer wrapperPeer = peer.GetWrapperPeer();
if (wrapperPeer != null)
{
wrapperPeer.EventsSource = peer;
if (peer.ChildrenValid && peer.Children == null && this.AncestorsInvalid)
{
peer.AncestorsInvalid = true;
wrapperPeer.AncestorsInvalid = true;
}
}
}
//protection from indistinguishable items - for example, 2 strings with same value
//this scenario does not work in ItemsControl however is not checked for.
// Our parent's ItemPeerStorage collection may not have been cleared,
// this would cause us to report 0 children, if the peer is already in the collection
// check its parent, if it has been set to us, we should add it to the return collection,
// but only if we haven't added a peer for this item during this GetChildrenCore call.
bool itemMissingPeerInGlobalStorage = itemsControlAP.ItemPeers[item] == null;
if (peer != null && (itemMissingPeerInGlobalStorage
|| (peer.GetParent() == this && addedChildren[item] == null)))
{
children.Add(peer);
addedChildren[item] = peer;
if (itemMissingPeerInGlobalStorage)
{
itemsControlAP.ItemPeers[item] = peer;
}
}
}
}
return children;
}
}
return null;
}
// *** DEAD CODE Only call is from dead code when UseNetFx472CompatibleAccessibilityFeatures==true ***
internal void InvalidateGroupItemPeersContainingRecentlyRealizedPeers(List<ItemAutomationPeer> recentlyRealizedPeers)
{
ItemsControl itemsControl = ItemsControl.ItemsControlFromItemContainer(Owner);
if (itemsControl != null)
{
CollectionViewGroupInternal cvg = itemsControl.ItemContainerGenerator.ItemFromContainer(Owner) as CollectionViewGroupInternal;
if (cvg != null)
{
for (int i=0; i<recentlyRealizedPeers.Count; i++)
{
ItemAutomationPeer peer = recentlyRealizedPeers[i];
object item = peer.Item;
if (cvg.LeafIndexOf(item) >= 0)
{
AncestorsInvalid = true;
ChildrenValid = true;
}
}
}
}
}
override protected void SetFocusCore()
{
GroupItem owner = (GroupItem)Owner;
if (!AccessibilitySwitches.UseNetFx472CompatibleAccessibilityFeatures && owner.Expander != null)
{
if (owner.Expander.ExpanderToggleButton?.Focus() != true)
{
throw new InvalidOperationException(SR.SetFocusFailed);
}
}
else
{
base.SetFocusCore();
}
}
protected override bool IsKeyboardFocusableCore()
{
if (_expanderPeer != null)
{
return _expanderPeer.IsKeyboardFocusable();
}
else
{
return base.IsKeyboardFocusableCore();
}
}
override protected bool HasKeyboardFocusCore()
{
if (_expanderPeer != null)
{
return _expanderPeer.HasKeyboardFocus();
}
return base.HasKeyboardFocusCore();
}
private AutomationPeer _expanderPeer = null;
}
}
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