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//---------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
// File: TreeViewDataItemAutomationPeer.cs
//
// Description: Data Item Automation peer for TreeViewItem, it may be associated with the
// full-fleged peer called wrapper peer, TreeViewItemAutomationPeer, if the item is realized.
//
// History:
// 20/12/2008 : Microsoft - Added
//
//---------------------------------------------------------------------------
using System;
using System.Collections;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Security;
using System.Text;
using System.Windows;
using System.Windows.Automation.Provider;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Interop;
using System.Windows.Media;
using System.Windows.Threading;
using MS.Internal;
using MS.Win32;
namespace System.Windows.Automation.Peers
{
public class TreeViewDataItemAutomationPeer : ItemAutomationPeer, ISelectionItemProvider, IScrollItemProvider, IExpandCollapseProvider
{
///
public TreeViewDataItemAutomationPeer(object item, ItemsControlAutomationPeer itemsControlAutomationPeer, TreeViewDataItemAutomationPeer parentDataItemAutomationPeer)
: base(item, null)
{
if(itemsControlAutomationPeer.Owner is TreeView || parentDataItemAutomationPeer == null)
ItemsControlAutomationPeer = itemsControlAutomationPeer;
_parentDataItemAutomationPeer = parentDataItemAutomationPeer;
}
///
override public object GetPattern(PatternInterface patternInterface)
{
if (patternInterface == PatternInterface.ExpandCollapse)
{
return this;
}
else if (patternInterface == PatternInterface.SelectionItem)
{
return this;
}
else if (patternInterface == PatternInterface.ScrollItem)
{
return this;
}
else if ((patternInterface == PatternInterface.ItemContainer) || (patternInterface == PatternInterface.SynchronizedInput))
{
TreeViewItemAutomationPeer treeViewItemAutomationPeer = GetWrapperPeer() as TreeViewItemAutomationPeer;
if (treeViewItemAutomationPeer != null)
{
if(patternInterface == PatternInterface.SynchronizedInput)
{
return treeViewItemAutomationPeer.GetPattern(patternInterface);
}
else
{
return treeViewItemAutomationPeer;
}
}
}
return base.GetPattern(patternInterface);
}
///
override internal AutomationPeer GetWrapperPeer()
{
AutomationPeer wrapperPeer = base.GetWrapperPeer();
TreeViewItemAutomationPeer treeViewItemWrapperPeer = wrapperPeer as TreeViewItemAutomationPeer;
if (treeViewItemWrapperPeer != null)
{
treeViewItemWrapperPeer.AddDataPeerInfo(this);
}
return wrapperPeer;
}
///
override protected string GetClassNameCore()
{
return "TreeViewItem";
}
///
override protected AutomationControlType GetAutomationControlTypeCore()
{
return AutomationControlType.TreeItem;
}
public TreeViewDataItemAutomationPeer ParentDataItemAutomationPeer
{
get
{
return _parentDataItemAutomationPeer;
}
}
// Return the ItemsControlAP (wrapper peer) corresponding to parent data item, as that will have most up-to-date reference. Sometime along with items even the parent could
// be virtualized as well, for eg in case of muti-level TreeView, intermediate TreeView item nodes could be virtualized and realized at any point in time, in that wrapper peer will be
// recreated as well.
override internal ItemsControlAutomationPeer GetItemsControlAutomationPeer()
{
if(_parentDataItemAutomationPeer == null)
return base.GetItemsControlAutomationPeer();
else
{
return _parentDataItemAutomationPeer.GetWrapperPeer() as ItemsControlAutomationPeer;
}
}
///
override internal void RealizeCore()
{
RecursiveScrollIntoView();
}
///
void IExpandCollapseProvider.Expand()
{
TreeViewItemAutomationPeer wrapperPeer = GetWrapperPeer() as TreeViewItemAutomationPeer;
if (wrapperPeer != null)
{
IExpandCollapseProvider iExpandCollapseProvider = wrapperPeer as IExpandCollapseProvider;
iExpandCollapseProvider.Expand();
}
else
ThrowElementNotAvailableException();
}
///
void IExpandCollapseProvider.Collapse()
{
TreeViewItemAutomationPeer wrapperPeer = GetWrapperPeer() as TreeViewItemAutomationPeer;
if (wrapperPeer != null)
{
IExpandCollapseProvider iExpandCollapseProvider = wrapperPeer as IExpandCollapseProvider;
iExpandCollapseProvider.Collapse();
}
else
ThrowElementNotAvailableException();
}
ExpandCollapseState IExpandCollapseProvider.ExpandCollapseState
{
get
{
TreeViewItemAutomationPeer wrapperPeer = GetWrapperPeer() as TreeViewItemAutomationPeer;
if (wrapperPeer != null)
{
IExpandCollapseProvider iExpandCollapseProvider = wrapperPeer as IExpandCollapseProvider;
return iExpandCollapseProvider.ExpandCollapseState;
}
else
ThrowElementNotAvailableException();
return ExpandCollapseState.LeafNode;
}
}
//
[System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining)]
internal void RaiseExpandCollapseAutomationEvent(bool oldValue, bool newValue)
{
RaisePropertyChangedEvent(
ExpandCollapsePatternIdentifiers.ExpandCollapseStateProperty,
oldValue ? ExpandCollapseState.Expanded : ExpandCollapseState.Collapsed,
newValue ? ExpandCollapseState.Expanded : ExpandCollapseState.Collapsed);
}
#region ISelectionItemProvider
/// <summary>
/// Selects this element, removing any other element from the selection.
/// </summary>
void ISelectionItemProvider.Select()
{
TreeViewItemAutomationPeer wrapperPeer = GetWrapperPeer() as TreeViewItemAutomationPeer;
if (wrapperPeer != null)
{
ISelectionItemProvider iSelectionItemProvider = wrapperPeer as ISelectionItemProvider;
iSelectionItemProvider.Select();
}
else
ThrowElementNotAvailableException();
}
/// <summary>
/// Selects this item.
/// </summary>
void ISelectionItemProvider.AddToSelection()
{
TreeViewItemAutomationPeer wrapperPeer = GetWrapperPeer() as TreeViewItemAutomationPeer;
if (wrapperPeer != null)
{
ISelectionItemProvider iSelectionItemProvider = wrapperPeer as ISelectionItemProvider;
iSelectionItemProvider.AddToSelection();
}
else
ThrowElementNotAvailableException();
}
/// <summary>
/// Unselects this item.
/// </summary>
void ISelectionItemProvider.RemoveFromSelection()
{
TreeViewItemAutomationPeer wrapperPeer = GetWrapperPeer() as TreeViewItemAutomationPeer;
if (wrapperPeer != null)
{
ISelectionItemProvider iSelectionItemProvider = wrapperPeer as ISelectionItemProvider;
iSelectionItemProvider.RemoveFromSelection();
}
else
ThrowElementNotAvailableException();
}
/// <summary>
/// Returns whether the item is selected.
/// </summary>
bool ISelectionItemProvider.IsSelected
{
get
{
// Virtualized Element are treated as not selected.
TreeViewItemAutomationPeer wrapperPeer = GetWrapperPeer() as TreeViewItemAutomationPeer;
if (wrapperPeer != null)
{
ISelectionItemProvider iSelectionItemProvider = wrapperPeer as ISelectionItemProvider;
return iSelectionItemProvider.IsSelected;
}
return false;
}
}
/// <summary>
/// The logical element that supports the SelectionPattern for this item.
/// </summary>
IRawElementProviderSimple ISelectionItemProvider.SelectionContainer
{
get
{
TreeViewItemAutomationPeer wrapperPeer = GetWrapperPeer() as TreeViewItemAutomationPeer;
if (wrapperPeer != null)
{
ISelectionItemProvider iSelectionItemProvider = wrapperPeer as ISelectionItemProvider;
return iSelectionItemProvider.SelectionContainer;
}
else
ThrowElementNotAvailableException();
return null;
}
}
void IScrollItemProvider.ScrollIntoView()
{
TreeViewItemAutomationPeer wrapperPeer = GetWrapperPeer() as TreeViewItemAutomationPeer;
if (wrapperPeer != null)
{
IScrollItemProvider iScrollItemProvider = wrapperPeer as IScrollItemProvider;
iScrollItemProvider.ScrollIntoView();
}
else
{
RecursiveScrollIntoView();
}
}
//
[System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining)]
internal void RaiseAutomationIsSelectedChanged(bool isSelected)
{
RaisePropertyChangedEvent(
SelectionItemPatternIdentifiers.IsSelectedProperty,
!isSelected,
isSelected);
}
#endregion
private void RecursiveScrollIntoView()
{
ItemsControlAutomationPeer itemsControlAutomationPeer = ItemsControlAutomationPeer;
// to check if the parent of this item is TreeViewItem.
if (ParentDataItemAutomationPeer != null)
{
// there might be a possibility that it's parent item is itself virtualized so we have to realize it and make a second attempt
if (itemsControlAutomationPeer == null)
{
ParentDataItemAutomationPeer.RecursiveScrollIntoView();
itemsControlAutomationPeer = ItemsControlAutomationPeer;
}
}
if (itemsControlAutomationPeer != null)
{
TreeViewItemAutomationPeer treeViewItemAutomationPeer = itemsControlAutomationPeer as TreeViewItemAutomationPeer;
if (treeViewItemAutomationPeer != null && (treeViewItemAutomationPeer as IExpandCollapseProvider).ExpandCollapseState == ExpandCollapseState.Collapsed)
{
(treeViewItemAutomationPeer as IExpandCollapseProvider).Expand();
}
ItemsControl parent = itemsControlAutomationPeer.Owner as ItemsControl;
if (parent != null)
{
if (parent.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
{
parent.OnBringItemIntoView(Item);
}
else
{
// The items aren't generated, try at a later time
Dispatcher.BeginInvoke(DispatcherPriority.Loaded, new DispatcherOperationCallback(parent.OnBringItemIntoView), Item);
}
}
}
}
// This is needed for scenarios where there is a deeply nested tree and client has hold of leaf DataItemPeer, now as it gets virtualized
// it’s parent’s WrapperPeer goes away but WeakRef collection won't as they will be reffered in this DataPeer corresponding to that parent.
// And at later time when it gets realized the Wrapper will use the collection stored here.
internal ItemPeersStorage<WeakReference> WeakRefElementProxyStorageCache
{
get
{
return _WeakRefElementProxyStorageCache;
}
set
{
_WeakRefElementProxyStorageCache = value;
}
}
private TreeViewDataItemAutomationPeer _parentDataItemAutomationPeer;
private ItemPeersStorage<WeakReference> _WeakRefElementProxyStorageCache;
}
}
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