///
protected override List<AutomationPeer> GetChildrenCore()
{
// To avoid the situation on legacy systems which may not have new unmanaged core. with this change with old unmanaged core
// the behavior would be same as earlier.
if (IsVirtualized)
return base.GetChildrenCore();
else
{
ItemsControl owner = (ItemsControl)Owner;
ItemCollection items = owner.Items;
List<AutomationPeer> children = null;
ItemPeersStorage<ItemAutomationPeer> oldChildren = ItemPeers; //cache the old ones for possible reuse
ItemPeers = new ItemPeersStorage<ItemAutomationPeer>();
if (items.Count > 0)
{
children = new List<AutomationPeer>(items.Count);
for (int i = 0; i < items.Count; i++)
{
TreeViewItem treeViewItem = owner.ItemContainerGenerator.ContainerFromIndex(i) as TreeViewItem;
if (treeViewItem != null)
{
ItemAutomationPeer peer = oldChildren[items[i]];
if (peer == null)
peer = CreateItemAutomationPeer(items[i]);
// 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;
}
}
// Not to add same Item again
if (ItemPeers[items[i]] == null)
{
children.Add(peer);
ItemPeers[items[i]] = peer;
}
}
}
return children;
}
}
return null;
}
///
protected override List<AutomationPeer> GetChildrenCore()
{
List<AutomationPeer> children = null;
ItemPeersStorage<ItemAutomationPeer> oldChildren = ItemPeers; //cache the old ones for possible reuse
ItemPeers = new ItemPeersStorage<ItemAutomationPeer>();
TreeViewItem owner = Owner as TreeViewItem;
if (owner != null)
{
iterate(this, owner,
(IteratorCallback)delegate(AutomationPeer peer)
{
if (children == null)
children = new List<AutomationPeer>();
children.Add(peer);
return (false);
}, ItemPeers, oldChildren);
}
return children;
}
///
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)
{
ItemContainerGenerator generator = owner.Generator;
if (generator != null)
{
IList items = generator.Items;
List<AutomationPeer> children = new List<AutomationPeer>(items.Count);
ItemPeersStorage<ItemAutomationPeer> oldChildren = _dataChildren; //cache the old ones for possible reuse
_dataChildren = new ItemPeersStorage<ItemAutomationPeer>();
if (items.Count > 0)
{
foreach (object item in items)
{
CollectionViewGroup cvg = item as CollectionViewGroup;
if (cvg != null)
{
GroupItem groupItem = generator.ContainerFromItem(item) as GroupItem;
if (groupItem != null)
{
GroupItemAutomationPeer peer = groupItem.CreateAutomationPeer() as GroupItemAutomationPeer;
if (peer != null)
children.Add(peer);
}
}
else
{
//try to reuse old peer if it exists
ItemAutomationPeer peer = oldChildren[item];
//no old peer - create new one
if (peer == null)
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.
if (_dataChildren[item] == null)
{
children.Add(peer);
_dataChildren[item] = peer;
// Update ItemsControl cache too
// ItemPeers needs to be updated because used in Selector and other ItemsControl subclasses to access item peers directly
if (itemsControlAP.ItemPeers[item] == null)
{
itemsControlAP.ItemPeers[item] = peer;
}
}
}
}
return children;
}
}
}
}
return null;
}
///<summary>
/// Creates Children peers.
///
/// GetChildrenCore and FindItemByProperty are almost straight copies of the
/// ItemControlAutomationPeer code; however since DataGridColumHeaderPresenter
/// returns the Column.Header's as the items some specialized code was needed to
/// create and store peers.
///</summary>
protected override List<AutomationPeer> GetChildrenCore()
{
List<AutomationPeer> children = null;
ItemPeersStorage<ItemAutomationPeer> oldChildren = ItemPeers; //cache the old ones for possible reuse
ItemPeers = new ItemPeersStorage<ItemAutomationPeer>();
ItemsControl owner = (ItemsControl)Owner;
if (OwningDataGrid.Columns.Count > 0)
{
IList childItems = null;
Panel itemHost = owner.ItemsHost;
// To avoid the situation on legacy systems which may not have new unmanaged core. this check with old unmanaged core
// ensures the older behavior as ItemContainer pattern won't be available.
if (ItemContainerPatternIdentifiers.Pattern != null)
{
if (itemHost == null)
return null;
childItems = itemHost.Children;
}
else
{
childItems = OwningDataGrid.Columns;
}
children = new List<AutomationPeer>(childItems.Count);
foreach (object item in childItems)
{
DataGridColumn dataItem;
if (item is DataGridColumnHeader)
{
dataItem = ((DataGridColumnHeader) item).Column;
}
else
{
dataItem = item as DataGridColumn;
}
// try to reuse old peer if it exists either in Current AT or in WeakRefStorage of Peers being sent to Client
ItemAutomationPeer peer = oldChildren[dataItem];
if (peer == null)
{
peer = GetPeerFromWeakRefStorage(dataItem);
// As cached peer is getting used it must be invalidated.
if (peer != null)
{
peer.AncestorsInvalid = false;
peer.ChildrenValid = false;
}
}
if (peer == null)
{
peer = CreateItemAutomationPeer(dataItem);
}
// 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;
}
}
// protection from indistinguishable items - for example, 2 strings with same value
// this scenario does not work in ItemsControl however is not checked for.
if (ItemPeers[dataItem] == null)
{
children.Add(peer);
ItemPeers[dataItem] = peer;
}
}
return children;
}
return null;
}
//
private static bool iterate(TreeViewItemAutomationPeer logicalParentAp, DependencyObject parent, IteratorCallback callback, ItemPeersStorage<ItemAutomationPeer> dataChildren, ItemPeersStorage<ItemAutomationPeer> oldChildren)
{
bool done = false;
if (parent != null)
{
AutomationPeer peer = null;
int count = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < count && !done; i++)
{
DependencyObject child = VisualTreeHelper.GetChild(parent, i);
if (child != null
&& child is UIElement)
{
if (child is TreeViewItem)
{
object dataItem = (child as UIElement) != null ? (logicalParentAp.Owner as ItemsControl).GetItemOrContainerFromContainer(child as UIElement) : child;
peer = oldChildren[dataItem];
if (peer == null)
{
peer = logicalParentAp.GetPeerFromWeakRefStorage(dataItem);
if (peer != null)
{
// As cached peer is getting used it must be invalidated.
peer.AncestorsInvalid = false;
peer.ChildrenValid = false;
}
}
if (peer == null)
{
peer = logicalParentAp.CreateItemAutomationPeer(dataItem);
}
//perform hookup so the events sourced from wrapper peer are fired as if from the data item
if (peer != null)
{
AutomationPeer wrapperPeer = (peer as ItemAutomationPeer).GetWrapperPeer();
if (wrapperPeer != null)
{
wrapperPeer.EventsSource = peer;
}
if (dataChildren[dataItem] == null && peer is ItemAutomationPeer)
{
callback(peer);
dataChildren[dataItem] = peer as ItemAutomationPeer;
}
}
}
else
{
peer = CreatePeerForElement((UIElement)child);
if (peer != null)
done = callback(peer);
}
if(peer == null)
done = iterate(logicalParentAp, child, callback, dataChildren, oldChildren);
}
else
{
done = iterate(logicalParentAp, child, callback, dataChildren, oldChildren);
}
}
}
return done;
}
/// <summary>
/// Realized Columns only
/// </summary>
/// <returns></returns>
internal List<AutomationPeer> GetCellItemPeers()
{
List<AutomationPeer> children = null;
ItemPeersStorage<DataGridCellItemAutomationPeer> newChildren = new ItemPeersStorage<DataGridCellItemAutomationPeer>();
IList childItems = null;
bool usingItemsHost = false;
DataGridRow row = GetWrapper() as DataGridRow;
if (row != null)
{
if (row.CellsPresenter != null)
{
Panel itemHost = row.CellsPresenter.ItemsHost;
if (itemHost != null)
{
childItems = itemHost.Children;
usingItemsHost = true;
}
}
}
if (!usingItemsHost)
{
childItems = OwningDataGrid.Columns;
}
if (childItems != null)
{
children = new List<AutomationPeer>(childItems.Count);
foreach (object childItem in childItems)
{
DataGridColumn column = null;
if (usingItemsHost)
{
column = (childItem as DataGridCell).Column;
}
else
{
column = childItem as DataGridColumn;
}
if (column != null)
{
DataGridCellItemAutomationPeer peer = GetOrCreateCellItemPeer(column,/*addParentInfo*/ false );
children.Add(peer);
newChildren[column] = peer;
}
}
}
// Cache children for reuse
CellItemPeers = newChildren;
return children;
}
