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using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Windows.Automation;
using System.Windows.Automation.Provider;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Media;
namespace System.Windows.Automation.Peers
{
/// <summary>
/// AutomationPeer for DataGrid
/// Supports Grid, Table, Selection and Scroll patters
/// </summary>
public sealed class DataGridAutomationPeer : ItemsControlAutomationPeer,
IGridProvider, ISelectionProvider, ITableProvider
{
#region Constructors
/// <summary>
/// Default contructor
/// </summary>
/// <param name="owner">DataGrid</param>
public DataGridAutomationPeer(DataGrid owner)
: base(owner)
{
if (owner == null)
{
throw new ArgumentNullException("owner");
}
}
#endregion
#region AutomationPeer Overrides
/// <summary>
/// Gets the control type for the element that is associated with the UI Automation peer.
/// </summary>
/// <returns>The control type.</returns>
protected override AutomationControlType GetAutomationControlTypeCore()
{
return AutomationControlType.DataGrid;
}
protected override List<AutomationPeer> GetChildrenCore()
{
List<AutomationPeer> children = base.GetChildrenCore();
DataGridColumnHeadersPresenter columnsHeaderPresenter = this.OwningDataGrid.ColumnHeadersPresenter;
// Add ColumnsHeaderPresenter if it is visible
if (columnsHeaderPresenter != null && columnsHeaderPresenter.IsVisible)
{
AutomationPeer columnsHeaderPresenterPeer = FrameworkElementAutomationPeer.CreatePeerForElement(columnsHeaderPresenter);
if (columnsHeaderPresenterPeer != null)
{
if (children == null)
{
children = new List<AutomationPeer>(1);
}
children.Insert(0, columnsHeaderPresenterPeer);
}
}
return children;
}
/// <summary>
/// Called by GetClassName that gets a human readable name that, in addition to AutomationControlType,
/// differentiates the control represented by this AutomationPeer.
/// </summary>
/// <returns>The string that contains the name.</returns>
protected override string GetClassNameCore()
{
return Owner.GetType().Name;
}
/// <summary>
/// Gets the control pattern that is associated with the specified System.Windows.Automation.Peers.PatternInterface.
/// </summary>
/// <param name="patternInterface">A value from the System.Windows.Automation.Peers.PatternInterface enumeration.</param>
/// <returns>The object that supports the specified pattern, or null if unsupported.</returns>
public override object GetPattern(PatternInterface patternInterface)
{
switch (patternInterface)
{
case PatternInterface.Grid:
case PatternInterface.Selection:
case PatternInterface.Table:
return this;
case PatternInterface.Scroll:
{
ScrollViewer scrollViewer = this.OwningDataGrid.InternalScrollHost;
if (scrollViewer != null)
{
AutomationPeer scrollPeer = UIElementAutomationPeer.CreatePeerForElement(scrollViewer);
IScrollProvider scrollProvider = scrollPeer as IScrollProvider;
if (scrollPeer != null && scrollProvider != null)
{
scrollPeer.EventsSource = this;
return scrollProvider;
}
}
break;
}
}
return base.GetPattern(patternInterface);
}
override protected ItemAutomationPeer CreateItemAutomationPeer(object item)
{
return new DataGridItemAutomationPeer(item, this);
}
internal override bool IsPropertySupportedByControlForFindItem(int id)
{
return SelectorAutomationPeer.IsPropertySupportedByControlForFindItemInternal(id);
}
internal override object GetSupportedPropertyValue(ItemAutomationPeer itemPeer, int propertyId)
{
return SelectorAutomationPeer.GetSupportedPropertyValueInternal(itemPeer, propertyId);
}
#endregion
#region IGridProvider
int IGridProvider.ColumnCount
{
get
{
return this.OwningDataGrid.Columns.Count;
}
}
int IGridProvider.RowCount
{
get
{
return this.OwningDataGrid.Items.Count;
}
}
IRawElementProviderSimple IGridProvider.GetItem(int row, int column)
{
if (row >= 0 && row < this.OwningDataGrid.Items.Count &&
column >= 0 && column < this.OwningDataGrid.Columns.Count)
{
object item = this.OwningDataGrid.Items[row];
DataGridColumn dataGridColumn = this.OwningDataGrid.Columns[column];
this.OwningDataGrid.ScrollIntoView(item, dataGridColumn);
this.OwningDataGrid.UpdateLayout();
DataGridItemAutomationPeer itemPeer = this.FindOrCreateItemAutomationPeer(item) as DataGridItemAutomationPeer;
if (itemPeer != null)
{
DataGridCellItemAutomationPeer cellItemPeer = itemPeer.GetOrCreateCellItemPeer(dataGridColumn);
if (cellItemPeer != null)
{
return ProviderFromPeer(cellItemPeer);
}
}
}
return null;
}
#endregion
#region ISelectionProvider
IRawElementProviderSimple[] ISelectionProvider.GetSelection()
{
List<IRawElementProviderSimple> selectedProviders = new List<IRawElementProviderSimple>();
switch (this.OwningDataGrid.SelectionUnit)
{
case DataGridSelectionUnit.Cell:
{
AddSelectedCells(selectedProviders);
break;
}
case DataGridSelectionUnit.FullRow:
{
AddSelectedRows(selectedProviders);
break;
}
case DataGridSelectionUnit.CellOrRowHeader:
{
AddSelectedRows(selectedProviders);
AddSelectedCells(selectedProviders);
break;
}
default:
{
Debug.Assert(false);
break;
}
}
return selectedProviders.ToArray();
}
bool ISelectionProvider.CanSelectMultiple
{
get
{
return this.OwningDataGrid.SelectionMode == DataGridSelectionMode.Extended;
}
}
bool ISelectionProvider.IsSelectionRequired
{
get
{
return false;
}
}
#endregion
#region ITableProvider
RowOrColumnMajor ITableProvider.RowOrColumnMajor
{
get
{
return RowOrColumnMajor.RowMajor;
}
}
IRawElementProviderSimple[] ITableProvider.GetColumnHeaders()
{
if ((this.OwningDataGrid.HeadersVisibility & DataGridHeadersVisibility.Column) == DataGridHeadersVisibility.Column)
{
List<IRawElementProviderSimple> providers = new List<IRawElementProviderSimple>();
DataGridColumnHeadersPresenter dataGridColumnHeadersPresenter = this.OwningDataGrid.ColumnHeadersPresenter;
if (dataGridColumnHeadersPresenter != null)
{
DataGridColumnHeadersPresenterAutomationPeer dataGridColumnHeadersPresenterPeer = dataGridColumnHeadersPresenter.GetAutomationPeer() as DataGridColumnHeadersPresenterAutomationPeer;
if (dataGridColumnHeadersPresenterPeer != null)
{
for (int i = 0; i < this.OwningDataGrid.Columns.Count; i++)
{
AutomationPeer peer = dataGridColumnHeadersPresenterPeer.FindOrCreateItemAutomationPeer(this.OwningDataGrid.Columns[i]);
if (peer != null)
{
providers.Add(ProviderFromPeer(peer));
}
}
if (providers.Count > 0)
{
return providers.ToArray();
}
}
}
}
return null;
}
// Row virtualization does not allow us to enumerate all the row headers because
// Their visual and bindings cannot be predicted before the row is devirtualized
// This method will return only the list of devirtualized rows headers.
IRawElementProviderSimple[] ITableProvider.GetRowHeaders()
{
if ((this.OwningDataGrid.HeadersVisibility & DataGridHeadersVisibility.Row) == DataGridHeadersVisibility.Row)
{
List<IRawElementProviderSimple> providers = new List<IRawElementProviderSimple>();
foreach (object item in this.OwningDataGrid.Items)
{
DataGridItemAutomationPeer dataGridItemAutomationPeer = FindOrCreateItemAutomationPeer(item) as DataGridItemAutomationPeer;
AutomationPeer rowHeaderAutomationPeer = dataGridItemAutomationPeer.RowHeaderAutomationPeer;
if (rowHeaderAutomationPeer != null)
{
providers.Add(ProviderFromPeer(rowHeaderAutomationPeer));
}
}
if (providers.Count > 0)
{
return providers.ToArray();
}
}
return null;
}
#endregion
#region Private Helpers
private DataGrid OwningDataGrid
{
get
{
return (DataGrid)Owner;
}
}
// Private helper returning the automation peer coresponding to cellInfo
// Cell can be virtualized
private DataGridCellItemAutomationPeer GetCellItemPeer(DataGridCellInfo cellInfo)
{
if (cellInfo.IsValid)
{
DataGridItemAutomationPeer dataGridItemAutomationPeer = FindOrCreateItemAutomationPeer(cellInfo.Item) as DataGridItemAutomationPeer;
if (dataGridItemAutomationPeer != null)
{
return dataGridItemAutomationPeer.GetOrCreateCellItemPeer(cellInfo.Column);
}
}
return null;
}
// This method is called from DataGrid.OnSelectedCellsChanged
// Raises the selection events when Cell selection changes
internal void RaiseAutomationCellSelectedEvent(SelectedCellsChangedEventArgs e)
{
// If the result of an AddToSelection or RemoveFromSelection is a single selected cell,
// then all we raise is the ElementSelectedEvent for single item
if (AutomationPeer.ListenerExists(AutomationEvents.SelectionItemPatternOnElementSelected) &&
this.OwningDataGrid.SelectedCells.Count == 1 && e.AddedCells.Count == 1)
{
DataGridCellItemAutomationPeer cellPeer = GetCellItemPeer(e.AddedCells[0]);
if (cellPeer != null)
{
cellPeer.RaiseAutomationEvent(AutomationEvents.SelectionItemPatternOnElementSelected);
}
}
else
{
int i;
if (AutomationPeer.ListenerExists(AutomationEvents.SelectionItemPatternOnElementAddedToSelection))
{
for (i = 0; i < e.AddedCells.Count; i++)
{
DataGridCellItemAutomationPeer cellPeer = GetCellItemPeer(e.AddedCells[i]);
if (cellPeer != null)
{
cellPeer.RaiseAutomationEvent(AutomationEvents.SelectionItemPatternOnElementAddedToSelection);
}
}
}
if (AutomationPeer.ListenerExists(AutomationEvents.SelectionItemPatternOnElementRemovedFromSelection))
{
for (i = 0; i < e.RemovedCells.Count; i++)
{
DataGridCellItemAutomationPeer cellPeer = GetCellItemPeer(e.RemovedCells[i]);
if (cellPeer != null)
{
cellPeer.RaiseAutomationEvent(AutomationEvents.SelectionItemPatternOnElementRemovedFromSelection);
}
}
}
}
}
// This method is called from DataGrid.OnBeginningEdit/OnCommittingEdit/OnCancelingEdit
// Raises Invoked event when row begin/cancel/commit edit
internal void RaiseAutomationRowInvokeEvents(DataGridRow row)
{
DataGridItemAutomationPeer dataGridItemAutomationPeer = FindOrCreateItemAutomationPeer(row.Item) as DataGridItemAutomationPeer;
if (dataGridItemAutomationPeer != null)
{
dataGridItemAutomationPeer.RaiseAutomationEvent(AutomationEvents.InvokePatternOnInvoked);
}
}
// This method is called from DataGrid.OnBeginningEdit/OnCommittingEdit/OnCancelingEdit
// Raises Invoked event when cell begin/cancel/commit edit
internal void RaiseAutomationCellInvokeEvents(DataGridColumn column, DataGridRow row)
{
DataGridItemAutomationPeer dataGridItemAutomationPeer = FindOrCreateItemAutomationPeer(row.Item) as DataGridItemAutomationPeer;
if (dataGridItemAutomationPeer != null)
{
DataGridCellItemAutomationPeer cellPeer = dataGridItemAutomationPeer.GetOrCreateCellItemPeer(column);
if (cellPeer != null)
{
cellPeer.RaiseAutomationEvent(AutomationEvents.InvokePatternOnInvoked);
}
}
}
// This method is called from DataGrid.OnSelectionChanged
// Raises the selection events when Items selection changes
internal void RaiseAutomationSelectionEvents(SelectionChangedEventArgs e)
{
int numSelected = this.OwningDataGrid.SelectedItems.Count;
int numAdded = e.AddedItems.Count;
// If the result of an AddToSelection or RemoveFromSelection is a single selected item,
// then all we raise is the ElementSelectedEvent for single item
if (AutomationPeer.ListenerExists(AutomationEvents.SelectionItemPatternOnElementSelected) &&
numSelected == 1 && numAdded == 1)
{
ItemAutomationPeer peer = FindOrCreateItemAutomationPeer(this.OwningDataGrid.SelectedItem);
if (peer != null)
{
peer.RaiseAutomationEvent(AutomationEvents.SelectionItemPatternOnElementSelected);
}
}
else
{
int i;
if (AutomationPeer.ListenerExists(AutomationEvents.SelectionItemPatternOnElementAddedToSelection))
{
for (i = 0; i < e.AddedItems.Count; i++)
{
ItemAutomationPeer peer = FindOrCreateItemAutomationPeer(e.AddedItems[i]);
if (peer != null)
{
peer.RaiseAutomationEvent(AutomationEvents.SelectionItemPatternOnElementAddedToSelection);
}
}
}
if (AutomationPeer.ListenerExists(AutomationEvents.SelectionItemPatternOnElementRemovedFromSelection))
{
for (i = 0; i < e.RemovedItems.Count; i++)
{
ItemAutomationPeer peer = FindOrCreateItemAutomationPeer(e.RemovedItems[i]);
if (peer != null)
{
peer.RaiseAutomationEvent(AutomationEvents.SelectionItemPatternOnElementRemovedFromSelection);
}
}
}
}
}
private void AddSelectedCells(List<IRawElementProviderSimple> cellProviders)
{
if (cellProviders == null)
{
throw new ArgumentNullException("cellProviders");
}
// Add selected cells to selection
if (this.OwningDataGrid.SelectedCells != null)
{
foreach (DataGridCellInfo cellInfo in this.OwningDataGrid.SelectedCells)
{
DataGridItemAutomationPeer itemPeer = this.FindOrCreateItemAutomationPeer(cellInfo.Item) as DataGridItemAutomationPeer;
if (itemPeer != null)
{
IRawElementProviderSimple provider = ProviderFromPeer(itemPeer.GetOrCreateCellItemPeer(cellInfo.Column));
if (provider != null)
{
cellProviders.Add(provider);
}
}
}
}
}
private void AddSelectedRows(List<IRawElementProviderSimple> itemProviders)
{
if (itemProviders == null)
{
throw new ArgumentNullException("itemProviders");
}
// Add selected items to selection
if (this.OwningDataGrid.SelectedItems != null)
{
foreach (object item in this.OwningDataGrid.SelectedItems)
{
IRawElementProviderSimple provider = ProviderFromPeer(FindOrCreateItemAutomationPeer(item));
if (provider != null)
{
itemProviders.Add(provider);
}
}
}
}
#endregion
}
}
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