Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Framework / System / Windows / Controls / Primitives / DataGridCellsPresenter.cs / 1305600 / DataGridCellsPresenter.cs
//----------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
//---------------------------------------------------------------------------
using System;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Diagnostics;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using MS.Internal;
namespace System.Windows.Controls.Primitives
{
///
/// A control that will be responsible for generating cells.
/// This control is meant to be specified within the template of a DataGridRow.
/// The APIs from ItemsControl do not match up nicely with the meaning of a
/// row, which is why this is being factored out.
///
/// The data item for the row is added n times to the Items collection,
/// where n is the number of columns in the DataGrid. This is implemented
/// using a special collection to avoid keeping multiple references to the
/// same object.
///
public class DataGridCellsPresenter : ItemsControl
{
#region Constructors
///
/// Instantiates global information.
///
static DataGridCellsPresenter()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(DataGridCellsPresenter), new FrameworkPropertyMetadata(typeof(DataGridCellsPresenter)));
ItemsPanelProperty.OverrideMetadata(typeof(DataGridCellsPresenter), new FrameworkPropertyMetadata(new ItemsPanelTemplate(new FrameworkElementFactory(typeof(DataGridCellsPanel)))));
FocusableProperty.OverrideMetadata(typeof(DataGridCellsPresenter), new FrameworkPropertyMetadata(false));
HeightProperty.OverrideMetadata(typeof(DataGridCellsPresenter), new FrameworkPropertyMetadata(OnNotifyHeightPropertyChanged, OnCoerceHeight));
MinHeightProperty.OverrideMetadata(typeof(DataGridCellsPresenter), new FrameworkPropertyMetadata(OnNotifyHeightPropertyChanged, OnCoerceMinHeight));
VirtualizingStackPanel.IsVirtualizingProperty.OverrideMetadata(
typeof(DataGridCellsPresenter),
new FrameworkPropertyMetadata(false, new PropertyChangedCallback(OnIsVirtualizingPropertyChanged), new CoerceValueCallback(OnCoerceIsVirtualizingProperty)));
VirtualizingStackPanel.VirtualizationModeProperty.OverrideMetadata(typeof(DataGridCellsPresenter), new FrameworkPropertyMetadata(VirtualizationMode.Recycling));
}
///
/// Instantiates a new instance of this class.
///
public DataGridCellsPresenter()
{
}
#endregion
#region Row Communication
///
/// Tells the row owner about this element.
///
public override void OnApplyTemplate()
{
#if BindingGroups
if (ItemBindingGroup == null)
{
ItemBindingGroup = new BindingGroup();
}
#endif
base.OnApplyTemplate();
DataGridRow owningRow = DataGridRowOwner;
if (owningRow != null)
{
owningRow.CellsPresenter = this;
Item = owningRow.Item;
}
// At the time that a Row is prepared we can't [....] because the CellsPresenter isn't created yet.
// Doing it here ensures that the CellsPresenter is in the visual tree.
SyncProperties(false);
}
///
/// Update all properties that get a value from the DataGrid
///
///
/// See comment on DataGridRow.SyncProperties
///
internal void SyncProperties(bool forcePrepareCells)
{
var dataGridOwner = DataGridOwner;
if (dataGridOwner == null)
{
return;
}
DataGridHelper.TransferProperty(this, HeightProperty);
DataGridHelper.TransferProperty(this, MinHeightProperty);
DataGridHelper.TransferProperty(this, VirtualizingStackPanel.IsVirtualizingProperty);
// This is a convenient way to walk through all cells and force them to call CoerceValue(StyleProperty)
NotifyPropertyChanged(this, new DependencyPropertyChangedEventArgs(DataGrid.CellStyleProperty, null, null), DataGridNotificationTarget.Cells);
// We may have missed an Add / Remove of a column from the grid (DataGridRow.OnColumnsChanged)
// [....] the MultipleCopiesCollection count and update the Column on changed cells
MultipleCopiesCollection cellItems = ItemsSource as MultipleCopiesCollection;
if (cellItems != null)
{
DataGridCell cell;
ObservableCollection columns = dataGridOwner.Columns;
int newColumnCount = columns.Count;
int oldColumnCount = cellItems.Count;
int dirtyCount = 0;
if (newColumnCount != oldColumnCount)
{
cellItems.SyncToCount(newColumnCount);
// Newly added or removed containers will be updated by the generator via PrepareContainer.
// All others may have a different column
dirtyCount = Math.Min(newColumnCount, oldColumnCount);
}
else if (forcePrepareCells)
{
dirtyCount = newColumnCount;
}
DataGridRow row = DataGridRowOwner;
bool arrangeInvalidated = false;
// Prepare the cells until dirtyCount is reached. Also invalidate the cells panel's measure
// and arrange if there is a mismatch between cell.ActualWidth and Column.Width.DisplayValue
for (int i = 0; i < dirtyCount; i++)
{
cell = (DataGridCell)ItemContainerGenerator.ContainerFromIndex(i);
if (cell != null)
{
cell.PrepareCell(row.Item, this, row);
if (!arrangeInvalidated && !DoubleUtil.AreClose(cell.ActualWidth, columns[i].Width.DisplayValue))
{
InvalidateDataGridCellsPanelMeasureAndArrange();
arrangeInvalidated = true;
}
}
}
// Keep searching for the mismatch between cell.ActualWidth
// and Column.Width.DisplayValue
if (!arrangeInvalidated)
{
for (int i = dirtyCount; i < newColumnCount; i++)
{
cell = (DataGridCell)ItemContainerGenerator.ContainerFromIndex(i);
if (cell != null)
{
if (!DoubleUtil.AreClose(cell.ActualWidth, columns[i].Width.DisplayValue))
{
InvalidateDataGridCellsPanelMeasureAndArrange();
break;
}
}
}
}
}
}
private static object OnCoerceHeight(DependencyObject d, object baseValue)
{
var cellsPresenter = d as DataGridCellsPresenter;
return DataGridHelper.GetCoercedTransferPropertyValue(
cellsPresenter,
baseValue,
HeightProperty,
cellsPresenter.DataGridOwner,
DataGrid.RowHeightProperty);
}
private static object OnCoerceMinHeight(DependencyObject d, object baseValue)
{
var cellsPresenter = d as DataGridCellsPresenter;
return DataGridHelper.GetCoercedTransferPropertyValue(
cellsPresenter,
baseValue,
MinHeightProperty,
cellsPresenter.DataGridOwner,
DataGrid.MinRowHeightProperty);
}
#endregion
#region Data Item
///
/// The item that the row represents. This item is an entry in the list of items from the DataGrid.
/// From this item, cells are generated for each column in the DataGrid.
///
public object Item
{
get
{
return _item;
}
internal set
{
if (_item != value)
{
object oldItem = _item;
_item = value;
OnItemChanged(oldItem, _item);
}
}
}
///
/// Called when the value of the Item property changes.
///
/// The old value of Item.
/// The new value of Item.
protected virtual void OnItemChanged(object oldItem, object newItem)
{
ObservableCollection columns = Columns;
if (columns != null)
{
// Either update or create a collection that will return the row's data item
// n number of times, where n is the number of columns.
MultipleCopiesCollection cellItems = ItemsSource as MultipleCopiesCollection;
if (cellItems == null)
{
cellItems = new MultipleCopiesCollection(newItem, columns.Count);
ItemsSource = cellItems;
}
else
{
cellItems.CopiedItem = newItem;
}
}
}
#endregion
#region Cell Container Generation
///
/// Determines if an item is its own container.
///
/// The item to test.
/// true if the item is a DataGridCell, false otherwise.
protected override bool IsItemItsOwnContainerOverride(object item)
{
return item is DataGridCell;
}
///
/// Method which returns the result of IsItemItsOwnContainerOverride to be used internally
///
internal bool IsItemItsOwnContainerInternal(object item)
{
return IsItemItsOwnContainerOverride(item);
}
///
/// Instantiates an instance of a container.
///
/// A new DataGridCell.
protected override DependencyObject GetContainerForItemOverride()
{
return new DataGridCell();
}
///
/// Prepares a new container for a given item.
///
/// The new container.
/// The item that the container represents.
protected override void PrepareContainerForItemOverride(DependencyObject element, object item)
{
DataGridCell cell = (DataGridCell)element;
DataGridRow rowOwner = DataGridRowOwner;
if (cell.RowOwner != rowOwner)
{
cell.Tracker.StartTracking(ref _cellTrackingRoot);
}
cell.PrepareCell(item, this, rowOwner);
}
///
/// Clears a container of references.
///
/// The container being cleared.
/// The data item that the container represented.
protected override void ClearContainerForItemOverride(DependencyObject element, object item)
{
DataGridCell cell = (DataGridCell)element;
DataGridRow rowOwner = DataGridRowOwner;
if (cell.RowOwner == rowOwner)
{
cell.Tracker.StopTracking(ref _cellTrackingRoot);
}
cell.ClearCell(rowOwner);
}
///
/// Notification from the DataGrid that the columns collection has changed.
///
/// The columns collection.
/// The event arguments from the collection's change event.
protected internal virtual void OnColumnsChanged(ObservableCollection columns, NotifyCollectionChangedEventArgs e)
{
// Update the ItemsSource for the cells
MultipleCopiesCollection cellItems = ItemsSource as MultipleCopiesCollection;
if (cellItems != null)
{
cellItems.MirrorCollectionChange(e);
}
// For a reset event the only thing the MultipleCopiesCollection can do is set its count to 0.
Debug.Assert(
e.Action != NotifyCollectionChangedAction.Reset || columns.Count == 0,
"A Reset event should only be fired for a Clear event from the columns collection");
}
#endregion
#region Notification Propagation
///
/// Notification of Height & MinHeight changes.
///
private static void OnNotifyHeightPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
((DataGridCellsPresenter)d).NotifyPropertyChanged(d, e, DataGridNotificationTarget.CellsPresenter);
}
///
/// General notification for DependencyProperty changes from the grid or from columns.
///
internal void NotifyPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e, DataGridNotificationTarget target)
{
NotifyPropertyChanged(d, string.Empty, e, target);
}
///
/// General notification for DependencyProperty changes from the grid or from columns.
///
internal void NotifyPropertyChanged(DependencyObject d, string propertyName, DependencyPropertyChangedEventArgs e, DataGridNotificationTarget target)
{
if (DataGridHelper.ShouldNotifyCellsPresenter(target))
{
if (e.Property == DataGridColumn.WidthProperty ||
e.Property == DataGridColumn.DisplayIndexProperty)
{
if (((DataGridColumn)d).IsVisible)
{
InvalidateDataGridCellsPanelMeasureAndArrange();
}
}
else if (e.Property == DataGrid.FrozenColumnCountProperty ||
e.Property == DataGridColumn.VisibilityProperty ||
e.Property == DataGrid.CellsPanelHorizontalOffsetProperty ||
e.Property == DataGrid.HorizontalScrollOffsetProperty ||
string.Compare(propertyName, "ViewportWidth", StringComparison.Ordinal) == 0 ||
string.Compare(propertyName, "DelayedColumnWidthComputation", StringComparison.Ordinal) == 0)
{
InvalidateDataGridCellsPanelMeasureAndArrange();
}
else if (string.Compare(propertyName, "RealizedColumnsBlockListForNonVirtualizedRows", StringComparison.Ordinal) == 0)
{
InvalidateDataGridCellsPanelMeasureAndArrange(/* withColumnVirtualization */ false);
}
else if (string.Compare(propertyName, "RealizedColumnsBlockListForVirtualizedRows", StringComparison.Ordinal) == 0)
{
InvalidateDataGridCellsPanelMeasureAndArrange(/* withColumnVirtualization */ true);
}
else if (e.Property == DataGrid.RowHeightProperty || e.Property == HeightProperty)
{
DataGridHelper.TransferProperty(this, HeightProperty);
}
else if (e.Property == DataGrid.MinRowHeightProperty || e.Property == MinHeightProperty)
{
DataGridHelper.TransferProperty(this, MinHeightProperty);
}
else if (e.Property == DataGrid.EnableColumnVirtualizationProperty)
{
DataGridHelper.TransferProperty(this, VirtualizingStackPanel.IsVirtualizingProperty);
}
}
if (DataGridHelper.ShouldNotifyCells(target) ||
DataGridHelper.ShouldRefreshCellContent(target))
{
ContainerTracking tracker = _cellTrackingRoot;
while (tracker != null)
{
tracker.Container.NotifyPropertyChanged(d, propertyName, e, target);
tracker = tracker.Next;
}
}
}
#endregion
#region GridLines
// Different parts of the DataGrid draw different pieces of the GridLines.
// Rows draw a single horizontal line on the bottom. The DataGridDetailsPresenter is the element that handles it.
///
/// Measure. This is overridden so that the row can extend its size to account for a grid line on the bottom.
///
///
///
/// Arrange. This is overriden so that the row can position its content to account for a grid line on the bottom.
///
/// Arrange size
protected override Size ArrangeOverride(Size finalSize)
{
// We don't need to adjust the Arrange position of the content. By default it is arranged at 0,0 and we're
// adding a line to the bottom. All we have to do is compress and extend the size, just like Measure.
var row = DataGridRowOwner;
if (row == null)
{
return base.ArrangeOverride(finalSize);
}
var dataGrid = row.DataGridOwner;
if (dataGrid == null)
{
return base.ArrangeOverride(finalSize);
}
if (DataGridHelper.IsGridLineVisible(dataGrid, /*isHorizontal = */ true))
{
double thickness = dataGrid.HorizontalGridLineThickness;
Size returnSize = base.ArrangeOverride(DataGridHelper.SubtractFromSize(finalSize, thickness, /*height = */ true));
returnSize.Height += thickness;
return returnSize;
}
else
{
return base.ArrangeOverride(finalSize);
}
}
///
/// OnRender. Overriden to draw a horizontal line underneath the content.
///
///
protected override void OnRender(DrawingContext drawingContext)
{
base.OnRender(drawingContext);
var row = DataGridRowOwner;
if (row == null)
{
return;
}
var dataGrid = row.DataGridOwner;
if (dataGrid == null)
{
return;
}
if (DataGridHelper.IsGridLineVisible(dataGrid, /*isHorizontal = */ true))
{
double thickness = dataGrid.HorizontalGridLineThickness;
Rect rect = new Rect(new Size(RenderSize.Width, thickness));
rect.Y = RenderSize.Height - thickness;
drawingContext.DrawRectangle(dataGrid.HorizontalGridLinesBrush, null, rect);
}
}
#endregion
#region Column Virtualization
///
/// Property changed callback for VirtualizingStackPanel.IsVirtualizing property
///
private static void OnIsVirtualizingPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
DataGridCellsPresenter cellsPresenter = (DataGridCellsPresenter)d;
DataGridHelper.TransferProperty(cellsPresenter, VirtualizingStackPanel.IsVirtualizingProperty);
if (e.OldValue != cellsPresenter.GetValue(VirtualizingStackPanel.IsVirtualizingProperty))
{
cellsPresenter.InvalidateDataGridCellsPanelMeasureAndArrange();
}
}
///
/// Coercion callback for VirtualizingStackPanel.IsVirtualizing property
///
private static object OnCoerceIsVirtualizingProperty(DependencyObject d, object baseValue)
{
var cellsPresenter = d as DataGridCellsPresenter;
return DataGridHelper.GetCoercedTransferPropertyValue(
cellsPresenter,
baseValue,
VirtualizingStackPanel.IsVirtualizingProperty,
cellsPresenter.DataGridOwner,
DataGrid.EnableColumnVirtualizationProperty);
}
///
/// Helper method which invalidate the underlying itemshost's measure and arrange
///
internal void InvalidateDataGridCellsPanelMeasureAndArrange()
{
if (_internalItemsHost != null)
{
_internalItemsHost.InvalidateMeasure();
_internalItemsHost.InvalidateArrange();
}
}
///
/// Helper method which invalidate the underlying itemshost's measure and arrange
///
///
/// True to invalidate only when virtualization is on.
/// False to invalidate only when virtualization is off.
///
private void InvalidateDataGridCellsPanelMeasureAndArrange(bool withColumnVirtualization)
{
// Invalidates measure and arrange if the flag and the virtualization
// are either both true or both false.
if (withColumnVirtualization == VirtualizingStackPanel.GetIsVirtualizing(this))
{
InvalidateDataGridCellsPanelMeasureAndArrange();
}
}
///
/// Workaround for not being able to access the panel instance of
/// itemscontrol directly
///
internal Panel InternalItemsHost
{
get { return _internalItemsHost; }
set { _internalItemsHost = value; }
}
///
/// Method which tries to scroll a cell for given index into the scroll view
///
///
internal void ScrollCellIntoView(int index)
{
DataGridCellsPanel itemsHost = InternalItemsHost as DataGridCellsPanel;
if (itemsHost != null)
{
itemsHost.InternalBringIndexIntoView(index);
return;
}
}
#endregion
#region Helpers
///
/// The DataGrid that owns this control
///
private DataGrid DataGridOwner
{
get
{
DataGridRow parent = DataGridRowOwner;
if (parent != null)
{
return parent.DataGridOwner;
}
return null;
}
}
///
/// The DataGridRow that owns this control.
///
internal DataGridRow DataGridRowOwner
{
get { return DataGridHelper.FindParent(this); }
}
private ObservableCollection Columns
{
get
{
DataGridRow owningRow = DataGridRowOwner;
DataGrid owningDataGrid = (owningRow != null) ? owningRow.DataGridOwner : null;
return (owningDataGrid != null) ? owningDataGrid.Columns : null;
}
}
internal ContainerTracking CellTrackingRoot
{
get { return _cellTrackingRoot; }
}
#endregion
#region Data
private object _item;
private ContainerTracking _cellTrackingRoot; // Root of a linked list of active cell containers
private Panel _internalItemsHost;
#endregion
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
//----------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
//---------------------------------------------------------------------------
using System;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Diagnostics;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using MS.Internal;
namespace System.Windows.Controls.Primitives
{
///
/// A control that will be responsible for generating cells.
/// This control is meant to be specified within the template of a DataGridRow.
/// The APIs from ItemsControl do not match up nicely with the meaning of a
/// row, which is why this is being factored out.
///
/// The data item for the row is added n times to the Items collection,
/// where n is the number of columns in the DataGrid. This is implemented
/// using a special collection to avoid keeping multiple references to the
/// same object.
///
public class DataGridCellsPresenter : ItemsControl
{
#region Constructors
///
/// Instantiates global information.
///
static DataGridCellsPresenter()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(DataGridCellsPresenter), new FrameworkPropertyMetadata(typeof(DataGridCellsPresenter)));
ItemsPanelProperty.OverrideMetadata(typeof(DataGridCellsPresenter), new FrameworkPropertyMetadata(new ItemsPanelTemplate(new FrameworkElementFactory(typeof(DataGridCellsPanel)))));
FocusableProperty.OverrideMetadata(typeof(DataGridCellsPresenter), new FrameworkPropertyMetadata(false));
HeightProperty.OverrideMetadata(typeof(DataGridCellsPresenter), new FrameworkPropertyMetadata(OnNotifyHeightPropertyChanged, OnCoerceHeight));
MinHeightProperty.OverrideMetadata(typeof(DataGridCellsPresenter), new FrameworkPropertyMetadata(OnNotifyHeightPropertyChanged, OnCoerceMinHeight));
VirtualizingStackPanel.IsVirtualizingProperty.OverrideMetadata(
typeof(DataGridCellsPresenter),
new FrameworkPropertyMetadata(false, new PropertyChangedCallback(OnIsVirtualizingPropertyChanged), new CoerceValueCallback(OnCoerceIsVirtualizingProperty)));
VirtualizingStackPanel.VirtualizationModeProperty.OverrideMetadata(typeof(DataGridCellsPresenter), new FrameworkPropertyMetadata(VirtualizationMode.Recycling));
}
///
/// Instantiates a new instance of this class.
///
public DataGridCellsPresenter()
{
}
#endregion
#region Row Communication
///
/// Tells the row owner about this element.
///
public override void OnApplyTemplate()
{
#if BindingGroups
if (ItemBindingGroup == null)
{
ItemBindingGroup = new BindingGroup();
}
#endif
base.OnApplyTemplate();
DataGridRow owningRow = DataGridRowOwner;
if (owningRow != null)
{
owningRow.CellsPresenter = this;
Item = owningRow.Item;
}
// At the time that a Row is prepared we can't [....] because the CellsPresenter isn't created yet.
// Doing it here ensures that the CellsPresenter is in the visual tree.
SyncProperties(false);
}
///
/// Update all properties that get a value from the DataGrid
///
///
/// See comment on DataGridRow.SyncProperties
///
internal void SyncProperties(bool forcePrepareCells)
{
var dataGridOwner = DataGridOwner;
if (dataGridOwner == null)
{
return;
}
DataGridHelper.TransferProperty(this, HeightProperty);
DataGridHelper.TransferProperty(this, MinHeightProperty);
DataGridHelper.TransferProperty(this, VirtualizingStackPanel.IsVirtualizingProperty);
// This is a convenient way to walk through all cells and force them to call CoerceValue(StyleProperty)
NotifyPropertyChanged(this, new DependencyPropertyChangedEventArgs(DataGrid.CellStyleProperty, null, null), DataGridNotificationTarget.Cells);
// We may have missed an Add / Remove of a column from the grid (DataGridRow.OnColumnsChanged)
// [....] the MultipleCopiesCollection count and update the Column on changed cells
MultipleCopiesCollection cellItems = ItemsSource as MultipleCopiesCollection;
if (cellItems != null)
{
DataGridCell cell;
ObservableCollection columns = dataGridOwner.Columns;
int newColumnCount = columns.Count;
int oldColumnCount = cellItems.Count;
int dirtyCount = 0;
if (newColumnCount != oldColumnCount)
{
cellItems.SyncToCount(newColumnCount);
// Newly added or removed containers will be updated by the generator via PrepareContainer.
// All others may have a different column
dirtyCount = Math.Min(newColumnCount, oldColumnCount);
}
else if (forcePrepareCells)
{
dirtyCount = newColumnCount;
}
DataGridRow row = DataGridRowOwner;
bool arrangeInvalidated = false;
// Prepare the cells until dirtyCount is reached. Also invalidate the cells panel's measure
// and arrange if there is a mismatch between cell.ActualWidth and Column.Width.DisplayValue
for (int i = 0; i < dirtyCount; i++)
{
cell = (DataGridCell)ItemContainerGenerator.ContainerFromIndex(i);
if (cell != null)
{
cell.PrepareCell(row.Item, this, row);
if (!arrangeInvalidated && !DoubleUtil.AreClose(cell.ActualWidth, columns[i].Width.DisplayValue))
{
InvalidateDataGridCellsPanelMeasureAndArrange();
arrangeInvalidated = true;
}
}
}
// Keep searching for the mismatch between cell.ActualWidth
// and Column.Width.DisplayValue
if (!arrangeInvalidated)
{
for (int i = dirtyCount; i < newColumnCount; i++)
{
cell = (DataGridCell)ItemContainerGenerator.ContainerFromIndex(i);
if (cell != null)
{
if (!DoubleUtil.AreClose(cell.ActualWidth, columns[i].Width.DisplayValue))
{
InvalidateDataGridCellsPanelMeasureAndArrange();
break;
}
}
}
}
}
}
private static object OnCoerceHeight(DependencyObject d, object baseValue)
{
var cellsPresenter = d as DataGridCellsPresenter;
return DataGridHelper.GetCoercedTransferPropertyValue(
cellsPresenter,
baseValue,
HeightProperty,
cellsPresenter.DataGridOwner,
DataGrid.RowHeightProperty);
}
private static object OnCoerceMinHeight(DependencyObject d, object baseValue)
{
var cellsPresenter = d as DataGridCellsPresenter;
return DataGridHelper.GetCoercedTransferPropertyValue(
cellsPresenter,
baseValue,
MinHeightProperty,
cellsPresenter.DataGridOwner,
DataGrid.MinRowHeightProperty);
}
#endregion
#region Data Item
///
/// The item that the row represents. This item is an entry in the list of items from the DataGrid.
/// From this item, cells are generated for each column in the DataGrid.
///
public object Item
{
get
{
return _item;
}
internal set
{
if (_item != value)
{
object oldItem = _item;
_item = value;
OnItemChanged(oldItem, _item);
}
}
}
///
/// Called when the value of the Item property changes.
///
/// The old value of Item.
/// The new value of Item.
protected virtual void OnItemChanged(object oldItem, object newItem)
{
ObservableCollection columns = Columns;
if (columns != null)
{
// Either update or create a collection that will return the row's data item
// n number of times, where n is the number of columns.
MultipleCopiesCollection cellItems = ItemsSource as MultipleCopiesCollection;
if (cellItems == null)
{
cellItems = new MultipleCopiesCollection(newItem, columns.Count);
ItemsSource = cellItems;
}
else
{
cellItems.CopiedItem = newItem;
}
}
}
#endregion
#region Cell Container Generation
///
/// Determines if an item is its own container.
///
/// The item to test.
/// true if the item is a DataGridCell, false otherwise.
protected override bool IsItemItsOwnContainerOverride(object item)
{
return item is DataGridCell;
}
///
/// Method which returns the result of IsItemItsOwnContainerOverride to be used internally
///
internal bool IsItemItsOwnContainerInternal(object item)
{
return IsItemItsOwnContainerOverride(item);
}
///
/// Instantiates an instance of a container.
///
/// A new DataGridCell.
protected override DependencyObject GetContainerForItemOverride()
{
return new DataGridCell();
}
///
/// Prepares a new container for a given item.
///
/// The new container.
/// The item that the container represents.
protected override void PrepareContainerForItemOverride(DependencyObject element, object item)
{
DataGridCell cell = (DataGridCell)element;
DataGridRow rowOwner = DataGridRowOwner;
if (cell.RowOwner != rowOwner)
{
cell.Tracker.StartTracking(ref _cellTrackingRoot);
}
cell.PrepareCell(item, this, rowOwner);
}
///
/// Clears a container of references.
///
/// The container being cleared.
/// The data item that the container represented.
protected override void ClearContainerForItemOverride(DependencyObject element, object item)
{
DataGridCell cell = (DataGridCell)element;
DataGridRow rowOwner = DataGridRowOwner;
if (cell.RowOwner == rowOwner)
{
cell.Tracker.StopTracking(ref _cellTrackingRoot);
}
cell.ClearCell(rowOwner);
}
///
/// Notification from the DataGrid that the columns collection has changed.
///
/// The columns collection.
/// The event arguments from the collection's change event.
protected internal virtual void OnColumnsChanged(ObservableCollection columns, NotifyCollectionChangedEventArgs e)
{
// Update the ItemsSource for the cells
MultipleCopiesCollection cellItems = ItemsSource as MultipleCopiesCollection;
if (cellItems != null)
{
cellItems.MirrorCollectionChange(e);
}
// For a reset event the only thing the MultipleCopiesCollection can do is set its count to 0.
Debug.Assert(
e.Action != NotifyCollectionChangedAction.Reset || columns.Count == 0,
"A Reset event should only be fired for a Clear event from the columns collection");
}
#endregion
#region Notification Propagation
///
/// Notification of Height & MinHeight changes.
///
private static void OnNotifyHeightPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
((DataGridCellsPresenter)d).NotifyPropertyChanged(d, e, DataGridNotificationTarget.CellsPresenter);
}
///
/// General notification for DependencyProperty changes from the grid or from columns.
///
internal void NotifyPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e, DataGridNotificationTarget target)
{
NotifyPropertyChanged(d, string.Empty, e, target);
}
///
/// General notification for DependencyProperty changes from the grid or from columns.
///
internal void NotifyPropertyChanged(DependencyObject d, string propertyName, DependencyPropertyChangedEventArgs e, DataGridNotificationTarget target)
{
if (DataGridHelper.ShouldNotifyCellsPresenter(target))
{
if (e.Property == DataGridColumn.WidthProperty ||
e.Property == DataGridColumn.DisplayIndexProperty)
{
if (((DataGridColumn)d).IsVisible)
{
InvalidateDataGridCellsPanelMeasureAndArrange();
}
}
else if (e.Property == DataGrid.FrozenColumnCountProperty ||
e.Property == DataGridColumn.VisibilityProperty ||
e.Property == DataGrid.CellsPanelHorizontalOffsetProperty ||
e.Property == DataGrid.HorizontalScrollOffsetProperty ||
string.Compare(propertyName, "ViewportWidth", StringComparison.Ordinal) == 0 ||
string.Compare(propertyName, "DelayedColumnWidthComputation", StringComparison.Ordinal) == 0)
{
InvalidateDataGridCellsPanelMeasureAndArrange();
}
else if (string.Compare(propertyName, "RealizedColumnsBlockListForNonVirtualizedRows", StringComparison.Ordinal) == 0)
{
InvalidateDataGridCellsPanelMeasureAndArrange(/* withColumnVirtualization */ false);
}
else if (string.Compare(propertyName, "RealizedColumnsBlockListForVirtualizedRows", StringComparison.Ordinal) == 0)
{
InvalidateDataGridCellsPanelMeasureAndArrange(/* withColumnVirtualization */ true);
}
else if (e.Property == DataGrid.RowHeightProperty || e.Property == HeightProperty)
{
DataGridHelper.TransferProperty(this, HeightProperty);
}
else if (e.Property == DataGrid.MinRowHeightProperty || e.Property == MinHeightProperty)
{
DataGridHelper.TransferProperty(this, MinHeightProperty);
}
else if (e.Property == DataGrid.EnableColumnVirtualizationProperty)
{
DataGridHelper.TransferProperty(this, VirtualizingStackPanel.IsVirtualizingProperty);
}
}
if (DataGridHelper.ShouldNotifyCells(target) ||
DataGridHelper.ShouldRefreshCellContent(target))
{
ContainerTracking tracker = _cellTrackingRoot;
while (tracker != null)
{
tracker.Container.NotifyPropertyChanged(d, propertyName, e, target);
tracker = tracker.Next;
}
}
}
#endregion
#region GridLines
// Different parts of the DataGrid draw different pieces of the GridLines.
// Rows draw a single horizontal line on the bottom. The DataGridDetailsPresenter is the element that handles it.
///
/// Measure. This is overridden so that the row can extend its size to account for a grid line on the bottom.
///
///
///
/// Arrange. This is overriden so that the row can position its content to account for a grid line on the bottom.
///
/// Arrange size
protected override Size ArrangeOverride(Size finalSize)
{
// We don't need to adjust the Arrange position of the content. By default it is arranged at 0,0 and we're
// adding a line to the bottom. All we have to do is compress and extend the size, just like Measure.
var row = DataGridRowOwner;
if (row == null)
{
return base.ArrangeOverride(finalSize);
}
var dataGrid = row.DataGridOwner;
if (dataGrid == null)
{
return base.ArrangeOverride(finalSize);
}
if (DataGridHelper.IsGridLineVisible(dataGrid, /*isHorizontal = */ true))
{
double thickness = dataGrid.HorizontalGridLineThickness;
Size returnSize = base.ArrangeOverride(DataGridHelper.SubtractFromSize(finalSize, thickness, /*height = */ true));
returnSize.Height += thickness;
return returnSize;
}
else
{
return base.ArrangeOverride(finalSize);
}
}
///
/// OnRender. Overriden to draw a horizontal line underneath the content.
///
///
protected override void OnRender(DrawingContext drawingContext)
{
base.OnRender(drawingContext);
var row = DataGridRowOwner;
if (row == null)
{
return;
}
var dataGrid = row.DataGridOwner;
if (dataGrid == null)
{
return;
}
if (DataGridHelper.IsGridLineVisible(dataGrid, /*isHorizontal = */ true))
{
double thickness = dataGrid.HorizontalGridLineThickness;
Rect rect = new Rect(new Size(RenderSize.Width, thickness));
rect.Y = RenderSize.Height - thickness;
drawingContext.DrawRectangle(dataGrid.HorizontalGridLinesBrush, null, rect);
}
}
#endregion
#region Column Virtualization
///
/// Property changed callback for VirtualizingStackPanel.IsVirtualizing property
///
private static void OnIsVirtualizingPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
DataGridCellsPresenter cellsPresenter = (DataGridCellsPresenter)d;
DataGridHelper.TransferProperty(cellsPresenter, VirtualizingStackPanel.IsVirtualizingProperty);
if (e.OldValue != cellsPresenter.GetValue(VirtualizingStackPanel.IsVirtualizingProperty))
{
cellsPresenter.InvalidateDataGridCellsPanelMeasureAndArrange();
}
}
///
/// Coercion callback for VirtualizingStackPanel.IsVirtualizing property
///
private static object OnCoerceIsVirtualizingProperty(DependencyObject d, object baseValue)
{
var cellsPresenter = d as DataGridCellsPresenter;
return DataGridHelper.GetCoercedTransferPropertyValue(
cellsPresenter,
baseValue,
VirtualizingStackPanel.IsVirtualizingProperty,
cellsPresenter.DataGridOwner,
DataGrid.EnableColumnVirtualizationProperty);
}
///
/// Helper method which invalidate the underlying itemshost's measure and arrange
///
internal void InvalidateDataGridCellsPanelMeasureAndArrange()
{
if (_internalItemsHost != null)
{
_internalItemsHost.InvalidateMeasure();
_internalItemsHost.InvalidateArrange();
}
}
///
/// Helper method which invalidate the underlying itemshost's measure and arrange
///
///
/// True to invalidate only when virtualization is on.
/// False to invalidate only when virtualization is off.
///
private void InvalidateDataGridCellsPanelMeasureAndArrange(bool withColumnVirtualization)
{
// Invalidates measure and arrange if the flag and the virtualization
// are either both true or both false.
if (withColumnVirtualization == VirtualizingStackPanel.GetIsVirtualizing(this))
{
InvalidateDataGridCellsPanelMeasureAndArrange();
}
}
///
/// Workaround for not being able to access the panel instance of
/// itemscontrol directly
///
internal Panel InternalItemsHost
{
get { return _internalItemsHost; }
set { _internalItemsHost = value; }
}
///
/// Method which tries to scroll a cell for given index into the scroll view
///
///
internal void ScrollCellIntoView(int index)
{
DataGridCellsPanel itemsHost = InternalItemsHost as DataGridCellsPanel;
if (itemsHost != null)
{
itemsHost.InternalBringIndexIntoView(index);
return;
}
}
#endregion
#region Helpers
///
/// The DataGrid that owns this control
///
private DataGrid DataGridOwner
{
get
{
DataGridRow parent = DataGridRowOwner;
if (parent != null)
{
return parent.DataGridOwner;
}
return null;
}
}
///
/// The DataGridRow that owns this control.
///
internal DataGridRow DataGridRowOwner
{
get { return DataGridHelper.FindParent(this); }
}
private ObservableCollection Columns
{
get
{
DataGridRow owningRow = DataGridRowOwner;
DataGrid owningDataGrid = (owningRow != null) ? owningRow.DataGridOwner : null;
return (owningDataGrid != null) ? owningDataGrid.Columns : null;
}
}
internal ContainerTracking CellTrackingRoot
{
get { return _cellTrackingRoot; }
}
#endregion
#region Data
private object _item;
private ContainerTracking _cellTrackingRoot; // Root of a linked list of active cell containers
private Panel _internalItemsHost;
#endregion
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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