/// <summary>
/// Called due to the cell's column definition changing.
/// Not called due to changes within the current column definition.
/// </summary>
/// <remarks>
/// Coerces ContentTemplate and ContentTemplateSelector.
/// </remarks>
/// <param name="oldColumn">The old column definition.</param>
/// <param name="newColumn">The new column definition.</param>
protected virtual void OnColumnChanged(DataGridColumn oldColumn, DataGridColumn newColumn)
{
// We need to call BuildVisualTree after changing the column (PrepareCell does this).
Content = null;
DataGridHelper.TransferProperty(this, StyleProperty);
DataGridHelper.TransferProperty(this, IsReadOnlyProperty);
}
/// <summary>
/// Fired when the Row is attached to the DataGrid. The scenario here is if the user is scrolling and
/// the Row is a recycled container that was just added back to the visual tree. Properties that rely on a value from
/// the Grid should be reevaluated because they may be stale.
/// </summary>
/// <remarks>
/// Properties can obviously be stale if the DataGrid's value changes while the row is disconnected. They can also
/// be stale for unobvious reasons.
///
/// For example, the Style property is invalidated when we detect a new Visual parent. This happens for
/// elements in the row (such as the RowHeader) before Prepare is called on the Row. The coercion callback
/// will thus be unable to find the DataGrid and will return the wrong value.
///
/// There is a potential for perf work here. If we know a DP isn't invalidated when the visual tree is reconnected
/// and we know that the Grid hasn't modified that property then its value is likely fine. We could also cache whether
/// or not the Grid's property is the one that's winning. If not, no need to redo the coercion. This notification
/// is pretty fast already and thus not worth the work for now.
/// </remarks>
private void SyncProperties(bool forcePrepareCells)
{
// Coerce all properties on Row that depend on values from the DataGrid
// Style is ok since it's equivalent to ItemContainerStyle and has already been invalidated.
DataGridHelper.TransferProperty(this, BackgroundProperty);
DataGridHelper.TransferProperty(this, HeaderStyleProperty);
DataGridHelper.TransferProperty(this, HeaderTemplateProperty);
DataGridHelper.TransferProperty(this, HeaderTemplateSelectorProperty);
DataGridHelper.TransferProperty(this, ValidationErrorTemplateProperty);
DataGridHelper.TransferProperty(this, DetailsTemplateProperty);
DataGridHelper.TransferProperty(this, DetailsTemplateSelectorProperty);
DataGridHelper.TransferProperty(this, DetailsVisibilityProperty);
CoerceValue(VisibilityProperty); // Handle NewItemPlaceholder case
RestoreAttachedItemValue(this, DetailsVisibilityProperty);
var cellsPresenter = CellsPresenter;
if (cellsPresenter != null)
{
cellsPresenter.SyncProperties(forcePrepareCells);
RestoreAttachedItemValue(cellsPresenter, DataGridCellsPresenter.HeightProperty);
}
if (DetailsPresenter != null)
{
DetailsPresenter.SyncProperties();
}
if (RowHeader != null)
{
RowHeader.SyncProperties();
}
}
/// <summary>
/// General notification for DependencyProperty changes from the grid or from columns.
/// </summary>
internal void NotifyPropertyChanged(DependencyObject d, string propertyName, DependencyPropertyChangedEventArgs e, NotificationTarget target)
{
DataGridColumn column = d as DataGridColumn;
if ((column != null) && (column != Column))
{
// This notification does not apply to this cell
return;
}
// All the notifications which are to be handled by the cell
if (DataGridHelper.ShouldNotifyCells(target))
{
if (e.Property == DataGridColumn.WidthProperty)
{
DataGridHelper.OnColumnWidthChanged(this, e);
}
else if (e.Property == DataGrid.CellStyleProperty || e.Property == DataGridColumn.CellStyleProperty || e.Property == StyleProperty)
{
DataGridHelper.TransferProperty(this, StyleProperty);
}
else if (e.Property == DataGrid.IsReadOnlyProperty || e.Property == DataGridColumn.IsReadOnlyProperty || e.Property == IsReadOnlyProperty)
{
DataGridHelper.TransferProperty(this, IsReadOnlyProperty);
}
else if (e.Property == DataGridColumn.DisplayIndexProperty)
{
TabIndex = column.DisplayIndex;
}
}
// All the notifications which needs forward to columns
if (DataGridHelper.ShouldRefreshCellContent(target))
{
if (column != null && NeedsVisualTree)
{
if (!string.IsNullOrEmpty(propertyName))
{
column.RefreshCellContent(this, propertyName);
}
else if (e != null && e.Property != null)
{
column.RefreshCellContent(this, e.Property.Name);
}
}
}
}
/// <summary>
/// Prepares a cell for use.
/// </summary>
/// <remarks>
/// Updates the column reference.
/// </remarks>
internal void PrepareCell(object item, DataGridRow ownerRow, int index)
{
Debug.Assert(_owner == null || _owner == ownerRow, "_owner should be null before PrepareCell is called or the same value as the ownerRow.");
_owner = ownerRow;
DataGrid dataGrid = _owner.DataGridOwner;
if (dataGrid != null)
{
// The index of the container should correspond to the index of the column
if ((index >= 0) && (index < dataGrid.Columns.Count))
{
// Retrieve the column definition and pass it to the cell container
DataGridColumn column = dataGrid.Columns[index];
Column = column;
TabIndex = column.DisplayIndex;
IsTabStop = !column.DisableTab;
}
if (IsEditing)
{
// If IsEditing was left on and this container was recycled, reset it here.
// Setting this property will result in BuildVisualTree being called.
IsEditing = false;
}
else if ((Content as FrameworkElement) == null)
{
// If there isn't already a visual tree, then create one.
BuildVisualTree();
if (!NeedsVisualTree)
{
Content = item;
}
}
// Update cell Selection
bool isSelected = dataGrid.SelectedCellsInternal.Contains(this);
SyncIsSelected(isSelected);
}
DataGridHelper.TransferProperty(this, StyleProperty);
DataGridHelper.TransferProperty(this, IsReadOnlyProperty);
CoerceValue(ClipProperty);
}
/// <summary>
/// General notification for DependencyProperty changes from the grid or from columns.
/// </summary>
internal void NotifyPropertyChanged(DependencyObject d, string propertyName, DependencyPropertyChangedEventArgs e, NotificationTarget target)
{
if (DataGridHelper.ShouldNotifyRows(target))
{
if (e.Property == DataGrid.RowBackgroundProperty || e.Property == DataGrid.AlternatingRowBackgroundProperty ||
e.Property == BackgroundProperty || e.Property == AlternationIndexProperty)
{
DataGridHelper.TransferProperty(this, BackgroundProperty);
}
else if (e.Property == DataGrid.RowHeaderStyleProperty || e.Property == HeaderStyleProperty)
{
DataGridHelper.TransferProperty(this, HeaderStyleProperty);
}
else if (e.Property == DataGrid.RowHeaderTemplateProperty || e.Property == HeaderTemplateProperty)
{
DataGridHelper.TransferProperty(this, HeaderTemplateProperty);
}
else if (e.Property == DataGrid.RowHeaderTemplateSelectorProperty || e.Property == HeaderTemplateSelectorProperty)
{
DataGridHelper.TransferProperty(this, HeaderTemplateSelectorProperty);
}
else if (e.Property == DataGrid.RowValidationErrorTemplateProperty || e.Property == ValidationErrorTemplateProperty)
{
DataGridHelper.TransferProperty(this, ValidationErrorTemplateProperty);
}
else if (e.Property == DataGrid.RowDetailsTemplateProperty || e.Property == DetailsTemplateProperty)
{
DataGridHelper.TransferProperty(this, DetailsTemplateProperty);
DataGridHelper.TransferProperty(this, DetailsVisibilityProperty);
}
else if (e.Property == DataGrid.RowDetailsTemplateSelectorProperty || e.Property == DetailsTemplateSelectorProperty)
{
DataGridHelper.TransferProperty(this, DetailsTemplateSelectorProperty);
DataGridHelper.TransferProperty(this, DetailsVisibilityProperty);
}
else if (e.Property == DataGrid.RowDetailsVisibilityModeProperty || e.Property == DetailsVisibilityProperty || e.Property == IsSelectedProperty)
{
DataGridHelper.TransferProperty(this, DetailsVisibilityProperty);
}
else if (e.Property == ItemProperty)
{
OnItemChanged(e.OldValue, e.NewValue);
}
else if (e.Property == HeaderProperty)
{
OnHeaderChanged(e.OldValue, e.NewValue);
}
else if (e.Property == BindingGroupProperty)
{
// Re-run validation, but wait until Binding has occured.
Dispatcher.BeginInvoke(new DispatcherOperationCallback(DelayedValidateWithoutUpdate), DispatcherPriority.DataBind, e.NewValue);
}
}
if (DataGridHelper.ShouldNotifyDetailsPresenter(target))
{
if (DetailsPresenter != null)
{
DetailsPresenter.NotifyPropertyChanged(d, e);
}
}
if (DataGridHelper.ShouldNotifyCellsPresenter(target) ||
DataGridHelper.ShouldNotifyCells(target) ||
DataGridHelper.ShouldRefreshCellContent(target))
{
DataGridCellsPresenter cellsPresenter = CellsPresenter;
if (cellsPresenter != null)
{
cellsPresenter.NotifyPropertyChanged(d, propertyName, e, target);
}
}
if (DataGridHelper.ShouldNotifyRowHeaders(target) && RowHeader != null)
{
RowHeader.NotifyPropertyChanged(d, e);
}
}
