private void AdjustCellTabIndex( TableViewColumnVirtualizationManagerBase columnVirtualizationManager )
{
// The order of the children in the panel is not guaranteed to be good. We do not reorder children because we will have to remove
// and add them at a different location. Doing that will cause more calculations to occur, so we only change the TabIndex.
VirtualizingCellCollection collection = this.ParentRowCells;
if( collection == null )
return;
var fieldNameToPositionMapping = columnVirtualizationManager.GetFieldNameToPosition( m_parentRow.LevelCache );
var fieldNames = columnVirtualizationManager.GetFixedFieldNames( m_parentRow.LevelCache )
.Concat( columnVirtualizationManager.GetScrollingFieldNames( m_parentRow.LevelCache ) )
.Concat( m_permanentScrollingFieldNames );
foreach( var fieldName in fieldNames )
{
Cell cell = collection.GetCell( fieldName, false );
Debug.Assert( cell != null );
int tabIndex;
if( fieldNameToPositionMapping.TryGetValue( fieldName, out tabIndex ) )
{
KeyboardNavigation.SetTabIndex( cell, tabIndex );
}
else
{
cell.ClearValue( Cell.TabIndexProperty );
}
}
}
private void UpdateChildren( DataGridContext dataGridContext, TableViewColumnVirtualizationManagerBase columnVirtualizationManager, VirtualizingCellCollection parentRowCells )
{
//Prevent reentrance
if( ( parentRowCells == null ) || m_parentRowCells.IsUpdating )
return;
using( m_parentRowCells.SetIsUpdating() )
{
this.ClearPermanentScrollingFieldNames();
//Retrieve the cells that aren't needed anymore.
var unusedCells = ( from cell in parentRowCells.BindedCells
where !columnVirtualizationManager.GetScrollingFieldNames( m_parentRow.LevelCache ).Contains( cell.FieldName )
&& !columnVirtualizationManager.GetFixedFieldNames( m_parentRow.LevelCache ).Contains( cell.FieldName )
select cell ).ToList();
//Release the unused binded cells now in order to minimize the number of cell's creation.
foreach( Cell cell in unusedCells )
{
this.AddCellToVisualTree( cell );
if( this.CanReleaseCell( cell ) )
{
// Ensure to close the ContextMenu if it is open and the Cell is virtualized to avoid problems with ContextMenus defined as static resources
// that won't be able to reopen again if the Close private method is called after the PlacementTarget is removed from the VisualTree
var contextMenu = cell.ContextMenu;
if( ( contextMenu != null ) && ( contextMenu.IsOpen ) )
{
contextMenu.IsOpen = false;
}
cell.ClearContainer();
parentRowCells.Release( cell );
}
//Since the cell cannot be released, it will not be collapsed. We must keep the field
//name in order to let the scrolling sub-panel measure and arrange the cell out of view.
else
{
//Certain non recyclable cells like StatCells needs their content binding to be removed when they become out of view.
cell.RemoveContentBinding();
this.AddPermanentScrollingFieldNames( cell.FieldName );
}
}
//Add the missing cells to the fixed region.
foreach( string fieldName in columnVirtualizationManager.GetFixedFieldNames( m_parentRow.LevelCache ) )
{
//The cell is created if it is missing.
Cell cell = parentRowCells[ fieldName ];
//Certain non recyclable cells like StatCells need their content binding to be updated when they become (or stay) in view.
cell.AddContentBinding( dataGridContext, this.ParentRow, this.Columns[ cell.FieldName ] );
//Make sure the cell is in the appropriate panel.
this.MoveCellToFixedPanel( cell );
}
//Add the missing cells to the scrolling region.
foreach( string fieldName in columnVirtualizationManager.GetScrollingFieldNames( m_parentRow.LevelCache ) )
{
//The cell is created if it is missing.
Cell cell = parentRowCells[ fieldName ];
//Certain non recyclable cells like StatCells need their content binding to be updated when they become (or stay) in view.
cell.AddContentBinding( dataGridContext, this.ParentRow, this.Columns[ cell.FieldName ] );
//Make sure the cell is in the appropriate panel.
this.MoveCellToScrollingPanel( cell );
}
if( m_clearUnusedCellsDispatcherOperation == null )
{
m_clearUnusedCellsDispatcherOperation = this.Dispatcher.BeginInvoke( new Action( this.ClearUnusedCells ), DispatcherPriority.ApplicationIdle );
}
m_fixedPanel.InvalidateMeasure();
m_scrollingCellsDecorator.InvalidateMeasure();
m_scrollingPanel.InvalidateMeasure();
}
}