internal void RestoreDataGridContextState( DataGridContext dataGridContext )
{
if( ( m_dataGridContextsStateDictionary == null ) || ( m_dataGridContextsStateDictionary.Count == 0 ) )
return;
if( dataGridContext == null )
throw new ArgumentNullException( "dataGridContext" );
// A call to RestoreDataGridContextState can be made while processing a save or a restore
// of a DataGridContext because the Generator forces the call in EnsureNodeTreeCreated
// when public methods are accessed. If we are saving, already restoring or pending restoring
// we ignore this call
if( dataGridContext.IsSavingState
|| dataGridContext.IsDeferRestoringState
|| dataGridContext.IsRestoringState )
return;
WeakDataGridContextKey weakDataGridContextKey = new WeakDataGridContextKey( dataGridContext );
SaveRestoreDataGridContextStateVisitor saveRestoreDataGridContextStateVisitor;
if( m_dataGridContextsStateDictionary.TryGetValue( weakDataGridContextKey, out saveRestoreDataGridContextStateVisitor ) )
{
try
{
dataGridContext.IsRestoringState = true;
// Restoring this dataGridContext state's will expand sub items that should be expanded.
// Their expansion will make the customItemGenerator generate sub detailNodes, which in turn will try
// to be restored to their previous state.
saveRestoreDataGridContextStateVisitor.RestoreState( ( IDataGridContextVisitable )dataGridContext );
Debug.WriteLineIf( this.DebugSaveRestore, "RESTORING DataGridContext state for WeakDataGridContextKey: " + weakDataGridContextKey.GetHashCode().ToString() + " RESTORED!" );
}
catch
{
Debug.WriteLineIf( this.DebugSaveRestore, "RESTORING DataGridContext state for WeakDataGridContextKey: " + weakDataGridContextKey.GetHashCode().ToString() + " FAILED!" );
}
finally
{
m_dataGridContextsStateDictionary.Remove( weakDataGridContextKey );
dataGridContext.IsRestoringState = false;
}
}
else
{
Debug.WriteLineIf( this.DebugSaveRestore, "Cannot Restore. No state saved for WeakDataGridContextKey: " + weakDataGridContextKey.GetHashCode().ToString() );
}
}
internal void SaveDataGridContextState( DataGridContext dataGridContext, bool handleExpandedItems, int maxGroupLevel )
{
if( dataGridContext == null )
throw new ArgumentNullException( "dataGridContext" );
Debug.Assert( !dataGridContext.IsRestoringState );
if( dataGridContext.IsSavingState )
return;
dataGridContext.IsSavingState = true;
try
{
WeakDataGridContextKey weakDataGridContextKey = new WeakDataGridContextKey( dataGridContext );
if( m_dataGridContextsStateDictionary == null )
{
m_dataGridContextsStateDictionary = new Dictionary<WeakDataGridContextKey, SaveRestoreDataGridContextStateVisitor>();
}
else if( m_dataGridContextsStateDictionary.ContainsKey( weakDataGridContextKey ) )
{
// Already a state saved for this context. Don't overwrite it.
Debug.WriteLineIf( this.DebugSaveRestore, "Already a state saved for WeakDataGridContextKey: " + weakDataGridContextKey.GetHashCode().ToString() );
return;
}
SaveRestoreDataGridContextStateVisitor saveRestoreDataGridContextStateVisitor = new SaveRestoreDataGridContextStateVisitor( handleExpandedItems, maxGroupLevel, false );
try
{
saveRestoreDataGridContextStateVisitor.SaveState( ( IDataGridContextVisitable )dataGridContext );
m_dataGridContextsStateDictionary.Add( weakDataGridContextKey, saveRestoreDataGridContextStateVisitor );
Debug.WriteLineIf( this.DebugSaveRestore, "SAVING DataGridContext state for WeakDataGridContextKey: " + weakDataGridContextKey.GetHashCode().ToString() + " SAVED!" );
}
catch
{
Debug.WriteLineIf( this.DebugSaveRestore, "SAVING DataGridContext state for WeakDataGridContextKey: " + weakDataGridContextKey.GetHashCode().ToString() + " FAILED!" );
}
}
finally
{
dataGridContext.IsSavingState = false;
}
}