internal void HandlePageDownNavigation()
{
DataGridContext dataGridContext = DataGridControl.GetDataGridContext(this);
if (dataGridContext == null)
{
return;
}
DataGridControl dataGridControl = dataGridContext.DataGridControl;
FrameworkElement hostPanel = dataGridControl.ItemsHost;
if (hostPanel != null)
{
// First thing to do here is the force the relayout of the ItemsHostPanel so that the target element gets "visible"
hostPanel.UpdateLayout();
// Then retrieve the last visible item in this panel
FrameworkElement lastVisibleItem = ScrollViewerHelper.GetLastVisibleContainer(
dataGridControl, hostPanel, this) as FrameworkElement;
if (lastVisibleItem != null)
{
DataGridContext lastVisibleItemDataGridContext = DataGridControl.GetDataGridContext(lastVisibleItem);
object oldItem = dataGridContext.InternalCurrentItem;
bool focused;
// Make the last visible item the current and focused.
// in order to cancel the current column in mixed mode when paged-Down
if (dataGridControl.NavigationBehavior == NavigationBehavior.RowOrCell)
{
focused = dataGridControl.SetFocusHelper(
lastVisibleItem, null, true, true);
}
else
{
focused = dataGridControl.SetFocusHelper(
lastVisibleItem, lastVisibleItemDataGridContext.CurrentColumn, true, true);
}
if (((!focused) || (oldItem == lastVisibleItemDataGridContext.InternalCurrentItem)) &&
(!dataGridControl.HasValidationError))
{
// The current item was already the first item, move focus down.
DataGridItemsHost.ProcessMoveFocus(Key.Down);
}
}
}
}
protected virtual void HandlePageDownKey(KeyEventArgs e)
{
// Ensure to at least process the PageDown as Key.Down
// to avoid the TableViewScrollViewer to process the key
// directly without moving the focus.
e.Handled = DataGridItemsHost.ProcessMoveFocus(Key.Down);
// We were not able to move focus out of the
// SynchronizedScrollViewer but the focus is still inside.
// Mark the key as handled to avoid the DataGridScrollViewer
// to process the PageDown.
if (!e.Handled && this.IsKeyboardFocusWithin)
{
e.Handled = true;
}
}
protected virtual void HandleRightKey(KeyEventArgs e)
{
e.Handled = DataGridItemsHost.ProcessMoveFocus(e.Key);
}