| public IndexFromContainer ( DependencyObject container ) : int | ||
| container | DependencyObject | |
| return | int | |
/// <summary>
/// Sets focus to the next item in the ContextMenu.
/// </summary>
/// <param name="down">True to move the focus down; false to move it up.</param>
private void FocusNextItem(bool down)
{
int count = Items.Count;
int startingIndex = down ? -1 : count;
MenuItem focusedMenuItem = FocusManager.GetFocusedElement() as MenuItem;
if (null != focusedMenuItem && (this == focusedMenuItem.ParentMenuBase))
{
startingIndex = ItemContainerGenerator.IndexFromContainer(focusedMenuItem);
}
int index = startingIndex;
do
{
index = (index + count + (down ? 1 : -1)) % count;
MenuItem container = ItemContainerGenerator.ContainerFromIndex(index) as MenuItem;
if (null != container)
{
if (container.IsEnabled && container.Focus())
{
break;
}
}
}while (index != startingIndex);
}
/// <summary>
/// This is the method that responds to the KeyDown event.
/// </summary>
/// <param name="e"></param>
protected override void OnKeyDown(KeyEventArgs e)
{
TabItem nextTabItem = null;
// Handle [Ctrl][Shift]Tab, Home and End cases
// We have special handling here because if focus is inside the TabItem content we cannot
// cycle through TabItem because the content is not part of the TabItem visual tree
int direction = 0;
int startIndex = -1;
switch (e.Key)
{
case Key.Tab:
if ((e.KeyboardDevice.Modifiers & ModifierKeys.Control) == ModifierKeys.Control)
{
startIndex = ItemContainerGenerator.IndexFromContainer(ItemContainerGenerator.ContainerFromItem(SelectedItem));
if ((e.KeyboardDevice.Modifiers & ModifierKeys.Shift) == ModifierKeys.Shift)
{
direction = -1;
}
else
{
direction = 1;
}
}
break;
case Key.Home:
direction = 1;
startIndex = -1;
break;
case Key.End:
direction = -1;
startIndex = Items.Count;
break;
}
nextTabItem = FindNextTabItem(startIndex, direction);
if (nextTabItem != null && nextTabItem != SelectedItem)
{
e.Handled = nextTabItem.SetFocus();
}
if (!e.Handled)
{
base.OnKeyDown(e);
}
}
private void SetRangeSelection(ListBoxItem item)
{
int itemIndex = ItemContainerGenerator.IndexFromContainer(item);
int selectionAnchorIndex = ItemContainerGenerator.IndexFromContainer(selectionAnchor);
int rangeStartIndex = itemIndex.Min(selectionAnchorIndex);
int rangeEndIndex = itemIndex.Max(selectionAnchorIndex);
for (int i = 0; i < ItemContainerGenerator.ItemsCount; i++)
{
DependencyObject itemContainer = ItemContainerGenerator.Generate(i);
itemContainer.SetCurrentValue(Selector.IsSelectedProperty, rangeStartIndex <= i && i <= rangeEndIndex);
}
}
private int ElementIndex(ListBoxItem listItem)
{
return(ItemContainerGenerator.IndexFromContainer(listItem));
}
/// <summary>
/// Called by ListBoxItem instances when they get focus
/// </summary>
/// <param name="listBoxItemNewFocus">ListBoxItem that got focus</param>
internal override void NotifyListItemGotFocus(ListBoxItem listBoxItemNewFocus)
{
// Track the focused index
_focusedIndex = ItemContainerGenerator.IndexFromContainer(listBoxItemNewFocus);
}
// update container and index with current values
internal ItemInfo Refresh(ItemContainerGenerator generator)
{
if (Container == null && Index < 0)
{
Container = generator.ContainerFromItem(Item);
}
if (Index < 0 && Container != null)
{
Index = generator.IndexFromContainer(Container);
}
if (Container == null && Index >= 0)
{
Container = generator.ContainerFromIndex(Index);
}
if (Container == SentinelContainer && Index >= 0)
{
Container = null; // caller explicitly wants null container
}
return this;
}