private PresentationSource CriticalGetActiveSource()
{
IntPtr hwnd = MS.Win32.UnsafeNativeMethods.GetActiveWindow();
if (hwnd != IntPtr.Zero)
{
return(HwndSource.CriticalFromHwnd(hwnd));
}
return(null);
}
private void RestorePreviousFocus()
{
if (base.IsKeyboardFocusWithin)
{
IntPtr focus = UnsafeNativeMethods.GetFocus();
HwndSource hwndSource = (focus != IntPtr.Zero) ? HwndSource.CriticalFromHwnd(focus) : null;
if (hwndSource != null)
{
Keyboard.Focus(null);
return;
}
Keyboard.ClearFocus();
}
}
internal static Visual GetElementFromPoint(IntPtr hwnd, Visual root, Point pointScreen)
{
HwndSource hwndSource = HwndSource.CriticalFromHwnd(hwnd);
if (hwndSource == null)
{
return(null);
}
Point pointClient = PointUtil.ScreenToClient(pointScreen, hwndSource);
Point pointRoot = PointUtil.ClientToRoot(pointClient, hwndSource);
PointHitTestResult result = VisualTreeUtils.AsNearestPointHitTestResult(VisualTreeHelper.HitTest(root, pointRoot));
Visual visual = (result != null) ? result.VisualHit : null;
return(visual);
}
private void RestorePreviousFocus()
{
// Only restore focus if focus is still within the menu. If
// focus has already been moved outside of the menu, then
// we don't want to disturb it.
if (IsKeyboardFocusWithin)
{
// Only restore WPF focus if the HWND with focus is an
// HwndSource. This enables child HWNDs, other top-level
// non-WPF HWNDs, or even child HWNDs of other WPF top-level
// windows to retain focus when menus are dismissed.
IntPtr hwndWithFocus = MS.Win32.UnsafeNativeMethods.GetFocus();
HwndSource hwndSourceWithFocus = hwndWithFocus != IntPtr.Zero ? HwndSource.CriticalFromHwnd(hwndWithFocus) : null;
if (hwndSourceWithFocus != null)
{
// We restore focus by setting focus to the parent's focus
// scope. This may not seem correct, because it presumes
// the focus came from the logical-focus element of the
// parent scope. In fact, it could have come from any
// number of places. However, we have not figured out a
// better solution for restoring focus across scenarios
// such as:
//
// 1) A context menu of a menu item.
// 2) Two menus side-by-side
// 3) A menu and a toolbar side-by-side
//
// Simply remembering the last element with focus and
// restoring focus to it does not work. For example,
// two menus side-by-side will end up remembering each
// other, and you can get stuck in an infinite loop.
//
// Restoring focus through the parent's focus scope will
// not directly work if you open one window's menu from
// another window. Visual Studio, as an example, will
// intercept the focus change events and forward
// appropriately for the scenario of restoring focus to
// an element in a different top-level window.
// DependencyObject parent = Parent;
// if (parent == null)
// {
// If there is no logical parent, use the visual parent.
// parent = VisualTreeHelper.GetParent(this);
// }
// if (parent != null)
// {
// IInputElement parentScope = FocusManager.GetFocusScope(parent) as IInputElement;
// if (parentScope != null)
// {
// Keyboard.Focus(parentScope);
// }
// }
// Unfortunately setting focus to the parent focusscope tripped up VS in the scenario where
// Menus are contained within ToolBars. In this case when the Menu is dismissed they want
// focus to be restored to the element in the main window that previously had focus. However
// since ToolBar is the parent focusscope for the Menu we end up restoring focus to its
// focusedelment. It is also noted that this implementation is a behavioral change from .Net 3.5.
// Hence we are putting back the old behavior which is to set Keyboard.Focus to null which will
// delegate focus through the main window to its focusedelement.
Keyboard.Focus(null);
}
else
{
// In the case where Win32 focus is not on a WPF
// HwndSource, we just clear WPF focus completely.
//
// Note that calling Focus(null) will set focus to the root
// element of the active source, which is not what we want.
Keyboard.ClearFocus();
}
}
}
