// We need to treat MSAA's FOCUS winevents differently depending on the OBJID -
// OBJID_CLIENT gets routed to the proxies; _MENU and _SYSMENU get speical treatment.
private AutomationElement GetFocusedElementFromWinEvent(IntPtr hwnd, int idObject, int idChild)
{
try
{
IRawElementProviderSimple provider = null;
// These are the only object types that oleacc proxies allow to take focus.
// (Native IAccessibles can send focus for other custom OBJID valus, but those are no use
// to us.)
// Try and get providers for them ourself - if we don't get anything, then
// defer to core to get the element for the HWND itself.
if (idObject == UnsafeNativeMethods.OBJID_CLIENT)
{
// regular focus - pass it off to a proxy...
provider = ProxyManager.ProxyProviderFromHwnd(NativeMethods.HWND.Cast(hwnd), idChild, UnsafeNativeMethods.OBJID_CLIENT);
}
else if (idObject == UnsafeNativeMethods.OBJID_MENU)
{
// menubar focus - see if there's a menubar pseudo-proxy registered...
ClientSideProviderFactoryCallback factory = ProxyManager.NonClientMenuBarProxyFactory;
if (factory != null)
{
provider = factory(hwnd, idChild, idObject);
}
}
else if (idObject == UnsafeNativeMethods.OBJID_SYSMENU)
{
// system menu box focus - see if there's a sysmenu pseudo-proxy registered...
ClientSideProviderFactoryCallback factory = ProxyManager.NonClientSysMenuProxyFactory;
if (factory != null)
{
provider = factory(hwnd, idChild, idObject);
}
}
else if (idObject <= 0)
{
return(null);
}
else
{
// This covers OBJID_CLIENT and custom OBJID cases.
// Pass it to the proxy manager: most proxies will just handle OBJID_CLIENT,
// but the MSAA proxy can potentally handle other OBJID values.
provider = ProxyManager.ProxyProviderFromHwnd(NativeMethods.HWND.Cast(hwnd), idChild, idObject);
}
if (provider != null)
{
// Ask the fragment root if any of its children really have the focus
IRawElementProviderFragmentRoot fragment = provider as IRawElementProviderFragmentRoot;
if (fragment != null)
{
// if we get back something that is different than what we started with and its not null
// use that instead. This is here to get the subset link in the listview but could be usefull
// for listview subitems as well.
IRawElementProviderSimple realFocus = fragment.GetFocus();
if (realFocus != null && !Object.ReferenceEquals(realFocus, provider))
{
provider = realFocus;
}
}
SafeNodeHandle hnode = UiaCoreApi.UiaNodeFromProvider(provider);
return(AutomationElement.Wrap(hnode));
}
else
{
// Didn't find a proxy to handle this hwnd - pass off to core...
return(AutomationElement.FromHandle(hwnd));
}
}
catch (Exception e)
{
if (Misc.IsCriticalException(e))
{
throw;
}
return(null);
}
}