Function SetForegroundWindowEx

source/window.cpp:152–314

HWND SetForegroundWindowEx(HWND aTargetWindow)
// Caller must have ensured that aTargetWindow is a valid window or NULL, since we
// don't call IsWindow() here.
{
	if (!aTargetWindow)
		return NULL;  // When called this way (as it is sometimes), do nothing.

	// v1.0.42.03: Calling IsWindowHung() once here rather than potentially more than once in AttemptSetForeground()
	// solves a crash that is not fully understood, nor is it easily reproduced (it occurs only in release mode,
	// not debug mode).  It's likely a bug in the API's IsHungAppWindow(), but that is far from confirmed.
	DWORD target_thread = GetWindowThreadProcessId(aTargetWindow, NULL);
	if (target_thread != g_MainThreadID && IsWindowHung(aTargetWindow)) // Calls to IsWindowHung should probably be avoided if the window belongs to our thread.  Relies upon short-circuit boolean order.
		return NULL;

#ifdef _DEBUG_WINACTIVATE
	TCHAR win_name[64];
	GetWindowText(aTargetWindow, win_name, _countof(win_name));
#endif

	HWND orig_foreground_wnd = GetForegroundWindow();
	// AutoIt3: If there is not any foreground window, then input focus is on the TaskBar.
	// MY: It is definitely possible for GetForegroundWindow() to return NULL, even on XP.
	// Lexikos: It can be easily reproduced by calling GetForegroundWindow() in a tight
	//  loop on Windows 10 and switching windows with Alt+Esc.  In such cases the taskbar
	//  is definitely NOT active, and if our caller requested activation of the taskbar,
	//  it should not be skipped just because !orig_foreground_wnd.
	// MSDN: "The foreground window can be NULL in certain circumstances, such as when a
	//  window is losing activation."
	//if (!orig_foreground_wnd)
	//	orig_foreground_wnd = FindWindow(_T("Shell_TrayWnd"), NULL);

	// Fix for v1.1.28.02: Restore the window *before* checking if it is already active.
	// This was supposed to be done in v1.1.20, but was only done for WinTitle = "A".
	// See "IsIconic" in WinActivate() for comments.
	if (IsIconic(aTargetWindow))
		// This might never return if aTargetWindow is a hung window.  But it seems better
		// to do it this way than to use the PostMessage() method, which might not work
		// reliably with apps that don't handle such messages in a standard way.
		// A minimized window must be restored or else SetForegroundWindow() always(?)
		// won't work on it.  UPDATE: ShowWindowAsync() would prevent a hang, but
		// probably shouldn't use it because we rely on the fact that the message
		// has been acted on prior to trying to activate the window (and all Async()
		// does is post a message to its queue):
		ShowWindow(aTargetWindow, SW_RESTORE);

	if (aTargetWindow == orig_foreground_wnd) // It's already the active window.
		return aTargetWindow;

	// This causes more trouble than it's worth.  In fact, the AutoIt author said that
	// he didn't think it even helped with the IE 5.5 related issue it was originally
	// intended for, so it seems a good idea to NOT to this, especially since I'm 80%
	// sure it messes up the Z-order in certain circumstances, causing an unexpected
	// window to pop to the foreground immediately after a modal dialog is dismissed:
	//BringWindowToTop(aTargetWindow); // AutoIt3: IE 5.5 related hack.

	HWND new_foreground_wnd;

	if (!g_WinActivateForce)