Windows 7: how to bring a window to the front no m

Question

I'm implementing a task-bar replacement, dock-like application-switcher style program. It's doing some unique stuff with OpenGL, and with keyboard shortcuts, so the way it's set up, the window doesn't always have focus. I'd like to implement it such that I can bring an arbitrary window to the foreground, much like a taskbar or an ALT-TAB program would.

However, my code simply causes the application icon to flash in the taskbar. The Windows API documentation says that this is what is supposed to happen, but I'm looking for a way to work around this.

I've adapted my code from the following examples, which say that attaching to the foreground thread should allow you to set the foreground window. Here are the sites:

http://www.voidnish.com/Articles/ShowArticle.aspx?code=dlgboxtricks

http://invers2008.blogspot.com/2008/10/mfc-how-to-steal-focus-on-2kxp.html

My code looks like this. Note that it's using the win32 wrappers for python (self.hwnd is the handle of the window I want to bring to the front):

fgwin = win32gui.GetForegroundWindow()
fg = win32process.GetWindowThreadProcessId(fgwin)[0]
current = win32api.GetCurrentThreadId()
if current != fg:
    win32process.AttachThreadInput(fg, current, True)
    win32gui.SetForegroundWindow(self.hwnd)
    win32process.AttachThreadInput(fg, win32api.GetCurrentThreadId(), False)

However, unless my window is the foreground window (which it isn't usually), this just causes the program's icon to flash.

Am I doing the thread attaching wrong? Is there another way to work around this? I figure there must be, as there are lots of application switchers out there that seem to be able to do this just fine.

I'm writing this in python, but if there is a solution in another language I will use wrappers or do whatever is necessarry to get this up and running.

Thanks in advance!

EDIT: I'd be open to a way to make it work only on my particular computer, i.e. a way to enable, on my machine, a way for any application to take focus.

SOLVED: What you have to do is disable the foreground lock. Turns out it was as easy as this:

win32gui.SystemParametersInfo(win32con.SPI_SETFOREGROUNDLOCKTIMEOUT, 0, win32con.SPIF_SENDWININICHANGE | win32con.SPIF_UPDATEINIFILE)

Answer 1

The documentation for the SetForegroundWindow function explains, that this is actually the intended behaviour; processes shouldn't be able to "steal" the focus. However, it's possible to adjust your code so that it works anyway.

Have a look at the remark section of LockSetForegroundWindow: it explains

The system automatically enables calls to SetForegroundWindow if the user presses the ALT key[..]

You can exploit this behaviour by making your program simulate pressing the Alt key using the SendInput function before calling SetForegroundWindow.

Answer 2

According to nspire, I've tried his solution with python 2.7 and W8, and it works like a charm, even if the window is minimized *.

win32gui.ShowWindow(HWND, win32con.SW_RESTORE)
win32gui.SetWindowPos(HWND,win32con.HWND_NOTOPMOST, 0, 0, 0, 0, win32con.SWP_NOMOVE + win32con.SWP_NOSIZE)  
win32gui.SetWindowPos(HWND,win32con.HWND_TOPMOST, 0, 0, 0, 0, win32con.SWP_NOMOVE + win32con.SWP_NOSIZE)  
win32gui.SetWindowPos(HWND,win32con.HWND_NOTOPMOST, 0, 0, 0, 0, win32con.SWP_SHOWWINDOW + win32con.SWP_NOMOVE + win32con.SWP_NOSIZE)

• Originally it was if the window it's not minimized, but thanks to Whome's comment win32gui.ShowWindow(HWND, win32con.SW_RESTORE), it now works in all situations .

Answer 3

If you're implementing hotkeys, use RegisterHotKey. As Raymond Chen puts it (companion blog article to the one already linked by Chris), "Pressing a registered hotkey gives you the foreground activation love".

Answer 4

I've had some code that's been running for years, going all the way back to Windows 95. When double clicking the applications system tray icon I always used Win32 API functions such as BringWindowToTop and SetForegroundWindow to bring my application windows to the foreground. This all stopped working as intended on Windows 7, where my input window would end up behind other windows and the window icon would flash on the status bar. The 'work around' that I came up with was this; and it seems to work on all versions of Windows.

//-- show the window as you normally would, and bring window to foreground.
//   for example;
::ShowWindow(hWnd,SW_SHOW); 
::BringWindowToTop(hWnd);
::SetForegroundWindow(hWnd);

//-- on Windows 7, this workaround brings window to top
::SetWindowPos(hWnd,HWND_NOTOPMOST,0,0,0,0, SWP_NOMOVE | SWP_NOSIZE);
::SetWindowPos(hWnd,HWND_TOPMOST,0,0,0,0,SWP_NOMOVE | SWP_NOSIZE);
::SetWindowPos(hWnd,HWND_NOTOPMOST,0,0,0,0,SWP_SHOWWINDOW | SWP_NOMOVE | SWP_NOSIZE);

Answer 5

I don't like these suggestions of using win32gui because you can't easily install that via pip. So here's my solution:

First, install pywinauto via pip. If you're on Python 2.7.9 or a newer version on the 2 branch, or Python 3.4.0 or a newer version from the 3 branch, pip is already installed. For everyone else, update Python to get it (or you can manually download and install it by running this script, if you must run an older version of Python.)

Just run this from the command line (not from within Python):

pip install pywinauto

Next, import what you need from pywinauto:

from pywinauto.findwindows    import find_window
from pywinauto.win32functions import SetForegroundWindow

Finally, it's just one actual line:

SetForegroundWindow(find_window(title='taskeng.exe'))