Python Window Activation

Question

How would I programmatically activate a window in Windows using Python? I'm sending keystrokes to it and at the moment I'm just making sure it's the last application used then sending the keystroke Alt+Tab to switch over to it from the DOS console. Is there a better way (since I've learned by experience that this way is by no means foolproof)?

Answer 1

You can use the win32gui module to do that. First you need to get a valid handle on your window. You can use the win32gui.FindWindow if you know the window class name or the exact title. If not, you can enumerate the windows with the win32gui.EnumWindows and try to find the right one.

Once you have the handle, you can call the win32gui.SetForegroundWindow with the handle. It will activate the window and will be ready for getting your keystrokes.

See an example below. I hope it helps

import win32gui
import re


class WindowMgr:
    """Encapsulates some calls to the winapi for window management"""

    def __init__ (self):
        """Constructor"""
        self._handle = None

    def find_window(self, class_name, window_name=None):
        """find a window by its class_name"""
        self._handle = win32gui.FindWindow(class_name, window_name)

    def _window_enum_callback(self, hwnd, wildcard):
        """Pass to win32gui.EnumWindows() to check all the opened windows"""
        if re.match(wildcard, str(win32gui.GetWindowText(hwnd))) is not None:
            self._handle = hwnd

    def find_window_wildcard(self, wildcard):
        """find a window whose title matches the wildcard regex"""
        self._handle = None
        win32gui.EnumWindows(self._window_enum_callback, wildcard)

    def set_foreground(self):
        """put the window in the foreground"""
        win32gui.SetForegroundWindow(self._handle)


w = WindowMgr()
w.find_window_wildcard(".*Hello.*")
w.set_foreground()

Answer 2

Pywinauto and SWAPY will probably require the least effort to set the focus of a window.

Use SWAPY to auto-generate the python code necessary to retrieve the window object, e.g.:

import pywinauto

# SWAPY will record the title and class of the window you want activated
app = pywinauto.application.Application()
t, c = u'WINDOW SWAPY RECORDS', u'CLASS SWAPY RECORDS'
handle = pywinauto.findwindows.find_windows(title=t, class_name=c)[0]
# SWAPY will also get the window
window = app.window_(handle=handle)

# this here is the only line of code you actually write (SWAPY recorded the rest)
window.SetFocus()

If by chance other windows are in front of the window of interest, not a problem. This additional code or this will make sure it is shown before running the above code:

# minimize then maximize to bring this window in front of all others
window.Minimize()
window.Maximize()
# now you can set its focus
window.SetFocus()

Answer 3

import ctypes, platform

if platform.system() == 'Windows':
    Active_W = ctypes.windll.user32.GetActiveWindow()
    ctypes.windll.user32.SetWindowPos(Active_W,0,0,0,0,0,0x0002|0x0001)

Here we go. you just need to store the value of the active window.