How to make python window run as “Always On Top”?

问题

I am running a little program in python that launches a small window that needs to stay on top of all the other windows. I believe this is OS specific, how is it done in GNU-Linux with GNOME?

[Update - Solution for Windows]

Lovely, I think I got it working. I am using Python 2.5.4 with Pygame 1.9.1 in Eclipse on Vista 64-bit. Thus, this is for windows systems. The SetWindowPos function is documented Here. I will refer to this in my explanation.

Imports:

from ctypes import windll

Then I set up a variable that calls the "SetWindowPos" in user32:

SetWindowPos = windll.user32.SetWindowPos

Now, let's say I just made a window:

screen = pygame.display.set_mode((100,100), pygame.NOFRAME)

The next line is the key. This sets the window to be on top of other windows.

SetWindowPos(pygame.display.get_wm_info()['window'], -1, x, y, 0, 0, 0x0001)

Basically, You supply the hWnd(Window Handle) with the window ID returned from a call to display.get_wm_info(). Now the function can edit the window you just initialized.

The -1 is our hWndInsertAfter.

The MSDN site says:

A window can be made a topmost window either by setting the hWndInsertAfter parameter to HWND_TOPMOST and ensuring that the SWP_NOZORDER flag is not set, or by setting a window's position in the Z order so that it is above any existing topmost windows. When a non-topmost window is made topmost, its owned windows are also made topmost. Its owners, however, are not changed.

So, the -1 makes sure the window is above any other existing topmost windows, but this may not work in all cases. Maybe a -2 beats a -1? It currently works for me. :)

The x and y specify the new coordinates for the window being set. I wanted the window to stay at its current position when the SetWindowPos function was called on it. Alas, I couldn't find a way to easily pass the current window (x,y) position into the function. I was able to find a work around, but assume I shouldn't introduce a new topic into this question.

The 0, 0, are supposed to specify the new width and height of the window, in pixels. Well, that functionality is already in your pygame.display.set_mode() function, so I left them at 0. The 0x0001 ignores these parameters.

0x0001 corresponds to SWP_NOSIZE and is my only uFlag. A list of all the available uFlags are on the provided documentation page. Some of their Hex representations are as follows:

SWP_NOSIZE = 0x0001
SWP_NOMOVE = 0x0002
SWP_NOZORDER = 0x0004
SWP_NOREDRAW = 0x0008
SWP_NOACTIVATE = 0x0010
SWP_FRAMECHANGED = 0x0020
SWP_SHOWWINDOW = 0x0040
SWP_HIDEWINDOW = 0x0080
SWP_NOCOPYBITS = 0x0100
SWP_NOOWNERZORDER = 0x0200
SWP_NOSENDCHANGING = 0x0400

That should be it! Hope it works for you!

Credit to John Popplewell at john@johnnypops.demon.co.uk for his help.

回答1:

The question is more like which windowing toolkit are you using ? PyGTK and similar educated googling gave me this:


gtk.Window.set_keep_above

As mentioned previously it is upto the window manager to respect this setting or not.

Edited to include SDL specific stuff Pygame uses SDL to do display work and apprently does not play nice with Windowing toolkits. SDL Window can be put on top is discussed here.

回答2:

I really don't know much Python at all, but Googling "pygtk always on top" gave me this:

http://www.mail-archive.com/pygtk@daa.com.au/msg01370.html

The solution posted there was:

transient.set_transient_for(main_window)

You might also want to search things like "x11 always on top". The underlying concept seems to be that you're giving the window manager a "hint" that it should keep the window above the others. The window manager, however, has free reign and can do whatever it wants.

I've also seen the concept of layers when using window managers like Fluxbox, so maybe there's a way to change the layer on which the window appears.