Detect application windows

Question

I use CBT Windows Hook to detect window creation/deletion/min-max/move-size events.

I works well, but I need to filter whose events coming from normal widgets. Practically I need to being notified by CBT hook only for those windows that the user consider windows.

The problem that I'm facing make me mad, since I continuosly get spurious events even if I filter window as follow:

BOOL FilterWindowHandle(HWND hwnd)
{
    // Filtered window having WS_CHILDWINDOW style
    if ((GetWindowLongPtr(hwnd, GWL_STYLE) & WS_CHILDWINDOW) != 0)
        return (TRUE);
    // Filtered window not having WS_CAPTION style
    if ((GetWindowLongPtr(hwnd, GWL_STYLE) & WS_CAPTION) == 0)
        return (TRUE);
    // Not filtered
    return (FALSE);
}

Those spurious events comes from shadow effects, menus and everything displayed on screen.

Is there a robust method to filter real windows from its children?

I avoid the test of WS_BORDER or similar, since some applications could create their main window without border... or am I wrong?

you are the one with a certain criteria. you have in your mind a definition for what a "real window" is, and that's different than what the OS considers a window. Define that criteria, and write your code to match it. Tip: Use Spy++ to look at window styles of windows on your system, and this plus MSDN should help lead you to the solution. — tenfour, Aug 13 '10 at 15:36
maybe, but either way in the end you must know what you're doing, and what the styles mean. Nobody said programming was easy :) — tenfour, Aug 13 '10 at 15:42
You could use accessibility tools such as Windows Automation: http://blogs.msdn.com/b/winuiautomation/archive/2009/06/03/windows-automation-api-sdk-tools.aspx or http://msdn.microsoft.com/en-us/windows/bb735024 as these are supposed to "filter" non-meaningful windows. — Simon Mourier, Dec 25 '10 at 22:12

score 1 · Accepted Answer · answered Dec 25 '10 at 22:59

A good fit for "things the user considers windows" is the set of windows displayed in the Alt-Tab list (or on the Taskbar).

This OldNewThing article explains the rules (although the rules are not fixed or guaranteed to remain the same):

Which windows appear in the Alt+Tab list?

The general rule is:

For each visible window, walk up its owner chain until you find the root owner. Then walk back down the visible last active popup chain until you find a visible window. If you're back to where you're started, then put the window in the Alt+Tab list.

This can be overridden with explicit window styles:

A window with the WS_EX_TOOLWINDOW extended style is treated as if it weren't visible, even if it is. A window with the WS_EX_APPWINDOW extended style is treated as if it has no owner, even if it does.

See the full OldNewThing post which those two quotes come from for more detail.

score 0 · Answer 2 · answered Dec 25 '10 at 22:07

0

A useful criteria that I've used in the past is to test whether the window is a top-level window, i.e. its parent is NULL.

answered Dec 25 '10 at 22:07

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Detect application windows

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