EnumClaw, documented as returning "the child or the parent of the window", was a joke, but there's a function whose behavior is just as confusing as the joke function
GetParent function returns the parent window, or owner window, or possibly neither. All that's left is for it to be a floor wax and it'll have everything covered.
The idea behind
GetParent is that it returns the parent window. Only child windows have parents, so what happens if you pass something that isn't a child window? Well, we shouldn't let a parameter go to waste, right? So let's have it return the owner window if you pass in a top-level window. But wait, we're not going to return the owner window for all top-level windows, just for top-level windows which have the
This last bit regarding the
WS_POPUP style is a leftover from Windows 1.0, where there was a distinction made between "tiled windows" and "popup windows." Popup windows could overlap, whereas tiled windows could not, and the function was only interested in windows that can overlap. Of course, now that all windows can overlap, the rejection of tiled windows is just a compatibility remnant.
Anyway, the algorithm for
GetParent goes like this:
- If the window is a child window, then return the parent window.
- Else, the window is a top-level window. If
WS_POPUPstyle is set, and the window has an owner, then return the owner.
- Else, return
Here it is in tabular form, since I've discovered that people like tables:
The upper left entry of the table (corresponding to
WS_POPUP both set) is left as N/A because that combination of styles is illegal.
Fortunately, you don't have to deal with all the craziness of the
GetParent function. There are ways to get the parent or owner separately and explicitly without having to deal with
- To get the parent window, call
- To get the owner window, call
Compatibility requirements prevent
GetParent from ever going away, but that doesn't mean you are forced to continue using it. Use one of the less confusing alternatives. That's why they're there.