Alt-spacebar and native title bars

Windows
1

I’ve posted about this before in the main forum, but I learned some more and this is a Windows -only topic.

If you have a window with a native titlebar, then this is OK:

-click on the titlebar
-press alt-spacebar
-system menu is shown correctly

This doesn’t work:

-click somewhere in the content component
-press alt-spacebar
-system menu doesn’t show up

I did some debugging and I noticed that in both cases, the window is still receiving WM_SYSCOMMAND. So I’m wondering - is the menu showing up in the second case, but isn’t being painted properly because the z-order is different?

Matt

2

no, the menu’s not appearing, though I can’t figure out why - none of the windows messages that could interfere with it are getting overridden. I’m a bit stumped on that one, actually.

3

I think I figured it out - you only get the menu if the window isn’t set for mouse capture.

So here’s my change to peerWindowProc :

[code] case WM_SYSCOMMAND :
if ((styleFlags & windowHasTitleBar) != 0)
{
switch (wParam & 0xfff0)
{
case SC_CLOSE :
handleUserClosingWindow();
break;

					case SC_KEYMENU :
						if (h == GetCapture())
							ReleaseCapture();
						break;
				}
			}

			break;[/code]
4

aha! Very smart, I could have stared at it for a long time before figuring that one out!

Cheers matt, I’ll put that fix in there.

5

Thanks; I just applied my usual technique of poking randomly at it until I learned something. : )

However, the fix I posted broke the demo; if you had the demo in native title bar mode and clicked the close button, my change caused the app to try and shut down twice. First you get the WM_SYSCOMMAND with SC_CLOSE, which causes the window to close, followed by WM_CLOSE, which tries to close the window again.

This results in the JUCE shutdown code running twice, which toggles a jassert.

So I changed it to this:

[code] case WM_SYSCOMMAND :
if ((styleFlags & windowHasTitleBar) != 0)
{
switch (wParam & 0xfff0)
{
case SC_CLOSE :
PostMessage(h,WM_CLOSE,0,0);
return 0;

					case SC_KEYMENU :
						if (h == GetCapture())
							ReleaseCapture();
						break;
				}
			}

			break;

[/code]

This doesn’t pass the SC_CLOSE to DefWindowProc, which prevents the double WM_CLOSE message. It seems to handle all the cases - pressing alt-F4, double clicking the system menu icon, using the system menu, or pressing the close button.

Matt

6

ok, cool. Nice work!