如何在OSX中执行时强制Qt应用程序成为活动/前台窗口？

Question

I'm going through Qt tutorials on OSX. One thing I noticed is that when I launch the executable (eg the push button hello world example), the app will launch as a background window and I have to switch tasks to bring it into the foreground. How can I force the Qt application window to be the foreground window upon execution?

I'd like to do this since it's how most apps behave, not to mention that manually switching tasks slows down my edit-compile-run-debug cycle).

Answer 1

The behavior you observe is due to interaction with the debugger when you start the application under the debugger using ⌘-Y. If you simply run it using ⌘-R, it behaves as you expect. Your application itself is fine.

Starting OS X applications by directly firing up the executable from within the app bundle from the terminal will act similarly to running them using ⌘-Y -- they all start in the background. Qt is probably mimicking whatever magic Finder does when it starts the process via ⌘-R -- said magic may reduce to simply bringing the child app to the foreground. gdb on OS X is not so "clever", and probably for a good reason.

OS X approach is to try harder not to steal focus -- a good thing IMHO.

If you merely want to run the application, not debug it, then modify your launch command to look like open -a '/Users/daj/foo/bar/baz.app' , where baz.app is the app bundle folder. Do not append a trailing slash.

If you can coax your debugger to follow through to child processes, then you can of course launch open itself under gdb, and it will work as expected -- with your child application on top.