How do you force a java swt program to "move itself to the foreground"?

Question

Currently with swt, I sometimes want a program to arbitrarily come to the foreground (like an alarm clock might).

Typically the following works (jruby):

@shell.setMinimized(false)
@shell.forceActive

This brings the shell to the front if it was minimized.

Creating a new shell at any time also brings the (new shell) to the front.

So far so good, however, if the shell is not minimized, the above code just flashes (blinks) the app's icon in the taskbar. Well actually the first time you run it, it brings it to the front. After that, it just blinks in the taskbar. That's windows. On Linux it appears to only blink in the taskbar (ubuntu default).

Does anybody know of a cross platform way of getting the app to come to the front, in swt?

It seems that no incantation of forceActive setActive setMinimized(false) setFocus forceFocus and setVisible can accomplish this thing.

I'm pretty sure it is possible (at least in windows), as the E Text Editor does it. Well, that's not swt, but at least some other apps have been known to do it.

I'm thinking maybe this is a swt bug one, two?

Many thanks.

Related:

http://stackoverflow.com/questions/309023/howto-bring-a-java-window-to-the-front
http://book.javanb.com/swt-the-standard-widget-toolkit/ch11lev1sec4.html
http://dev.eclipse.org/newslists/news.eclipse.platform.swt/msg35192.html
http://stackoverflow.com/questions/1576463/keep-window-in-foreground-even-if-it-loses-focus https://bugs.eclipse.org/bugs/show_bug.cgi?id=244597 http://stackoverflow.com/questions/204181/need-to-bring-application-to-foreground-on-windows

Answer 1

http://github.com/rdp/redcar/commit/d7dfeb8e77f13e5596b11df3027da236f23c83f0

shows how I did it in windows, anyway (using ffi).

A couple of helpful tricks "may" be

add a 'sleep 0.1' after the BringToFront.SetForegroundWindow(wanted) call (hopefully this one isn't actually necessary).

add a shell.set_active after you have brought the window to the foreground. For some reason forceActive doesn't call setActive.

NB that setActive does a user32.dll BringWindowToTop call, and needs to be done before you detach thread input.

Note also that it appears if you can do you calls in the right order you may not need to use the thread input hack at all (?)

http://betterlogic.com/roger/?p=2950

(contains several good hints on how to actually do this right)

On Linux, forceActive does work--but only until you move to another few windows,, then it blinks in the taskbar after that (only). Guessing swt bug. [1]

Also related:

http://stackoverflow.com/questions/309023/howto-bring-a-java-window-to-the-front

http://github.com/jarmo/win32screenshot/blob/master/lib/win32/screenshot/bitmap_maker.rb#L110 "set_foreground" which seems to work with both xp and windows 7

[1] http://stackoverflow.com/questions/204181/need-to-bring-application-to-foreground-on-windows and https://bugs.eclipse.org/bugs/show_bug.cgi?id=303710

Answer 2

This is actually a feature of Windows, which can be enabled via the Tweak UI power toy (at least for Windows XP). When enabled the O/S deliberately prevents a window from forcing itself to be the focused window to stop it "stealing focus". As such, the action to grab focus is changed to just flashing the taskbar icon - since the O/S is deliberately converting the action at the user's request, there will be nothing you can do about it (and this is a good thing).

This was (probably) done because so many applications abused the bring-to-front API and the behavior both annoyed users and caused them to input into the wrong application.