<AWT Dev> [7u4] Review request for 7145818: [macosx] dialogs not showing when JFrame is in full screen mode

Mike Swingler swingler at apple.com
Thu Mar 1 15:14:33 PST 2012

On Mar 1, 2012, at 1:10 PM, Anthony Petrov wrote:

> Hi Mike,
> Thanks for the review! Please see my comments inline.
> On 3/1/2012 9:31 PM, Mike Swingler wrote:
>> On Feb 29, 2012, at 6:58 AM, Anthony Petrov wrote:
>>> http://cr.openjdk.java.net/~anthony/x-21-popupInFullscreen-7145818.0/
>> A few points to consider:
>> * To protect against the unrecognized selector problem, you should test if the AWTWindow object -respondsToSelector:@selector(toggleFullScreen) before just calling it.
> I'm aware of -respondsToSelector. But I suppose that in that case this simply won't work on 10.6.8 at all. Since
> a) presently it does work on 10.6.8 for reasons unknown, and

If OpenJDK is built on Snow Leopard, it works fine. I believe the problem is the X11/FreeType versions in Lion are newer, and DYLD won't load libraries linked against older versions. But that is going to start me on my rant about how OpenJDK should bundle it's own FreeType...

> b) we officially support 10.7+ only, hence the check makes little sense in theory, and

Please think of OpenJDK, not just Oracle's proprietary binaries. There are other users who currently compile on Snow Leopard and this is not an inconvenience, since 10.7-only API is very rare in the JDK.

> c) from ObjC perspective sending an unknown selector isn't an error, but just a warning,

It is extremely poor form. The -respondsToSelector: check is very cheap, and is very obvious what it is guarding against.

> it seems to me that having this warning printed out to the console (which isn't seen by 99% of users anyway) is OK when running on 10.6.8. Plus we get the full screen working there. Isn't it awesome?

We know there are developers and users who will be running OpenJDK on Mac OS X 10.6.8, so it is perfectly reasonable to add this as an OS guard. We should not actively damage our ability to run on 10.6 if it's trivially avoidable.

>> * Also, there is already API that calls -toggleFullScreen in the eAWT classes that you might not be aware of. You should probably test for interactions with that, since apps can opt their window into having a full screen widget icon and independently toggle fullscreen.
> Thanks for pointing this out. I'll rework this code to make sure calls from EAWT update the boolean flag.


>> * In some cases, seeing the menubar is actually desirable, where as in the "exclusive" mode, it's probably not. Perhaps you could consult a client property on the window to determine if the menu bar should be hidden?
> Excellent idea! I think that by default the menu should be hidden (for Java spec's sake). But if a client property is set, then the menu would be visible.

Cool. There are several client property readers already on the root AWT window that should be easily extendable.

>> I like this overall solution, because it uses the native platform concept of full screen which doesn't trap the user from switching spaces like the Java SE 6 implementation did.
> We've noticed an interesting detail with -toggleFullScreen when it's used in a multi-screen environment. In that case the window will go full screen on the biggest monitor (actually we have a MacBook with an external monitor connected.) The OS seems to ignore the screen where the window were before entering the FS mode (the main notebook display). Is this OK? Can we force it to use the same screen where the window is originally located for the FS mode?

It's actually the monitor with the menu bar (the primary, as designated in the Monitor's preference pane).

This is an issue with the OS, and should be filed at <http://bugreporter.apple.com> (it's known, but if you have a specific API suggestion to target a screen, or some sort of automatic behavior in mind, it would be good to provide specific suggestions in the bug).

Mike Swingler
Apple Inc.

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