Provide Quit handler for system menu bar

[Kevin Rushforth]

I like the idea of looking at this holistically, even if we do end up 
adding such features one at a time.

As for how to expose such an API, I don't much like the idea of exposing 
the underlying platform explicitly unless there is no viable 
alternative. A better approach is one where a feature is optional based 
on whether the platform you are running on supports that feature. 
Especially given, as you pointed out, that features that are only 
available in one platform today might make their way into other 
platforms tomorrow. As for how to let an application know whether they 
can use a particular API, we already have ConditionalFeature, so adding 
to that would be a reasonable thing to consider.

-- Kevin


On 9/19/2022 9:06 AM, Andy Goryachev wrote:
>
> Greetings!
>
> Thank you for proposing a solution, Florian.  I wonder if we should 
> extrapolate the problem further.  Given the fact that app developers 
> always need access to platform specific APIs, be it integration with 
> Mac menu, perhaps we should consider a way to do so in such a way that 
> does not require various tricks.
>
> For example, we might invent a way to query whether we are running on 
> a certain platform and get the corresponding APIs.  Let's say the 
> class is PlatformAPI:
>
> These methods allow for querying whether the specific platform APIs 
> are available
>
> PlatformAPI.isWindows();
>
> PlatformAPI.isMacOS();
>
> PlatformAPI.isLinux(); // isUnix()? isPosix() ?
>
> and these will actually return a service object that provides access 
> to the APIs, or throws some kind of exception:
>
> IWindowsAPI PlatformAPI.getWindowsAPI();
>
> IMacOSAPI PlatformAPI.getMacOSAPI();
>
> the service object returned by one of these methods might provide 
> further information about the platform version, as well as access to 
> platform-specific APIs.
>
> Another thought is perhaps we ought to think about expanding 
> functionality that became available on every platform in the XXI 
> century (example: going to sleep/hibernate).  Possibly external 
> shutdown via Mac menu or a signal discussed by the OP would be 
> considered as platform-independent.
>
> What do you think?
>
> -andy
>
> *From: *openjfx-dev <openjfx-dev-retn at openjdk.org> on behalf of 
> Florian Kirmaier <florian.kirmaier at gmail.com>
> *Date: *Tuesday, 2022/09/13 at 08:11
> *To: *openjfx-dev at openjdk.java.net <openjfx-dev at openjdk.java.net>
> *Subject: *Provide Quit handler for system menu bar
>
> Hi Everyone,
>
>
> In one project, we have to handle the quit-logic for MacOS ourselves,
> when the <quit app> menu entry is used.
> As background information - this menu entry is set in the 
> class com.sun.glass.ui.mac.MacApplication.
> It's basically hard coded. Currently, in this project, the menu entry 
> doesn't work in some cases.
>
> My Solution would be:
>
> Provide a method "Platform.setQuiteHandler(Supplier<Boolean>)"
> This handler is called when quit <appname> from the menu is called.
> If the handler returns true, all windows are closed. Otherwise, 
> nothing happens.
>
> It would look like the following:
> ```
> /**
>  * Sets the handler to be called when the application is about to quit.
>  * Currently, this can only happen on MacOS.
>  *
>  * This handler is called, when the user selects
>  * the "Quit <appname>" from the application menu.
>  * When the provided handler returns true,
>  * the application will close all windows.
>  * If the handler returns false, the application will not quit.
>  *
>  * @param The new quit handler.
>  */
> public static void setQuitHandler(Supplier x) {
>     ...
> }
> ```
> I've created a ticket for this topic. 
> https://bugs.openjdk.org/browse/JDK-8293700
>
>
> I've got a working version for this change.
>
> According to Kevin Rushforth this need a prior dicussion on the 
> mailing list.
>
> Any opinion regarding this?
>
> I could provide a pullrequest, if someone is interested.
>
> Florian Kirmaier
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.openjdk.org/pipermail/openjfx-dev/attachments/20220919/819328f7/attachment-0001.htm>