How Do I Make My Application "Feel" Faster

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Jason Cavett - 29 Nov 2006 20:31 GMT

I'm currently designign a GUI and, while it's going pretty well, I've
noticed when I do something like open an document using the GUI, the
drop down menu (File > Open) that I've created doesn't immediately
disappear. It seems to hang there for a moment and refreshes after the
document is starting to open. This happens with other things as well.

I tried turning on Swing's built in double-buffering on the menus, but
that doesn't seem to help any. I have also searched around on the web
to see if there was any information on how to fix this problem.

Basically, I'm wondering - how do I make my app "feel" faster so user's
don't get the impression that the application is lagging (even though
it really isn't).

Thanks

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J. David Boyd - 29 Nov 2006 21:30 GMT

> I'm currently designign a GUI and, while it's going pretty well, I've
> noticed when I do something like open an document using the GUI, the
[quoted text clipped - 9 lines]
> don't get the impression that the application is lagging (even though
> it really isn't).

Are you using multiple threads: 1 for the GUI, one for the file processing?

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Steve W. Jackson - 29 Nov 2006 21:33 GMT

> I'm currently designign a GUI and, while it's going pretty well, I've
> noticed when I do something like open an document using the GUI, the
[quoted text clipped - 11 lines]
>
> Thanks

Sounds like you're looking to "manage perceptions" for someone using
your app, which is good.

If you do everything that File>Open implies inside the actionPerformed
method of an ActionListener, which executes on the Event Dispatch Thread
(EDT), then the repainting of the menu and other GUI components occurs
later. This can give the appearance of slowness, in my experience,
whether it really is slow or not.

One step I've taken is to have that actionPerformed method create a
separate thread to do its work. That lets the method itself complete
quicker, thus allowing the GUI to update its appearance, redrawing the
menus, etc. Much of what's done in that separate thread is not likely
to require use of the EDT anyway, which is good.

The gotcha sometimes comes when the action *does* need to do some things
on the EDT, from what I've seen. If I know that to be the case, I try
experimenting to find my options. Often, I can launch that thread with
SwingUtilities.invokeLater (which should be EventQueue.invokeLater,
since that's what it calls as of 1.3). That will queue the new Runnable
and should let actionPerformed finish its work, along with anything else
already on the EDT's queue.

= Steve =

Signature

Steve W. Jackson
Montgomery, Alabama

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Jason Cavett - 30 Nov 2006 14:09 GMT

On Nov 29, 4:33 pm, "Steve W. Jackson" <stevewjack...@knology.net>
wrote:

> In article <1164832296.233748.5...@j44g2000cwa.googlegroups.com>,
>
[quoted text clipped - 39 lines]
> Steve W. Jackson
> Montgomery, Alabama- Hide quoted text -- Show quoted text -

That was a great explanation, thank you.

So, I attempted to create a thread in my actionPerformed with the
following code:

Thread appThread = new Thread() {
    public void run() {
        try {
            model.openProject();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
};

appThread.run();

However, the menu still seems a little sluggish. Am I approaching this
the right way? (I was never very strong with Threads, so things get a
little fuzzy here for me.)

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Andrew Thompson - 30 Nov 2006 14:36 GMT

> On Nov 29, 4:33 pm, "Steve W. Jackson" <stevewjack...@knology.net>
> wrote:
> > In article <1164832296.233748.5...@j44g2000cwa.googlegroups.com>,

...

> > > I'm currently designign a GUI and, while it's going pretty well, I've
> > > noticed when I do something like open an document using the GUI, the
> > > drop down menu (File > Open) that I've created doesn't immediately
> > > disappear.

....

> > If you do everything that File>Open implies inside the actionPerformed
> > method of an ActionListener, which executes on the Event Dispatch Thread
> > (EDT),

.....

> > One step I've taken is to have that actionPerformed method create a
> > separate thread to do its work.

...

> So, I attempted to create a thread in my actionPerformed with the
> following code:
[quoted text clipped - 3 lines]
> try {
> model.openProject();

....

> However, the menu still seems a little sluggish. Am I approaching this
> the right way? (I was never very strong with Threads, so things get a
> little fuzzy here for me.)

A simple test for whether the problem lies deeper is
to do absolutely nothing in the action performed, just
to check that the menu disappears quickly when
there is no process behind it..

..as an aside, please replace tabs with 2 or 3 spaces
before posting code to usenet, as some news clients,
and web based interfaces to usenet, expand tabs to
ridiculous widths.

Andrew T.

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Steve W. Jackson - 30 Nov 2006 14:59 GMT

[ snip ]

> So, I attempted to create a thread in my actionPerformed with the
> following code:
[quoted text clipped - 15 lines]
> the right way? (I was never very strong with Threads, so things get a
> little fuzzy here for me.)

When you call the run method of a Thread object, it simply executes in
line just like any other method. Instead, call "appThread.start()" in
your code, which causes the Thread object to run in its own separate
thread -- which was your goal. Then appThread will exist independently
of your actionPerformed method and the EDT on which it was invoked, and
will become eligible for garbage collection when its run method
completes.

Alternatively, you could create a Runnable instead of a Thread. If you
actually want to spawn it separately, you can then pass that Runnable as
the parameter to a Thread constructor and call start on the Thread. But
if you should need, as I did in some situations, to have it run on the
EDT, you could pass that Runnable to EventQueue.invokeLater.

= Steve =

Signature

Steve W. Jackson
Montgomery, Alabama

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Jason Cavett - 30 Nov 2006 15:17 GMT

On Nov 30, 9:59 am, "Steve W. Jackson" <stevewjack...@knology.net>
wrote:

> In article <1164895786.940642.122...@n67g2000cwd.googlegroups.com>,
>
[quoted text clipped - 36 lines]
> Steve W. Jackson
> Montgomery, Alabama- Hide quoted text -- Show quoted text -

That works great! :-) Thank you.

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steve - 29 Nov 2006 22:16 GMT

> I'm currently designign a GUI and, while it's going pretty well, I've
> noticed when I do something like open an document using the GUI, the
[quoted text clipped - 11 lines]
>
> Thanks

your on the wrong thread!!.

instead of jumping to your subroutine, when you detect the menu selection,
fire up another thread to process your subroutine and exit from the menu
selection code, straight away.

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Timasmith - 30 Nov 2006 03:45 GMT

> I'm currently designign a GUI and, while it's going pretty well, I've
> noticed when I do something like open an document using the GUI, the
[quoted text clipped - 11 lines]
>
> Thanks

Google swingworker (bundled in 1.6)

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