Tricks to getting Java Frames working on the OLPC

[Steve Lewis]

The following code allows Java JFrames to work properly on the OLPC -
it assumes - only one active frame and that the frame is full screen.
You can add it to common applications = the active sections work only on
the OLPC
The trick is to use showFrame and hideFrame instead of setVisible -
these cause the frame to become the graphic environments full screen
window -
With this I have menus forking. I have patched JEdit to use this and
have that application fully functional
on the OLPC - I also have a first cut at a Sugar jedit launcher -
Write me for code - I will look for a good place to post this

    // OLPC Patch Slewis  smlewis at lordjoe.com
    /**
     * true of the code is running on OLPC
     *
     * @return as above
     */
    public static boolean isOLPC() {
        String s = System.getProperty("os.name");
        if (!s.equalsIgnoreCase("Linux"))
            return false;
        s = System.getProperty("os.arch");
        if (!s.equalsIgnoreCase("i386"))
            return false;
        s = System.getProperty("os.version");
        if (!s.contains(".olpc."))
            return false;
        return true;
    }

    /**
     * a simgle active frame
     */
    private static JFrame gActiveFrame;

    /**
     * retrieve the current active frame
     * @return possibly null active frame
     */
    protected static JFrame getActiveFrame() {
        return gActiveFrame;
    }

    /**
     * set the active frame in effect setting is visible
     * @param pActiveFrame possibly null frame - null hides
     * @throws IllegalStateException if there is an active frame
different from the argument
     */
    protected static void setActiveFrame(JFrame pActiveFrame) throws
IllegalStateException
    {
        if(gActiveFrame != null)  {
            if(gActiveFrame == pActiveFrame)
                return;  // nothing to do
            if(pActiveFrame != null) {
                throw new IllegalStateException("Only one active frame
allowed");
            }
            else {
                if(gActiveFrame != null)
                    gActiveFrame.setVisible(false);  // is this needed???
             }
        }
        GraphicsEnvironment env = GraphicsEnvironment.
                getLocalGraphicsEnvironment();
        GraphicsDevice[] devices = env.getScreenDevices();
        // REMIND : Multi-monitor full-screen mode not yet supported
        GraphicsDevice dev = devices[0];
        boolean isFullScreen = dev.isFullScreenSupported();  // always
true on OLPC
        dev.setFullScreenWindow(pActiveFrame);
        if(pActiveFrame != null)
            pActiveFrame.setVisible(true);  // is this needed???
        gActiveFrame = pActiveFrame;
    }

    /**
     * Use this code instead of frame.setVisible(true)
     *
     * @param frame non-null frame
     */
    public static void showFrame(JFrame frame) {
        // OLPC Patch
        if (isOLPC()) {
            setActiveFrame(frame);
        } else {
            frame.setVisible(true);
        }
    }

    /**
     * Use this code instead of frame.setVisible(false)
     *
     * @param frame non-null frame
     */
    public static void hideFrame(JFrame frame) {
        // OLPC Patch
        if (isOLPC()) {
            if(getActiveFrame() == frame)
                setActiveFrame(null);
        } else {
            frame.setVisible(false);
        }
    }

-- 
Steven M. Lewis PhD
4221 105th Ave NE
Kirkland, WA 98033
425-889-2694
206-384-1340 (cell)
Skype lordjoe_com
AIM LordJoe2000
ICQ 127138272
email 
smlewis at lordjoe.com (permanent)