Question

I encoutered a strange behaviour of handling mouse position by Swing when maximizing JFrame:

When I execute this very simple code…

public class Test {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();

                JMenuBar menubar = new JMenuBar();
                JMenu menu = new JMenu("File");
                menu.add(new JMenuItem("New"));
                menubar.add(menu);
                frame.setJMenuBar(menubar);

                frame.setSize(200, 200);
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }
}

… I can normally click File (first click – press,release) -> New (second click). But when I maximize JFrame and click on File – context menu disappears on mouse release immediately.
Moreover when I hold mouse button – to prevent disappearance – I must move my mouse much further to focus on New item.

The red dot represents area (more or less) where I must move my mouse to focus on New after pressing File and holding mouse button.

I’ve observed the same behaviour when using “right-click context menu” for example when right clicking on chart from JFreeChart.

I thought it was JDK problem because I used Oracle’s JDK, but after installing OpenJDK I have the same results.

Did somebody observe this strange behaviour? Or am I missing something obvious?

I use:

• 1.7.0_147-icedtea (or 1.7.0_04 for java-7-oracle)
• OpenJDK Runtime Environment (IcedTea7 2.0) (7~b147-2.0-0ubuntu0.11.10.1)
• OpenJDK 64-Bit Server VM (build 21.0-b17, mixed mode)
• Linux Mint 12 (lisa) GNOME 3.2.1

Answer 1

Yes – this is a bug in JDK7 as @nIcE cOw mentioned.

I’ve installed JDK6 and I couldn’t reproduce this bug.

java version "1.6.0_23"
OpenJDK Runtime Environment (IcedTea6 1.11pre) (6b23~pre11-0ubuntu1.11.10.2)
OpenJDK 64-Bit Server VM (build 20.0-b11, mixed mode)