Adding key and mouse listener

Question

I tried to add key and mouse listener to JFrame, it didn't work, also i find out that JFrame can't get focus. I have a function which loads the buffered image where i want to add the mouse and key listener in entire image dimension.

  public void imageloader(BufferedImage image) throws InterruptedException {

        // frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Dimension dimension = new Dimension(image.getWidth(), image.getHeight());
        setSize(200, 100);
        setVisible(true);
        label.removeAll(); //label is Jlabel
        label.setIcon(new ImageIcon(image));
        frame.setSize(dimension);
        label.revalidate();
        JScrollPane pane = new JScrollPane(label,
                ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
                ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
        frame.getContentPane().add(pane);
        frame.setSize(dimension);
       // frame.setVisible(true);


    }

How can be mouse and key listener be added to this image frame without moving parts from this function?

hehehe you questions talks about 1st. from options :-), thanks for edit — mKorbel
– mKorbel, Commented Oct 31, 2011 at 14:31
hmmm maybe, not sure because you can't post required code, only code snipped, to try to wrap that into invokeLater() as discused here stackoverflow.com/questions/7966287/… — mKorbel
– mKorbel, Commented Nov 1, 2011 at 16:07

Community · Accepted Answer · 2017-05-23 11:47:58Z

2

Use KeyBindings instead of KeyListener, example for something similair is here

The reason for this is how events are handled by Swing. You need a widget with focus for KeyListener to work - without focus, any KeyListeners are ignored (otherwise, typing would add to all TextFields in your UI instead of only the one with the focus).

The raw KeyBindings API doesn't care about focus - if no child window processes the event, the listener will be called.

edited May 23, 2017 at 11:47

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answered Oct 31, 2011 at 14:29

mKorbel

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4 Comments

nebula Over a year ago

I don't have problem handling the events. I just want to add the listener to the image somehow.

Aaron Digulla Over a year ago

I updated the answer to make the difference between a KeyListener and a KeyBinding more obvious.

camickr Over a year ago

+1, for the key bindings. @aneal yes you will have a problem because labels don't get focus so a key event won't be generated.

nebula Over a year ago

I think its hard to understand. If i am not wrong KeyBinding is used for individuals key, but i am trying to get keycode of each pressed key irrespective of what key is pressed. So how can i do that with KeyBinding?

camickr · Accepted Answer · 2011-10-31 14:42:01Z

2

Add the MouseListener to the label. Use Key Bindings for the key events.

answered Oct 31, 2011 at 14:42

camickr

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Comments

nebula · Accepted Answer · 2011-12-03 12:10:02Z

0

I solved the problem using Layered panes. I used one pane to display buffered image and next pane to listen Mouse and Keyboard events.

answered Dec 3, 2011 at 12:10

nebula

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