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POJava Key Binding in a JApplet: What am I doing wrong?
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  1. POJava Key Binding in a JApplet: What am I doing wrong?
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    copied!<p>I'm trying to write a game applet that responds to keys typed by the player. I'm trying to use key bindings to accomplish this. But I can't get it to work. The applet (what little of it there is, at the moment) seems to display correctly in Appletviewer, but nothing happens when I press keys. I haven't been able to test it in a browser, as it doesn't always display correctly in a browser.</p> <p>I'm running Sun Java 6 on Ubuntu. I managed to find mention of a Ubuntu bug where iBus would block keyboard input to applets. However, I don't have iBus running, and I've been able to use keyboard input with other applets (not written by me).</p> <p>Here is the code so far</p> <pre><code>public class AlxTestVersion extends JApplet { private GridBagLayout layout; private GridBagConstraints layoutConstraints; private JPanel mainPanel; public void init() { this.setLayout ( new FlowLayout(FlowLayout.LEFT) ); //Main frame. mainPanel = new JPanel(); layout = new GridBagLayout(); layoutConstraints = new GridBagConstraints(); layoutConstraints.anchor = GridBagConstraints.NORTHWEST; layoutConstraints.fill = GridBagConstraints.NONE; mainPanel.setLayout(layout); mainPanel.setBackground(Color.pink); getContentPane().add(mainPanel); //Map display JPanel leftPanel = new JPanel(); GlobalData.mainMap = new MapCanvas(9); addComponent(GlobalData.mainMap, 0, 0, 1, 1); /* Define other components... */ } public class MapCanvas extends JPanel { private int tileSize; private int mapTileWidth; private int mapOffset; private int mapDim; private MapSquare screenTiles[]; public void paintComponent(Graphics g) { super.paintComponent(g); ImageIcon testImage = new ImageIcon("tiles/test_land.gif"); int x,y; for (x=0;x&lt;mapTileWidth;x++) { for (y=0;y&lt;mapTileWidth;y++) { g.drawImage(testImage.getImage(), x*tileSize + mapOffset, y*tileSize + mapOffset, this); } } } public MapCanvas(int numTiles) { //Set up window tileSize = 48; mapTileWidth = numTiles; mapOffset = 4; mapDim = (tileSize * mapTileWidth) + (2 * mapOffset); Dimension dim = new Dimension(mapDim, mapDim); this.setPreferredSize(dim); this.setMinimumSize(dim); this.setMaximumSize(dim); this.setLayout( new GridLayout(numTiles, numTiles, 0, 0) ); this.setBackground(Color.black); screenTiles = new MapSquare[numTiles^2]; //Map-related actions InputMap im = this.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW); ActionMap am = this.getActionMap(); AbstractAction north = new AbstractAction() { public void actionPerformed(ActionEvent e) { JOptionPane.showMessageDialog(null, "Just for testing", "testing", JOptionPane.PLAIN_MESSAGE); } }; am.put("North", north); im.put(KeyStroke.getKeyStroke('2'), "North"); im.put(KeyStroke.getKeyStroke('i'), "North"); } } </code></pre> <p>About the only difference I can find between what I've used and working examples found in various places is they add the keystroke to the inputmap before mapping the keystroke to the action. I tried switching the order, but it didn't seems to have any effect.</p> <p>Can anyone see what I'm doing wrong here? I just know I'm missing something obvious.</p>
 

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