CODEWITHSUNDEEP
javaswingcanvasjframelocation
Kris Rice
Kris Rice

Reputation: 1099

Java: issues relocating Canvas that's drawn into a JFrame

I can't get my Canvas to be drawn in the centre of my JFrame. My hope is to draw an image to the JFrame that will have a fancy border, then the Canvas will sit in the centre of the JFrame. I've tried canvas.setLocation(Point p) and canvas.setBounds(Rectangle r) and Canvas.setLocation(int x, int y) and I can't get any of them to work. I also tried the following before calling game.frame.pack():

game.frame.setLayout(new BorderLayout());
game.frame.add(game, BorderLayout.CENTER);

This is the setup for the Canvas:

public Game() {
    Dimension size = new Dimension((frameWidth * scale), frameHeight * scale);
    setPreferredSize(size);
    Game.game = this;
    //draw game items
    ....
}

Then this is the JFrame set up, which is done during the main method:

game = new Game();
    game.frame.setResizable(false);
    game.frame.setUndecorated(true); //Enable for full screen
    game.frame.setLayout(new BorderLayout()); //Doesn't work
    game.frame.add(game, BorderLayout.CENTER); //Doesn't work
    //game.frame.add(game); //Just calling this doesn't work
    game.frame.pack();
    game.frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);

    //Window listener exitListener
    ....

    game.frame.addWindowListener(exitListener);
    game.frame.setLocationRelativeTo(null);
    game.frame.setVisible(true);
    game.frame.requestFocus();
    game.start();

Also tried this:

    game = new Game();
    game.frame.setResizable(false);
    game.frame.setUndecorated(true); //Enable for full screen
    game.frame.setLayout(new GridBagLayout());
    game.frame.add(game, new GridBagConstraints());
    game.frame.pack();
    game.frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);

Which does nothing. Full code is here, it is too much to post in the space of a question.

Thanks for you're help

Upvotes: 0

Views: 77

Answers (1)

camickr
camickr

Reputation: 324147

I can't get my Canvas to be drawn in the centre of my JFrame.

The easiest way to do this is to use a GridBagLayout instead of a BorderLayout:

game.frame.setLayout(new GridBagLayout());
game.frame.add(game, new GridBagConstraints());

Read up on the weightx/weighty contraints as described in the Swing tutorial on How to Use GridBagLayout to understand why this works.

Upvotes: 2

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