Question

I have a panel with GridLayout(1, 3) but i want centralize the content of cells in this layout(without addition Panels):

public MainMenu() {
        setLayout(new GridLayout(1, 3));

        setBorder(BorderFactory.createLineBorder(Color.BLUE));
        setOpaque(false);


        ImageComponent img = new ImageComponent("resources/music.png", true, this);
        add(img);
        ImageComponent img1 = new ImageComponent("resources/video.png", true, this);
        add(img1);
        ImageComponent img2 = new ImageComponent("resources/audio", true, this);
        add(img2);


    }

Because if i just add this 3 ImageComponents to MainMenu they appears upwards.

Answer 1

GridLayout will size all components to fill the available space. So, if the dimensions of your 3 ImageComponents are 50×50, 50×50, and 75×75, they will all be sized to 75×75. From there it is up to ImageComponent how it paints itself.

Most likely ImageComponent implements paintComponent something like this:

protected void paintComponent(Graphics g) {
    g.drawImage(image, 0, 0, this);
}

That will paint the image in the upper-left corner, not centered.

This will paint a centered image:

protected void paintComponent(Graphics g)
{
    super.paintComponent(g);
    int iw = image.getWidth(this);
    int ih = image.getHeight(this);

    if (iw != -1 && ih != -1)
    {
        int w = getWidth();
        int h = getHeight();
        g.drawImage(image, (w -iw)/2, (h-ih)/2, this);
    }
}