Dynamically changing the size of JFrame when exposed to different screen resolutions

Question

So for a school project I made a grade book in java. When creating the gui I used hardcoded values in the setBounds() methods. Now this worked when I had a 1024×768 screen resolution it looked alright, but when I got a new laptop and it had a 4k screen it looked super small when I ran the program.

So my question would be is there a way to dynamically change the size of the Jframe and all of the associated objects on the frame so it matches the resolution of the screen?

I know that you can get the screen resolution from this

Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();

double width = screenSize.getWidth();

double height = screenSize.getHeight();

but I do not know what would be the best way to do this.

Answer 1

Taking your approach as example and taking this answer and this tutorial as base, here you have the clues:

import java.awt.Dimension;
import java.awt.Rectangle;
import java.awt.Toolkit;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;

import javax.swing.JFrame;


public class Q1 extends JFrame {
    public static void main(String[] args) {
        Q1 frame = new Q1();

        frame.setSize(300, 300);
        frame.setMinimumSize(new Dimension(300, 300));
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);     
    }

    public Q1() {
        this.addComponentListener(new ComponentAdapter() {
            public void componentResized(ComponentEvent e) {
                // This is only called when the user releases the mouse button.
                System.out.println("componentResized");
            }
        });
    }

    @Override
    public void validate() {
        resize();
        super.validate();

    };

    private void resize() {
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();

        double width = screenSize.getWidth();

        double height = screenSize.getHeight();

        System.out.println(width + "," + height);
    }
}

This will print the size of the screen when your resize the frame, so you just need to add an if/else in the resize method to make frame bigger

OUTPUT

1366.0,768.0
1366.0,768.0
componentResized
1366.0,768.0
1366.0,768.0
componentResized
1366.0,768.0
1366.0,768.0
componentResized

Answer 2

A layout manager is an object that implements the LayoutManager interface* and determines the size and position of the components within a container. Although components can provide size and alignment hints, a container's layout manager has the final say on the size and position of the components within the container.

See the example I found using layout managers.Hope you get some idea.THe original author is here Set a layout manager like BorderLayout and then define more specifically, where your panel should go: like

MainPanel mainPanel = new MainPanel();
JFrame mainFrame = new JFrame();
mainFrame.setLayout(new BorderLayout());
mainFrame.add(mainPanel, BorderLayout.CENTER);
mainFrame.pack();
mainFrame.setVisible(true);

puts the panel into the center area of the frame and lets it grow automatically when resizing the frame.See below example for full usage:

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class TestLayoutManagers {

    private JPanel northFlowLayoutPanel;
    private JPanel southBorderLayoutPanel;
    private JPanel centerGridBagLayoutPanel;
    private JPanel westBoxLayoutPanel;
    private JPanel eastGridLayoutPanel;

    private final JButton northButton = new JButton("North Button");
    private final JButton southButton = new JButton("South Button");
    private final JButton centerButton = new JButton("Center Button");
    private final JButton eastButton = new JButton("East Button");
    private final JButton westButton = new JButton("West Button");

    public TestLayoutManagers() {
        northFlowLayoutPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
        southBorderLayoutPanel = new JPanel(new BorderLayout());
        centerGridBagLayoutPanel = new JPanel(new GridBagLayout());
        eastGridLayoutPanel = new JPanel(new GridLayout(1, 1));
        Box box = Box.createHorizontalBox();
        westBoxLayoutPanel = new JPanel();

        northFlowLayoutPanel.add(northButton);
        northFlowLayoutPanel.setBorder(BorderFactory.createTitledBorder("Flow Layout"));

        southBorderLayoutPanel.add(southButton);
        southBorderLayoutPanel.setBorder(BorderFactory.createTitledBorder("Border Layout"));

        centerGridBagLayoutPanel.add(centerButton);
        centerGridBagLayoutPanel.setBorder(BorderFactory.createTitledBorder("GridBag Layout"));

        eastGridLayoutPanel.add(eastButton);
        eastGridLayoutPanel.setBorder(BorderFactory.createTitledBorder("Grid Layout"));

        box.add(westButton);
        westBoxLayoutPanel.add(box);
        westBoxLayoutPanel.setBorder(BorderFactory.createTitledBorder("Box Layout"));

        JFrame frame = new JFrame("Test Layout Managers");
        frame.setLayout(new BorderLayout());      // This is the deafault layout
        frame.add(northFlowLayoutPanel, BorderLayout.PAGE_START);
        frame.add(southBorderLayoutPanel, BorderLayout.PAGE_END);
        frame.add(centerGridBagLayoutPanel, BorderLayout.CENTER);
        frame.add(eastGridLayoutPanel, BorderLayout.LINE_END);
        frame.add(westBoxLayoutPanel, BorderLayout.LINE_START);

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
        frame.setExtendedState(JFrame.MAXIMIZED_BOTH);

}

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                TestLayoutManagers testLayoutManagers
                        = new TestLayoutManagers();
            }
        });
    }
}