Advice on how to implement this GUI ?

[Albert Kam]

Hello,

My name is albert kam .. I hope you could give me pointers about these matters.

I need gui components that is also available in these screenshots of partition magic 8.

At screenshot 2, where there are 3 partitions. If i were to
- right click one of the partition, and choose resize,
- i can resize the partition from the partition boxes by hovering it,
- and the cursor changes into left and right arrow,
- and then i can drag to the left or right, and then release.

What's the better way to do this in Java GUI ?
My imagination says to use JLabel for this, where i could implement own's coloring by playing with it's Graphics2D.

Also, i could add the right click popup listener.

But to be dragable to left and right, and to change the cursor while hovering the edge of the partition box, how do i achieve that ?

Please advice ..

Regards,
Albert Kam

[Ulf Dittmer]

That's what the JSplitPane class does.

[Craig Wood]

Here's an idea:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.event.MouseInputAdapter;
 
public class AdjustableLabels extends JPanel {
    JLabel[] labels;
 
    public AdjustableLabels() {
        setLayout(null);
        String[] strs = {
            "left label", "center label", "right label"
        };
        Border insideBorder =
            BorderFactory.createLineBorder(Color.magenta, 3);
        Border outsideBorder =
            BorderFactory.createLineBorder(Color.cyan, 3);
        labels = new JLabel[strs.length];
        int x = 0;
        Dimension d = getPreferredSize();
        int xInc = d.width/labels.length;
        for(int j = 0; j < labels.length; j++) {
            labels[j] = new JLabel(strs[j]);
            labels[j].setBorder(BorderFactory.createCompoundBorder(
                                    outsideBorder, insideBorder));
            add(labels[j]);
            labels[j].setBounds(x, 0, xInc, d.height);
            x += xInc;
        }
        addMouseListener(mia);
        addMouseMotionListener(mia);
    }
 
    private JPanel getContent() {
        JPanel panel = new JPanel(new GridBagLayout());
        panel.add(this, new GridBagConstraints());
        return panel;
    }
 
    public Dimension getPreferredSize() {
        return new Dimension(350, 50);
    }
 
    public static void main(String[] args) {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new AdjustableLabels().getContent());
        f.setSize(500,240);
        f.setLocation(200,200);
        f.setVisible(true);
    }
 
    private MouseInputAdapter mia = new MouseInputAdapter() {
        Cursor defaultCursor = Cursor.getDefaultCursor();
        Cursor resizeCursor =
            Cursor.getPredefinedCursor(Cursor.E_RESIZE_CURSOR);
        int selectedIndex = -1;
        int offset = 0;
        boolean dragging = false;
 
        public void mousePressed(MouseEvent e) {
            if(getCursor() == resizeCursor) {
                offset = labels[selectedIndex].getX() - e.getX();
                dragging = true;
            }
        }
 
        public void mouseReleased(MouseEvent e) {
            dragging = false;
        }
 
        public void mouseDragged(MouseEvent e) {
            if(dragging) {
                // Adjust x of labels[selectedIndex-1].
                int x = e.getX() - offset;
                int y = labels[selectedIndex].getY();
                labels[selectedIndex].setLocation(x, y);
                // Adjust width of labels[selectedIndex-1].
                Rectangle r = labels[selectedIndex-1].getBounds();
                int dw = (int)(r.getMaxX() - x);
                labels[selectedIndex-1].setSize(r.width-dw, r.height);
                // Adjust width of labels[selectedIndex].
                Dimension d = labels[selectedIndex].getSize();
                labels[selectedIndex].setSize(d.width+dw, d.height);
            }
        }
 
        public void mouseMoved(MouseEvent e) {
            int x = e.getX();
            boolean hovering = false;
            for(int i = 1; i < labels.length; i++) {
                if(Math.abs(labels[i].getX() - x) < 5) {
                    hovering = true;
                    if(getCursor() == defaultCursor) {
                        selectedIndex = i;
                        setCursor(resizeCursor);
                    }
                    break;
                }
            }
            if(!hovering && getCursor() == resizeCursor) {
                selectedIndex = -1;
                setCursor(defaultCursor);
            }
        }
    };
}

[Albert Kam]

Hello all !

I was told to use a split pane too, but i assumed that split pane only split into 2, and in the screenshots there are several partitions .. But i'll take a look into this component as i'm not familiar with it yet. Thanks !

I've tried running the code, it runs great after editing it to become f.getContentPane().add(xxx). I'll study this code as soon as i get home ! Thank you !

Regards,
Albert Kam

[Ulf Dittmer]

Yes, split panes always have two components. If your GUI has more than two panes, you'd create a hierarchy of panes, in other words, a toplevel split pane that contains two JPanels that contain second-level split panes.