TextLayoutWithMouseClickDrag.java Source code

Introduction

Here is the source code for TextLayoutWithMouseClickDrag.java

Source

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Shape;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.font.FontRenderContext;
import java.awt.font.TextHitInfo;
import java.awt.font.TextLayout;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class TextLayoutWithMouseClickDrag {
    public static void main(String arg[]) {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add("Center", new DisplayPanel());
        frame.pack();
        frame.setSize(new Dimension(400, 300));
        frame.setVisible(true);
    }
}

class DisplayPanel extends JPanel {
    FontRenderContext frc = new FontRenderContext(null, false, false);
    Font font = new Font("Arial", Font.PLAIN, 36);
    Rectangle2D rect;
    float rx, ry, rw, rh;

    TextHitInfo hitInfo;
    Color caretColor;
    int hit1, hit2;
    int w = 400, h = 200;
    TextLayout layout = new TextLayout("j a v a 2 s . c o m", font, frc);

    public DisplayPanel() {
        setSize(400, 200);
        addMouseListener(new MouseHandler());
        addMouseMotionListener(new MouseMotionHandler());

        rx = (float) (w / 2 - layout.getBounds().getWidth() / 2);
        ry = (float) 3 * h / 4;
        rw = (float) (layout.getBounds().getWidth());
        rh = (float) (layout.getBounds().getHeight());
        rect = new Rectangle2D.Float(rx, ry, rw, rh);

    }

    public void update(Graphics g) {
        g.clearRect(0, 0, getWidth(), getHeight());
        paintComponent(g);
    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D) g;

        AffineTransform at = AffineTransform.getTranslateInstance(rx, ry);

        Shape hilight = layout.getLogicalHighlightShape(hit1, hit2);
        hilight = at.createTransformedShape(hilight);
        g2.setColor(Color.lightGray);
        g2.fill(hilight);

        g2.setColor(Color.black);
        layout.draw(g2, rx, ry);

        Shape[] caretShapes = layout.getCaretShapes(hit1);
        Shape caret = at.createTransformedShape(caretShapes[0]);
        g2.setColor(caretColor);
        g2.draw(caret);
    }

    public int getHitLocation(int mouseX, int mouseY) {
        hitInfo = layout.hitTestChar(mouseX, mouseY, rect);
        return hitInfo.getInsertionIndex();
    }

    class MouseHandler extends MouseAdapter {
        public void mouseClicked(MouseEvent e) {
            caretColor = getForeground();
            hit1 = getHitLocation(e.getX(), e.getY());
            hit2 = hit1;
            repaint();
        }

        public void mousePressed(MouseEvent e) {
            caretColor = getForeground();
            hit1 = getHitLocation(e.getX(), e.getY());
            hit2 = hit1;
            repaint();
        }

        public void mouseReleased(MouseEvent e) {
            hit2 = getHitLocation(e.getX(), e.getY());
            repaint();
        }
    }

    class MouseMotionHandler extends MouseMotionAdapter {
        public void mouseDragged(MouseEvent e) {
            caretColor = getBackground();
            hit2 = getHitLocation(e.getX(), e.getY());
            repaint();
        }
    }
}