Move a texture painted rectangle around the applet window with Java 2D - Java 2D Graphics

Description

Move a texture painted rectangle around the applet window with Java 2D

Demo Code

import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;
import java.awt.image.*;

/*//  ww  w  .j a v  a 2  s . co m
 * This applet allows the user to move a texture painted rectangle around the applet
 * window.  The rectangle flickers and draws slowly because this applet does not use 
 * double buffering.
 */
public class ShapeMover extends Applet {

    static protected Label label;

    public void init() {

        setLayout(new BorderLayout());
        add(new SMCanvas());

        label = new Label("Drag rectangle around within the area");
        add("South", label);
    }

    public static void main(String s[]) {
        Frame f = new Frame("ShapeMover");
        f.addWindowListener(new WindowAdapter() {

            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        Applet applet = new ShapeMover();
        f.add("Center", applet);
        applet.init();
        f.pack();
        f.setSize(new Dimension(550, 250));
        f.setVisible(true);
    }
}

class SMCanvas extends Canvas implements MouseListener, MouseMotionListener {

    Rectangle rect = new Rectangle(0, 0, 100, 50);
    BufferedImage bi;
    Graphics2D big;
    // Holds the coordinates of the user's last mousePressed event.
    int last_x, last_y;
    boolean firstTime = true;
    TexturePaint fillPolka, strokePolka;
    Rectangle area;
    // True if the user pressed, dragged or released the mouse outside of the rectangle; false otherwise.
    boolean pressOut = false;

    public SMCanvas() {
        setBackground(Color.white);
        addMouseMotionListener(this);
        addMouseListener(this);

        // Creates the fill texture paint pattern.
        bi = new BufferedImage(5, 5, BufferedImage.TYPE_INT_RGB);
        big = bi.createGraphics();
        big.setColor(Color.pink);
        big.fillRect(0, 0, 7, 7);
        big.setColor(Color.cyan);
        big.fillOval(0, 0, 3, 3);
        Rectangle r = new Rectangle(0, 0, 5, 5);
        fillPolka = new TexturePaint(bi, r);
        big.dispose();

        //Creates the stroke texture paint pattern.
        bi = new BufferedImage(5, 5, BufferedImage.TYPE_INT_RGB);
        big = bi.createGraphics();
        big.setColor(Color.cyan);
        big.fillRect(0, 0, 7, 7);
        big.setColor(Color.pink);
        big.fillOval(0, 0, 3, 3);
        r = new Rectangle(0, 0, 5, 5);
        strokePolka = new TexturePaint(bi, r);
        big.dispose();

    }

    // Handles the event of the user pressing down the mouse button.
    public void mousePressed(MouseEvent e) {
        last_x = rect.x - e.getX();
        last_y = rect.y - e.getY();

        // Checks whether or not the cursor is inside of the rectangle while the
        // user is pressing the mouse.
        if (rect.contains(e.getX(), e.getY())) {
            pressOut = false;
            updateLocation(e);
        } else {
            ShapeMover.label
                    .setText("First position the cursor on the rectangle "
                            + "and then drag.");
            pressOut = true;
        }
    }

    // Handles the event of a user dragging the mouse while holding down the
    // mouse button.
    public void mouseDragged(MouseEvent e) {
        if (!pressOut) {
            updateLocation(e);
        } else {
            ShapeMover.label
                    .setText("First position the cursor on the rectangle "
                            + "and then drag.");
        }
    }

    // Handles the event of a user releasing the mouse button.
    public void mouseReleased(MouseEvent e) {

        // Checks whether or not the cursor is inside of the rectangle when the
        // user releases the mouse button.
        if (rect.contains(e.getX(), e.getY())) {
            if (!pressOut) {
                updateLocation(e);
            }
        } else {
            ShapeMover.label
                    .setText("First position the cursor on the rectangle "
                            + "and then drag.");
        }
    }

    // This method required by MouseListener.

    public void mouseMoved(MouseEvent e) {
    }

    // These methods are required by MouseMotionListener.
    public void mouseClicked(MouseEvent e) {
    }

    public void mouseExited(MouseEvent e) {
    }

    public void mouseEntered(MouseEvent e) {
    }

    // Updates the coordinates representing the location of the current rectangle.
    public void updateLocation(MouseEvent e) {
        rect.setLocation(last_x + e.getX(), last_y + e.getY());
        /*
         * Updates the label to reflect the location of the
         * current rectangle
         * if checkRect returns true; otherwise, returns error message.
         */
        if (checkRect()) {
            ShapeMover.label.setText("Rectangle located at " + rect.getX()
                    + ", " + rect.getY());
        } else {
            ShapeMover.label.setText("Please don't try to "
                    + " drag outside the area.");
        }

        repaint();
    }

    public void paint(Graphics g) {
        update(g);
    }

    public void update(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
        Dimension dim = getSize();
        int w = (int) dim.getWidth();
        int h = (int) dim.getHeight();
        g2.setStroke(new BasicStroke(8.0f));

        if (firstTime) {
            area = new Rectangle(dim);
            rect.setLocation(w / 2 - 50, h / 2 - 25);
            firstTime = false;
        }

        // Clears the rectangle that was previously drawn.
        g2.setPaint(Color.white);
        g2.fillRect(0, 0, w, h);

        // Draws and fills the newly positioned rectangle.
        g2.setPaint(strokePolka);
        g2.draw(rect);
        g2.setPaint(fillPolka);
        g2.fill(rect);

    }

    /*
     * Checks if the rectangle is contained within the applet window.  If the rectangle
     * is not contained withing the applet window, it is redrawn so that it is adjacent
     * to the edge of the window and just inside the window.
     */
    boolean checkRect() {

        if (area == null) {
            return false;
        }

        if (area.contains(rect.x, rect.y, 100, 50)) {
            return true;
        }
        int new_x = rect.x;
        int new_y = rect.y;

        if ((rect.x + 100) > area.getWidth()) {
            new_x = (int) area.getWidth() - 99;
        }
        if (rect.x < 0) {
            new_x = -1;
        }
        if ((rect.y + 50) > area.getHeight()) {
            new_y = (int) area.getHeight() - 49;
        }
        if (rect.y < 0) {
            new_y = -1;
        }
        rect.setLocation(new_x, new_y);
        return false;
    }
}

/*
 * Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Oracle or the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

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