/* * 1.1 Swing version. */import javax.swing.*;import javax.swing.border.Border;import javax.swing.event.*;import java.awt.*;import java.awt.event.*;/*  * This displays a framed area.  When the user drags within * the area, this program displays a rectangle and a string * indicating the bounds of the rectangle. */public class SelectionDemo extends JApplet {    JLabel label;    static String starFile = "images/starfield.gif";    //Called only when this is run as an applet.    public void init() {        ImageIcon image = new ImageIcon(getImage(getCodeBase(),                                                 starFile));        buildUI(getContentPane(), image);    }    void buildUI(Container container, ImageIcon image) {        container.setLayout(new BoxLayout(container,                                          BoxLayout.Y_AXIS));        JPanel framedArea = frameItUp(new SelectionArea(image, this));        container.add(framedArea);        label = new JLabel("Drag within the framed area.");        container.add(label);        //Align the left edges of the components.        framedArea.setAlignmentX(LEFT_ALIGNMENT);        label.setAlignmentX(LEFT_ALIGNMENT); //redundant    }    JPanel frameItUp(Component insides) {        Border raisedBevel, loweredBevel, compound;        raisedBevel = BorderFactory.createRaisedBevelBorder();        loweredBevel = BorderFactory.createLoweredBevelBorder();        compound = BorderFactory.createCompoundBorder                        (raisedBevel, loweredBevel);        JPanel framedArea = new JPanel();        framedArea.setBorder(compound);        framedArea.setLayout(new GridLayout(1,0));        framedArea.add(insides);        return framedArea;    }    public void updateLabel(Rectangle rect) {        int width = rect.width;        int height = rect.height;        //Make the coordinates look OK if a dimension is 0.        if (width == 0) {            width = 1;        }        if (height == 0) {            height = 1;        }        label.setText("Rectangle goes from ("                      + rect.x + ", " + rect.y + ") to ("                      + (rect.x + width - 1) + ", "                      + (rect.y + height - 1) + ").");    }    public static void main(String[] args) {        JFrame f = new JFrame("SelectionDemo");        f.addWindowListener(new WindowAdapter() {            public void windowClosing(WindowEvent e) {                System.exit(0);            }        });        SelectionDemo controller = new SelectionDemo();        controller.buildUI(f.getContentPane(),                           new ImageIcon(starFile));        f.pack();        f.setVisible(true);    }}class SelectionArea extends JLabel {    Rectangle currentRect = null;    Rectangle rectToDraw = null;    Rectangle previousRectDrawn = new Rectangle();    SelectionDemo controller;    public SelectionArea(ImageIcon image, SelectionDemo controller) {        super(image); //This component displays an image.        this.controller = controller;        setOpaque(true);        setMinimumSize(new Dimension(10,10)); //don't hog space        MyListener myListener = new MyListener();        addMouseListener(myListener);        addMouseMotionListener(myListener);    }    class MyListener extends MouseInputAdapter {        public void mousePressed(MouseEvent e) {            int x = e.getX();            int y = e.getY();            currentRect = new Rectangle(x, y, 0, 0);            updateDrawableRect(getWidth(), getHeight());            repaint();        }        public void mouseDragged(MouseEvent e) {            updateSize(e);        }        public void mouseReleased(MouseEvent e) {            updateSize(e);        }        /*          * Update the size of the current rectangle         * and call repaint.  Because currentRect         * always has the same origin, translate it         * if the width or height is negative.         *          * For efficiency (though         * that isn't an issue for this program),         * specify the painting region using arguments         * to the repaint() call.         *          */        void updateSize(MouseEvent e) {            int x = e.getX();            int y = e.getY();            currentRect.setSize(x - currentRect.x,                                y - currentRect.y);            updateDrawableRect(getWidth(), getHeight());            Rectangle totalRepaint = rectToDraw.union(previousRectDrawn);            repaint(totalRepaint.x, totalRepaint.y,                    totalRepaint.width, totalRepaint.height);        }    }    public void paintComponent(Graphics g) {        super.paintComponent(g); //paints the background and image        //If currentRect exists, paint a box on top.        if (currentRect != null) {            //Draw a rectangle on top of the image.// XXX: We used to use XOR mode, but in 1.2, due to bugs 4188795// XXX: and 4219548, that causes an off-by-one error.            //g.setXORMode(Color.white); //Color of line varies                                         //depending on image colors	    g.setColor(Color.white);            g.drawRect(rectToDraw.x, rectToDraw.y,                        rectToDraw.width - 1, rectToDraw.height - 1);            controller.updateLabel(rectToDraw);        }    }    void updateDrawableRect(int compWidth, int compHeight) {        int x = currentRect.x;        int y = currentRect.y;        int width = currentRect.width;        int height = currentRect.height;        //Make the width and height positive, if necessary.        if (width < 0) {            width = 0 - width;            x = x - width + 1;             if (x < 0) {                width += x;                 x = 0;            }        }        if (height < 0) {            height = 0 - height;            y = y - height + 1;             if (y < 0) {                height += y;                 y = 0;            }        }        //The rectangle shouldn't extend past the drawing area.        if ((x + width) > compWidth) {            width = compWidth - x;        }        if ((y + height) > compHeight) {            height = compHeight - y;        }              //Update rectToDraw after saving old value.        if (rectToDraw != null) {            previousRectDrawn.setBounds(                        rectToDraw.x, rectToDraw.y,                         rectToDraw.width, rectToDraw.height);            rectToDraw.setBounds(x, y, width, height);        } else {            rectToDraw = new Rectangle(x, y, width, height);        }    }}