source: other-projects/rsyntax-textarea/src/java/org/fife/ui/rsyntaxtextarea/focusabletip/SizeGrip.java@ 25584

/*
 * 12/23/2008
 *
 * SizeGrip.java - A size grip component that sits at the bottom of the window,
 * allowing the user to easily resize that window.
 * 
 * This library is distributed under a modified BSD license.  See the included
 * RSyntaxTextArea.License.txt file for details.
 */
package org.fife.ui.rsyntaxtextarea.focusabletip;

import java.awt.Color;
import java.awt.ComponentOrientation;
import java.awt.Cursor;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Point;
import java.awt.Window;
import java.awt.event.MouseEvent;
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.event.MouseInputAdapter;


/**
 * A component that allows its parent window to be resizable, similar to the
 * size grip seen on status bars.
 *
 * @author Robert Futrell
 * @version 1.0
 */
class SizeGrip extends JPanel {

    /**
     * The size grip to use if we're on OS X.
     */
    private Image osxSizeGrip;


    public SizeGrip() {
        MouseHandler adapter = new MouseHandler();
        addMouseListener(adapter);
        addMouseMotionListener(adapter);
        setPreferredSize(new Dimension(16, 16));
    }


    /**
     * Overridden to ensure that the cursor for this component is appropriate
     * for the orientation.
     *
     * @param o The new orientation.
     */
    public void applyComponentOrientation(ComponentOrientation o) {
        possiblyFixCursor(o.isLeftToRight());
        super.applyComponentOrientation(o);
    }


    /**
     * Creates and returns the OS X size grip image.
     *
     * @return The OS X size grip.
     */
    private Image createOSXSizeGrip() {
        ClassLoader cl = getClass().getClassLoader();
        URL url = cl.getResource("org/fife/ui/autocomplete/osx_sizegrip.png");
        if (url==null) {
            // We're not running in a jar - we may be debugging in Eclipse,
            // for example
            File f = new File("../AutoComplete/src/org/fife/ui/autocomplete/osx_sizegrip.png");
            if (f.isFile()) {
                try {
                    url = f.toURI().toURL();
                } catch (MalformedURLException mue) { // Never happens
                    mue.printStackTrace();
                    return null;
                }
            }
            else {
                return null; // Can't find resource or image file
            }
        }
        Image image = null;
        try {
            image = ImageIO.read(url);
        } catch (IOException ioe) { // Never happens
            ioe.printStackTrace();
        }
        return image;
    }


    /**
     * Paints this panel.
     *
     * @param g The graphics context.
     */
    protected void paintComponent(Graphics g) {

        super.paintComponent(g);

        Dimension dim = getSize();
        Color c1 = UIManager.getColor("Label.disabledShadow");
        Color c2 = UIManager.getColor("Label.disabledForeground");

        if (osxSizeGrip!=null) {
            g.drawImage(osxSizeGrip, dim.width-16, dim.height-16, null);
            return;
        }

        ComponentOrientation orientation = getComponentOrientation();

        if (orientation.isLeftToRight()) {
            int width = dim.width  -= 3;
            int height = dim.height -= 3;
            g.setColor(c1);
            g.fillRect(width-9,height-1, 3,3);
            g.fillRect(width-5,height-1, 3,3);
            g.fillRect(width-1,height-1, 3,3);
            g.fillRect(width-5,height-5, 3,3);
            g.fillRect(width-1,height-5, 3,3);
            g.fillRect(width-1,height-9, 3,3);
            g.setColor(c2);
            g.fillRect(width-9,height-1, 2,2);
            g.fillRect(width-5,height-1, 2,2);
            g.fillRect(width-1,height-1, 2,2);
            g.fillRect(width-5,height-5, 2,2);
            g.fillRect(width-1,height-5, 2,2);
            g.fillRect(width-1,height-9, 2,2);
        }
        else {
            int height = dim.height -= 3;
            g.setColor(c1);
            g.fillRect(10,height-1, 3,3);
            g.fillRect(6,height-1, 3,3);
            g.fillRect(2,height-1, 3,3);
            g.fillRect(6,height-5, 3,3);
            g.fillRect(2,height-5, 3,3);
            g.fillRect(2,height-9, 3,3);
            g.setColor(c2);
            g.fillRect(10,height-1, 2,2);
            g.fillRect(6,height-1, 2,2);
            g.fillRect(2,height-1, 2,2);
            g.fillRect(6,height-5, 2,2);
            g.fillRect(2,height-5, 2,2);
            g.fillRect(2,height-9, 2,2);
        }

    }


    /**
     * Ensures that the cursor for this component is appropriate for the
     * orientation.
     *
     * @param ltr Whether the current component orientation is LTR.
     */
    protected void possiblyFixCursor(boolean ltr) {
        int cursor = Cursor.NE_RESIZE_CURSOR;
        if (ltr) {
            cursor = Cursor.NW_RESIZE_CURSOR;
        }
        if (cursor!=getCursor().getType()) {
            setCursor(Cursor.getPredefinedCursor(cursor));
        }
    }


    public void updateUI() {
        super.updateUI();
        // TODO: Key off of Aqua LaF, not just OS X, as this size grip looks
        // bad on other LaFs on Mac such as Nimbus.
        if (System.getProperty("os.name").indexOf("OS X")>-1) {
            if (osxSizeGrip==null) {
                osxSizeGrip = createOSXSizeGrip();
            }
        }
        else { // Clear memory in case of runtime LaF change.
            osxSizeGrip = null;
        }

    }


    /**
     * Listens for mouse events on this panel and resizes the parent window
     * appropriately.
     *
     * @author Robert Futrell
     * @version 1.0
     */
    /*
     * NOTE: We use SwingUtilities.convertPointToScreen() instead of just using
     * the locations relative to the corner component because the latter proved
     * buggy - stretch the window too wide and some kind of arithmetic error
     * started happening somewhere - our window would grow way too large.
     */
    private class MouseHandler extends MouseInputAdapter {

        private Point origPos;

        public void mouseDragged(MouseEvent e) {
            Point newPos = e.getPoint();
            SwingUtilities.convertPointToScreen(newPos, SizeGrip.this);
            int xDelta = newPos.x - origPos.x;
            int yDelta = newPos.y - origPos.y;
            Window wind = SwingUtilities.getWindowAncestor(SizeGrip.this);
            if (wind!=null) { // Should always be true
                if (getComponentOrientation().isLeftToRight()) {
                    int w = wind.getWidth();
                    if (newPos.x>=wind.getX()) {
                        w += xDelta;
                    }
                    int h = wind.getHeight();
                    if (newPos.y>=wind.getY()) {
                        h += yDelta;
                    }
                    wind.setSize(w,h);
                }
                else { // RTL
                    int newW = Math.max(1, wind.getWidth()-xDelta);
                    int newH = Math.max(1, wind.getHeight()+yDelta);
                    wind.setBounds(newPos.x, wind.getY(), newW, newH);
                }
                // invalidate()/validate() needed pre-1.6.
                wind.invalidate();
                wind.validate();
            }
            origPos.setLocation(newPos);
        }

        public void mousePressed(MouseEvent e) {
            origPos = e.getPoint();
            SwingUtilities.convertPointToScreen(origPos, SizeGrip.this);
        }

        public void mouseReleased(MouseEvent e) {
            origPos = null;
        }

    }


}