Symantec Visual Cafe for Java 2.5/symantec-visual-cafe-2.5-database-dev-edition.iso/Visual Cafe Pro v1.0/SOURCE.BIN/ImageButton.java

Java Source | 1997-06-19 | 10.8 KB | 408 lines

package symantec.itools.awt;


import java.awt.AWTException;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Event;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.image.FilteredImageSource;
import java.awt.image.RGBImageFilter;
import java.net.URL;

//    01/18/97    RKM    Changed setImageURL to handle getImage returning null, added call to invalidate
//    01/29/97    TWB    Integrated changes from Macintosh

/* *
 * The ImageButton component is similar to a regular button except that it
 * displays an image on the button's face. The image to use is specified with
 * a URL.
 * @version 1.0, Nov 26, 1996
 * @author Symantec
 */

/**
 * <b>Description</b>
 * <p>
 * This component creates a rectangular button, with an image label, that
 * initiates an action. ImageButton extends the Button class.
 * <p>
 * Use an ImageButton to:
 * <UL>
 * <DT>╖ display an image instead of text on a button.</DT>
 * <DT>╖ generate a train of action events when the user clicks the button.</DT>
 * </UL>
 * <b>Properties</b>
 * <p>
 * To select and display an image on the button, use the URL property. Specify
 * a file name for the JPEG or GIF image you want displayed. Then to scale the
 * image to fit in the button, set the Scale Mode property.
 * <p>
 * To send a train of action events when the button is clicked, set the Notify
 * While Pressed property to ôtrueö and specify a Notify Delay property value
 * in milliseconds.
 * <p>
 * To create an interaction with another component, use the Interaction Wizard.
 * <p>
 * @version 1.0, Nov 26, 1996
 * @author Symantec
 */

//    01/18/97    RKM    Changed setImageURL to handle getImage returning null, added call to invalidate

public class ImageButton
    extends ButtonBase
{
    /**
     * Scale image to fit button.
     */
    protected boolean scale;
    private URL url;
    private Image enabledImage;
    private Image disabledImage;
    private boolean centerMode;

    /**
     * Construct a new default ImageButton. Image scaling off, center mode on.
     */
    public ImageButton()
    {
        scale           = false;
        enabledImage    = null;
        disabledImage   = null;
        url             = null;
        centerMode      = true;
    }

    /**
     * Sets the URL of the image to display on the button.
     * @param u URL of image to display
     * @see #getImageURL
     */
    public void setImageURL(URL u)
        // throws AWTException
    {
        // Remove old images

        enabledImage = null;
        if (disabledImage != null)
            disabledImage.flush();
        disabledImage = null;

        // Load new image

        url = u;
        Image image = getToolkit().getImage(url);
        if (image != null)
        {
            MediaTracker mt = new MediaTracker(this);
            if (mt != null)
            {
                try
                {
                    mt.addImage(image, 0);
                    mt.waitForAll();
                }
                catch (InterruptedException ie)
                {
                }

                if (mt.isErrorAny())
                {
                    System.err.println("Error loading image " + image.toString());
                    return;
                }

                enabledImage   = image;
                disabledImage  = createImage(
                    new FilteredImageSource(image.getSource(),
                            new ImageButtonDisableFilter()));

                //resize(image.getWidth(this) + bevel * 3 + 2, image.getHeight(this) + bevel * 3 + 2);
            }
        }

        invalidate();
    }

    /**
     * Returns the URL of the image being displayed on the button.
     * @see #setImageURL
     */
    public URL getImageURL()
    {
        return url;
    }

    /**
     * Sets the scale mode of the button image.
     * @param flag if true, the image is scaled to fit the button.  if false,
     * the image is not scaled.
     * @see #getScaleMode
     */
    public void setScaleMode(boolean flag)
    {
        if (scale != flag)
        {
            scale = flag;
            invalidate();
        }
    }

    /**
     * Returns the current scale mode of the button image.
     * @see #setScaleMode
     */
    public boolean getScaleMode()
    {
        return scale;
    }

    /**
     * Sets the centering mode of the button image.
     * @param flag if true, the image is centered on the button.  if false,
     * the image is displayed starting in the upper-left corner.
     * @see #getCenterMode
     */
    public void setCenterMode(boolean flag)
    {
        if (centerMode != flag)
        {
            centerMode = flag;
            invalidate();
        }
    }

    /**
     * Returns the current centering mode of the button image.
     * @see #setCenterMode
     */
    public boolean getCenterMode()
    {
        return centerMode;
    }

    /**
     * Paints this component using the given graphics context.
     * This is a standard Java AWT method which typically gets called
     * by the AWT to handle painting this component. It paints this component
     * using the given graphics context. The graphics context clipping region
     * is set to the bounding rectangle of this component and its <0,0>
     * coordinate is this component's top-left corner.
     *
     * @param g the graphics context used for painting
     * @see java.awt.Component#repaint
     * @see #update
     */
    public void paint(Graphics g)
    {
        Image img = isEnabled() ? enabledImage : disabledImage;

        if (img == null)
        {
            super.paint(g);
            return;
        }

        paintHelper(g, img);

        Dimension s;
        int x;
        int y;
        int w;
        int h;

        s = size();
        x = bevel + 1 + pressedAdjustment;
        y = bevel + 1 + pressedAdjustment;
        w = s.width  - 1;
        h = s.height - 1;

       if (symantec.itools.lang.OS.isMacintosh())
       {
           if (scale)
           {
                x = bevel + pressedAdjustment;
                y = bevel + pressedAdjustment;
                g.drawImage(img, x, y, w - bevel - bevel, h - bevel - bevel, this);
           }
           else
           {
                   if(centerMode)
                {
                    x += (w - bevel - bevel - img.getWidth(this)) >> 1;
                    y += (h - bevel - bevel - img.getHeight(this)) >> 1;
                 }

                g.drawImage(img, x, y, this);
           }
        }
        else
        {
            if (centerMode && !scale)
            {
                x += (w - img.getWidth(this)) / 2;
                y += (h - img.getHeight(this)) / 2;
            }

            if(scale)
            {
                g.drawImage(img, x, y, w - bevel * 2, h - bevel * 2, this);
            }
            else
            {
                g.drawImage(img, x, y, this);
            }
        }
    }

    /**
     * Handles redrawing of this component on the screen.
     * This is a standard Java AWT method which gets called by the Java
     * AWT (repaint()) to handle repainting this component on the screen.
     * The graphics context clipping region is set to the bounding rectangle
     * of this component and its <0,0> coordinate is this component's
     * top-left corner.
     * Typically this method paints the background color to clear the
     * component's drawing space, sets graphics context to be the foreground
     * color, and then calls paint() to draw the component.
     *
     * It is overridden here to prevent the flicker associated with the standard
     * update() method's repainting of the background before painting the component
     * itself.
     *
     * @param g the graphics context
     * @see java.awt.Component#repaint
     * @see #paint
     */
    public void update(Graphics g)
    {
        paint(g);
    }

    private void paintHelper(Graphics g, Image img)
    {
        Dimension s;
        int width;
        int height;
        int imgx;
        int imgy;
        int imgw;
        int imgh;
        int x;
        int y;
        int w;
        int h;
        int i;

        s        = size();
        width    = s.width;
        height    = s.height;
        x        = bevel  + 1;
        y        = bevel  + 1;
        w        = width  - 1;
        h        = height - 1;
        imgx    = bevel + 1;
        imgy    = bevel + 1;
           imgw    = img.getWidth(this);
        imgh    = img.getHeight(this);

        g.setColor(Color.lightGray);

        if (centerMode && !scale)
        {
            imgx += (width - 1 - bevel - bevel - imgw) >> 1;
            imgy += (height - 1 - bevel - bevel - imgh) >> 1;
        }

        if (pressed)
        {
            if(!scale)
            {
                 //Clean up artifacts
                g.fillRect(0, 0, imgx + bevel, height);
                g.fillRect(imgx + imgw + bevel, 0, width - imgx + imgw + bevel, height);
                g.fillRect(imgx + bevel, 0, imgw, imgy + bevel);
                g.fillRect(imgx + bevel, imgy + imgh + bevel, imgw, height - imgy + imgh + bevel);
                //End clean up
               }
            y = x += bevel > 0 ? 2 : 1;
            g.setColor(Color.lightGray);

            for(i = 1; i < bevel + 1; i++)
            {
                g.drawLine(i, h - i, w - i, h - i);
                g.drawLine(w - i, h - i, w - i, i);
            }

            g.setColor(Color.gray);

            for(i = 1; i < bevel + 1; ++i)
            {
                g.drawLine(i, h, i, i);
                g.drawLine(i, i, w, i);
            }
        }
        else
        {
            if(!scale)
            {
                //Clean up artifacts
                g.fillRect(0, 0, imgx, height);
                g.fillRect(imgx + imgw, 0, width - imgx + imgw, height);
                g.fillRect(imgx, 0, imgw, imgy);
                g.fillRect(imgx, imgy + imgh, imgw, height - imgy + imgh);
                //End clean up
            }

            g.setColor(Color.white);

            for(i = 1; i < bevel + 1; i++)
            {
                g.drawLine(i, h - i, i, i);
                g.drawLine(i, i, w - i, i);
            }

            g.setColor(Color.gray);

            for(i = 1; i < bevel + 2; ++i)
            {
                g.drawLine(i, h - i, w - i, h - i);
                g.drawLine(w - i, h - i, w - i, i);
            }
        }

        g.setColor(Color.black);
        g.drawLine(1, 0, width - 2, 0);
        g.drawLine(0, 1, 0, height - 2);
        g.drawLine(1, height - 1, width - 2, height - 1);
        g.drawLine(width - 1, height - 2, width - 1, 1);

        if(showInfoTip)
        {
            if (doInfoTip)
            {
                drawInfoTip();
            }
        }
    }
}

class ImageButtonDisableFilter
    extends RGBImageFilter
{
    public ImageButtonDisableFilter()
    {
        canFilterIndexColorModel = true;
    }


    public int filterRGB(int x, int y, int rgb)
    {
        return (rgb & ~0xff000000) | 0x80000000;
    }
}