CD Ware Multimedia 1999 February/CDW0299.iso/Demos/Cafe/Source.bin/ImageViewer.java

Java Source | 1998-03-18 | 14.8 KB | 566 lines

package symantec.itools.multimedia;

import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Toolkit;
import java.net.URL;
import java.net.MalformedURLException;
import java.beans.PropertyVetoException;
import java.beans.PropertyChangeListener;
import java.beans.VetoableChangeListener;
import java.io.ObjectInputStream;
import java.io.IOException;
import java.util.ResourceBundle;
import java.text.MessageFormat;

//    01/29/97    TWB    Integrated changes from Windows
//    02/19/97    RKM    Changed default for centerMode to correspond with DES file
//                    Changed setCenterMode to call repaint instead of invalidate
//                    Changed setCenterMode to repaint only if value had changed
//
//    05/29/97    MSH    Updated to support Java 1.1
//  07/16/97    CAR marked fields transient as needed
//                  implemented readObject to load an Image after deserialization
//  07/17/97    CAR added add/remove property/vetoable ChangeListner methods
//  08/04/97    LAB Made lightweight.  Implemented setStyle and getStyle.  Deprecated
//                    setCentered and getCentered.
//  08/27/97    CAR update setURL and setFileName to "erase" image if URL or String is null
//  08/04/97    LAB Deprecated URL property and replaced it with ImageURL property (Addresses
//                    Mac Bug #7689).  Changed names of strings in PropertyChangeEvent handling
//                    to follow Bean Spec naming conventions.

/**
 * ImageViewer component. Provides a platform-independent display of an Image.
 * @version 1.1, August 4, 1997
 * @author    Symantec
 */
public class ImageViewer extends Component implements java.io.Serializable
{
    /**
     * A constant indicating the image is to be tiled in the size of this component.
     */
    public static final int IMAGE_TILED = 0;
    /**
     * A constant indicating the image is to be centered in the size of this component.
     */
    public static final int IMAGE_CENTERED = 1;
    /**
     * A constant indicating the image is to be scaled to fit the size of this component.
     */
    public static final int IMAGE_SCALED_TO_FIT = 2;
    /**
     * A constant indicating the image is to be drawn normally in the upper left corner.
     */
    public static final int IMAGE_NORMAL = 3;

    /**
     * Create default image viewer.
     */
    public ImageViewer()
    {
        image        = null;
        fileName    = null;
        url            = null;
        imageStyle    = IMAGE_CENTERED;
    }

    /**
     * Crate image viewer with filename.  The specified filename is used as
     * the image source.
     *
     * @param str name of file containing the image source
     * @exception MalformedURLException Thrown if URL cannot be generated from filename
     *
     */
    public ImageViewer(String str) throws MalformedURLException
    {
        this();

        try
        {
            setFileName(str);
        }
        catch(PropertyVetoException e){}
    }

    /**
     * Create image viewer with URL.  The specified URL is used as
     * the image source.
     *
     * @param url the URL of the image to be displayed
     */
    public ImageViewer(URL url)
    {
        this();

        try
        {
             setURL(url);
        }
        catch ( PropertyVetoException e ) { }
    }

    /**
     * Create image viewer with image.  The specified image is used as
     * the image source
     *
     * @param img the image to be displayed
     */
    public ImageViewer(Image img)
    {
        this();

        try
        {
            setImage(img);
        }
        catch ( PropertyVetoException e ) { }
    }

    /**
     * Specify or change the image filename.
     *
     * @param str name of file containing image source
     *
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setFileName(String str) throws PropertyVetoException
    {
        String oldValue = fileName;

        try
        {
            vetos.fireVetoableChange("fileName", oldValue, str );

           fileName = str;
           if(fileName != null && fileName != "")
               setURL(new URL(fileName));
           else
               setURL(null);

        }
        catch(MalformedURLException e)
        {
            //System.out.println("malformed URL");
            fileName = oldValue;
        }
        repaint();

        changes.firePropertyChange("fileName", oldValue, str );
    }

    /**
     * Obtain the filename associated with the current image.
     *
     * @return the name of the file, if any, associated with this image.  If
     * no file is associated with this image, returns null
     */
    public String getFileName()
    {
        return fileName;
    }

    /**
     * Specify or change the image URL.
     *
     * @param aUrl the URL of the image to be displayed
     *
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setImageURL(URL aUrl) throws PropertyVetoException
    {
        URL oldValue = url;
        vetos.fireVetoableChange("imageURL", oldValue, aUrl );

        url = aUrl;
        fileName = null;
        Image loadedImage = null;
        if(url != null){
            loadedImage = getToolkit().getImage(url);
        }
        setImage(loadedImage);
        repaint();
        changes.firePropertyChange("imageURL", oldValue, aUrl );
    }

   /**
     * Obtain the URL associated with the current image.  If the image
     * was specified by file name, or URL, it will have a URL which
     * indicates its source.  Images created using the constructor
     * with an Image parameter will have no associated URL.
     *
     * @return the name of the URL, if any, associated with this image.  If
               no URL is associated with this image, returns null
     */
    public URL getImageURL()
    {
        return url;
    }

    /**
     * @deprecated
     * @see #setImageURL
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setURL(URL aUrl) throws PropertyVetoException
    {
        setImageURL(aUrl);
    }

   /**
     * @deprecated
     * @see #getImageURL
     */
    public URL getURL()
    {
        return getImageURL();
    }

    /**
     * @deprecated
     * @see #setStyle
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setCenterMode(boolean flag) throws PropertyVetoException
    {
        if(flag)
        {
            if(getStyle() != IMAGE_CENTERED)
                setStyle(IMAGE_CENTERED);
        }
        else
        {
            if(getStyle() != IMAGE_NORMAL)
                setStyle(IMAGE_NORMAL);
        }
    }

    /**
     * @deprecated
     * @see #getStyle
     */
    public boolean getCenterMode()
    {
        return (getStyle() == IMAGE_CENTERED);
    }

    /**
     * Sets the new panel image style.
     * @param newStyle the new panel image style, one of
     * IMAGE_TILED, IMAGE_CENTERED, or IMAGE_SCALED_TO_FIT
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     * @see #getStyle
     * @see #IMAGE_TILED
     * @see #IMAGE_CENTERED
     * @see #IMAGE_SCALED_TO_FIT
     * @see #IMAGE_NORMAL
     */
    public void setStyle(int newStyle) throws PropertyVetoException
    {
        if (newStyle != imageStyle)
        {
            Integer oldValue = new Integer(imageStyle);
            Integer newValue = new Integer(newStyle);

            vetos.fireVetoableChange("style", oldValue, newValue);

            imageStyle = newStyle;
            repaint();

            changes.firePropertyChange("style", oldValue, newValue);
        }
    }

    /**
     * Gets the current panel image style.
     * @return the current panel image style, one of
     * IMAGE_TILED, IMAGE_CENTERED, or IMAGE_SCALED_TO_FIT
     * @see #setStyle
     * @see #IMAGE_TILED
     * @see #IMAGE_CENTERED
     * @see #IMAGE_SCALED_TO_FIT
     */
    public int getStyle()
    {
        return imageStyle;
    }

    /**
     * Set or change the current image.  Call this method if you want to
     * specify directly the image to display.
     *
     * @param img the image to be displayed
     *
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setImage(Image img) throws PropertyVetoException
    {
        fileName = null;
        Image oldValue = image;

        vetos.fireVetoableChange( "image", oldValue, img );

        image    = img;

        if (img != null)
        {
            MediaTracker tracker;

            try
            {
                tracker = new MediaTracker(this);
                tracker.addImage(image, 0);
                tracker.waitForID(0);
            }
            catch(InterruptedException e) { }
        }
        else
              repaint();

        changes.firePropertyChange( "image", oldValue, img );
    }

    /**
     * Obtain the image currently being displayed.
     *
     * @return the image currently displayed or null if no image
     */
    public Image getImage()
    {
        return image;
    }

    /**
     * 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 java.awt.Component#update
     */
    public void paint(Graphics g)
    {
        super.paint(g);

        Dimension dim = size();
        if (image != null)
        {

            int imageWidth = image.getWidth(this);
            int imageHeight = image.getHeight(this);

            switch(imageStyle)
            {
                case IMAGE_CENTERED:
                default:
                {
                    g.drawImage
                        (image,
                         (dim.width - imageWidth) / 2,
                         (dim.height - imageHeight) / 2,
                         imageWidth,
                         imageHeight,
                         this);

                    break;
                }

                case IMAGE_TILED:
                {
                    //Calculate number of images that should be drawn horizontally
                    int numHImages = dim.width / imageWidth;

                    //Don't forget remainders
                    if (dim.width % imageWidth != 0)
                        numHImages++;

                    //Calculate number of images that should be drawn vertically
                    int numVImages = dim.height / imageHeight;

                    //Don't forget remainders
                    if (dim.height % imageHeight != 0)
                        numVImages++;

                    int h;
                    int v = 0;
                    for (int vCount = 0;vCount < numVImages;vCount++)
                    {
                        h = 0;
                        for (int hCount = 0;hCount < numHImages;hCount++)
                        {
                            g.drawImage(image, h, v, imageWidth, imageHeight, this);

                            //Increment to next column
                            h += imageWidth;
                        }

                        //Increment to next row
                        v += imageHeight;
                    }

                    break;
                }


                case IMAGE_SCALED_TO_FIT:
                {
                    g.drawImage(image, 0, 0, dim.width, dim.height, this);

                    break;
                }

                case IMAGE_NORMAL:
                {
                    g.drawImage(image, 0, 0, this);
                    break;
                }
            }//switch
        }
        else
        {
            g.clearRect(0, 0, dim.width, dim.height);
        }
    }

    /**
     * Returns the recommended dimensions to properly display this component.
     * This is a standard Java AWT method which gets called to determine
     * the recommended size of this component.
     *
     * @return  If no image has been loaded, a dimension of 10 by 10 is returned.
     *          If an image has been loaded, the height and width of the image
     *          is returned.
     *
     * @see #minimumSize
     */
    public Dimension preferredSize()
    {
        if (image != null)
            return (new Dimension(image.getWidth(this), image.getHeight(this)));
        else
            return new Dimension(10, 10);
    }


    /**
     * Returns the minimum dimensions to properly display this component.
     * This is a standard Java AWT method which gets called to determine
     * the minimum size of this component.
     *
     * @return  If no image has been loaded, a dimension of 10 by 10 is returned.
     *          If an image has been loaded, the height and width of the image
     *          is returned.
     * @see #preferredSize
     */
    public Dimension minimumSize()
    {
        return preferredSize();
    }

    /**
     * Adds a listener for all event changes.
     * @param PropertyChangeListener listener the listener to add.
     * @see #removePropertyChangeListener
     */
    public void addPropertyChangeListener(PropertyChangeListener listener)
    {
        //super.addPropertyChangeListener(listener);
        changes.addPropertyChangeListener(listener);
    }

    /**
     * Removes a listener for all event changes.
     * @param PropertyChangeListener listener the listener to remove.
     * @see #addPropertyChangeListener
     */
    public void removePropertyChangeListener(PropertyChangeListener listener)
    {
        //super.removePropertyChangeListener(listener);
        changes.removePropertyChangeListener(listener);
    }

    /**
     * Adds a vetoable listener for all event changes.
     * @param VetoableChangeListener listener the listener to add.
     * @see #removeVetoableChangeListener
     */
    public void addVetoableChangeListener(VetoableChangeListener listener)
    {
         //super.addVetoableChangeListener(listener);
        vetos.addVetoableChangeListener(listener);
    }

    /**
     * Removes a vetoable listener for all event changes.
     * @param VetoableChangeListener listener the listener to remove.
     * @see #addVetoableChangeListener
     */
    public void removeVetoableChangeListener(VetoableChangeListener listener)
    {
        //super.removeVetoableChangeListener(listener);
        vetos.removeVetoableChangeListener(listener);
    }

    private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
        stream.defaultReadObject();

        errors = ResourceBundle.getBundle("symantec.itools.resources.ErrorsBundle");

        if (url != null) {
            image = getToolkit().getImage(url);

            MediaTracker tracker = new MediaTracker(this);
            tracker.addImage(image, 0);
            try {
                tracker.waitForAll();
            }
            catch(InterruptedException e) {
            Object[] args = { url };
            throw new IOException(MessageFormat.format(errors.getString("ErrorLoadingImageForURL"), args));
            }
        }
    }

   /**
     * Image that this viewer is displaying.
     */
    transient protected Image image;

    /**
     * Name of file, if any, associated with this image.
     */
    protected String fileName;

    /**
     * URL of the image being displayed.
     */
    protected URL url;

    /**
     * Determines how to draw the image.
     */
    protected int imageStyle;

    /**
     * Error strings.
     */
    transient protected ResourceBundle errors;

    private symantec.itools.beans.VetoableChangeSupport vetos   = new symantec.itools.beans.VetoableChangeSupport(this);
    private symantec.itools.beans.PropertyChangeSupport changes = new symantec.itools.beans.PropertyChangeSupport(this);

}