Chip 1998 November/Chip_1998-11_cd.bin/tema/Cafe/Source.bin/Animator.java

Text File | 1998-03-18 | 17KB | 640 lines

package symantec.itools.multimedia;

import java.awt.Graphics;
import java.awt.MediaTracker;
import java.awt.Canvas;
import java.awt.Image;
import java.awt.Dimension;
import java.net.URL;
import java.util.Vector;
import java.util.Enumeration;
import java.beans.PropertyVetoException;
import java.beans.PropertyChangeListener;
import java.beans.VetoableChangeListener;
import java.beans.PropertyChangeEvent;

//    01/29/97    TWB    Integrated changes from Windows
//    05/30/97    RKM    Changed symantec.beans references to java.beans
//                    Moved AnimatorImage class into its own file as the compiler suggested
//    05/31/97    RKM    Updated to support Java 1.1
//                    Made properties bound & constrained
//  07/15/97    CAR marked fields transient as needed
//                  modified addImage to call the AnimatorImage constructor which takes a Component reference
//  08/27/97    CAR setting repeatMode from false to true will re-start the animation

/**
 * This is a simple animation component. <br>
 * It creates an animation by displaying a series of images in sequence.
 * The programmer can specify the delay between frames in milliseconds.
 * The animation can loop for a specific
 * number of iterations or can run forever.
 *
 * @version 1.0, Nov 26, 1996
 * @author Symantec
 */

public class Animator  extends Canvas implements Runnable, PropertyChangeListener
{
    /**
     * Constructs a default Animator.  The animator defaults to a 500 millisecond delay, and loops forever.
     */
    public Animator()
    {
        delay         = 500;
        numLoops      = 1;
        forever       = true;
        images        = new Vector();
        currentImage  = null;
        clearFrame    = false;
        previewMode   = false;

        maxWidth      = 0;
        maxHeight     = 0;

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

        changes.addPropertyChangeListener(this);
    }

    //
    // Properties
    //

    /**
     * Sets the delay between animation frames.
     * @param i animation delay, in milliseconds
     * @see #getDelay
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setDelay(int newDelay)
        throws PropertyVetoException
    {
        if (delay != newDelay)
        {
            Integer oldDelayInt = new Integer(delay);
            Integer newDelayInt = new Integer(newDelay);

            vetos.fireVetoableChange("Delay", oldDelayInt, newDelayInt);

            delay = newDelay;

            changes.firePropertyChange("Delay", oldDelayInt, newDelayInt);
        }
    }

    /**
     * Returns the current delay between animation frames.
     * @return current animation delay, in milliseconds
     * @see #setDelay
     */
    public int getDelay()
    {
        return delay;
    }

    /**
     * Sets the number of loops to perform when displaying
     * the animation set.
     * @param i loop count
     * @see #getNumLoops
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setNumLoops(int newNumLoops)
        throws PropertyVetoException
    {
        if (numLoops != newNumLoops)
        {
            Integer oldNumLoopsInt = new Integer(numLoops);
            Integer newNumLoopsInt = new Integer(newNumLoops);

            vetos.fireVetoableChange("NumLoops", oldNumLoopsInt, newNumLoopsInt);

            numLoops = newNumLoops;

            changes.firePropertyChange("NumLoops", oldNumLoopsInt, newNumLoopsInt);
        }
    }

    /**
     * Returns the current animation set loop count.
     * @return loop count
     * @see #setNumLoops
     */
    public int getNumLoops()
    {
        return numLoops;
    }

    /**
     * Sets the repeat mode setting.
     * @param b repeat mode, repeats if true
     * @see #getRepeatMode
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setRepeatMode(boolean newRepeatMode)
        throws PropertyVetoException
    {
        if (forever != newRepeatMode)
        {
            Boolean oldRepeatModeBool = new Boolean(forever);
            Boolean newRepeatModeLoopsBool = new Boolean(newRepeatMode);

            vetos.fireVetoableChange("RepeatMode", oldRepeatModeBool, newRepeatModeLoopsBool);

            forever = newRepeatMode;

            changes.firePropertyChange("RepeatMode", oldRepeatModeBool, newRepeatModeLoopsBool);
        }
    }

    /**
     * @deprecated
     * @see #isRepeatMode
     */
    public boolean getRepeatMode()
    {
        return isRepeatMode();
    }

    /**
     * Returns the current repeat mode setting.
     * @return current repeat mode setting, true if repeat forever
     * @see #setRepeatMode
     */
    public boolean isRepeatMode()
    {
        return forever;
    }

    /**
     * Sets the image list.  Images in this list are displayed in
     * sequence to form the animation.
     * @param list array of image URLs
     * @see #getImageList
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public synchronized void setImageList(URL[] newImageList)
        throws PropertyVetoException
    {
        //???RKM??? I'm not comparing the two lists here, should I?

        boolean wasAnimating = (displayThread != null);

        if (wasAnimating)
            stopAnimation();

        URL[] oldImageList = getImageList();

        vetos.fireVetoableChange("ImageList", oldImageList, newImageList);

        currentImage = null;

        images = new Vector();
        for (int i = 0; i < newImageList.length; ++i)
            addImage(newImageList[i]);

        changes.firePropertyChange("ImageList", oldImageList, newImageList);

        if (wasAnimating || previewMode || !java.beans.Beans.isDesignTime())
        {
            startAnimation();
        }
        else if (newImageList.length > 0)
        {
            currentImage = ((AnimatorImage)images.elementAt(0)).image;
        }

        repaint();
    }

    /**
     * Returns the image list.
     * @return URL list of images
     * @see #setImageList
     */
    public synchronized URL[] getImageList()
    {
        URL[] list = new URL[images.size()];

        int i = 0;
        Enumeration enum = images.elements();
        while (enum.hasMoreElements())
        {
            list[i++] = ((AnimatorImage)enum.nextElement()).url;
        }

        return list;
    }

    /**
     * Sets whether or not the animation frame area is cleared
     * between each frame.
     * @param newClearFrame if true, the frame area is cleared between each
     * animation frame; if false, the frame area is not cleared.
     * @see #getClearFrame
     * @exception PropertyVetoException
     * if the specified property value is unacceptable
     */
    public void setClearFrame(boolean newClearFrame)
        throws PropertyVetoException
    {
        if (clearFrame = newClearFrame)
        {
            Boolean oldClearFrameBool = new Boolean(clearFrame);
            Boolean newClearFrameBool = new Boolean(newClearFrame);

            vetos.fireVetoableChange("ClearFrame", oldClearFrameBool, newClearFrameBool);

            clearFrame = newClearFrame;

            changes.firePropertyChange("ClearFrame", oldClearFrameBool, newClearFrameBool);
        }
    }

    /**
     * @deprecated
     * @see #isClearFrame
     */
    public boolean getClearFrame()
    {
        return isClearFrame();
    }

    /**
     * Gets the current clear frame setting.
     * @return boolean - if true, the frame area is cleared
     * between each animation frame; if false, the frame area
     * is not cleared.
     * @see #setClearFrame
     */
    public boolean isClearFrame()
    {
        return clearFrame;
    }

    /**
     * Sets the preview mode flag.  This flag is used by Visual Cafe to
     * determine if this component should be run during design time.
     * @param newPreviewMode new preview mode
     * @see #getPreviewMode
     */
    public void setPreviewMode(boolean newPreviewMode)
    {
        if (previewMode != newPreviewMode)
        {
            if (java.beans.Beans.isDesignTime())
            {
                previewMode = newPreviewMode;

                if (previewMode && (images.size() > 0))
                    startAnimation();
                else
                    stopAnimation();
            }
        }
    }

    /**
     * @deprecated
     * @see #setPreviewMode
     */
    public boolean getPreviewMode()
    {
        return isPreviewMode();
    }

    /**
     * Gets the preview mode flag. This flag is used by Visual Cafe to
     * determine if this component should be run during design time.
     * @see #setPreviewMode
     */
    public boolean isPreviewMode()
    {
        return previewMode;
    }

    //
    // Methods
    //

    /**
     * Adds an image to the animation set.
     * @param url URL of the image to add
     */
    public synchronized void addImage(URL url)
    {
        Image image = getToolkit().getImage(url);

        boolean loadWait = images.size() == 0 || previewMode || !java.beans.Beans.isDesignTime();

        if (loadWait)
        {
            imageLoadWait(image);
        }

        images.addElement(new AnimatorImage(url, image, loadWait, this));
    }

    /**
     * Starts the animation.
     * @see #stopAnimation
     */
    public void startAnimation()
    {
        if (displayThread == null)
        {
            displayThread = new Thread(this);
            displayThread.start();
        }
        else
        {
            try {
                displayThread.join();
            } catch (InterruptedException e) {}
            displayThread = new Thread(this);
            displayThread.start();
        }
    }

    /**
     * Stops the animation.
     * @see #startAnimation
     */
    public void stopAnimation()
    {
        if (displayThread != null)
        {
            displayThread.stop();
            displayThread = null;
        }
    }

    /**
     * Body of Animation Thread.  This method is called by the Java Virtual Machine
     * in response to a call to the start method of this object.
     */

    public synchronized void run()
    {
        for (int i = 0; i < numLoops || forever; ++i)
        {
            if (images.size() == 0)
            {
                try
                {
                    wait(delay);
                }
                catch(InterruptedException e)
                {
                }

            }
            else
            {

                for (int j = 0; j < images.size(); ++j)
                {
                   synchronized(this)
                   {
                        try
                        {
                            wait(delay);
                        }
                        catch(InterruptedException e)
                        {
                        }

                        AnimatorImage ai = (AnimatorImage)images.elementAt(j);

                        if (!ai.loaded)
                        {
                            imageLoadWait(ai.image);
                            images.setElementAt(new AnimatorImage(ai.url, ai.image, true), j);
                        }

                        currentImage = ai.image;
                    }

                    repaint();
                }
            }
        }
    }

    /**
     * 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 synchronized void paint(Graphics g)
    {
        if (currentImage != null)
            g.drawImage(currentImage, 0, 0, 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 make clearing the background before painting
     * optional. If the clearFrame flag is true the background will be erased
     * before painting begins.
     *
     * @param g the graphics context
     * @see java.awt.Component#repaint
     * @see #paint
     */
    public void update(Graphics g)
    {
        if (clearFrame)
            super.update(g);
        else
            paint(g);
    }

    /**
     * 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 images have been loaded, a dimension of 10 by 10 is returned.
     *          If one or more images have been loaded, the largest height and the
     *          largest width of any image is returned.
     *
     * @see #minimumSize
     */
    public Dimension preferredSize()
    {
        if (images == null || images.size() == 0)
            return new Dimension(10, 10);

        return new Dimension(maxWidth, maxHeight);
    }

    /**
     * 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 images have been loaded, a dimension of 10 by 10 is returned.
     *         If one or more images have been loaded, the largest height and the
     *         largest width of any image is returned.
     *
     * @see #preferredSize
     */
    public Dimension minimumSize()
    {
        return preferredSize();
    }

    /**
     * A method of the PropertyChangeListener interface.
     * This method is called when a property of this component changes.
     * It starts the animation when the Repeat Mode property is set.
     * @param the event
     * @see java.awt.PropertyChangeListener
     */
    public void propertyChange(PropertyChangeEvent evt)
    {
        String property = evt.getPropertyName();

        if(property != null) {
            if(property.equalsIgnoreCase("RepeatMode")) {
                startAnimation();
            }
        }

    }

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

    void imageLoadWait(Image image)
    {
        MediaTracker tracker = new MediaTracker(this);

        tracker.addImage(image, 0);

        try
        {
            tracker.waitForAll();
        }
        catch(InterruptedException e)
        {
        }

        int size;

        if ((size = image.getWidth(this)) > maxWidth)
            maxWidth = size;

        if ((size = image.getHeight(this)) > maxHeight)
            maxHeight = size;
    }

    /**
     * Delay time between images, in milliseconds.
     */
    protected int delay;

    /**
     * Number of times to show the animation sequence.
     */
    protected int numLoops;

    /**
     * Run animation forever. If false, use numLoops.
     */
    protected boolean forever;

    /**
     * Images to be displayed.
     */
    protected Vector images;

    /**
     * Image currently being shown.
     */
    transient protected Image currentImage;

    /**
     * Thread which runs the animation.
     */
    transient protected Thread displayThread;

    /**
     * Dimension of largest image in sequence.
     */
    protected int maxWidth, maxHeight;

    /**
     * Clear frame between each image.
     */
    protected boolean clearFrame;

    /**
     * Preview this component at design time.
     */
    protected boolean previewMode;

    // Private members
    private symantec.itools.beans.VetoableChangeSupport vetos;
    private symantec.itools.beans.PropertyChangeSupport changes;
}