Changeset 11564

Timestamp:

2006-04-03T09:59:58+12:00 (18 years ago)

Author:

shaoqun

Message:

changed the code handling threads

File:

• trunk/gsdl/src/java/org/nzdl/gsdl/GsdlCollageApplet/DownloadImages.java (modified) (3 diffs)

trunk/gsdl/src/java/org/nzdl/gsdl/GsdlCollageApplet/DownloadImages.java

@@ -5 +5 @@
 import java.net.*;
 import java.util.*;
+import java.awt.image.*;
+import java.awt.geom.*;
 
 /** 
@@ -50 +52 @@
     }
 
-    /** The amount of output to produce to the screen */
-    int verbosity_       = 0;
-    /** Holds the images that have been downloaded and are waiting to be used */
-    Vector image_array_  = null;
+
+   
+    ImageUrlTriple downloaded_image;
+    CollageImage collage_image; 
+
+    /** Refers to applet */
+    GsdlCollageApplet app_ = null;
+    boolean isJava2_;
+    int num_of_downloads;
+    boolean stopDownload;
+ 
+  
 
     /** Initialises an empty vector to store downloaded images in and sets
      *  the verbosity for this class */
-    public DownloadImages(int verbosity)
+    public DownloadImages(GsdlCollageApplet app, int verbosity, boolean isJava2)
     {
-    verbosity_ = verbosity;
-    image_array_ = new Vector();
-    }
-
-    /** Get the number of images currently downloaded and waiting for use
-     *  @return the number of images currently downloaded */
-    public synchronized int size()
-    {
-    return image_array_.size();
-    }
-
-   //   /** Get the image from the specified position in the array of downloaded images
-//       *  @return an ImageUrlTriple containing the image, url and image name */
-//      public synchronized ImageUrlTriple get(int pos)
-//      {
-//      return (ImageUrlTriple)image_array_.get(pos);
-//      }
+    
+        app_=app;
+        isJava2_= isJava2;
+    }
+
 
     /** Push a new image into the vector of downloaded images
@@ -81 +79 @@
      *  @param url the source url of the image
      *  @param name the name of the image to add */
-    public synchronized void push(Image image, String url, String name)
+    public  synchronized int downloadImage(MediaTracker tracker, URL url, String urlString, String name)
     {
-    ImageUrlTriple iutriple = new ImageUrlTriple(image,url,name);
-
-    image_array_.addElement(iutriple);
+
+    while (downloaded_image != null ){
+        System.out.println(Thread.currentThread().getName() + " wait to download..."); 
+        try{
+        wait();
+        }
+        catch(InterruptedException e){
+        return 0;
+        }
+
+    }
+        Image image = Toolkit.getDefaultToolkit().getImage(url);
+
+         tracker.addImage(image,num_of_downloads);
+
+         try{
+           System.out.println( "   downloading ..."); 
+         tracker.waitForID(num_of_downloads);
+                System.out.println(Thread.currentThread().getName() + " get!!!"); 
+           }
+           catch (InterruptedException e){
+            return 0;
+         }
+     
+    downloaded_image  = new ImageUrlTriple(image,urlString,name);
+    num_of_downloads++;
+
+    if (num_of_downloads == app_.maxDownloads()){
+        stopDownload = true;
+            System.out.println("num_of_downloads "+num_of_downloads);
+
+    }   
+    //System.out.println("num_of_downloads "+num_of_downloads +" ");
+    notify();
+       
+    return num_of_downloads ;
     }
 
     /** Remove the image from the specified position in the array of downloaded images
      *  @return an ImageUrlTriple containing the image, url and image name */
-    public synchronized ImageUrlTriple retrieve(int pos)
+    public synchronized CollageImage getCollageImage()
     {
-    if (image_array_.size() == 0)
-        return null;
-
-    if (pos >= (image_array_.size() - 1))
-        pos = 0;
-
-    ImageUrlTriple u = (ImageUrlTriple) image_array_.elementAt(pos);
-    image_array_.removeElementAt(pos);
-    return u;
-    }
-
-    /** gets the oldest downloaded image, checks that the downloaded images are
-     *  not empty.
-     *  @return an ImageUrlTriple containing the image, url and image name */
-    public synchronized ImageUrlTriple shift()
-    {   
-    if (image_array_.size()==0) {
-        return null;
-    }
-
-    ImageUrlTriple u = (ImageUrlTriple) image_array_.elementAt(0);
-    image_array_.removeElementAt(0);
-    return u;
-    }
+    if (stopDownload)  return null;   
+
+    while (downloaded_image == null && !stopDownload){
+        System.out.println(Thread.currentThread().getName() + " wait to get Collage image...");
+        try{
+        wait();
+        }
+        catch(InterruptedException e){
+        return null;
+        }
+    }
+
+    collage_image = process(downloaded_image);
+    downloaded_image = null;
+       
+        notify();
+    System.out.println(Thread.currentThread().getName() + " get Collage image!!!");
+        return collage_image;
+
+    }
+
+    public void stopDownload(){
+        stopDownload = true;
+    }
+
+    private CollageImage process(ImageUrlTriple iutriple){
+            Image image     = iutriple.image();
+        String from_url = iutriple.url();
+        String img_name = iutriple.name();
+ 
+        CollageImage collage_image = new CollageImage(image,from_url,img_name);
+
+        image = collage_image.image_;
+        // images x and y dimensions
+        int image_x_dim = image.getWidth(app_);
+        int image_y_dim = image.getHeight(app_);
+
+        if ((image_x_dim>0) && (image_y_dim>0))
+        {
+        collage_image.setDimensions(image_x_dim,image_y_dim);
+        
+        // places and sizes the image
+        MyAffineTransform af = new MyAffineTransform(image_x_dim,image_y_dim);
+        
+        // sets location & size of collage image
+        collage_image.setAffineTransform(af, isJava2_);
+        
+         if (isJava2_ ) {
+            collage_image.image_ 
+            = restoreAlpha(collage_image.image_, 0, 0, 
+                       collage_image.image_x_dim_, collage_image.image_y_dim_); 
+            
+        }
+            
+            
+        }
+     
+        collage_image.fresh = false;
+        return collage_image;
+    }
+
+  /** Resets the alpha channel of an image so that it appears solid
+     *
+     *  @param img the image to restore
+     *  @param x the x co-ordinate of the image
+     *  @param y the y co-ordinate of the image
+     *  @param w the width of the image
+     *  @param h the height of the image */
+    public Image restoreAlpha(Image img, int x, int y, int w, int h) {
+      
+    // declare an array to hold the pixels
+    int[] pixels = new int[w * h];
+
+    // get the pixels of the image into the pixels array
+    PixelGrabber pg = new PixelGrabber(img, x, y, w, h, pixels, 0, w);
+
+    try {
+        System.err.println("  grab pixels....");
+        pg.grabPixels();
+        System.err.println("  got pixels!!!");
+    } catch (InterruptedException e) {
+        System.err.println("interrupted waiting for pixels!");
+        return img;
+    }
+
+      
+    // check for any failures
+    if ((pg.getStatus() & ImageObserver.ABORT) != 0) {
+        System.err.println(" image fetch aborted or errored");
+        return img;
+    }
+
+    // loop through every pixel in the picture and handle it
+    for (int j = 0; j < h; j++) {
+        for (int i = 0; i < w; i++) {
+        pixels[j * w + i] |= (255 << 24) & 0xff000000;
+        }
+    }
+
+    // set the pixels of the whole picture to the pixels array
+    pg.setPixels(0, 0, w, h, pg.getColorModel(), pixels, 0, w);
+
+    // create the new image and return it
+    return( app_.createImage(new MemoryImageSource(w, h, pixels, 0, w)) );
+    
+    }
+
+
 }