Changeset 38937 for main/trunk/greenstone3/src

Timestamp:

2024-04-22T16:15:36+12:00 (4 weeks ago)

Author:

anupama

Message:

Cleaning up the code somewhat.

Location:

main/trunk/greenstone3/src/java/org/greenstone/applet

Files:

• GsdlCollageApplet/DisplayImages.java (modified) (2 diffs)
• GsdlCollageApplet/GsdlCollageApplet.java (modified) (23 diffs)
• phind/JPhind.java (modified) (1 diff)

main/trunk/greenstone3/src/java/org/greenstone/applet/GsdlCollageApplet/DisplayImages.java

@@ -123 +123 @@
     if(screen_buffer_ == null) {
         System.err.println("### why is screen_buffer_ null?");
-    }
+        if(java.awt.GraphicsEnvironment.isHeadless()) {
+        System.err.println("### It's running headless so screen_buffer_ is null");
+        }
+        if(!app_.isDisplayable()) {
+        System.err.println("### Collage app is not displayable, that's why screen_buffer_ is null");
+        }
+    }
+    
     screen_graphic_ = screen_buffer_.getGraphics();
     screen_graphic_.setColor(bgcolor_);
@@ -438 +445 @@
             Thread.sleep(1000);         
             continue;
-        }    
+        }
+        //System.err.println("#### DisplayImages.run(): moving to next image");
         CollageImage collage_image = download_images_.getCollageImage();
     

main/trunk/greenstone3/src/java/org/greenstone/applet/GsdlCollageApplet/GsdlCollageApplet.java

@@ -150 +150 @@
     super();
     
-    // status bar that applet has, but we want one also if we run JPhind as application
-    // And in fact, when webswing runs our applet, we never get a status bar. So we
-    // create a custom status bar now even if we're running as an applet.
-    // When this applet is run through the appletviewer we might end up with 2 status bars.
+    // status bar if run as application or as webswing applet,
+    // mimicing running as regular applet which gives us a status bar by default
+    // Useful for Phind, not for Collage where there are layout issues even if hidden
     //setLayout(new BorderLayout());
     //if(!isRunAsApplet) {
@@ -176 +175 @@
     }
 
+    /**
+     * This method is called (by main()) only when this class is run
+     * as an application, not as applet. It prepares the variables and
+     * commandline parameters to be set up, so the rest of the
+     * initialisation can be done in the usual way (with the
+     * Applet.getParameters() method) in the init() method called
+     * hereafter for both application and applet mode.
+     */
     public void applicationPreInit(String[] args) {
     // I copied the contents of this contructor for my code for the JPhind.java constructor
@@ -204 +211 @@
         if(key.equals("xtraParams")) {
             value = value.replace("&", "&"); // just in case we have html entities
-            parseXtraParams(value, "=", "&", appParams);
-            /*
-            String[] param_list = value.split("&", 0); // 0 for all occurrences
-            for(String key_val : param_list) {          
-            String[] paramPair = key_val.split("=", 2); // get first 2 strings, key and val
-            //System.err.println("key_val: " + key_val);
-            if(paramPair.length == 2) {
-                String xtraParamsKey = paramPair[0];
-                String xtraParamsVal = paramPair[1];
-                //System.err.println("key - val: " + xtraParamsKey + " - " + xtraParamsVal);
-                appParams.put(xtraParamsKey, xtraParamsVal);
-            }
-            }
-            */
+            parseXtraParams(value, "=", "&", appParams);            
         }
         
@@ -223 +217 @@
         }
     }
-
-    // TODO: we can possibly remove this as it's done in init() now before we need it
-    isWebswing = appParams.getOrDefault("webswing", "0").equals("1") ? true : false;
     
     // Need these parameters set before init(), so that the display works
@@ -318 +309 @@
     for(String key_val : param_list) {
         String[] paramPair = key_val.split(kvSeparator, 2); // get first 2 strings, key and val
-        System.err.println("key_val: " + key_val);
+        //System.err.println("key_val: " + key_val);
         if(paramPair.length == 2) {
         String xtraParamsKey = paramPair[0];
@@ -328 +319 @@
         }
 
-        if (verbosity_ >= 3) { 
+        if (verbosity_ >= 4) {
             System.err.println("*** xtraParams key - val: " + xtraParamsKey + " - " + xtraParamsVal);
         }
@@ -530 +521 @@
     }
 
-    // This block was a nice idea if it worked, but it doesn't work. It's here for syntax.
-    // Handle getting called by webswing JavaScript (but only if run in webswing mode):
-    // when the user navigates away from the webswing app's web page, do cleanup
+    // This block was a nice idea had it worked, but it doesn't
+    // work. It's here as sample syntax.  Handle getting called by
+    // webswing JavaScript (but only if run in webswing mode):
+    // when the user navigates away from the webswing app's web
+    // page, do cleanup
     // https://www.webswing.org/docs/23.2/integrate/jslink.html#invoking-java-from-javascript
     // https://vaadin.com/directory/component/webswing-vaadin1
     if(isWebswing) {
 
-        System.err.println("#### isWebswing, about to add listeners");
+        //System.err.println("#### isWebswing, about to add listeners");
         
         WebswingUtil.getWebswingApi().addBrowserActionListener(new WebActionListener() {
@@ -543 +536 @@
             public void actionPerformed(WebActionEvent actionEvent) {
 
-            System.err.println("******** JavaScript to Java: actionPerformed called.");
+            System.err.println("***JavaScript to Java comms: actionPerformed called");
             //System.err.println("actionEvent = ");
             
@@ -566 +559 @@
         // shutdown the way we'd like on the javascript kill()
         // command when the user navigates away from the collage
-        // page as that only generates a Java WindowClosingEvent
-        // by default if not shutdown handlers registered. And a
+        // page, as that only generates a Java WindowClosingEvent
+        // by default if no shutdown handlers registered. And a
         // WindowClosingEvent only has any effect on applications,
         // not applets. But we can write our own custom handler to
-        // mimic the applet shutdown sequence: refer to
+        // mimic the applet shutdown sequence of stop() then
+        // destroy() see
         // https://www.webswing.org/docs/20.2/integrate/api.html
-        // This code also written with the help of the source code
-        // to know the methods in interface WebswingShutdownListener
-        // and the import statements required for the methods.
-        // and then call System.exit(0) on top of usual applet
-        // behaviour to make sure we get rid of the applet
-        // "application" that webswing launched for us (it took
-        // the applet code and ran it, presumably like a java
-        // program, so a System.exit call may be warranted).
+        // This code also written with the help of webswing's
+        // source code to know the methods in interface
+        // WebswingShutdownListener and the import statements
+        // required for these methods.
+        // After stop() and destroy(), we call System.exit(0) on
+        // top of usual applet behaviour to make sure we get rid
+        // of the applet "application" that webswing launched for
+        // us (it took the applet code and ran it, presumably like
+        // a java program, so a System.exit call may be warranted,
+        // whereas System.exit() isn't called on a regular applet).
         WebswingUtil.getWebswingApi().addShutdownListener(new WebswingShutdownListener() {
-            // These are official API comments for info
+            // These are official webswing API comments for info
             /**
              * Invoked before Webswing requests application to exit.
@@ -614 +610 @@
             // We're like the browser now and so we should
             // honour the above contract.
-
-            System.err.println("------- WebswingShutdownListener.onShutdown() - our custom behaviour");
+            if (verbosity_ >= 3) {
+                System.err.println("------- GsdlCollageApplet WebswingShutdownListener.onShutdown() - our custom behaviour");
+                
+                // This message is sent to JavaScript too late: webpage has already
+                // finished unloading and the JS webswingInstance can't receive msgs.
+                // if(isWebswing && isRunAsApplet) {
+                //    WebswingUtil.getWebswingApi().sendActionEvent("javaToWebswingJSConsoleLog", "GsdlCollageApplet running as webswing applet - quitting now", null);
+                // }
+            }
             stop();
             destroy();
@@ -623 +626 @@
             // webswing.  And this handler/webswing stands
             // in place of a browser and controls what
-            // Ought to happen if a browser doesn't take
+            // *ought* to happen if a browser doesn't take
             // care of the applet life cycle and we ought
-            // to do it.
+            // to do it (here in the webswing handler).
             System.exit(0);
             }
@@ -631 +634 @@
     }
     
-    /*
-    System.err.println("XXX App width: " + this.getWidth());
-    System.err.println("XXX App height: " + this.getHeight());
-
-    
-    // webswing applet doesn't have dimensions set because there's no applet element setting it
-    // so we need to set the size on the Collage Applet if launched with webswing and run in applet mode
-    if(isWebswing && isRunAsApplet) {       
-        //this.setPreferredSize(new Dimension(X_DIM(), Y_DIM()));
-        this.setSize(X_DIM(), Y_DIM());
-        this.resize(X_DIM(), Y_DIM());
-
-        System.err.println("@@@@ App width: " + this.getWidth());
-        System.err.println("@@@@ App height: " + this.getHeight());
-        
-        if(!this.isShowing()) {
-        System.err.println("@@@@ The webswing Applet isn't showing!");
-        this.setVisible(true);
-        }
-        if(!this.isShowing()) {
-        System.err.println("@@@@ The webswing Applet is STILL not showing!");
-        }
-    }
-    */
         
     MediaTracker trk = new  MediaTracker(this);
@@ -665 +644 @@
                         image_url, href_musthave, image_mustnothave, 
                         image_ignore, imageType_,document_root,verbosity_,trk);
-
-    if(isShowing() && isDisplayable()) { //The case if(!(isRunAsApplet && isWebswing)) {
-        System.err.println("**** Creating display thread");
+    // If GsdlCollageApplet is launched as a *webswing applet*, it
+    // doesn't have dimensions, isn't showing nor is it even
+    // displayable at this point in the code. Only when webswing
+    // resizes the GsdlCollageApplet Component, does it have
+    // dimensions and do we know for sure it is showing.
+    if(isShowing() && isDisplayable()) { // case of: if(!(isRunAsApplet && isWebswing)) {
+        if (verbosity_ >= 4) {
+        System.err.println("**** Creating display thread");
+        }
         // starts the display image thread with the currently downloaded images
         display_thread_ = new DisplayImages(this, download_images_,isJava2_, bgcolor_);
     } else {
-        System.err.println("**** GsdlCollageApplet.init() - display_thread_ not yet showing.");
-        System.err.println("**** Will create and start display_thread_ later, in ComponentListener.resize()");
+        if (verbosity_ >= 4) {
+        System.err.println("**** GsdlCollageApplet.init() - display_thread_ not yet showing.");
+        System.err.println("**** Will create and start display_thread_ later, in ComponentListener.resize()");
+        }
     }
     // The display_thread_ needs the component showing before it can be started up.
@@ -688 +675 @@
 
     public void componentHidden(ComponentEvent e) {
-        System.err.println(e.getComponent().getClass().getName() + " --- Hidden");
+    if (verbosity_ >= 4) {
+        System.err.println(e.getComponent().getClass().getName() + " --- Hidden");
+    }
     }
 
     public void componentMoved(ComponentEvent e) {
-    System.err.println(e.getComponent().getClass().getName() + " --- Moved");
+    if (verbosity_ >= 4) {
+        System.err.println(e.getComponent().getClass().getName() + " --- Moved");
+    }
     }
 
     public void componentResized(ComponentEvent e) {
-    System.err.println(e.getComponent().getClass().getName() + " --- Resized");
-    
     if(display_thread_ == null) {
+        if (verbosity_ >= 4) {
+        System.err.println(e.getComponent().getClass().getName() + " --- Resized");
+        System.err.println("Ready to instantiate display thread");
+        }
         display_thread_ = new DisplayImages(this, download_images_,isJava2_, bgcolor_);
         display_thread_.start();
@@ -704 +697 @@
     }
 
-    public void componentShown(ComponentEvent e) {
-    System.err.println("XXXXX" + e.getComponent().getClass().getName() + " --- Shown");
+    public void componentShown(ComponentEvent e) {  
     if(display_thread_ == null) {
+        if (verbosity_ >= 4) {
+        System.err.println("@@@ " + e.getComponent().getClass().getName() + " --- Shown");
+        System.err.println("GsdlCollageApplet ready to instantiate display thread");
+        }
         display_thread_ = new DisplayImages(this, download_images_,isJava2_, bgcolor_);
         display_thread_.start();
@@ -718 +714 @@
     // TODO: Do I need to follow
     // https://stackoverflow.com/questions/5861894/how-to-synchronize-or-lock-upon-variables-in-java
+    // I just followed the Java API's recommendations about what to do
+    // as replacement around Thread.stop() and Thread.destroy() being
+    // deprecated (note: not Applet.stop() and
+    // Applet.destroy(). https://docs.oracle.com/javase/8/docs/api/java/lang/Thread.html#stop--
     public void stopRunning() {
     if(verbosity_ >= 3) {
@@ -741 +741 @@
     }
 
+    // Applet's mouseDown() is deprecated, so we implement mousePressed
     protected class CollageMouseAdapter extends MouseAdapter {
  
@@ -748 +749 @@
     public void mousePressed(MouseEvent e)
     {
-
-    System.err.println("Mouse pressed");
     int x = e.getX();
     int y = e.getY();
@@ -782 +781 @@
             System.err.println("@@@GsdlCollageApplet.CollageMouseAdapter.mousePressed()"
                + "\n\topening url " + from_url + "\n\t"
-               + "for non-applet and non-webswing application is not yet implemented.");
+               + "for non-applets and non-webswing applications is not yet implemented.");
         }
         } 
@@ -790 +789 @@
 
     }
-        //return true;
     }
     }
@@ -797 +795 @@
     public void start() 
     {
-    // starts the display image thread with the currently downloaded images
-    //display_thread_ = new DisplayImages(this, download_images_,isJava2_, bgcolor_);
-    //this.setVisible(true);    
     download_thread_.start();   
 
@@ -838 +833 @@
     public void stop() 
     {
-    System.err.println("\n\n*** Stopping collage Applet: stopping threads...");
+    if(verbosity_ >= 3) {
+        System.err.println("\n\n@@@ GsdlCollageApplet.stop() called: stopping threads...");
+    }
     //download_thread_.stop();
     //display_thread_.stop();
     stopRunning();
     // TODO: maybe we want to unset the interrupt variable on the threads to restart
-    // on start() getting called? No: we system.exit() in the webswing shutdown handler
-    
-    //download_thread_ = null;
-    //display_thread_ = null;
-    
-    }
-
-    /** Destroys threads for downloading and displaying images */
+    // on start() getting called? No: because we system.exit() in the webswing
+    // shutdown handler we implemented. 
+    }
+
+    /** Destroys threads for downloading and displaying images Java
+     * API method specification for destroy(): "Called by the browser
+     * or applet viewer to inform this applet that it is being
+     * reclaimed and that it should destroy any resources that it has
+     * allocated. The stop method will always be called before
+     * destroy."
+     */
     public void destroyed() 
     {
-
-    System.err.println("@@@@@@@@@ GsdlCollageApplet.destroy() called");
-
-    // Let's be sure to have stopped running
-    //stopRunning();
-    
+    if(verbosity_ >= 3) {
+        System.err.println("@@@@@@@@@ GsdlCollageApplet.destroy() called");
+    }
     download_thread_ = null;
     
@@ -887 +884 @@
         System.err.println("Applet still trying to paint!!");
         }
-
-    
-    
-    }
-
+    
+    }
   
     

main/trunk/greenstone3/src/java/org/greenstone/applet/phind/JPhind.java

@@ -350 +350 @@
     add(resultPanel, BorderLayout.CENTER);
 
-    // status bar that applet has, but we want one also if we run JPhind as application
-    // And in fact, when webswing runs our applet, we never get a status bar. So we
-    // create a custom status bar now even if we're running as an applet.
-    // When this applet is run through the appletviewer we might end up with 2 status bars.
+    // Manual status bar to mimic applet's default one, in case we
+    // want one if we run Collage as application And in fact, when
+    // webswing runs our applet, we never get a status bar. So we
+    // can create a custom status bar now even if we're running as
+    // an applet.  When this applet is run through the
+    // appletviewer we might end up with 2 status bars.
+    
     //if(!isRunAsApplet) {
         statusBar = new JLabel();