imagealbum.java

相册是J2me MIDLet 的一个demo程序

/*
 *	Filename: ImageAlbum.java
 *  - contains definition of the Main Class: ImageAlbum. It serves as the main object with static variables storing
 *  information about number of images in Album. It has methods for image display control - move forward/backward 
 *  within Album and start slide show. The CommandListener receives command that contains in images-showing Canvas.
 *	The constructor read images/descriptions from phone storage and prepare them in memory for use when the MIDlet is
 *  launched.    
 *
 *
 *  Application Name: Image Album Demo 
 *  Version: 2.0
 *  Release Date: 27th September, 2002
 *  Author:	Edmund Wong, Application Engineer, Metrowerks Hong Kong
 *
 *  Image Album is a J2ME MIDlet demo program for viewing PNG format images on handsets, user can view 
 *	images by either changing it one by one manually or in the form of slide show. The images can be 
 *  packed in the J2ME JAR package before installing on phone or download from web server over-the-air (OTA).
 *  Users can also add their own descriptions to images. 
 * 
 *  Please see ReadMe.txt for instructions on how to use Image Album Demo.
 *  
 *  (c) Copyright. 2002. Metrowerks Corp. ALL RIGHTS RESERVED.
 *	This code is provided "AS IS" without warranty of any kind and subject to Metrowerks Sample Application
 *  End User License Agreement. NO EXTERNAL DISTRIBUTION OR COMMERCIALIZATION OF THE SOFTWARE IS PERMITTED
 *  EXCEPT BY WRITTEN AGREEMENT OF METROWERKS."
 *
 */

import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
import java.util.*;
//import javax.microedition.rms.*;


/**
 * The Main Class - ImageAlbum 
 */
 
public class ImageAlbum extends MIDlet implements CommandListener{


    /**
     * Define the static variable for storing the no. of image that the Album contains
     * initialize to 0 first, will be stored with the actual no. after reading the PNG files from jar file and 
     * reading image data from RecrodStore  
     */
	
	public static int imageNumberInJAR = 0; // number of images in JAR package
	
	public static int imageNumberInRecordStore = 0; // number of images in RecordStore
	
	public static int totalImageNumber = 0; // total number of images in Album (i.e. # of images in JAR package + # of images in RMS)
	
	
	/**
     * Define a counter for counting image
     */	
     
	public static int imageShowCounter;
		
	
	/**
     * Define command for displayable
     */     
    
    
    // for image Canvas used in View Album function	
	Command nextImageCommand = new Command("Next",Command.SCREEN,0);
	
	Command previousImageCommand = new Command("Previous Image",Command.SCREEN,1);
	
	Command deleteImageCommand = new Command("Delete Image",Command.SCREEN,2);
	
	Command editDescriptionCommand = new Command("Edit description",Command.SCREEN,1);
	
	
	// for Edit Description Form 
	Command saveEditedDescriptionCommand = new Command("Save Description",Command.SCREEN,0);
        	
    Command backToViewAlbum = new Command("Back",Command.BACK,1);
		
	
	// for image Canvas used in both View Album and Slide Show functions	
	Command pauseCommand = new Command("Pause",Command.STOP,0);
	
	Command continueSlideShowCommand = new Command("Continue Slide Show",Command.SCREEN,0);
	
	
	// static mainMenuCommand for various Displayables  
	public static Command mainMenuCommand = new Command("Main menu",Command.SCREEN,4);
	
	
	// Text Field for edit description Form to edit description
	TextField editDescriptionTextField; 
	
	
	byte [] byteArray;							
    
       
    /**
     * Create Alert components for alerting user of reaching start/end of Album
     */
    
    public Alert startOfAlbumAlert = new Alert("Oops!","Reach start of Album!",null,null);
    
    public Alert endOfAlbumAlert = new Alert("Oops!","Reach end of Album!",null,null);   
    
    public Alert endSlideShowAlert = new Alert("Oops!","Reach end of Album.\nEnd of Slide Show!!",null,null);
    
       	
      	
    /**
     * Create an image and description vector, initial size set to 10, capacity increment is set to 3
     */
     
     	Vector imageVector = new Vector (10,3);
     	
      	Vector descriptionsVector = new Vector (10,3);
    
          
   	/**
     * Create a RMSOperations object for manipulating Record Store
     */
      	RMSOperations rmsOperations = new RMSOperations();
      	
     
          
    /**
     * Create a Photo Canvas for View Album function
     */ 
     
     public PhotoCanvas viewAlbumCanvas = new PhotoCanvas(null, " ", this);
     
     
    /**
     * Create a Photo Canvas for Slide Show function
     */ 
     
     public PhotoCanvas slideShowCanvas = new PhotoCanvas(null, " ", this);
     
     
    /**
     * Define a variable for storing the time interval between slides (in Slide Show)
     */
     
     int timerTime = 0;
     
     
    /**
     * Create a Timer for slide show 
     */
   
   	 Timer t = new Timer();
   	 
   	 
   	/**
     * Create a TimerTask for slide show 
     */
     
   	 MyTimerTask slideTask;
   	 
   	   	  
   	/**
     * Create a boolean variable for showing whether it is in a Slide Showing state 
     */
        	
   	 public static boolean slideShowing;
   	 
   	           	         
    /**
     * Reference to the Display
     */
     
     public static Display myDisplay;
    
     
     /**
     * Create form to display Help
     */
     //public HelpDisplayForm helpDisplayForm = new HelpDisplayForm(this);
     
     
    /**
     * Create form to Input Options
     */
     public OptionsInputForm optionsInputForm = new OptionsInputForm(this);
            
     
    /**
     * Create form to Input Options
     */
     public DownloadFromURLForm downloadFromURLForm = new DownloadFromURLForm(this);
     
     
    /**
     * Create selectList as MainMenu to Input Options
     */
     public MainMenu selectList;
     
       
    /**
     * Constructor of ImageAlbum
     */
     
     public ImageAlbum() {

        myDisplay = Display.getDisplay(this);
        
        /*
        try{
        
        	RecordStore.deleteRecordStore("ImageDB");
              
        	RecordStore.deleteRecordStore("DescriptionsDB");  
        
        }
        
        catch (Exception e){
        
        	System.out.println("Exception: " + e.toString());
        
        }*/
        
        
        /**
     	 * Set display time for Alert message
     	 */
     	 
        startOfAlbumAlert.setTimeout(2000); 
        
        endOfAlbumAlert.setTimeout(2000); 
        
        endSlideShowAlert.setTimeout(2000);
        
       
        
               
        /**
     	 * Create Image from PNG files in JAR package
     	 */
                
        int i=0;
        
        while (i>=0) {
        
        	try {
        	    
        	    imageVector.addElement(Image.createImage("/"+Integer.toString(i+1)+".png"));   	
        		
        		
        	} catch (Exception e) {
        		        		    		        		  		
        		// when no more images can be loaded, set the current i to imageNumberInJAR, which is the current no. of images 
        		// in JAR package
        		
        		imageNumberInJAR = i;
        		
        		// set i to -2, so that it will be a negative no. during testing i's value and quit the while loop. 
        		
        		i = -2;
        	}
        	
        	i++;
        }  
        
        
        
        /**
     	 * Create Image from bytes array in ImageDB
     	 */     	  	 		
     	 
     	 byte [] byteArray = null;
     	 		
     	// open the RecordStore "ImageDB"
     	 		
     	rmsOperations.openRecordStore("ImageDB", true);
     	 		 				
												
								
		// get number of records in Image Record Store 				
						
		imageNumberInRecordStore = rmsOperations.getNumberOfRecords();
							
				
				
		// total no. of images = no. of images in JAR package + no. of images in RecordStore
								
		totalImageNumber = imageNumberInJAR + imageNumberInRecordStore;
				
		System.out.println("total Image number:" + totalImageNumber+" no. of Image in JAR:"+ imageNumberInJAR);
				
				
				
		if (imageNumberInRecordStore > 0) {
				
			for (i = 1; i <= imageNumberInRecordStore; i++){
																				
														
			//byteArray = rmsOperations.getRecord(rmsOperations.getPreviousRecordID());  // for SEMC phone
																					
			byteArray = rmsOperations.getRecord(rmsOperations.getNextRecordID());  // for Motorola phone
																					
			imageVector.addElement(Image.createImage(byteArray, 0, byteArray.length));
							
			System.out.println("current Image # in vector " + imageVector.size());				
									
			}	
				
		}		
     	 	     	         
        		 
        // close RecordStore "ImageDB"
        		
        rmsOperations.closeRecordStore();
				       			
        
        byteArray = null;
       
              
      
       
       	/**
     	 * Create and store default descriptions for the image resided in the Jar package during the first run after installation
     	 */          			
       			
       			
       	// open the RecordStore "DescriptionsDB"
       
       	rmsOperations.openRecordStore("DescriptionsDB", true);
       											
								
				
		// create descriptions for images in JAR for first run after installation, and storing into descriptions vector 				
				
		if (rmsOperations.getNumberOfRecords() == 0) {
				
			
			System.out.println("first run");
					
			for (i=1; i <= imageNumberInJAR; i++){
						
				// convert string into byte data
				try{
														
					byteArray = StringByteOperations.stringToByteConvertion("JAR Package - "+ i +".png");
							
				}
							
				catch(Exception e){
						
					System.out.println("Exception: " + e.toString());
							
				}
						
							
				// write the byte array of the string into RecordStore "DescriptionsDB"
													
				System.out.println("index:" + i + "  Add Des DB recID:" + rmsOperations.addRecord(byteArray));
							
												
				// write default description string into descriptionsVector making it ready for display use
																			
				descriptionsVector.addElement(new String("JAR Package - "+ i +".png"));
							
					
			}
			
				
		}
		
		else {	// not first run after installation, read all image descriptions from RecordStore "DescriptionsDB"
				
							
				
			// read all image descriptions from RecordStore "DescriptionsDB" and store into descriptionsVector
								
			for (i = 1; i <= totalImageNumber; i++) { 
					
										
				//byteArray = rmsOperations.getRecord(rmsOperations.getPreviousRecordID());  // for SEMC phone
							
				byteArray = rmsOperations.getRecord(rmsOperations.getNextRecordID());  // for Motorola phone
				
				try {
							
					descriptionsVector.addElement(StringByteOperations.byteToStringConvertion(byteArray));
							
				}
						
				catch(Exception e){
					
					System.out.println("Exception: " + e.toString());
						
				}
							
									
			}
				
		
		// close RecordStore DescriptionsDB
				
		rmsOperations.closeRecordStore();
			
				
		}
					
				
	   /**
     	* Add command for the Canvas used in viewing Album manually (viewAlbumCanvas)
     	*/
		
		viewAlbumCanvas.addCommand(nextImageCommand);
       	
       	viewAlbumCanvas.addCommand(previousImageCommand);
       	
       	viewAlbumCanvas.addCommand(mainMenuCommand); 
       	
       	viewAlbumCanvas.addCommand(editDescriptionCommand);	
       	
       	viewAlbumCanvas.addCommand(deleteImageCommand);       
       	
       	viewAlbumCanvas.setCommandListener(this);
       	
       	
       	/**
     	* Add command for the Canvas used in viewing Album in Slide Show Mode (slideShowCanvas)
     	*/
     	
       	slideShowCanvas.addCommand(nextImageCommand);
       	
       	slideShowCanvas.addCommand(previousImageCommand);
       	
       	slideShowCanvas.addCommand(pauseCommand); 
       	       	
       	slideShowCanvas.addCommand(continueSlideShowCommand);
       	
       	slideShowCanvas.addCommand(mainMenuCommand);
       	
       	slideShowCanvas.setCommandListener(this);       	
       	
        		    
     }
     
     
     /**
     * Starts the MIDlet
     */
     protected void startApp() throws MIDletStateChangeException {
     
     selectList = new MainMenu(this);
     
     myDisplay.setCurrent(selectList);
     			        	
    }


    /**
     * Stop the MIDlet
     */
     
    protected void pauseApp() {