btcanvas.java

A Java Framework for connecting to and exchanging data from GPS units to J2ME Mobile Devices. Serial

package com.libGPS4j2me.io.bt;

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.bluetooth.*;
import java.util.*;

import com.libGPS4j2me.examples.StdGPSTest;
        
public class BTCanvas extends Canvas implements Runnable{

    private MIDlet midlet;
    private BTConnector btConnect; // class used to get the bluetooth devices.

    private boolean active = true; // active while thread is running.

    private Vector devices; // A vector with the devices received form the BTConnector.
    private String []deviceNames; // An array with the device names

    private int index=-1; // Keep track of the bluetooth device that is selected.
    private int midIndex;

    private final int WIDTH, HEIGHT; // Height and width of the canvas.

    // used for the connection animation
    private boolean connecting = false;
    private int connectX = 10;
    
    // Used for the device searching animation
    private int searchAnimDeg = 0;
    private float []sinTable = new float[640];

    public BTCanvas(MIDlet m){
        midlet = m;
        setFullScreenMode(true);

        // Create the sinus table that are used for the searching animation.
        for(int i=0; i<640; i++){
            sinTable[i] = (float)Math.sin(Math.toRadians((double)i)) * 5;
        }
        
        WIDTH = getWidth();
        HEIGHT = getHeight();
        connectX = WIDTH/2 - 40;
        
        midIndex= ((HEIGHT-20)/20)/2;
        System.out.println("midIndex=" + midIndex);
        
        btConnect = new BTConnector();
        devices = btConnect.getDevices();
        
        
        Thread t = new Thread(this);
        t.setPriority(Thread.MAX_PRIORITY);
        t.start();
    }

    public void paint(Graphics g){
        g.setColor(0xFFFFFF);
        g.fillRect(0, 0, WIDTH, HEIGHT);
        g.setColor(0x000000);

        deviceNames = btConnect.getDeviceNames();
        
        // Display all the devices that are found by the BTConnector.
        if(!connecting){
            for(int i=0; i<btConnect.getSize(); i++){
                int offset = 0;
                if(btConnect.getSize()*20 > HEIGHT - 40){
                    if(index > midIndex){
                        offset = (index-midIndex)*20;
                    }
                }
                if(i==index){
                    g.setColor(0x00FF00);
                    g.drawString(deviceNames[i], 0, 20 + i*20 - offset, 0);
                    g.setColor(0x000000);
                }else{
                    g.drawString(deviceNames[i], 0, 20 + i*20 - offset, 0);
                }
            }

            g.setColor(0xFFFFFF);
            g.fillRect(0, 0, WIDTH, 20);
            g.setColor(0x000000);
            g.drawString("Bluetooth Devices found...", 0, 0, Graphics.LEFT | Graphics.TOP);

            // Paint a little animation while searching for devices.
            if(!btConnect.doneSearchingDevices()){
                searchAnimDeg = searchAnimDeg>=360?searchAnimDeg-360:searchAnimDeg+5;
                int centerX = WIDTH - 15; 
                int centerY = 7; 
                int x1 = (int)sinTable[searchAnimDeg] +centerX;
                int y1 = (int)sinTable[searchAnimDeg+90] + centerY;
                int x2 = (int)sinTable[searchAnimDeg + 180] + centerX;
                int y2 = (int)sinTable[searchAnimDeg + 180 +90] + centerY;
                g.drawLine(x1, y1, x2, y2);
            }

            g.fillRect(0, 15, WIDTH, 2);

            g.setColor(0xFFFFFF);
            g.fillRect(0, HEIGHT-20, WIDTH, 20);
            g.setColor(0x000000);

            g.fillRect(0, HEIGHT-18, WIDTH, 2);
            g.drawString("Exit", 0, HEIGHT, Graphics.LEFT | Graphics.BOTTOM);
            g.drawString("Connect...", WIDTH, HEIGHT, Graphics.RIGHT | Graphics.BOTTOM);

        // Paint a connecting animation when searching for a bluetooth service.
        }else{
            g.drawString("Connecting...", WIDTH/2-40, HEIGHT/2-12, Graphics.LEFT | Graphics.BOTTOM);
            g.drawRect(WIDTH/2-40, HEIGHT/2-10, 80, 20);
            g.fillRect(connectX, HEIGHT/2-10, 5, 20);
            connectX = connectX >=WIDTH/2+40?WIDTH/2-45:connectX+1;

            g.setColor(0xFFFFFF);
            g.fillRect(WIDTH/2-45, HEIGHT/2-10, 5, 21);
            g.fillRect(WIDTH/2+41, HEIGHT/2-10, 5, 21);
            g.setColor(0x000000);

            g.drawString("Exit", 0, HEIGHT, Graphics.LEFT | Graphics.BOTTOM);
            g.drawString("Back...", WIDTH, HEIGHT, Graphics.RIGHT | Graphics.BOTTOM);
        }
    }

    public void keyPressed(int key){
        switch(key){
            case -1:
                index = index > 0?index-1:index;
                break;
            case -2:
                index = index < btConnect.getSize()-1?index+1:index;
                break;
            case -3:
                break;
            case -4:
                break;
            case -6: // Left soft key, used to exit the midlet
                midlet.notifyDestroyed();
                break;
            case -7: // Right soft key is used to connect to a device or to start a new search.
                if(!connecting && index != -1){
                    btConnect.connect(index);
                    connecting = true;
                }else if(connecting){
                    index = -1;
                    connecting = false;
                    btConnect.startSearch();
                }
                break;
        }
    }

    public void run(){

        while(active){
            repaint();

            // If a connection do a device is completed and a bt service is found
            if(btConnect.doneSearchingServices() && btConnect.getUrl().compareTo("") != 0){
                active = false;
            }
            
            try{
                Thread.sleep(10);
            }catch(Exception e){}
        }
        
        // Start the gps reading.
        StdGPSTest gpsTest = (StdGPSTest) midlet;
        gpsTest.start();
    }
    
}