/*
 * 進(jìn)度條與線程模型
 */
package com.favo.ui;

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.Gauge;

/**
 * @author Favo
 * 新版本的pgUI，主要是增加了cancel task的能力，通過回調(diào)CancelableObject的
 * cancel方法實(shí)現(xiàn)。 
 * Preferences - Java - Code Style - Code Templates
 */
public class ProgressGaugeUI implements ProgressObserver, CommandListener {

	private static final int GAUGE_MAX = 8;

	private static final int GAUGE_LEVELS = 4;

	private static ProgressGaugeUI pgUI;

	private Form f;

	private Gauge gauge;

	private Command stopCMD;

	boolean stopped;

	boolean stoppable;
	
	int current;
	
	Cancelable cancelableObject;

	protected ProgressGaugeUI() {
		f = new Form("");
		gauge = new Gauge("", false, GAUGE_MAX, 0);
		stopCMD = new Command("Cancel", Command.STOP, 10);
		f.append(gauge);
		f.setCommandListener(this);
	}

	public static ProgressGaugeUI getInstance() {
		if (pgUI == null) {
			return new ProgressGaugeUI();
		}
		return pgUI;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.favo.ui.ProgressObserver#reset(java.lang.Object)
	 */
	public void reset() {
		current=0;
		gauge.setValue(0);
		stopped=false;
		setStoppable(false);
		setTitle("");
		setPrompt("");
		cancelableObject=null;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.favo.ui.ProgressObserver#updateProgress(java.lang.Object)
	 */
	public void updateProgress(Object param1) {
		// TODO Auto-generated method stub
		current=(current+1)%GAUGE_LEVELS;
		gauge.setValue(current * GAUGE_MAX/GAUGE_LEVELS);
		if(param1!=null && param1 instanceof String){
			setPrompt((String)param1);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.favo.ui.ProgressObserver#isStoppable()
	 */
	public boolean isStoppable() {
		return stoppable;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.favo.ui.ProgressObserver#setStoppable(boolean)
	 */
	public void setStoppable(boolean stoppable) {
		this.stoppable = stoppable;
		if(stoppable){
			f.addCommand(stopCMD);
		}else{
			f.removeCommand(stopCMD);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.favo.ui.ProgressObserver#isStopped()
	 */
	public boolean isStopped() {
		// TODO Auto-generated method stub
		return stopped;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.favo.ui.ProgressObserver#setTitle(java.lang.String)
	 */
	public void setTitle(String title) {
		// TODO Auto-generated method stub
		f.setTitle(title);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.favo.ui.ProgressObserver#setPrompt(java.lang.String)
	 */
	public void setPrompt(String prompt) {
		gauge.setLabel(prompt);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see javax.microedition.lcdui.CommandListener#commandAction(javax.microedition.lcdui.Command,
	 *      javax.microedition.lcdui.Displayable)
	 */
	public void commandAction(Command arg0, Displayable arg1) {
		if(arg0==stopCMD){
			if(isStoppable())
				if(!isStopped()){//保證僅被調(diào)用一次
					setStopped(true);
					if(cancelableObject!=null)
						cancelableObject.cancel();
				}
			else{
				setPrompt("can't stop!");
			}
		}
	}

	/* (non-Javadoc)
	 * @see com.favo.ui.ProgressObserver#show(javax.microedition.lcdui.Display)
	 */
	public void show(Display display) {
		display.setCurrent(f);
	}

	/* (non-Javadoc)
	 * @see com.favo.ui.ProgressObserver#exit()
	 */
	public void exit() {
		cancelableObject=null;
	}

	/* (non-Javadoc)
	 * @see com.favo.ui.ProgressObserver#setMax()
	 */
	public void setMax() {
		gauge.setValue(GAUGE_MAX);
	}

	/* (non-Javadoc)
	 * @see com.favo.ui.ProgressObserver#setStopped(boolean)
	 */
	public void setStopped(boolean stopped) {
		this.stopped=stopped;
	}
	
	public void setCancelalbeObject(Cancelable co){
		this.cancelableObject=co;
	}

}