noterecordlist.java

本程序用JavaME语言描述了一个运行在手机上的电子书系统

import javax.microedition.lcdui.Alert;
import javax.microedition.lcdui.AlertType;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.List;
import javax.microedition.lcdui.TextBox;
import javax.microedition.lcdui.TextField;
import javax.microedition.rms.RecordEnumeration;
import javax.microedition.rms.RecordStore;


public class NoteRecordList extends List implements CommandListener {					//标注列表

	final public static int MAXNUM = 100;													//最大条目数
	private TxtReader bookReader = null;													//主程序reference
	private String txtName = null;
	private int[] idList = new int[MAXNUM];												//选项ID列表
	private RecordStore rs;
	private TextBox viewBox = null;
	
	private Image ErrorIcon = null;
	private Image NoteIcon = null;
	
	//是否处于viewBox显示状态
	private boolean isViewMode = false;
	
	//命令集合
	private static Command CMD_back = new Command("返回", Command.BACK, 1);
	private static Command CMD_view = new Command("阅读", Command.SCREEN, 1);
	private static Command CMD_del = new Command("删除", Command.SCREEN, 3);
	private static Command CMD_delAll = new Command("全部删除", Command.SCREEN, 4);
	private static Command CMD_goTo = new Command("进入文章", Command.SCREEN, 2);
	private static Command CMD_save = new Command("保存", Command.SCREEN, 2);
	
	
	//唯一的构造方法
	public NoteRecordList(TxtReader midlet, String txtName){
		//List初始化
		super(txtName+" - 札记列表", List.IMPLICIT);
		this.setSelectCommand(CMD_view);
		//主程序Ｒｅｆｅｒｅｎｃｅ
		bookReader = midlet;
		//打开/创建 RecordStore
		try{
			rs = RecordStore.openRecordStore(txtName+"NRL", true);
			ErrorIcon = Image.createImage("/icon/Error.png");
			NoteIcon = Image.createImage("/icon/Note.png");
		}catch (Exception e){
			e.printStackTrace();
		}
		//文本名称有用D
		this.txtName = txtName;
		//添加Command 设置响应器
		this.addCommand(CMD_back);
		this.addCommand(CMD_view);
		this.addCommand(CMD_del);
		this.addCommand(CMD_delAll);
		this.addCommand(CMD_goTo);
		this.setCommandListener(this);
		//初始化idList 以及选项
		for (int i=0; i<MAXNUM; ++i)
			idList[i] = -1;
		update();
		//viewBox的初始化
		viewBox = new TextBox(this.txtName, "", 128, TextField.ANY);
		viewBox.addCommand(CMD_back);
		viewBox.addCommand(CMD_save);
		viewBox.setCommandListener(this);
	}
	
	public String getTxtName(){
		return this.txtName;
	}
	//返回ＲeadingＢoard
	private void back(){
		if (isViewMode){
			viewBox.setString("");
			Display.getDisplay(bookReader).setCurrent(this);
			isViewMode = false;
		}else{
			Display.getDisplay(bookReader).setCurrent(bookReader.getDisplayable(TxtReader.READINGBORD));
		}
	}
	
	//察看和修改
	private void view(){
		int pos = this.getSelectedIndex();
		if (-1!=pos){
			try{
				NoteRecord nr = NoteRecord.deserialization(rs.getRecord(idList[pos]));
				String text = nr.getNote();
				viewBox.setString(text);
				Display.getDisplay(bookReader).setCurrent(viewBox);
				isViewMode = true;
			}catch (Exception e){
				e.printStackTrace();
			}
		}else{
			Display.getDisplay(bookReader).setCurrent(new Alert("错误", "请选择注释!", ErrorIcon, AlertType.ERROR));
		}
	}
	
	//删除条目()
	private void del(){
		int pos = this.getSelectedIndex();
		try{
			if (-1!=pos){
				rs.deleteRecord(idList[pos]);
				update();
			}else{
				Display.getDisplay(bookReader).setCurrent(new Alert("错误", "请选择注释!", ErrorIcon, AlertType.ERROR));
			}
		}catch (Exception e){
			System.out.println(e.getMessage());
			e.printStackTrace();
		}
	}
	
	//删除全部条目
	private void delAll(){
		try{
			for (int i=0; i!=MAXNUM && idList[i]!=-1; ++i){	
				rs.deleteRecord(idList[i]);
				idList[i] = -1;
			}
		}
		catch (Exception e){
			e.printStackTrace();
		}
		update();
	}
	
	//转到标注在ReadingBoard中的位置
	private void goTo(){
		int pos = this.getSelectedIndex();
		if (pos!=-1){
			try{
				NoteRecord nr = NoteRecord.deserialization(rs.getRecord(idList[pos]));
				ReadingBoard rb = (ReadingBoard)bookReader.getDisplayable(TxtReader.READINGBORD);
				Display.getDisplay(bookReader).setCurrent(rb);
				rb.goByMark(nr.getLine());
			}catch (Exception e){
				e.printStackTrace();
			}
		}
	}
	
	//显示列表
	public void showList(){
		Display.getDisplay(bookReader).setCurrent(this);
	}
	
	//添加NoteRecord,失败返回false
	public boolean addRecord(NoteRecord nr){
		int num = 0;
		for (num=0; num<MAXNUM; ++num)
			if (idList[num]==-1)
				break;
		if (num==MAXNUM){
			Display.getDisplay(bookReader).setCurrent(new Alert("错误", "注释记录已满!", ErrorIcon, AlertType.ERROR));
			return false;
		}
		if (nr!=null){
			try{
				byte[] data = nr.serialization();
				int pos = 0;
				for (int i=0;idList[i]!=-1; ++i){
					++pos;
				}
				idList[pos] = rs.getNextRecordID();
				this.append(nr.getNote(), NoteIcon);
				rs.addRecord(data, 0, data.length);
			}catch (Exception e){
				e.printStackTrace();
			}
			return true;
		}
		return false;
	}
	
	//在ViewMode下，保存修改
	private void save(){
		String str = viewBox.getString();
		if (str.equals("")){
			Display.getDisplay(bookReader).setCurrent(new Alert("错误", "注释不能为空!", ErrorIcon, AlertType.ERROR));
		}else{
			try{
				int pos = this.getSelectedIndex();
				NoteRecord nr = NoteRecord.deserialization(rs.getRecord(idList[pos]));
				nr.setNote(str);
				rs.deleteRecord(idList[pos]);
				nr.setID(rs.getNextRecordID());
				byte[] data = nr.serialization();
				rs.addRecord(data, 0, data.length);
				update();
				back();
			}catch (Exception e){
				e.printStackTrace();
			}
		}
	}
	
	//命令响应
	public void commandAction(Command c, Displayable d) {
		if (c==CMD_back){
			back();
		}else if (c==CMD_view || c==NoteRecordList.SELECT_COMMAND){
			view();
		}else if (c==CMD_del){
			del();
		}else if (c==CMD_delAll){
			delAll();
		}else if (c==CMD_goTo){
			goTo();
		}else if (c==CMD_save){
			save();
		}
	}
	
	//更新ｉｄＬｉｓｔ和List选项
	private void update(){
		this.deleteAll();
		NoteRecord nr = null;
		try{
			RecordEnumeration re = rs.enumerateRecords(null, null, false);
			for (int i=0; i<re.numRecords(); ++i){
				idList[i] = re.nextRecordId();
				nr = NoteRecord.deserialization(rs.getRecord(idList[i]));
				this.append(nr.getNote(), NoteIcon);
			}
			for (int i=re.numRecords(); i<MAXNUM; ++i){
				idList[i] = -1;
			}
			re.destroy();
		}catch (Exception e){
			System.out.println(e.getMessage());
			e.printStackTrace();
		}
	}
	
	//返回全部NoteRecord
	public NoteRecord[] getAll(){
		try{
			int num = 0;
			for (int i=0; i<MAXNUM; ++i)
				if (idList[i]==-1){
					num = i;
					break;
				}
			NoteRecord[] list = new NoteRecord[num];
			for (int i=0; i<num; ++i)
				list[i] = NoteRecord.deserialization(rs.getRecord(idList[i]));
			return list;
		}catch (Exception e){
			e.printStackTrace();
		}
		return null;
	}
}