JavaMe开发绘制文本框TextEdit-eolink官网

JavaMe开发绘制文本框TextEdit

【问题描述】

TextEdit是采用GameCanvas绘制的文本编辑器。本文结合实例给出实现的方法。

【原理】

1 运用Graphics、GameCanvas绘制文本框和光标。

2 检测到输入事件时，跳转到高级界面->TextBox 。通过系统调用输入法完成输入。

3 将TextBox输入的值返回给TextEdit对象。

【设计模式】

这个过程有点类似装饰模式，实际上，实现输入的还是TextBox，只是给TextBox装饰了一下，形成了一个漂亮的外观。

【代码清单】

TextEdit.java

package com.token.view.components;

import javax.microedition.lcdui.Font;

import javax.microedition.lcdui.Graphics;

import javax.microedition.lcdui.game.GameCanvas;

public class TextEdit extends GameCanvas

{

private Font ft;

public int width;

public int height;

public TextEdit(GameCanvas canvas)

{

super(false);

}

//绘制文本框

public void drawTextBox(GameCanvas canvas, Graphics graphics, String text, int x, int y, boolean cursorBlinkOn)

{

//System.out.println("draw");

int padding = 4;

int margin = 2;

ft = Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_PLAIN,Font.SIZE_MEDIUM);

graphics.setFont(ft);

width = 3*canvas.getWidth()/5+2*padding;

height = ft.getHeight()+2*padding;

graphics.setColor(Color.frame);

graphics.fillRect(x+1,y+1,width+margin,height+margin);

graphics.setColor(Color.frameBg);

graphics.draxacgPfEIwRect(x, y,width, height);

graphics.setColor(Color.background);

graphics.fillRect(x+1, y+1,width-1,height-1);

graphics.setColor(Color.text);

graphics.drawString(text, x+padding, y+padding, Graphics.TOP|Graphics.LEFT);

drawCursor(graphics, x+ft.stringWidth(text)+padding, y+padding, 1, ft.getHeight(), cursorBlinkOn);

canvas.flushGraphics(x,y,width,height);

}

//绘制光标

public void drawCursor(Graphics graphics, int x, int y, int width, int height, boolean cursorBlinkOn)

{

if(cursorBlinkOn)

{

ft = Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_PLAIN,Font.SIZE_MEDIUM);

graphics.setFont(ft);

graphics.setColor(0x0,0x0,0x0);

graphics.drawLine(x+width,y,x+width,y+height);

}

PopUpTextBox.java

package com.token.view;

import javax.microedition.lcdui.Command;

import javax.microedition.lcdui.CommandListener;

import javax.microedition.lcdui.Displayable;

import javax.microedition.lcdui.TextBox;

import com.token.util.UIController;

public class PopUpTextBox extends TextBox {

private UIController controller;

protected String canvasText = "";

private Command okCommand;

private Command cancelCommand;

private String object_name = null;

private String editor = null;

private Object args_t[];

private Object[] args;

public PopUpTextBox(UIController control, String title, String text, int maxsize, int constraints)

{

super(title, text, maxsize, constraints);

controller = control;

args = new Object[6];

okCommand = new Command("确定", Command.OK, 1);

cancelCommand = new Command("取消", Command.CANCEL, 1);

this.addCommand(okCommand);

this.addCommand(cancelCommand);

this.setCommandListener(new TextBoxListener());

}

public void init(Object[] args)

{

object_name = ((String)args[0]!=null)?(String)args[0]:"";

editor = ((String)args[1]!=null)?(String)args[1]:"";

//System.out.println(object_name);

//System.out.println(editor);

args_t = args;

this.setString("");

}

protected void closeTextBox(boolean update) {

if (update) canvasText = this.getString();

//System.out.println(canvasText);

if(object_name.equals("registScreen"))

{

if(editor.equals("regist_name"))

{

if(args_t[3]!=""||args_t[3]!=null||args_t[4]!=""||args_t[4]!=null)

{

args[0] = object_name;

args[1] = editor;

args[2] = this.canvasText;

args[3] = args_t[3];

args[4] = args_t[4];

}

controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT_BACK,args);

}

else if(editor.equals("regist_passwd"))

{

if(args_t[2]!=""||args_t[2]!=null||args_t[4]!=""||args_t[4]!=null)

{

args[0] = object_name;

args[1] = editor;

args[2] = args_t[2];

args[3] = this.canvasText;

args[4] = args_t[4];

}

controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT_BACK,args);

}

else if(editor.equals("regist_passwd_re"))

{

if(args_t[2]!=""||args_t[2]!=null||args_t[3]!=""||args_t[3]!=null)

{

args[0] = object_name;

args[1] = editor;

args[2] = args_t[2];

args[3] = args_t[3];

args[4] = this.canvasText;

}

controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT_BACK,args);

}

//...

}

private class TextBoxListener implements CommandListener

{

public void commandAction(Command command, Displayable disp)

{

if(command==okCommand)

{

closeTextBox(true);

}

else if(command==cancelCommand)

{

closeTextBox(false);

}

UserRegist.java

package com.token.view;

import javax.microedition.lcdui.Font;

import javax.microedition.lcdui.Graphics;

import javax.microedition.lcdui.game.GameCanvas;

import com.token.model.*;

import com.token.util.*;

import com.token.view.components.*;

public class UserRegist extends GameCanvas implements Runnable {

private UIController controller;

private Graphics graphics;

private Font ft;

private Menu menu;

private Head head;

private BackGroud backGroud;

private UserDataRecord userRecord;

private String title;

private TextEdit textEdit_name;

private TextEdit textEdit_passwd;

private TextEdit textEdit_passwd_re;

private int textEdit_name_x;

private int textEdit_name_y;

private int textEdit_passwd_x;

private int textEdit_passwd_y;

private int textEdit_passwd_re_x;

private int textEdit_passwd_re_y;

private int currentlySelectedIndex = 0;

private String username;

private String passwd;

private String passwd_re;

long caretBlinkDelay = 500L;

long lastCaretBlink = 0;

private String object_name;

private String editor;

private boolean cursorBlinkOn1;

private boolean cursorBlinkOn2;

private boolean cursorBlinkOn3;

private int width;

private int height;

public UserRegist(UIController control)

{

super(false);

this.controller=control;

this.title = "用户注册";

setFullScreenMode(true);

graphics = getGraphics();

width = getWidth();

height = getHeight();

menu = new Menu(this);

head = new Head(this);

backGroud = new BackGroud(this);

userRecord = new UserDataRecord();

textEdit_name = new TextEdit(this);

textEdit_passwd = new TextEdit(this);

textEdit_passwd_re = new TextEdit(this);

}

public void show(Object[] args) {

// TODO Auto-generated method stub

setFullScreenMode(true);

object_name = ((String)args[0]!=null)?(String)args[0]:"";

editor = ((String)args[1]!=null)?(String)args[1]:"";

username = ((String)args[2]!=null)?(String)args[2]:"";

passwd = ((String)args[3]!=null)?(String)args[3]:"";

passwd_re = ((String)args[4]!=null)?(String)args[4]:"";

if(editor.equals("regist_name"))

{

cursorBlinkOn1 = true;

cursorBlinkOn2 = false;

cursorBlinkOn3 = false;

currentlySelectedIndex =0;

}

else if(editor.equals("regist_passwd"))

{

cursorBlinkOn1 = false;

cursorBlinkOn2 = true;

cursorBlinkOn3 = false;

currentlySelectedIndex =1;

}

else if(editor.equals("regist_passwd_re"))

{

cursorBlinkOn1 = false;

cursorBlinkOn2 = false;

cursorBlinkOn3 = true;

currentlySelectedIndex =2;

}

//System.out.println(object_name);

//System.out.println(editor);

draw();

redraw();

}

public void draw()

{

//clearScreen();

backGroud.drawBackGroud(this, graphics);

head.drawHead(this,graphics,this.title);

menu.drawMenu(this,graphics,"下一步","退出");

drawBody();

}

private void redraw()

{

switch(currentlySelectedIndex)

{

case 0:

{

cursorBlinkOn2 = false;

cursorBlinkOn3 = false;

editor = "regist_name";

break;

}

case 1:

{

cursorBlinkOn1 = false;

cursorBlinkOn3 = false;

editor = "regist_passwd";

break;

}

case 2:

{

cursorBlinkOn1 = false;

cursorBlinkOn2 = false;

editor = "regist_passwd_re";

break;

}

default:;

}

textEdit_name.drawTextBox(this, graphics, username, textEdit_name_x, textEdit_name_y, cursorBlinkOn1);

textEdit_passwd.drawTextBox(this, graphics, passwd, textEdit_passwd_x, textEdit_passwd_y, cursorBlinkOn2);

textEdit_passwd.drawTextBox(this, graphics, passwd_re, textEdit_passwd_re_x, textEdit_passwd_re_y, cursorBlinkOn3);

textEdit_name.flushGraphics();

}

public void drawBody()

{

int margin =5;

ft = Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_BOLD,Font.SIZE_LARGE);

String info = "用户名：\n";

String info_wrap1[] = StringDealMethod.format(info, width-10, ft);

graphics.setFont(ft);

graphics.setColor(Color.text);

for(int i=0; i

{

graphics.drawString(info_wrap1[i],5, (i) * ft.getHeight()+40, Graphics.TOP|Graphics.LEFT);

}

textEdit_name_x = 5;

textEdit_name_y = info_wrap1.length * ft.getHeight()+40;

textEdit_name.drawTextBox(this, graphics, username, textEdit_name_x, textEdit_name_y, cursorBlinkOn1);

info = "用户密码：\n";

String info_wrap2[] = StringDealMethod.format(info, width-10, ft);

graphics.setFont(ft);

graphics.setColor(Color.text);

for(int i=0; i

{

graphics.drawString(info_wrap2[i],5, (i+info_wrap1.length) * ft.getHeight()+textEdit_name.height+margin+40, Graphics.TOP|Graphics.LEFT);

}

textEdit_passwd_x = 5;

textEdit_passwd_y = (info_wrap1.length+info_wrap2.length) * ft.getHeight()+textEdit_name.height+margin+40;

textEdit_passwd.drawTextBox(this, graphics, passwd, textEdit_passwd_x, textEdit_passwd_y, cursorBlinkOn2);

info = "密码确认：\n";

String info_wrap3[] = StringDealMethod.format(info, width-10, ft);

graphics.setFont(ft);

graphics.setColor(Color.text);

for(int i=0; i

{

graphics.drawString(info_wrap3[i],5, (i+info_wrap1.length+info_wrap2.length) * ft.getHeight()+textEdit_name.height+textEdit_passwd.height+2*margin+40, Graphics.TOP|Graphics.LEFT);

}

textEdit_passwd_re_x = 5;

textEdit_passwd_re_y = (info_wrap1.length+info_wrap2.length+info_wrap3.length) * ft.getHeight()+textEdit_name.height+textEdit_passwd.height+2*margin+40;

textEdit_passwd_re.drawTextBox(this, graphics, passwd_re, textEdit_passwd_re_x, textEdit_passwd_re_y, cursorBlinkOn3);

}

public void clearScreen()

{

graphics.setColor(0xff,0xff,0xff);

graphics.fillRect(0, 0, width, height);

}

public void checkTimeStamp()

{

long currentTime = System.currentTimeMillis();

//System.out.println("1");

if(lastCaretBlink + caretBlinkDelay < currentTime)

{

//System.out.println("2");

if(editor.equals("regist_name"))

{

cursorBlinkOn1 =! cursorBlinkOn1;

cursorBlinkOn2 = false;

cursorBlinkOn3 = false;

}

else if(editor.equals("regist_passwd"))

{

cursorBlinkOn1 = false;

cursorBlinkOn2 =! cursorBlinkOn2;

cursorBlinkOn3 = false;

}

else if(editor.equals("regist_passwd_re"))

{

cursorBlinkOn1 = false;

cursorBlinkOn2 = false;

cursorBlinkOn3 =! cursorBlinkOn3;

}

lastCaretBlink = currentTime;

}

public void run()

{

//System.out.println("run");

while(true)

{

checkTimeStamp();

redraw();

try

{

synchronized(this)

{

//System.out.println("3");

wait(50L);

}

catch(Exception e)

{

e.printStackTrace();

}

protected void keyPressed(int keyCode)

{

switch(keyCode)

{

case KeyID.SOFT_RIGHT:

{

controller.handleEvent(UIController.EventID.EVENT_EXIT,null);

break;

}

case KeyID.SOFT_LEFT:

{

if(username!="" && passwd!=""&&passwd_re!="")

{

if(passwd.equals(passwd_re))

{

userRecord.db_deleteAllRecord();

if(userRecord.db_getRecord(1)==null)

{

UserDataItem userItem = new UserDataItem(1,(username+","+passwd).getBytes());

userRecord.db_addRecord(userItem);

userItem = null;

System.gc();

}

String update = "start";

Object [] args = {"activeScreen", null, update};

controller.handleEvent(UIController.EventID.EVENT_NEXT_ACTIVE_TOKEN_SCREEN,args);

}

break;

}

case KeyID.KEY_EDIT:

case KEY_NUM0:

case KEY_NUM1:

case KEY_NUM2:

case KEY_NUM3:

case KEY_NUM4:

case KEY_NUM5:

case KEY_NUM6:

case KEY_NUM7:

case KEY_NUM8:

case KEY_NUM9:

{

//System.out.println(editor);

Object[] args = {object_name,editor,username,passwd,passwd_re};

controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT,args);

break;

}

default:;

}

keyCode = getGameAction(keyCode);

switch(keyCode)

{

case UP:

case LEFT:

{

currentlySelectedIndex--;

if(currentlySelectedIndex<0)

{

currentlySelectedIndex=0;

}

else

{

redraw();

}

break;

}

case DOWN:

case RIGHT:

{

currentlySelectedIndex++;

if(currentlySelectedIndex>2)

{

currentlySelectedIndex=2;

}

else

{

redraw();

}

break;

}

【分析】

1 文本框的绘制(TextEdit.java)

需要传递GameCanvas、Graphics对象，实现绘图，策略是谁使用，谁传递该参数。此外需要床底文本框左上角坐标(x，y)以及控制光标闪烁的变量cursorBlinkOn。

public void drawTextBox(GameCanvas canvas, Graphics graphics, String text, int x, int y, boolean cursorBlinkOn)

{

//System.out.println("draw");

int padding = 4;

int margin = 2;

ft = Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_PLAIN,Font.SIZE_MEDIUM);

graphics.setFont(ft);

width = 3*canvas.getWidth()/5+2*padding;

height = ft.getHeight()+2*padding;

graphics.setColor(Color.frame);

graphics.fillRect(x+1,y+1,width+margin,height+margin);

graphics.setColor(Color.frameBg);

graphics.drawRect(x, y,width, height);

graphics.setColor(Color.background);

graphics.fillRect(x+1, y+1,width-1,height-1);

graphics.setColor(Color.text);

graphics.drawString(text, x+padding, y+padding, Graphics.TOP|Graphics.LEFT);

drawCursor(graphics, x+ft.stringWidth(text)+padding, y+padding, 1, ft.getHeight(), cursorBlinkOn);

canvas.flushGraphics(x,y,width,height);

}

2 绘制光标(TextEdit.java)

public void drawCursor(Graphics graphics, int x, int y, int width, int height, boolean cursorBlinkOn)

{

if(cursorBlinkOn)

{

ft = Font.getFont(Font.FACE_PROPORTIONAL,Font.STYLE_PLAIN,Font.SIZE_MEDIUM);

graphics.setFont(ft);

graphics.setColor(0x0,0x0,0x0);

graphics.drawLine(x+width,y,x+width,y+height);

}

3 实现光标闪烁

光标闪烁的实现需要用到线程，在UIController.java类中，需要绘制文本框的视图类，需要实现线程接口。

UIController.java

case EventID.EVENT_NEXT_USER_REGIST_SCREEN:

case EventID.EVENT_USER_REGIST_EDIT_BACK:

{

reg.show(args);

Thread thread = new Thread(reg);

thread.start();

midlet.setCurrent(reg);

break;

}

UserRegist.java

public void checkTimeStamp()

{

long currentTime = System.currentTimeMillis();

//System.out.println("1");

if(lastCaretBlink + caretBlinkDelay < currentTime)

{

//System.out.println("2");

if(editor.equals("regist_name"))

{

cursorBlinkOn1 =! cursorBlinkOn1;

cursorBlinkOn2 = false;

cursorBlinkOn3 = false;

}

else if(editor.xacgPfEIequals("regist_passwd"))

{

cursorBlinkOn1 = false;

cursorBlinkOn2 =! cursorBlinkOn2;

cursorBlinkOn3 = false;

}

else if(editor.equals("regist_passwd_re"))

{

cursorBlinkOn1 = false;

cursorBlinkOn2 = false;

cursorBlinkOn3 =! cursorBlinkOn3;

}

lastCaretBlink = currentTime;

}

public void run()

{

//System.out.println("run");

while(true)

{

checkTimeStamp();

redraw();

try

{

synchronized(this)

{

//System.out.println("3");

wait(50L);

}

catch(Exception e)

{

e.printStackTrace();

}

4 调用高级界面TextBox子类PopUpTextBox

调用时，将调用对象名、编辑对象名、以及编辑框参数传递给PopUpTextBox对象(一定要有，目的是保存编辑框的值，否则多次调用返回时，不同编辑框的值被刷新为空了)

UserRegist.java(KeyPressed)

case KeyID.KEY_EDIT:

case KEY_NUM0:

case KEY_NUM1:

case KEY_NUM2:

case KEY_NUM3:

case KEY_NUM4:

case KEY_NUM5:

case KEY_NUM6:

case KEY_NUM7:

case KEY_NUM8:

case KEY_NUM9:

{

//System.out.println(editor);

Object[] args = {object_name,editor,username,passwd,passwd_re};

controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT,args);

break;

}

UIController.java

case EventID.EVENT_USER_REGIST_EDIT:

{

textBox.init(args);

midlet.setCurrent(textBox);

break;

}

5 PopUpTextBox参数的接收

public void init(Object[] args)

{

object_name = ((String)args[0]!=null)?(String)args[0]:"";

editor = ((String)args[1]!=null)?(String)args[1]:"";

//System.out.println(object_name);

//System.out.println(editor);

args_t = args;

this.setString("");

}

6 PopUpTextBox返回输入法输入的值

if (update) canvasText = this.getString();

7 PopUpTextBox输入值处理

依据调用的对象，以及编辑对象，对输入的值进行处理，传递给父对象编辑框

if(object_name.equals("registScreen"))

{

if(editor.equals("regist_name"))

{

if(args_t[3]!=""||args_t[3]!=null||args_t[4]!=""||args_t[4]!=null)

{

args[0] = object_name;

args[1] = editor;

args[2] = this.canvasText;

args[3] = args_t[3];

args[4] = args_t[4];

}

controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT_BACK,args);

}

else if(editor.equals("regist_passwd"))

{

if(args_t[2]!=""||args_t[2]!=null||args_t[4]!=""||args_t[4]!=null)

{

args[0] = object_name;

args[1] = editor;

args[2] = args_t[2];

args[3] = this.canvasText;

args[4] = args_t[4];

}

controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT_BACK,args);

}

else if(editor.equals("regist_passwd_re"))

{

if(args_t[2]!=""||args_t[2]!=null||args_t[3]!=""||args_t[3]!=null)

{

args[0] = object_name;

args[1] = editor;

args[2] = args_t[2];

args[3] = args_t[3];

args[4] = this.canvasText;

}

controller.handleEvent(UIController.EventID.EVENT_USER_REGIST_EDIT_BACK,args);

}

8 输入值的显示

(1) 新建对象

private TextEdit textEdit_name;

textEdit_name = new TextEdit(this);

(2) 接受输入的参数

object_name = ((String)args[0]!=null)?(String)args[0]:"";

editor = ((String)args[1]!=null)?(String)args[1]:"";

username = ((String)args[2]!=null)?(String)args[2]:"";

passwd = ((String)args[3]!=null)?(String)args[3]:"";

passwd_re = ((String)args[4]!=null)?(String)args[4]:"";

(3) 光标控制，定位到编辑对象，控制编辑对象的光标闪烁(run方法)

private void redraw()

{

switch(currentlySelectedIndex)

{

case 0:

{

cursorBlinkOn2 = false;

cursorBlinkOnxacgPfEI3 = false;

editor = "regist_name";

break;

}

case 1:

{

cursorBlinkOn1 = false;

cursorBlinkOn3 = false;

editor = "regist_passwd";

break;

}

case 2:

{

cursorBlinkOn1 = false;

cursorBlinkOn2 = false;

editor = "regist_passwd_re";

break;

}

default:;

}

//...

}

(4) 编辑框的绘制

private void redraw()

{

...

textEdit_name.drawTextBox(this, graphics, username, textEdit_name_x, textEdit_name_y, cursorBlinkOn1);

textEdit_passwd.drawTextBox(this, graphics, passwd, textEdit_passwd_x, textEdit_passwd_y, cursorBlinkOn2);

textEdit_passwd.drawTextBox(this, graphics, passwd_re, textEdit_passwd_re_x, textEdit_passwd_re_y, cursorBlinkOn3);

textEdit_name.flushGraphics();

}

实现的效果如图1所示：

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