设计可组装的j2me UI（六） Dialog(对话框）

      高级UI提供了一个Alert的控件可以有弹出对话框的效果。但是大家想不想自己实现一个呢。想不想知道sun是如何让Alert工作的呢？好请看下文
     设计思想是。建立一个 abstract   class Dialog extends Canvas。下面的事情就让我们一步步花出来吧。
     实现理念是先绘制整个Canvas然后通过图形Graphics描绘成透明，接着在整个屏幕的中间去出一块区域来，至于上面你要做什么那就是你的事情了。哈。
    好看代码，

java 代码

/********************************************************************
 *
 * 版权说明，此程序仅供学习参考。不能用于商业
 *
 ********************************************************************/
package org.pook.ui.form;

import java.util.TimerTask;

import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;

import org.pook.log.Log;
import org.pook.ui.Command;
import org.pook.ui.SoftButton;
import org.pook.ui.core.Platform;
import org.pook.ui.event.CommandListener;
import org.pook.ui.timer.TimerTaskManager;



/**
 * 类名：Dialog.java 
     编写日期: 2006-9-16
 * 程序功能描述：弹出窗�?,因为足球项目要求很多的弹出窗口的形式不同�?�? 定义�?个抽象的弹出窗口,把基本的功能再这个实�?,以下的�?�么绘制则交给具体的要求
 * 
     Demo: 
     Bug:
 *
 * 程序变更日期 �?
     变更作�?? �?
     变更说明 �?
 *
 * @author wuhua
 */
public abstract   class Dialog extends Canvas implements Runnable {
    private static Log log = Log.getLog("Dialog");

    protected final int X = 0;

    protected final int Y = 1;

    protected   final int WIDTH = 2;

    protected final int HEIGHT = 3;

    /** 显示主要部分.比如菜单的Icon,List的数据的位置 */
    protected int[] view = new int[4];

    /** Preset alternative containing OK */
    public static final int DIALOG_OK = 0;

    /** Preset alternative containing CANCEL = 1 */
    public static final int DIALOG_CANCEL = 2;

    /** Preset alternatives containing YES and NO */
    public static final int DIALOG_YES_NO = 3;

    /** Preset alternatives containing OK and CANCEL */
    public static final int DIALOG_OK_CANCEL = 4;

    /** Preset alternatives containing YES, NO, and CANCEL */
    public static final int DIALOG_YES_NO_CANCEL = 5;

    public static final int DIALOG_TEXT = 6;

    /**
     * 保存当前窗口,主要用�?�是,当前对话筐消失的时�??,要求重绘�?. 永远刷新父类
     */
    protected Panel parent;

    protected boolean hasFocus;

    /**
     * 定义超时参数
     */
    long timeOut;

    /**
     * 对话框类�?
     */
    int type;

    /** 对话框标�? */
    protected String title;

    /**
     * 把单行标题转换为多行以方便显�?
     */
    protected   String[] rowTitle;

    protected int bgColor;

    protected int fontColor;

    protected Font font = Font.getDefaultFont();

    /** 用于执行消失窗口 */
    protected TimerTask task;

    protected Display display;

    protected SoftButton softButton;





    /**
     * 构�?�一个默认的标题,父类的窗�?
     *
     * @param title
     * @param parent
     */
    public Dialog(String title, Panel parent, Display display) {
        this(title, parent, display, 3000);
    }

    /**
     * 构�?�一个指定时间的构�?�窗�?
     *
     * @param title
     * @param parent
     * @param timeOut
     */
    public Dialog(String title, Panel parent, Display display, long timeOut) {
        this(title, parent, display, Dialog.DIALOG_OK, timeOut);
    }

    /**
     * 构�?�一个指定窗口类�?,时间的窗�?
     *
     * @param title
     * @param parent
     * @param type
     * @param timeOut
     */
    public Dialog(String title, Panel parent, Display display, int type,
            long timeOut) {
        setFullScreenMode(true);

        this.parent = parent;
        checkParent();

        this.timeOut = timeOut;
        this.type = type;
        this.title = title;
        this.display = display;

        softButton = new SoftButton();



        if (timeOut != 0)
            task = TimerTaskManager.getInstace().add(this, timeOut);

        //设置默认的风�?
        setStyle(0x0033FF, 0xFFFFFF);

    }

    public void setStyle(int bgColor, int fontColor) {
        this.bgColor = bgColor;
        this.fontColor = fontColor;
    }

    public void cancel() {
        //log.debug("Stop...");
        if (parent == null)
            throw new NullPointerException("Parent is not Null.");

        task.cancel();
        if(parent == null)
            return;

        display.setCurrent(parent);

    }

    public void addCommand(Command cmd) {
        this.softButton.addCommand(cmd);
    }

    public void setSoftButtonListener(CommandListener cml) {
        this.softButton.setCommandListener(cml);
    }

    public void setSoftButtonStyle(int bgColor, int fontColor){
        this.softButton.setStyle(bgColor, fontColor);
    }

    public void run() {
        cancel();

    }

    /** 绘制透明�? * */
   public   void drawRGB(Graphics g) {
        int ai[] = new int[Platform.WIDTH];
        for (int j1 = 0; j1 < ai.length; j1++)
            ai[j1] = 0x90000000;
        g.drawRGB(ai, 0, 0, 0, 0, Platform.WIDTH, Platform.HEIGHT, true); // 绘制透明景色
    }





    private void checkParent() {
        if (parent == null){
             throw new NullPointerException("Parent is not null");
        }

    }

    protected void keyPressed(int keyCode) {
        softButton.onClick(keyCode);

    }

    public void setPanel(Panel panel) {
        this.parent = panel;

    }

    public void setTimeOut(long timeOut) {
        this.timeOut = timeOut;
    }

    public int getType() {
        return type;
    }

    public void setType(int type) {
        this.type = type;
    }
}

下面这段是弹出一个对话框实现

java 代码

/********************************************************************
 *
 * 版权说明，此程序仅供学习参考。不能用于商业
 *
 ********************************************************************/
package org.pook.ui.form;

import java.util.Vector;

import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;

import org.pook.Pook;
import org.pook.log.Log;
import org.pook.ui.Command;
import org.pook.ui.SelectedPart;
import org.pook.ui.core.Platform;
import org.pook.ui.event.CommandListener;
import org.pook.ui.util.FontUtil;
import org.pook.ui.util.GraphicsUtil;
import org.pook.util.StringUtil;


/**
 * 类名：MessageDialog.java
 * 编写日期: 2006-9-26
 * 程序功能描述：
 * Demo:
 * Bug:
 *
 * 程序变更日期 ：
 * 变更作者 ：
 * 变更说明 ：
 *
 * @author wuhua
 */
public class MessageDialog extends TextDialog implements CommandListener{
    private static Log log = Log.getLog("MessageDialog");


    private Command ok;

    private  SelectedPart plan;
    private int  planHeight;

    private int contentHeight;

    private int viewSize;
    private int space;


    private Vector content;
    private int selectIndex;
    private int contentY;

    public MessageDialog(String _title,String _message, long _timeOut) {
        super(_title,  Pook.MAINMENU, Pook.getDisplay(), _timeOut);
        ok = new Command("确定",Command.LEFT, Command.FIRST_PRIORITY);
        this.addCommand(ok);
        this.setSoftButtonListener(this);
        this.setMessage(_message);
        initView();
        this.setStyle(0x001D68, 0xFFFFFF);
        this.setSoftButtonStyle(0x0071BD,0xFFFFFF);
        this.setType(Dialog.DIALOG_OK);
    }

    public void setMessage(String message){

        skipMessage(message);
    }


    private void skipMessage(String message) {

        if(message == null)
            return ;

        content = new Vector();
        String[] text = StringUtil.split(message, "\n");

        for(int j =0; j < text.length; j++){

            String[] t = FontUtil.splitOnlyStringToRowString(font,text[j],view[WIDTH]-6);
            for(int i=0; i
                content.addElement(t[i]);
            }
            ///content.addElement("");
        }

        //log.debug(content.size());

        //new Plan





    }

    protected void keyPressed(int keyCode) {
        super.keyPressed(keyCode);
        this.thisUpAndDown(keyCode);
        this.repaint();
    }

    /**
     * 上下事件
     *
     * @param keyCode
     */
    private void thisUpAndDown(int keyCode) {

        if (this.content == null)
            return;

        if(this.content.size() < this.viewSize)
            return;

        switch (keyCode) {

        case Platform.KEY_UP: {

             selectIndex =  selectIndex <= 0 ? content.size() - viewSize - 1
                    : --selectIndex;
            // log.debug("Key");
            break;

        }
        case Platform.KEY_DOWN: {
             selectIndex =  selectIndex >=content.size() - viewSize - 1 ? 0
                    : ++selectIndex;
             //log.debug("Key1");

            break;
        }
        }
    }


    public void commandAction(Command cmd) {
        if(cmd == ok)
            this.cancel();

    }
    protected void paint(Graphics g) {
        parent.paint(g);
        drawRGB(g);
        this.softButton.paint(g);
        this.paintMessageDialog(g);

    }



    private void paintMessageDialog(Graphics g) {
        initView();
        g.setFont(font);
        GraphicsUtil.drawRectWithColor(g,0xFFD84F, view[X]-1,view[Y]-1,view[WIDTH]+1,view[HEIGHT]+1);
        paintTitleImpl(g);
        paintContent(g);
        paintState(g);
    }

    private void paintTitleImpl(Graphics g) {
        g.setColor(0x0071BC);
        g.fillRect(view[X],view[Y],view[WIDTH],font.getHeight() + 2);
        g.setColor(0xFFFFFF);
        g.drawString(title, view[X] + 4, view[Y] + 1,Graphics.TOP|Graphics.LEFT);
    }

    private void paintContent(Graphics g) {
        if(content.size() > viewSize ){
                this.plan = new SelectedPart();
                plan.setStyle(0xFFFFFF, 0x000000);
                this.planHeight = contentHeight/(content.size() - viewSize);
        }
        contentY = view[Y] + font.getHeight() + 4;

        g.setColor(0x001D68);
        g.fillRect(view[X],contentY,view[WIDTH],contentHeight);

        paintContentImpl(g);

    }

    private void paintContentImpl(Graphics g) {
        if(content == null)
            return ;

        int size = viewSize>content.size()?content.size():viewSize + selectIndex;

        g.setColor(0xFFFFFF);

        for(int i = selectIndex; i
            g.drawString((String) content.elementAt(i),view[X] + 2, contentY + space * (i-selectIndex), Graphics.TOP|Graphics.LEFT);
        }

        /**
         * 绘制状态条
         */
        if(plan != null){
            //log.debug("SelectIndex = " + selectIndex);
            plan.changePosition(view[WIDTH] + 4 , contentY + this.planHeight *selectIndex, 4,this.planHeight);
            plan.paint(g);
        }
    }

    private void paintState(Graphics g) {
        int height = Platform.HEIGHT - 30 - font.getHeight() - 2;
        g.setColor(0x0071BC);
        g.fillRect(view[X], height  ,view[WIDTH],font.getHeight() + 2);
        g.setColor(0xFFFFFF);
        g.drawLine(view[X],height,view[WIDTH] + 10, height);
        g.setColor(0xFFFFFF)

评论

1 楼 wuhua 2006-11-25  

Alert在不同的手机上可以有不同的效果。这是高级UI的特色
而自己实现的UI则可以在所有手机上有比较统一的效果。这也是我们自己的特色