tableitem.java

图书中的经典例子 好好看看 会有帮助的。java2me版本的

package itemex;
import javax.microedition.lcdui.*;

public class TableItem extends CustomItem
{
    private int rows, cols;//保存表格内行列数
    private int dx, dy;//保存单元格大小
    private int currentX ,currentY ;//保存当前选中位置
    private String[ ][ ] data; //保存各个单元格文字
    private int maxWidth, maxHeight;//保存当前对象要求大小
    private int curWidth, curHeight;//保存当前对象实际大小
    private boolean isShown=false; //保存当前是否处于显示状态
    private boolean isIn=false;//保存当前是否处于焦点状态
    
    //参数 label：标题
    //c,r：表格的列数和行数
    //w,h: 单元格的宽度和高度
    public TableItem(String label, int c, int r, int w, int h) 
    {
        super(label);
        currentX = currentY = 0;
        rows = r;
        cols = c;
        data = new String[rows][cols];
        dx =w;
        dy =h;
        maxWidth=dx* cols+1;
        maxHeight=dy* rows+1;
        isShown = false;
    }

    public void setCell(int w, int h)
    {//设置指定位置单元格的宽度和高度，同时重新计算对象大小
        dx =w;
        dy =h;
        maxWidth=dx* cols+1;
        maxHeight=dy* rows+1;
        invalidate();//要求
    }
    
    public int getCurrentX()
    {//得到当前选中的单元格的X坐标
        return currentX;
    }

    public int getCurrentY()
    {//得到当前选中的单元格的Y坐标
        return currentY;
    }

    public String getText(int x,int y) 
    {//得到单元格的文字
        if( data[y][x] ==null)
            data[y][x]="";
        return data[y][x];
    }

    public void setText(String text,int x, int y) 
    {//设置指定位置单元格的文字，同时刷新单元格区域
        data[y][x] = text;
        if( isShown)
            repaint(x * dx, y * dy, dx, dy);
    }
    //计算尺寸要求的相关重载函数
    protected int getMinContentHeight() 
    {
        System.out.println("getMinContentHeight return "+ maxHeight);
        return maxHeight;
    }

    protected int getMinContentWidth()
    {
        System.out.println("getMinContentWidth return "+ maxWidth);
        return maxWidth;
    }

    protected int getPrefContentHeight(int width) 
    {
        System.out.println("getPrefContentHeight return "+ maxHeight);
        return maxHeight;
    }

    protected int getPrefContentWidth(int height)
    {
        System.out.println("getPrefContentWidth return "+ maxWidth);
        return maxWidth;
    }
    //尺寸变化时的通知函数
    protected  void sizeChanged(int w, int h)
    {
        System.out.println("sizeChanged (w,h)=("+ w +","+ h +")");
        curWidth = w;
        curHeight = h;
    }
    //显示与隐藏时的通知函数
    protected  void showNotify()
    {
        System.out.println("showNotify");
        isShown = true;
    }

    protected  void hideNotify()
    {
        System.out.println("hideNotify");
        isShown = false;
    }
    //重绘函数
    protected void paint(Graphics g, int w, int h) 
    {
        System.out.println("paint (w,h) ("+w+","+h+")");
        g.setColor(0x00ffffff);//用白色填充整个区域
        g.fillRect(0, 0, w, h);
        g.setColor(0x00000000);//用黑色绘制线条
        for (int i = 0; i <= rows; i++) 
        {//绘制横线
            g.drawLine(0, i * dy, cols * dx, i * dy);
        }
        for (int i = 0; i <= cols; i++) 
        {//绘制竖线
            g.drawLine(i * dx, 0, i * dx, rows * dy);
        }
        g.setColor(0x00D0D0D0);//用灰色填充当前被选中单元格
        g.fillRect((currentX * dx) + 1, (currentY * dy) + 1, dx - 1, dy - 1);
        g.setColor(0x00000000);//用黑色显示文字
        for (int i = 0; i < rows; i++) 
        {//逐个绘制每个单元格
            for (int j = 0; j < cols; j++) 
            {
                if (data[i][j] != null) 
                {
                    g.setClip((j * dx) + 1, i * dy, dx - 1, dy - 1);
                    g.drawString(data[i][j], (j * dx) + 2, ((i + 1) * dy) - 2, 
                                 Graphics.BOTTOM | Graphics.LEFT);
                }
            }
        }
    }
   
    protected boolean traverse(int dir, int viewportWidth, int viewportHeight, int[] visRect_inout) 
    {//处理方向键事件
        System.out.println("viewport (w,h) ("+viewportWidth+","+viewportHeight +")");
        System.out.println("visRect_in ("+visRect_inout[0]+","+visRect_inout[1]+","+visRect_inout[2]+","+visRect_inout[3]+")");
        if(!isIn)
        {//得到焦点
            isIn = true;
            return true;
        }
        switch (dir) 
        {
            case Canvas.DOWN:
                if (currentY < (rows - 1)) 
                {
                    currentY++;
                    repaint(currentX * dx, (currentY - 1) * dy, dx, dy);
                    repaint(currentX * dx, currentY * dy, dx, dy);
                } 
                else
                    return false;
            break;
            case Canvas.UP:
                if (currentY > 0) 
                {
                    currentY--;
                    repaint(currentX * dx, (currentY + 1) * dy, dx, dy);
                    repaint(currentX * dx, currentY * dy, dx, dy);
                } 
                else 
                    return false;
            break;
            case Canvas.LEFT:
                if (currentX > 0) 
                {
                    currentX--;
                    repaint((currentX + 1) * dx, currentY * dy, dx, dy);
                    repaint(currentX * dx, currentY * dy, dx, dy);
                }
            break;
            case Canvas.RIGHT:
                if (currentX < (cols - 1)) 
                {
                    currentX++;
                    repaint((currentX - 1) * dx, currentY * dy, dx, dy);
                    repaint(currentX * dx, currentY * dy, dx, dy);
                }
            break;
        }

        visRect_inout[0] = currentX;
        visRect_inout[1] = currentY;
        visRect_inout[2] = dx;
        visRect_inout[3] = dy;
        System.out.println("visRect_out ("+visRect_inout[0]+","+visRect_inout[1]+","+visRect_inout[2]+","+visRect_inout[3]+")");

        return true;
    }
    
    protected  void traverseOut() 
    {
        System.out.println("traverseOut");
        isIn = false;
    }

    protected void keyPressed(int keyCode)
    {
        System.out.println("keyCode=" + keyCode);
        if (data[currentY][currentX] == null) 
            data[currentY][currentX] ="";
        
        if( keyCode == -8)// 清除键
        {//删除最后一个字符
            int len =data[currentY][currentX].length();
            if( len >0)
                data[currentY][currentX] = data[currentY][currentX].substring(0, len-1);
        }
        else if( (char)keyCode>='0' && (char)keyCode<='9')
            data[currentY][currentX]+= (char)keyCode; //添加到末尾
        repaint(currentX * dx, currentY * dy, dx, dy);//重绘屏幕
    }
    
    protected void pointerPressed(int x,int y)
    {
        System.out.println("pointerPressed (x,y)= ("+x+","+y+")");
        if( x>=0 && x<maxWidth && y>=0 && y<maxHeight)
        {
            currentX = x/dx;
            currentY = y/dy;
            repaint(currentX * dx, currentY * dy, dx, dy);//重绘屏幕
        }
    }
    


}