diamonditem.java

来自「J2ME高级用户界面的学习代码」· Java 代码 · 共 72 行

//DiamongdItemDemo.java

import javax.microedition.lcdui.*;

public class DiamondItem extends CustomItem
{
  private boolean mState;   //标志位，决定颜色是否取反
  public DiamondItem(String title)
  {
    super(title);
    mState =  false;
  }

  public void toggle()
  {
    mState = !mState;//颜色取反
    repaint();       //重新绘制
  }

  public int getMinContentWidth()
  {
    return 80;
  }

  public int getMinContentHeight()
  {
    return 40;
  }

  public int getPrefContentWidth(int width)
  {
    return getMinContentWidth();
  }

  public int getPrefContentHeight(int height)
  {
    return getMinContentHeight();
  }

  public void paint(Graphics g,int w,int h)
  {
    g.drawRect(0,0,w - 1,h - 1);
    int stepx = 8;
    int stepy = 16;
    for(int y = 0;y < h;y += stepy)
    {
      for(int x = 0;x < w;x += stepx)
      {
        g.drawLine(x,y,x + stepx,y + stepy);
        g.drawLine(x,y + stepy,x + stepx,y);
        if(mState == true)
        {
          int midx = x + stepx/2;
          int midy = y + stepy/2;
          g.fillTriangle(x,y,x + stepx,y,midx,midy);
          g.fillTriangle(midx,midy,x,y + stepy,x + stepx,y + stepy);
        }
      }
    }
  }

  protected void keyPressed(int keyCode)
  {
    toggle();
  }

  protected void pointerPressed(int x,int y)
  {
    toggle();
  }
}