Android开发中怎么实现一个文字倒影效果

/*
 * Copyright (C) 2011 TC Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License. You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language governing permissions and limitations under the
 * License. This code is base on the Android TextView and was Created by titanchen2000@yahoo.com.cn
 *
 * @author TC
 */
package com.tc.reflect;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.PorterDuff.Mode;
import android.graphics.Shader.TileMode;
import android.util.AttributeSet;
import android.widget.TextView;
public class ReflectTextView extends TextView {
  public ReflectTextView(Context context) {
    super(context);
  }
  public ReflectTextView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
  }
  public ReflectTextView(Context context, AttributeSet attrs) {
    super(context, attrs);
  }
  @Override
  protected void onDraw(Canvas canvas) {
    //draw the text from layout()
    super.onDraw(canvas);
    int height = getHeight();
    int width = getWidth();
    //make the shadow reverse of Y
    Matrix matrix = new Matrix();
    matrix.preScale(1, -1);
    //make sure you can use the cache
    setDrawingCacheEnabled(true);
    //create bitmap from cache,this is the most important of this
    Bitmap originalImage = Bitmap.createBitmap(getDrawingCache());
    //create the shadow
    Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,
        height / 3, width, height / 3, matrix, false);
    //draw the shadow
    canvas.drawBitmap(reflectionImage, 0, 8 * height / 12, null);
    //process shadow bitmap to make it shadow like
    Paint paint = new Paint();
    LinearGradient shader = new LinearGradient(0, 8 * height / 12, 0,
        height, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);
    paint.setShader(shader);
    paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
    canvas.drawRect(0, 8 * height / 12, width, height, paint);
  }
}