AndroidWaveView实现水流波动效果

package com.jingchen.waveview; 
 
import java.util.ArrayList; 
import java.util.List; 
import java.util.Timer; 
import java.util.TimerTask; 
 
import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.Paint.Align; 
import android.graphics.Paint.Style; 
import android.graphics.Region.Op; 
import android.graphics.Path; 
import android.graphics.RectF; 
import android.os.Handler; 
import android.os.Message; 
import android.util.AttributeSet; 
import android.view.View; 
 
/** 
 * 水流波动控件 
 * 
 * @author chenjing 
 * 
 */ 
public class WaveView extends View 
{ 
 
 private int mViewWidth; 
 private int mViewHeight; 
 
 /** 
  * 水位线 
  */ 
 private float mLevelLine; 
 
 /** 
  * 波浪起伏幅度 
  */ 
 private float mWaveHeight = 80; 
 /** 
  * 波长 
  */ 
 private float mWaveWidth = 200; 
 /** 
  * 被隐藏的最左边的波形 
  */ 
 private float mLeftSide; 
 
 private float mMoveLen; 
 /** 
  * 水波平移速度 
  */ 
 public static final float SPEED = 1.7f; 
 
 private List mPointsList; 
 private Paint mPaint; 
 private Paint mTextPaint; 
 private Path mWavePath; 
 private boolean isMeasured = false; 
 
 private Timer timer; 
 private MyTimerTask mTask; 
 Handler updateHandler = new Handler() 
 { 
 
  @Override 
  public void handleMessage(Message msg) 
  { 
   // 记录平移总位移 
   mMoveLen += SPEED; 
   // 水位上升 
   mLevelLine -= 0.1f; 
   if (mLevelLine <0) 
    mLevelLine = 0; 
   mLeftSide += SPEED; 
   // 波形平移 
   for (int i = 0; i = mWaveWidth) 
   { 
    // 波形平移超过一个完整波形后复位 
    mMoveLen = 0; 
    resetPoints(); 
   } 
   invalidate(); 
  } 
 
 }; 
 
 /** 
  * 所有点的x坐标都还原到初始状态，也就是一个周期前的状态 
  */ 
 private void resetPoints() 
 { 
  mLeftSide = -mWaveWidth; 
  for (int i = 0; i (); 
  timer = new Timer(); 
 
  mPaint = new Paint(); 
  mPaint.setAntiAlias(true); 
  mPaint.setStyle(Style.FILL); 
  mPaint.setColor(Color.BLUE); 
 
  mTextPaint = new Paint(); 
  mTextPaint.setColor(Color.WHITE); 
  mTextPaint.setTextAlign(Align.CENTER); 
  mTextPaint.setTextSize(30); 
 
  mWavePath = new Path(); 
 } 
 
 @Override 
 public void onWindowFocusChanged(boolean hasWindowFocus) 
 { 
  super.onWindowFocusChanged(hasWindowFocus); 
  // 开始波动 
  start(); 
 } 
 
 private void start() 
 { 
  if (mTask != null) 
  { 
   mTask.cancel(); 
   mTask = null; 
  } 
  mTask = new MyTimerTask(updateHandler); 
  timer.schedule(mTask, 0, 10); 
 } 
 
 @Override 
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) 
 { 
  super.onMeasure(widthMeasureSpec, heightMeasureSpec); 
  if (!isMeasured) 
  { 
   isMeasured = true; 
   mViewHeight = getMeasuredHeight(); 
   mViewWidth = getMeasuredWidth(); 
   // 水位线从最底下开始上升 
   mLevelLine = mViewHeight; 
   // 根据View宽度计算波形峰值 
   mWaveHeight = mViewWidth / 2.5f; 
   // 波长等于四倍View宽度也就是View中只能看到四分之一个波形，这样可以使起伏更明显 
   mWaveWidth = mViewWidth * 4; 
   // 左边隐藏的距离预留一个波形 
   mLeftSide = -mWaveWidth; 
   // 这里计算在可见的View宽度中能容纳几个波形，注意n上取整 
   int n = (int) Math.round(mViewWidth / mWaveWidth + 0.5); 
   // n个波形需要4n+1个点，但是我们要预留一个波形在左边隐藏区域，所以需要4n+5个点 
   for (int i = 0; i <(4 * n + 5); i++) 
   { 
    // 从P0开始初始化到P4n+4，总共4n+5个点 
    float x = i * mWaveWidth / 4 - mWaveWidth; 
    float y = 0; 
    switch (i % 4) 
    { 
    case 0: 
    case 2: 
     // 零点位于水位线上 
     y = mLevelLine; 
     break; 
    case 1: 
     // 往下波动的控制点 
     y = mLevelLine + mWaveHeight; 
     break; 
    case 3: 
     // 往上波动的控制点 
     y = mLevelLine - mWaveHeight; 
     break; 
    } 
    mPointsList.add(new Point(x, y)); 
   } 
  } 
 } 
 
 @Override 
 protected void onDraw(Canvas canvas) 
 { 
 
  mWavePath.reset(); 
  int i = 0; 
  mWavePath.moveTo(mPointsList.get(0).getX(), mPointsList.get(0).getY()); 
  for (; i 

package com.jingchen.waveview; 
 
import android.os.Bundle; 
import android.app.Activity; 
import android.view.Menu; 
 
public class MainActivity extends Activity 
{ 
 
 @Override 
 protected void onCreate(Bundle savedInstanceState) 
 { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.activity_main); 
 } 
 
 @Override 
 public boolean onCreateOptionsMenu(Menu menu) 
 { 
  getMenuInflater().inflate(R.menu.main, menu); 
  return true; 
 } 
 
}