Android自定义加载圈动画效果

package blog.csdn.net.mchenys.myanimationloading;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PointF;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.LinearInterpolator;
import android.view.animation.OvershootInterpolator;

/**
 * Created by mChenys on 2016/5/21.
 */
public class AnimationLoading extends View {
  private float mBigCircleRaduis = 90;//大圆的半径
  private float mSubCircleRadius = 20;//小圆的半径
  private PointF mBigCenterPoint;//大圆的圆心坐标
  private Paint mBgPaint;//绘制背景的画笔
  private Paint mFgPaint;//绘制前景色的画笔
  private AnimatorTemplet mTemplet;//动画模板
  float mBigCircleRotateAngle;//大圆旋转的角度
  float mDiagonalDist;//屏幕对角线一半的距离
  float mBgStrokeCircleRadius;//用于作为绘制背景空心圆的半径
  //6个小圆的颜色
  private int[] colors = new int[]{Color.RED, Color.DKGRAY, Color.YELLOW, Color.BLUE, Color.LTGRAY, Color.GREEN};

  public AnimationLoading(Context context) {
    this(context, null);
  }

  public AnimationLoading(Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
  }

  @Override
  protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);
    //确定大圆的圆心坐标
    mBigCenterPoint.x = w / 2f;
    mBigCenterPoint.y = h / 2f;
    //屏幕对角线的一半
    mDiagonalDist = (float) (Math.sqrt(w * w + h * h) / 2);
  }

  private void init() {
    mBigCenterPoint = new PointF();
    mFgPaint = new Paint();
    mFgPaint.setAntiAlias(true);
    mBgPaint = new Paint(mFgPaint);
    mBgPaint.setColor(Color.WHITE);
    mBgPaint.setStyle(Paint.Style.STROKE);

  }

  @Override
  protected void onDraw(Canvas canvas) {
    if (null == mTemplet) {
      //开启旋转动画
      mTemplet = new RotateState();
    }
    //传递Canvas对象
    mTemplet.drawState(canvas);
  }

  /**
   * 绘制圆
   *
   * @param canvas
   */
  private void drawCircle(Canvas canvas) {
    //获取每个小圆间隔的角度
    float rotateAngle = (float) (2 * Math.PI / colors.length);
    for (int i = 0; i < colors.length; i++) {
      //每个小圆的实际角度
      double angle = rotateAngle * i + mBigCircleRotateAngle; //这里加上大圆旋转的角度是为了带动小圆一起旋转
      //计算每个小圆的圆心坐标
      float cx = (float) (mBigCircleRaduis * Math.cos(angle)) + mBigCenterPoint.x;
      float cy = (float) (mBigCircleRaduis * Math.sin(angle)) + mBigCenterPoint.y;
      //绘制6个小圆
      mFgPaint.setColor(colors[i]);
      canvas.drawCircle(cx, cy, mSubCircleRadius, mFgPaint);
    }
  }

  /**
   * 绘制背景
   *
   * @param canvas
   */
  private void drawBackground(Canvas canvas) {
    if (mBgStrokeCircleRadius > 0f) {
      //不断扩散的空心圆,空心圆的半径为屏幕对角线的一半,空心圆的线宽则从线宽一半到0
      float strokeWidth = mDiagonalDist - mBgStrokeCircleRadius;//线宽从对角线的1/2 ~ 0
      mBgPaint.setStrokeWidth(strokeWidth);
      float radius = mBgStrokeCircleRadius + strokeWidth / 2;//半径从对角线的1/4 ~ 1/2
      canvas.drawCircle(mBigCenterPoint.x, mBigCenterPoint.y,radius , mBgPaint);
    } else {
      //绘制白色背景
      canvas.drawColor(Color.WHITE);

    }
  }

  private abstract class AnimatorTemplet {
    abstract void drawState(Canvas canvas);

  }

  /**
   * 绘制旋转动画
   */
  private class RotateState extends AnimatorTemplet {
    ValueAnimator mValueAnimator;

    public RotateState() {
      //旋转的过程,就是不断的获取大圆的角度,从0-2π
      mValueAnimator = ValueAnimator.ofFloat(0, (float) Math.PI * 2);
      mValueAnimator.setInterpolator(new LinearInterpolator());//匀速插值器
      mValueAnimator.setDuration(1200);
      mValueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
          //获取大圆旋转的角度
          mBigCircleRotateAngle = (float) animation.getAnimatedValue();
          //重绘
          invalidate();
        }
      });
      mValueAnimator.setRepeatCount(ValueAnimator.INFINITE);//无限循环
      mValueAnimator.start();
    }

    /**
     * 停止旋转动画,在数据加载完毕后供外部调用
     */
    public void stopRotate() {
      mValueAnimator.cancel();
    }

    @Override
    void drawState(Canvas canvas) {
      drawBackground(canvas);
      drawCircle(canvas);
    }
  }

  /**
   * 绘制聚合动画
   */
  private class MergingState extends AnimatorTemplet {

    public MergingState() {
      //聚合的过程,就是不断的改变大圆的半径,从mBigCircleRaduis~0
      ValueAnimator valueAnimator = ValueAnimator.ofFloat(mBigCircleRaduis, 0);
      valueAnimator.setInterpolator(new OvershootInterpolator(10f));//弹性插值器
      valueAnimator.setDuration(600);
      valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
          //获取大圆变化的半径
          mBigCircleRaduis = (float) animation.getAnimatedValue();
          //重绘
          invalidate();
        }
      });
      valueAnimator.addListener(new AnimatorListenerAdapter() {
        @Override
        public void onAnimationEnd(Animator animation) {
          //聚合执行完后进入下一个扩散动画
          mTemplet = new SpreadState();

        }
      });
      valueAnimator.start();
    }

    @Override
    void drawState(Canvas canvas) {
      drawBackground(canvas);
      drawCircle(canvas);
    }
  }

  /**
   * 绘制扩散动画
   */
  private class SpreadState extends AnimatorTemplet {

    public SpreadState() {
      //扩散的过程,就是不断的改变背景画绘制空心圆的半径,从0~mDiagonalDist
      ValueAnimator valueAnimator = ValueAnimator.ofFloat(0, mDiagonalDist);
      valueAnimator.setDuration(600);
      valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
          //获取大圆变化的半径
          mBgStrokeCircleRadius = (float) animation.getAnimatedValue();
          //重绘
          invalidate();
        }
      });

      valueAnimator.start();
    }

    @Override
    void drawState(Canvas canvas) {
      drawBackground(canvas);
    }
  }

  /**
   * 停止加载动画
   */
  public void stopLoading() {
    if (null != mTemplet && mTemplet instanceof RotateState) {
      ((RotateState) mTemplet).stopRotate();
      //开启下一个聚合动画
      post(new Runnable() {
        @Override
        public void run() {
          mTemplet = new MergingState();
        }
      });
    }
  }
}

package blog.csdn.net.mchenys.myanimationloading;

import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.widget.FrameLayout;
import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    FrameLayout content = new FrameLayout(this);
    content.setOnClickListener(null);
    ImageView bg = new ImageView(this);
    bg.setImageResource(R.drawable.fg);
    bg.setScaleType(ImageView.ScaleType.FIT_XY);
    content.addView(bg);
    final AnimationLoading loading = new AnimationLoading(this);
    content.addView(loading);
    setContentView(content);

    new Handler().postDelayed(new Runnable() {
      @Override
      public void run() {
        //3s后停止加载动画
        loading.stopLoading();
      }
    },3000);
  }
}