Android自定义实现顶部粘性下拉刷新效果

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import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.MotionEvent;
import android.view.View;
import android.widget.RelativeLayout;

import butterknife.BindView;
import trunk.doi.base.R;
import trunk.doi.base.base.BaseActivity;

public class ViewMvActivity extends BaseActivity {


 @BindView(R.id.cs_view)
 TouchPullView csView;
 @BindView(R.id.rl_view)
 RelativeLayout rl_view;

 private float mTouchStartY;
 private static final float TOUCH_MOVE_MAX_Y=600;

 @Override
 protected int initLayoutId() {
  return R.layout.activity_view_mv;
 }

 @Override
 protected void initView(@Nullable Bundle savedInstanceState) {

  rl_view.setOnTouchListener(new View.OnTouchListener() {
   @Override
   public boolean onTouch(View v, MotionEvent event) {

    int action=event.getActionMasked();
    switch (action){

     case MotionEvent.ACTION_DOWN:

      mTouchStartY=event.getY();

      return true;
     case MotionEvent.ACTION_MOVE:
      float y=event.getY();
      if(y>=mTouchStartY){
       float moveSize= y-mTouchStartY;
       float progress=moveSize>=TOUCH_MOVE_MAX_Y?1:moveSize/TOUCH_MOVE_MAX_Y;
       csView.setProgress(progress);
      }
      return true;
     case MotionEvent.ACTION_UP:

      csView.release();

      return true;

     default:
      break;

    }


    return false;
   }
  });

 }

 @Override
 protected void setListener() {

 }

 @Override
 protected void initData() {

 }


}

import android.animation.ValueAnimator;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.support.annotation.Nullable;
import android.support.annotation.RequiresApi;
import android.support.v4.view.animation.PathInterpolatorCompat;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.animation.DecelerateInterpolator;
import android.view.animation.Interpolator;

import trunk.doi.base.R;

/**
 * 作者：Mr.Lee on 2017-9-27 11:57
 * 邮箱：569932357@qq.com
 */

public class TouchPullView extends View {

 //圆的画笔
 private Paint mCirclePaint;
 //圆的半径
 private int mCircleRadius=50;
 private float mCirclePointX;
 private float mCirclePointY;
 private float mProgress;
 //可拖拽高度
 private int mDragHeigh=800;
 //目标宽度
 private int mTargetWidth=400;
 //贝塞尔曲线
 private Path mPath=new Path();
 private Paint mPathPaint;
 //重心点最终高度，决定控制点的Y坐标
 private int mTargetGravityHeight=10;
 //角度变换 0-135
 private int mTangentAngle=100;
 private Interpolator mProgressInterpolator=new DecelerateInterpolator();
 private Interpolator mTanentAngleInterpolator;

 private Drawable mContent=null;
 private int mContentMargin=0;


 public TouchPullView(Context context) {
  super(context);
  init(null);

 }

 public TouchPullView(Context context, @Nullable AttributeSet attrs) {
  super(context, attrs);
  init(attrs);
 }

 public TouchPullView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
  init(attrs);
 }

 @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
 public TouchPullView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
  super(context, attrs, defStyleAttr, defStyleRes);
  init(attrs);
 }

 /**
  * 初始化
  */
 private void init(AttributeSet attrs){


  final Context context=getContext();
  TypedArray array=context.obtainStyledAttributes(attrs, R.styleable.TouchPullView,0,0);
  int color=array.getColor(R.styleable.TouchPullView_pColor,0x20000000);

  mCircleRadius=(int)array.getDimension(R.styleable.TouchPullView_pRadius,mCircleRadius);
  mDragHeigh=array.getDimensionPixelOffset(R.styleable.TouchPullView_pDragHeight,mDragHeigh);
  mTangentAngle=array.getInteger(R.styleable.TouchPullView_pTangentAngle,mTangentAngle);
  mTargetWidth=array.getDimensionPixelOffset(R.styleable.TouchPullView_pDragHeight,mTargetWidth);
  mTargetGravityHeight=array.getDimensionPixelOffset(R.styleable.TouchPullView_pTargetGravityHeight,mTargetGravityHeight);
  mContent=array.getDrawable(R.styleable.TouchPullView_pContentDrawable);
  mContentMargin=array.getDimensionPixelOffset(R.styleable.TouchPullView_pContentDrawableMargin,0);
  array.recycle();

  Paint p=new Paint(Paint.ANTI_ALIAS_FLAG);
  //抗锯齿
  p.setAntiAlias(true);
  //防抖动
  p.setDither(true);
  //填充方式
  p.setStyle(Paint.Style.FILL);
  p.setColor(color);
  mCirclePaint=p;
  //初始化路径部分画笔
  p=new Paint(Paint.ANTI_ALIAS_FLAG);
  //抗锯齿
  p.setAntiAlias(true);
  //防抖动
  p.setDither(true);
  //填充方式
  p.setStyle(Paint.Style.FILL);
  p.setColor(color);
  mPathPaint=p;

  //切角路径插值器
  mTanentAngleInterpolator= PathInterpolatorCompat.create(
    (mCircleRadius*2.0f)/mDragHeigh,
    90.0f/mTangentAngle
  );

 }

 @Override
 protected void onSizeChanged(int w, int h, int oldw, int oldh) {
  super.onSizeChanged(w, h, oldw, oldh);
  updatePathLayout();

 }

 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
//  super.onMeasure(widthMeasureSpec, heightMeasureSpec);

  int widthMode=MeasureSpec.getMode(widthMeasureSpec);
  int width=MeasureSpec.getSize(widthMeasureSpec);
  int heighMode=MeasureSpec.getMode(heightMeasureSpec);
  int heigh=MeasureSpec.getSize(heightMeasureSpec);

  int iHeigh=(int)((mDragHeigh*mProgress+0.5)+ 2*mCircleRadius+getPaddingTop()+getPaddingBottom());
  int iWidth=2*mCircleRadius+getPaddingLeft()+getPaddingRight();
  int measureWidth,measureHeigh;

  if(widthMode==MeasureSpec.EXACTLY){
   measureWidth=width;
  }else if(widthMode==MeasureSpec.AT_MOST){
   measureWidth=Math.min(iWidth,width);
  }else{
   measureWidth=iWidth;
  }

  if(heighMode==MeasureSpec.EXACTLY){
   measureHeigh=heigh;
  }else if(heighMode==MeasureSpec.AT_MOST){
   measureHeigh=Math.min(iHeigh,heigh);
  }else{
   measureHeigh=iHeigh;
  }

  setMeasuredDimension(measureWidth,measureHeigh);

 }

 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  int count=canvas.save();
  float tranX=(getWidth()-getValueByLine(getWidth(),mTargetWidth,mProgress))/2;
  canvas.translate(tranX,0);
  canvas.drawPath(mPath,mPathPaint);
  //画圆
  canvas.drawCircle(mCirclePointX,mCirclePointY,mCircleRadius,mCirclePaint);
  Drawable drawable=mContent;
  if(drawable!=null){
   canvas.save();
   //剪切矩形区域
   canvas.clipRect(drawable.getBounds());
   //绘制
   drawable.draw(canvas);
   canvas.restore();
  }
  canvas.restoreToCount(count);


 }



 /**
  * 设置进度
  * @param progress
  */
 public void setProgress(float progress){

  Log.e("TAG","progress="+progress);
  mProgress=progress;
  //重新请求测量
  requestLayout();


 }


 private void updatePathLayout(){

  final float progress=mProgressInterpolator.getInterpolation(mProgress);
  //获取可绘制区域高度宽度
  final float w=getValueByLine(getWidth(),mTargetWidth,mProgress);
  final float h=getValueByLine(0,mDragHeigh,mProgress);

  //X对称轴的参数，圆的圆心X
  final float cPointX=w/2;
  //圆的半径
  final float cRadius=mCircleRadius;
  //圆的圆心Y坐标
  final float cPointY =h-cRadius;
  //控制点结束Y坐标
  final float endControlY=mTargetGravityHeight;

  mCirclePointX=cPointX;
  mCirclePointY= cPointY;

  final Path path=mPath;
  //重置
  path.reset();
  path.moveTo(0,0);

  //左边部分的结束点和控制点
  float lEndPointX,lEndPointY;
  float lControlPointX,lControlPointY;
  //角度转弧度

  float angle=mTangentAngle*mTanentAngleInterpolator.getInterpolation(progress);
  double radian=Math.toRadians(angle);
  float x=(float) (Math.sin(radian)*cRadius);
  float y=(float) (Math.cos(radian)*cRadius);

  lEndPointX=cPointX-x;
  lEndPointY= cPointY +y;

  //控制点y坐标变化
  lControlPointY=getValueByLine(0,endControlY,progress);
  //控制点与结束定之前的高度
  float tHeigh=lEndPointY-lControlPointY;
  //控制点与x坐标的距离
  float tWidth= (float) (tHeigh/Math.tan(radian));
  lControlPointX=lEndPointX-tWidth;
  //左边贝塞尔曲线
  path.quadTo(lControlPointX,lControlPointY,lEndPointX,lEndPointY);
  //连接到右边
  path.lineTo(cPointX+(cPointX-lEndPointX),lEndPointY);
  //右边贝塞尔曲线
  path.quadTo(cPointX+cPointX-lControlPointX,lControlPointY,w,0);
  //更新内容部分Drawable
  updateContentLayout(cPointX,cPointY,cRadius);

 }

 /**
  * 对内容部分进行测量并设置
  * @param cx
  * @param cy
  * @param radius
  */
 private void updateContentLayout(float cx,float cy,float radius){

  Drawable drawable=mContent;
  if(drawable!=null){
   int margin=mContentMargin;
   int l=(int)(cx-radius+margin);
   int r=(int)(cx+radius-margin);
   int t=(int)(cy-radius+margin);
   int b=(int)(cy+radius-margin);
   drawable.setBounds(l,t,r,b);
  }

 }

 //释放动画
 private ValueAnimator valueAnimator;

 /**
  * 添加释放动作
  */

 public void release(){

  if(valueAnimator==null){

   ValueAnimator animator=ValueAnimator.ofFloat(mProgress,0f);
   animator.setInterpolator(new DecelerateInterpolator());
   animator.setDuration(400);
   animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
    @Override
    public void onAnimationUpdate(ValueAnimator animation) {

     Object val=animation.getAnimatedValue();
     if(val instanceof Float){
      setProgress((Float) val);
     }

    }
   });
   valueAnimator=animator;

  }else{

   valueAnimator.cancel();
   valueAnimator.setFloatValues(mProgress,0f);

  }
  valueAnimator.start();


 }

 /**
  * 获取当前值
  * @param start
  * @param end
  * @param progress
  * @return
  */
 private float getValueByLine(float start,float end ,float progress){
  return start+(end-start)*progress;
 }
 }

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.os.Build;
import android.support.annotation.Nullable;
import android.support.annotation.RequiresApi;
import android.util.AttributeSet;
import android.view.View;

/**
 * 作者：Mr.Lee on 2017-9-27 18:08
 * 邮箱：569932357@qq.com
 */

public class TestViewBezer extends View {

 private Paint mPaint=new Paint(Paint.ANTI_ALIAS_FLAG);
 private Path mPath=new Path();

 public TestViewBezer(Context context) {
  super(context);
  init();
 }

 public TestViewBezer(Context context, @Nullable AttributeSet attrs) {
  super(context, attrs);
  init();
 }

 public TestViewBezer(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
  init();
 }

 @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
 public TestViewBezer(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
  super(context, attrs, defStyleAttr, defStyleRes);
  init();
 }

 private void init(){


  Paint paint=mPaint;
  paint.setAntiAlias(true);
  paint.setDither(true);
  mPaint.setColor(0xff000000);
  paint.setStyle(Paint.Style.STROKE);
  paint.setStrokeWidth(10);

  Path path=mPath;
  path.moveTo(100,100);
  path.lineTo(400,400);

  path.quadTo(600,100,800,400);

  path.moveTo(400,800);
  path.cubicTo(500,600,700,1200,800,800);


 }

 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  canvas.drawPath(mPath,mPaint);
  canvas.drawPoint(600,100,mPaint);
  canvas.drawPoint(500,600,mPaint);
  canvas.drawPoint(700,1200,mPaint);

 }
}

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