Android自定义实现顶部粘性下拉刷新效果

<?xml version="1.0" encoding="utf-8"? 
<RelativeLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 android:id="@+id/rl_view"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  

  <trunk.doi.base.ui.activity.test.TouchPullView
   android:id="@+id/cs_view"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   app:pColor="@color/cff3e19"
   app:pContentDrawable="@drawable/shape_circle"
   app:pContentDrawableMargin="2dp"
   app:pDragHeight="100dp"
   app:pTangentAngle="110"
   app:pRadius="15dp"
   app:pTargetGravityHeight="4dp"
   app:pTargetWidth="200dp"
   / 
  <trunk.doi.base.ui.activity.test.TestViewBezer
   android:layout_width="match_parent"
   android:visibility="gone"
   android:layout_height="wrap_content"
   / 

</RelativeLayout 

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);
}
}

<declare-styleable name="TouchPullView" 
<attr name="pColor" format="color" / 
<attr name="pRadius" format="dimension" / 
<attr name="pDragHeight" format="dimension" </attr 
<attr name="pTangentAngle" format="integer" / 
<attr name="pTargetWidth" format="dimension" / 
<attr name="pTargetGravityHeight" format="dimension" / 
<attr name="pContentDrawable" format="reference" / 
<attr name="pContentDrawableMargin" format="dimension" / 
</declare-styleable 

<?xml version="1.0" encoding="utf-8"? 
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval"
<solid android:color="#fff" / 
</shape