Android实现添加商品到购物车动画效果

package com.zlw.yzm.demo;
 
import android.animation.Animator;
import android.animation.ValueAnimator;
import android.graphics.Path;
import android.graphics.PathMeasure;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.LinearInterpolator;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;
 
import com.zlw.yzm.demo.view.AmountView;
 
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
 
public class MainActivity extends AppCompatActivity {
 
  private RecyclerView rvGoodsList;
  private ImageView ivGotoGouWuChe;
  private RelativeLayout llContainer;
 
  private List productList;
  private PathMeasure mPathMeasure;
  /**
   * 存储商品列表中对应position的商品数量
   */
  private Map amountMap = new HashMap<>();
  /**
   * 贝塞尔曲线中间过程的点的坐标
   */
  private float[] mCurrentPosition = new float[2];
 
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    initView();
    initData();
    bindData();
  }
 
  private void initView() {
    rvGoodsList = findViewById(R.id.main_rv_goods_list);
    ivGotoGouWuChe = findViewById(R.id.main_iv_goto_gwche);
    llContainer = findViewById(R.id.rlContainer);
  }
 
  private void initData() {
 
    productList = new ArrayList<>();
    Product product = null;
    for (int i = 0; i < 30; i++) {
      product = new Product();
      product.productId = 10000L + i;
      product.productName = "Product-" + i;
      product.productDesc = "productDesc-" + i;
      productList.add(product);
    }
  }
  private void bindData() {
    rvGoodsList.setLayoutManager(new LinearLayoutManager(this));
    MyAdapter myAdapter = new MyAdapter();
    rvGoodsList.setAdapter(myAdapter);
  }
  class MyAdapter extends RecyclerView.Adapter {
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
      View itemView = View.inflate(MainActivity.this, R.layout.rv_item, null);
      return new ViewHolder(itemView);
    }
    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
      final ViewHolder viewHolder = (ViewHolder) holder;
      Product product = productList.get(position);
      viewHolder.tvProductName.setText(product.productName);
      viewHolder.tvProductDesc.setText(product.productDesc);
      viewHolder.amountView.setGoods_storage(5);
      viewHolder.amountView.setPosition(position);
      final Integer amount = amountMap.get(position);
      if (amount == null) {
        viewHolder.amountView.setAmount(0);
        viewHolder.amountView.playCloseAnim(0);
      } else {
        viewHolder.amountView.setAmount(amount.intValue());
        if (amount.intValue() == 0) {
          viewHolder.amountView.playCloseAnim(0);
        } else if (amount.intValue() >= 1) {
          viewHolder.amountView.playOpenAnim(0);
        }
      }
 
      Log.e("tag1", "amount===" + amount);
      viewHolder.amountView.setOnAmountChangedListener(new AmountView.OnAmountChangedListener() {
        @Override
        public void onAmountChanged(View view, int amount, int position, boolean increase) {
 
          amountMap.put(position, amount);
 
          if (increase) {
 
            add2Cart(viewHolder.ivProductIcon);
          }
        }
      });
    }
 
    @Override
    public int getItemCount() {
      return productList != null ? productList.size() : 0;
    }
 
    class ViewHolder extends RecyclerView.ViewHolder {
 
      ImageView ivProductIcon;
      TextView tvProductName;
      TextView tvProductDesc;
      AmountView amountView;
 
      public ViewHolder(View itemView) {
        super(itemView);
        ivProductIcon = itemView.findViewById(R.id.rv_item_iv_product_Icon);
        tvProductName = itemView.findViewById(R.id.rv_item_tv_product_name);
        tvProductDesc = itemView.findViewById(R.id.rv_item_tv_product_desc);
        amountView = itemView.findViewById(R.id.rv_item_amountview);
      }
    }
  }
 
  /**
   * 添加到购物车
   *
   * @param ivProductIcon
   */
  private void add2Cart(ImageView ivProductIcon) {
 
    // 一、创建执行动画的主题---ImageView(该图片就是执行动画的图片，从开始位置出发，经过一个抛物线（贝塞尔曲线）。)
    final ImageView imageView = new ImageView(MainActivity.this);
    imageView.setImageDrawable(ivProductIcon.getDrawable());
    // 将执行动画的图片添加到开始位置。
    RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
    llContainer.addView(imageView, params);
 
 
    // 二、计算动画开始/结束点的坐标的准备工作
    // 得到父布局的起始点坐标（用于辅助计算动画开始/结束时的点的坐标）
    int[] parentLocation = new int[2];
    llContainer.getLocationInWindow(parentLocation);
    // 得到商品图片的坐标（用于计算动画开始的坐标）
    int[] startLoc = new int[2];
    ivProductIcon.getLocationInWindow(startLoc);
    // 得到购物车图片的坐标(用于计算动画结束后的坐标)
    int[] endLoc = new int[2];
    ivGotoGouWuChe.getLocationInWindow(endLoc);
 
    // 三、计算动画开始结束的坐标
    // 开始掉落的商品的起始点：商品起始点-父布局起始点+该商品图片的一半
    float startX = startLoc[0] - parentLocation[0] + ivProductIcon.getWidth() / 2;
    float startY = startLoc[1] - parentLocation[1] + ivProductIcon.getHeight() / 2;
    //商品掉落后的终点坐标：购物车起始点-父布局起始点+购物车图片的1/5
    float toX = endLoc[0] - parentLocation[0] + ivGotoGouWuChe.getWidth() / 5;
    float toY = endLoc[1] - parentLocation[1];
 
    // 四、计算中间动画的插值坐标（贝塞尔曲线）（其实就是用贝塞尔曲线来完成起终点的过程）
    //开始绘制贝塞尔曲线
    Path path = new Path();
    //移动到起始点（贝塞尔曲线的起点）
    path.moveTo(startX, startY);
    //使用二次萨贝尔曲线：注意第一个起始坐标越大，贝塞尔曲线的横向距离就会越大，一般按照下面的式子取即可
    path.quadTo((startX + toX) / 2, startY, toX, toY);
    //mPathMeasure用来计算贝塞尔曲线的曲线长度和贝塞尔曲线中间插值的坐标，
    // 如果是true，path会形成一个闭环
    mPathMeasure = new PathMeasure(path, false);
 
    //★★★属性动画实现（从0到贝塞尔曲线的长度之间进行插值计算，获取中间过程的距离值）
    ValueAnimator valueAnimator = ValueAnimator.ofFloat(0, mPathMeasure.getLength());
    valueAnimator.setDuration(1000);
    // 匀速线性插值器
    valueAnimator.setInterpolator(new LinearInterpolator());
    valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
      @Override
      public void onAnimationUpdate(ValueAnimator animation) {
        // 当插值计算进行时，获取中间的每个值，
        // 这里这个值是中间过程中的曲线长度（下面根据这个值来得出中间点的坐标值）
        float value = (Float) animation.getAnimatedValue();
        // ★★★★★获取当前点坐标封装到mCurrentPosition
        // boolean getPosTan(float distance, float[] pos, float[] tan) ：
        // 传入一个距离distance(0<=distance<=getLength())，然后会计算当前距
        // 离的坐标点和切线，pos会自动填充上坐标，这个方法很重要。
        mPathMeasure.getPosTan(value, mCurrentPosition, null);//mCurrentPosition此时就是中间距离点的坐标值
        // 移动的商品图片（动画图片）的坐标设置为该中间点的坐标
        imageView.setTranslationX(mCurrentPosition[0]);
        imageView.setTranslationY(mCurrentPosition[1]);
      }
    });
    //  五、 开始执行动画
    valueAnimator.start();
    //  六、动画结束后的处理
    valueAnimator.addListener(new Animator.AnimatorListener() {
      @Override
      public void onAnimationStart(Animator animation) {
      }
      //当动画结束后：
      @Override
      public void onAnimationEnd(Animator animation) {
        // 购物车的数量加1
        // 把移动的图片imageview从父布局里移除
        llContainer.removeView(imageView);
      }
      @Override
      public void onAnimationCancel(Animator animation) {
      }
      @Override
      public void onAnimationRepeat(Animator animation) {
      }
    });
  }
}

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package com.zlw.yzm.demo.view;
 
import android.animation.ValueAnimator;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.animation.LinearInterpolator;
import android.widget.RelativeLayout;
import android.widget.TextView;
 
import com.zlw.yzm.demo.R;
 
/**
 * Created by 13198 on 2018/6/28.
 * 对商品的添加和删除进行封装
 */
 
public class AmountView extends RelativeLayout implements View.OnClickListener {
 
  private Context context;
 
  private TextView tvDecrease;
  private TextView tvAmount;
  private TextView tvIncrease;
  private RelativeLayout rlContainer;
 
  private float leftStartX;
  private float centerStartX;
  private float finalX;
 
  // 商品位置
  private int position = -1;
  // 商品库存
  private int goods_storage = 10;
 
  // 购买数量
  private int amount = 0;
  private int rlContainerMeasuredWidth;
 
  public AmountView(Context context) {
    this(context, null);
  }
 
  public AmountView(Context context, AttributeSet attrs) {
    this(context, attrs, 0);
  }
 
  public AmountView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    this.context = context;
    initView();
    initListener();
  }
 
  private void initView() {
 
    LayoutInflater.from(context).inflate(R.layout.rl_add2cart, this, true);
    tvDecrease = findViewById(R.id.tv_decrease);
    tvAmount = findViewById(R.id.tv_amount);
    tvIncrease = findViewById(R.id.tv_increase);
    rlContainer = findViewById(R.id.rlContainer);
  }
 
  private void initListener() {
    tvDecrease.setOnClickListener(this);
    tvIncrease.setOnClickListener(this);
  }
 
  public void setVisiable(boolean b) {
    tvDecrease.setVisibility(!b ? View.GONE : View.VISIBLE);
    tvAmount.setVisibility(!b ? View.GONE : View.VISIBLE);
  }
 
  @Override
  public void onClick(View v) {
 
    int id = v.getId();
    if (id == R.id.tv_increase) {
      // 添加商品
      if (amount < goods_storage) {
        amount++;
        setAmount(amount);
        if (getAmount() == 1) {
          playOpenAnim(500);
        }
        if (onAmountChangedListener != null) {
          onAmountChangedListener.onAmountChanged(this, amount, position, true);
        }
      }
    } else {
      //删除商品
      if (amount > 0) {
        amount--;
        setAmount(amount);
        playCloseAnim(500);
        if (onAmountChangedListener != null) {
 
          onAmountChangedListener.onAmountChanged(this, amount, position, false);
        }
      }
    }
  }
 
  public void setPosition(int position) {
 
    this.position = position;
  }
 
  public void setAmount(int amount) {
    this.amount = amount;
    tvAmount.setText(String.valueOf(amount));
  }
 
  public int getAmount() {
 
    return amount;
  }
 
  public void setGoods_storage(int goods_storage) {
    this.goods_storage = goods_storage;
  }
 
 
  public void playOpenAnim(int duration) {
 
    rlContainer.measure(0, 0);
    rlContainerMeasuredWidth = tvDecrease.getMeasuredWidth();
    startAnim(tvDecrease, 0, -rlContainerMeasuredWidth / 3, duration);
    startAnim(tvAmount, 0, -rlContainerMeasuredWidth / 3, duration);
  }
 
  public void playCloseAnim(int duration) {
    rlContainer.measure(0, 0);
    rlContainerMeasuredWidth = rlContainer.getMeasuredWidth();
    if (getAmount() == 0) {
 
      startAnim(tvDecrease, 0, rlContainerMeasuredWidth / 3, duration);
      startAnim(tvAmount, 0, rlContainerMeasuredWidth / 3, duration);
    }
  }
 
  /**
   * 添加、移除购物车中商品的动画
   *
   * @param view
   * @param startX
   * @param endX
   * @param duration
   */
  private void startAnim(final View view, final float startX, final float endX, int duration) {
    ValueAnimator animator = ValueAnimator.ofFloat(0, endX - startX);
    animator.setDuration(duration);
    animator.setInterpolator(new LinearInterpolator());
    animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
      @Override
      public void onAnimationUpdate(ValueAnimator animation) {
 
        float currentX = (float) animation.getAnimatedValue();
        view.setTranslationX(currentX);
 
        float alpha = 0;
        float hudu = 0;
        float lenth = Math.abs(endX - startX);
        if (endX - startX > 0) {
          // 向右滑动=====>1--0
          alpha = (lenth - currentX) / lenth;
          hudu = currentX * 360 / lenth;
        } else {
          // 向左滑动====>0-1
          alpha = Math.abs(currentX) / lenth;
          hudu = 360 - (lenth - Math.abs(currentX)) * 360 / lenth;
        }
 
        view.setAlpha(alpha);
        view.setRotation(hudu);
        Log.e("tag", "view=====" + view.getId() + "=======currentX==========" + currentX);
      }
    });
    animator.start();
  }
 
  /**
   * 定义一个接口，监听数量变化
   */
  public interface OnAmountChangedListener {
    void onAmountChanged(View view, int amount, int position, boolean increase);
  }
 
  private OnAmountChangedListener onAmountChangedListener;
 
  public void setOnAmountChangedListener(OnAmountChangedListener onAmountChangedListener) {
    this.onAmountChangedListener = onAmountChangedListener;
  }
 
}

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