/**
   * Item开启动画
   *
   * @param btnItem
   * @param index
   * @param total
   * @param radius
   */
  private void btnItemStartAnimator(View btnItem, int index, int total, int radius) {
    if (btnItem.getVisibility() != View.VISIBLE) {
      btnItem.setVisibility(View.VISIBLE);
    }
    double degree = Math.toRadians(90) / (total - 1) * index;//Math中根据度数得到弧度值的函数
    int translationX = -(int) (radius * Math.sin(degree));
    int translationY = -(int) (radius * Math.cos(degree));

    AnimatorSet set = new AnimatorSet();
    //实现平移缩放和透明动画
    set.playTogether(
        ObjectAnimator.ofFloat(btnItem, "translationX", 0, translationX),
        ObjectAnimator.ofFloat(btnItem, "translationY", 0, translationY),
        ObjectAnimator.ofFloat(btnItem, "scaleX", 0, 1),
        ObjectAnimator.ofFloat(btnItem, "scaleY", 0, 1),
        ObjectAnimator.ofFloat(btnItem, "alpha", 0, 1)
    );
    set.setInterpolator(new BounceInterpolator());

    set.setDuration(500).start();
  }


  /**
   * Item关闭动画
   *
   * @param btnItem
   * @param index
   * @param total
   * @param radius
   */
  private void btnItemCloseAnimator(View btnItem, int index, int total, int radius) {

    double degree = Math.PI * index / ((total - 1) * 2);
    int translationX = -(int) (radius * Math.sin(degree));
    int translationY = -(int) (radius * Math.cos(degree));
    AnimatorSet set = new AnimatorSet();
    //包含平移、缩放和透明度动画
    set.playTogether(
        ObjectAnimator.ofFloat(btnItem, "translationX", translationX, 0),
        ObjectAnimator.ofFloat(btnItem, "translationY", translationY, 0),
        ObjectAnimator.ofFloat(btnItem, "scaleX", 1f, 0f),
        ObjectAnimator.ofFloat(btnItem, "scaleY", 1f, 0f),
        ObjectAnimator.ofFloat(btnItem, "alpha", 1f, 0f));
    set.setDuration(500).start();

    if (btnItem.getVisibility() == View.VISIBLE) {
      btnItem.setVisibility(View.INVISIBLE);
    }
  }

ObjectAnimator.ofFloat(btnItem, "translationX", 0, translationX),
    ObjectAnimator.ofFloat(btnItem, "translationY", 0, translationY),

 double degree = Math.toRadians(90) / (total - 1) * index;//Math中根据度数得到弧度值的函数
    int translationX = -(int) (radius * Math.sin(degree));

 double degree = Math.PI * index / ((total - 1) * 2);
     int translationX = -(int) (radius * Math.sin(degree));

package xsf.customView;

import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.view.View;
import android.view.animation.BounceInterpolator;
import android.widget.Button;
import android.widget.Toast;

import xsf.customView.base.BaseActvity;


public class StatelliteActivity extends BaseActvity {
  private Button btnMenu, btnItem1, btnItem2, btnItem3, btnItem4, btnItem5;
  private boolean isMenuOpen = false;

  @Override
  protected int setLayoutResourceId() {
    return R.layout.activity_statellite;
  }

  @Override
  protected void initView() {
    btnMenu = (Button) findViewById(R.id.btnMenu);
    btnMenu.setOnClickListener(this);
    btnItem1 = (Button) findViewById(R.id.btnItem1);
    btnItem1.setOnClickListener(this);

    btnItem2 = (Button) findViewById(R.id.btnItem2);
    btnItem2.setOnClickListener(this);
    btnItem3 = (Button) findViewById(R.id.btnItem3);
    btnItem3.setOnClickListener(this);
    btnItem4 = (Button) findViewById(R.id.btnItem4);
    btnItem4.setOnClickListener(this);
    btnItem5 = (Button) findViewById(R.id.btnItem5);
    btnItem5.setOnClickListener(this);
  }
  

  @Override
  public void onClick(View v) {
    btnMenu.requestFocus();

    switch (v.getId()) {

      case R.id.btnMenu:
        showItemAnimator();
        break;
      case R.id.btnItem1:
        Toast.makeText(StatelliteActivity.this, "点击了Item1", Toast.LENGTH_SHORT).show();
        break;
      case R.id.btnItem2:
        Toast.makeText(StatelliteActivity.this, "点击了Item2", Toast.LENGTH_SHORT).show();
        break;
      case R.id.btnItem3:
        Toast.makeText(StatelliteActivity.this, "点击了Item3", Toast.LENGTH_SHORT).show();
        break;
      case R.id.btnItem4:
        Toast.makeText(StatelliteActivity.this, "点击了Item4", Toast.LENGTH_SHORT).show();
        break;
      case R.id.btnItem5:
        Toast.makeText(StatelliteActivity.this, "点击了Item5", Toast.LENGTH_SHORT).show();
        break;
    }

  }

  private void showItemAnimator() {
    if (!isMenuOpen) {
      //此时menu是关闭的
      isMenuOpen = true;
      btnItemStartAnimator(btnItem1, 0, 5, 300);
      btnItemStartAnimator(btnItem2, 1, 5, 300);
      btnItemStartAnimator(btnItem3, 2, 5, 300);
      btnItemStartAnimator(btnItem4, 3, 5, 300);
      btnItemStartAnimator(btnItem5, 4, 5, 300);

    } else {
      //此时menu是打开的
      isMenuOpen = false;
      btnItemCloseAnimator(btnItem1, 0, 5, 300);
      btnItemCloseAnimator(btnItem2, 1, 5, 300);
      btnItemCloseAnimator(btnItem3, 2, 5, 300);
      btnItemCloseAnimator(btnItem4, 3, 5, 300);
      btnItemCloseAnimator(btnItem5, 4, 5, 300);
    }
  }

  /**
   * 关闭动画
   *
   * @param btnItem
   * @param index
   * @param total
   * @param radius
   */
  private void btnItemCloseAnimator(View btnItem, int index, int total, int radius) {

    double degree = Math.PI * index / ((total - 1) * 2);
    int translationX = -(int) (radius * Math.sin(degree));
    int translationY = -(int) (radius * Math.cos(degree));
    AnimatorSet set = new AnimatorSet();
    //包含平移、缩放和透明度动画
    set.playTogether(
        ObjectAnimator.ofFloat(btnItem, "translationX", translationX, 0),
        ObjectAnimator.ofFloat(btnItem, "translationY", translationY, 0),
        ObjectAnimator.ofFloat(btnItem, "scaleX", 1f, 0f),
        ObjectAnimator.ofFloat(btnItem, "scaleY", 1f, 0f),
        ObjectAnimator.ofFloat(btnItem, "alpha", 1f, 0f));
    set.setDuration(500).start();

    if (btnItem.getVisibility() == View.VISIBLE) {
      btnItem.setVisibility(View.INVISIBLE);
    }
  }

  /**
   * 开启动画
   *
   * @param btnItem
   * @param index
   * @param total
   * @param radius
   */
  private void btnItemStartAnimator(View btnItem, int index, int total, int radius) {
    if (btnItem.getVisibility() != View.VISIBLE) {
      btnItem.setVisibility(View.VISIBLE);
    }
    double degree = Math.toRadians(90) / (total - 1) * index;//Math中根据度数得到弧度值的函数
    int translationX = -(int) (radius * Math.sin(degree));
    int translationY = -(int) (radius * Math.cos(degree));

    AnimatorSet set = new AnimatorSet();
    //实现平移缩放和透明动画
    set.playTogether(
        ObjectAnimator.ofFloat(btnItem, "translationX", 0, translationX),
        ObjectAnimator.ofFloat(btnItem, "translationY", 0, translationY),
        ObjectAnimator.ofFloat(btnItem, "scaleX", 0, 1),
        ObjectAnimator.ofFloat(btnItem, "scaleY", 0, 1),
        ObjectAnimator.ofFloat(btnItem, "alpha", 0, 1)
    );
    set.setInterpolator(new BounceInterpolator());

    set.setDuration(500).start();


  }
}