Android 实现微信长按菜单 -FloatMenu

 private Menu mMenu;
 @NonNull
 @SuppressLint("RestrictedApi")
 public Menu getMenu() {
 if (mMenu == null) {
  mMenu = new MenuBuilder(mContext);
 }
 return mMenu;
 }
 @NonNull
 public MenuInflater getMenuInflater() {
 return new MenuInflater(mContext);
 }
 public void inflate(@MenuRes int menuRes) {
 getMenuInflater().inflate(menuRes, getMenu());
 }

private Point mPoint = new Point();
 @Override
 public boolean dispatchTouchEvent(MotionEvent ev) {
 if (ev.getAction() == MotionEvent.ACTION_DOWN) {
  mPoint.x = (int) ev.getRawX();
  mPoint.y = (int) ev.getRawY();
 }
 return super.dispatchTouchEvent(ev);
 }
 public void showPopup(View anchorView, int x, int y) {
 if (!getMenu().hasVisibleItems()) {
  return;
 }
 //set visible item data
 int size = getMenu().size();
 mMenuItems.clear();
 for (int i = 0; i < size; i++) {
  MenuItem item = getMenu().getItem(i);
  if (item.isVisible()) {
  mMenuItems.add(item);
  }
 }
 mMenuAdapter.notifyDataSetChanged();
 //show
 int menuHeight = Display.dip2px(mContext, DEFAULT_ITEM_HEIGHT * mMenuItems.size());
 if (x <= mScreenPoint.x / 2) {
  if (y + menuHeight < mScreenPoint.y) {
  setAnimationStyle(R.style.Animation_top_left);
  showAtLocation(anchorView, ANCHORED_GRAVITY, x + X_OFFSET, y);
  } else {
  setAnimationStyle(R.style.Animation_bottom_left);
  showAtLocation(anchorView, ANCHORED_GRAVITY, x + X_OFFSET, y - menuHeight);
  }
 } else {
  if (y + menuHeight < mScreenPoint.y) {
  setAnimationStyle(R.style.Animation_top_right);
  showAtLocation(anchorView, ANCHORED_GRAVITY, x - mMenuWidth - X_OFFSET, y);
  } else {
  setAnimationStyle(R.style.Animation_bottom_right);
  showAtLocation(anchorView, ANCHORED_GRAVITY, x - mMenuWidth + X_OFFSET, y - menuHeight);
  }
 }
 }