content: /*
   * Copyright (C) 2020 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.google.android.exoplayer2.ui;
  
  import android.graphics.Color;
  import androidx.annotation.ColorInt;
  import com.google.android.exoplayer2.util.Util;
  
  /**
   * Utility methods for generating HTML and CSS for use with {@link WebViewSubtitleOutput} and {@link
   * SpannedToHtmlConverter}.
   */
  /* package */ final class HtmlUtils {
  
    private HtmlUtils() {}
  
    public static String toCssRgba(@ColorInt int color) {
      return Util.formatInvariant(
          "rgba(%d,%d,%d,%.3f)",
          Color.red(color), Color.green(color), Color.blue(color), Color.alpha(color) / 255.0);
    }
  
    /**
     * Returns a CSS selector that selects all elements with {@code class=className} and all their
     * descendants.
     */
    public static String cssAllClassDescendantsSelector(String className) {
      return "." + className + ",." + className + " *";
    }
  }
  