chore(Ads): Create shaka.ads.AbstractAd class to remove duplicate code (shaka-project#9190)

Author: avelad

build/types/ads

@@ -1,5 +1,6 @@
 # Ad Insertion Functionality
 
++../../lib/ads/abstract_ad.js
 +../../lib/ads/ad_manager.js
 +../../lib/ads/ad_utils.js
 +../../lib/ads/ads_stats.js

lib/ads/abstract_ad.js

@@ -0,0 +1,277 @@
+/*! @license
+ * Shaka Player
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+
+goog.provide('shaka.ads.AbstractAd');
+
+/**
+ * @abstract
+ * @implements {shaka.extern.IAd}
+ * @export
+ */
+shaka.ads.AbstractAd = class {
+  /**
+   * @param {HTMLMediaElement=} video
+   */
+  constructor(video = null) {
+    /** @protected {HTMLMediaElement} */
+    this.video = video;
+  }
+
+  /**
+   * @override
+   */
+  needsSkipUI() {
+    return true;
+  }
+
+  /**
+   * @override
+   */
+  isClientRendering() {
+    return true;
+  }
+
+  /**
+   * @override
+   */
+  hasCustomClick() {
+    return false;
+  }
+
+  /**
+   * @override
+   */
+  isUsingAnotherMediaElement() {
+    return false;
+  }
+
+  /**
+   * @override
+   */
+  getDuration() {
+    return -1;
+  }
+
+  /**
+   * @override
+   */
+  getMinSuggestedDuration() {
+    return this.getDuration();
+  }
+
+  /**
+   * @override
+   */
+  getRemainingTime() {
+    return -1;
+  }
+
+  /**
+   * @override
+   */
+  isPaused() {
+    return this.video ? this.video.paused : false;
+  }
+
+  /**
+   * @override
+   */
+  isSkippable() {
+    return false;
+  }
+
+  /**
+   * @override
+   */
+  getTimeUntilSkippable() {
+    return 0;
+  }
+
+  /**
+   * @override
+   */
+  canSkipNow() {
+    return false;
+  }
+
+  /**
+   * @override
+   */
+  skip() {
+    // Nothing
+  }
+
+  /**
+   * @override
+   */
+  pause() {
+    if (this.video) {
+      this.video.pause();
+    }
+  }
+
+  /**
+   * @override
+   */
+  play() {
+    if (this.video) {
+      this.video.play();
+    }
+  }
+
+  /**
+   * @override
+   */
+  getVolume() {
+    return this.video ? this.video.volume : 1;
+  }
+
+  /**
+   * @override
+   */
+  setVolume(volume) {
+    if (this.video) {
+      this.video.volume = volume;
+    }
+  }
+
+  /**
+   * @override
+   */
+  isMuted() {
+    return this.video ? this.video.muted : false;
+  }
+
+  /**
+   * @override
+   */
+  isLinear() {
+    return true;
+  }
+
+  /**
+   * @override
+   */
+  resize(width, height) {
+    // Nothing
+  }
+
+  /**
+   * @override
+   */
+  setMuted(muted) {
+    if (this.video) {
+      this.video.muted = muted;
+    }
+  }
+
+
+  /**
+   * @override
+   */
+  getSequenceLength() {
+    return 1;
+  }
+
+  /**
+   * @override
+   */
+  getPositionInSequence() {
+    return 1;
+  }
+
+  /**
+   * @override
+   */
+  getTitle() {
+    return '';
+  }
+
+  /**
+   * @override
+   */
+  getDescription() {
+    return '';
+  }
+
+  /**
+   * @override
+   */
+  getVastMediaBitrate() {
+    return 0;
+  }
+
+  /**
+   * @override
+   */
+  getVastMediaHeight() {
+    return 0;
+  }
+
+  /**
+   * @override
+   */
+  getVastMediaWidth() {
+    return 0;
+  }
+
+  /**
+   * @override
+   */
+  getVastAdId() {
+    return '';
+  }
+
+  /**
+   * @override
+   */
+  getAdId() {
+    return '';
+  }
+
+  /**
+   * @override
+   */
+  getCreativeAdId() {
+    return '';
+  }
+
+  /**
+   * @override
+   */
+  getAdvertiserName() {
+    return '';
+  }
+
+  /**
+   * @override
+   */
+  getMediaUrl() {
+    return null;
+  }
+
+  /**
+   * @override
+   */
+  getTimeOffset() {
+    return 0;
+  }
+
+  /**
+   * @override
+   */
+  getPodIndex() {
+    return 0;
+  }
+
+  /**
+   * @override
+   */
+  release() {
+    this.video = null;
+  }
+};