feat: Add a stub text display class (shaka-project#5804)

kaidokert · Oct 25, 2023 · c9ee316 · c9ee316
1 parent 51870e9
commit c9ee316
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Showing 3 changed files with 61 additions and 1 deletion.
diff --git a/build/types/core b/build/types/core
@@ -61,6 +61,7 @@
 
 +../../lib/text/cue.js
 +../../lib/text/simple_text_displayer.js
++../../lib/text/stub_text_displayer.js
 +../../lib/text/text_engine.js
 +../../lib/text/text_utils.js
 +../../lib/text/ui_text_displayer.js

diff --git a/lib/player.js b/lib/player.js
@@ -34,6 +34,7 @@ goog.require('shaka.net.NetworkingEngine');
 goog.require('shaka.net.NetworkingUtils');
 goog.require('shaka.routing.Walker');
 goog.require('shaka.text.SimpleTextDisplayer');
+goog.require('shaka.text.StubTextDisplayer');
 goog.require('shaka.text.TextEngine');
 goog.require('shaka.text.UITextDisplayer');
 goog.require('shaka.text.WebVttGenerator');
@@ -5445,7 +5446,14 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
         return new shaka.text.UITextDisplayer(
             this.video_, this.videoContainer_);
       } else {
-        return new shaka.text.SimpleTextDisplayer(this.video_);
+        // eslint-disable-next-line no-restricted-syntax
+        if (HTMLMediaElement.prototype.addTextTrack) {
+          return new shaka.text.SimpleTextDisplayer(this.video_);
+        } else {
+          shaka.log.warning('Text tracks are not supported by the ' +
+                            'browser, disabling.');
+          return new shaka.text.StubTextDisplayer();
+        }
       }
     };
     return config;

diff --git a/lib/text/stub_text_displayer.js b/lib/text/stub_text_displayer.js
@@ -0,0 +1,51 @@
+/*! @license
+ * Shaka Player
+ * Copyright 2023 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+goog.provide('shaka.text.StubTextDisplayer');
+
+/**
+* A stub text displayer plugin that does nothing
+*
+* @implements {shaka.extern.TextDisplayer}
+* @export
+*/
+shaka.text.StubTextDisplayer = class {
+  /**
+   * @override
+   * @export
+   */
+  remove(start, end) {
+  }
+
+  /**
+   * @override
+   * @export
+   */
+  append(cues) {
+  }
+
+  /**
+   * @override
+   * @export
+   */
+  destroy() {
+  }
+
+  /**
+   * @override
+   * @export
+   */
+  isTextVisible() {
+    return false;
+  }
+
+  /**
+   * @override
+   * @export
+   */
+  setTextVisibility(on) {
+  }
+};