feat(cvaa): add TEXT_STYLE_CHANGED event (#138)

src/event/events.js

@@ -141,6 +141,10 @@ const CUSTOM_EVENTS: { [event: string]: string } = {
    * Fires when the player has selected the source to play
    */
   SOURCE_SELECTED: 'sourceselected',
+  /**
+   * Fires when the text track style has changed
+   */
+  TEXT_STYLE_CHANGED: 'textstylechanged',
   /**
    * Fired when ad data is available.
    */

src/player.js

@@ -794,6 +794,7 @@ export default class Player extends FakeEventTarget {
         sheet.insertRule(`#${this._playerId} .${SUBTITLES_CLASS_NAME} > div > div > div { ${style.toCSS()} }`, 0);
       }
       this._textStyle = style;
+      this.dispatchEvent(new FakeEvent(CustomEvents.TEXT_STYLE_CHANGED));
     } catch (e) {
       Player._logger.error(e.message);
     }

test/src/event/events.spec.js

@@ -40,6 +40,7 @@ describe('events', () => {
       PLAYER_STATE_CHANGED: 'playerstatechanged',
       FIRST_PLAY: 'firstplay',
       SOURCE_SELECTED: 'sourceselected',
+      TEXT_STYLE_CHANGED: 'textstylechanged',
       AD_LOADED: 'adloaded',
       AD_STARTED: 'adstarted',
       AD_RESUMED: 'adresumed',

test/src/player.spec.js

@@ -1388,6 +1388,25 @@ describe('events', function () {
       player.play();
     });
   });
+
+  describe('text style changed', () => {
+    let player;
+
+    beforeEach(() => {
+      player = new Player();
+    });
+
+    afterEach(() => {
+      player.destroy();
+    });
+
+    it('should fire text style changed', (done) => {
+      player.addEventListener(player.Event.TEXT_STYLE_CHANGED, () => {
+        done();
+      });
+      player.textStyle = new TextStyle();
+    });
+  });
 });
 
 describe('states', function () {