Hide language menus when empty

On iOS, for now, we do not have a list of tracks.  In this case, hide
the audio language menu.

This also cleans up the hiding and showing of the captions menu, which
no longer requires a special case for TS since we integrated
transmuxing with the tracks API.

Finally, this fixes a few minor indentation issues.

Issue #997

Change-Id: I1b5bc329431e3d43a0238cd4af7839d220aa9b6b

demo/common/demo_utils.js

@@ -82,26 +82,6 @@ ShakaDemoUtils.addLicenseRequestHeaders_ =
 };
 
 
-/**
- * Return true if the current content is in the Transport Stream format.
- * Used to decide if the caption button is shown all the time in the demo,
- * and whether to show 'Default Text' as a Text Track option.
- *
- * @param {shaka.Player} player
- * @return {boolean}
- */
-ShakaDemoUtils.isTsContent = function(player) {
-  let activeTracks = player.getVariantTracks().filter(function(track) {
-    return track.active == true;
-  });
-  let activeTrack = activeTracks[0];
-  if (activeTrack) {
-    return activeTrack.mimeType == 'video/mp2t';
-  }
-  return false;
-};
-
-
 /**
  * Creates a number of asset buttons, with selection functionality.
  * Clicking one of these elements will add the "selected" tag to it, and remove

ui/audio_language_selection.js

@@ -62,16 +62,16 @@ shaka.ui.AudioLanguageSelection = class extends shaka.ui.Element {
 
 
     this.eventManager.listen(this.player, 'trackschanged', () => {
-        this.updateAudioLanguages_();
-      });
+      this.onTracksChanged_();
+    });
 
     this.eventManager.listen(this.player, 'variantchanged', () => {
-        this.updateAudioLanguages_();
-      });
+      this.updateAudioLanguages_();
+    });
 
     this.eventManager.listen(this.languagesButton_, 'click', () => {
-          this.onLanguagesClick_();
-      });
+      this.onLanguagesClick_();
+    });
 
     // Set up all the strings in the user's preferred language.
     this.updateLocalizedStrings_();
@@ -171,6 +171,12 @@ shaka.ui.AudioLanguageSelection = class extends shaka.ui.Element {
         new shaka.util.FakeEvent('languageselectionupdated'));
   }
 
+  /** @private */
+  onTracksChanged_() {
+    const hasVariants = this.player.getVariantTracks().length > 0;
+    shaka.ui.Utils.setDisplay(this.languagesButton_, hasVariants);
+    this.updateAudioLanguages_();
+  }
 
   /**
    * @param {string} language

ui/text_selection.js

@@ -63,20 +63,20 @@ shaka.ui.TextSelection = class extends shaka.ui.Element {
       });
 
     this.eventManager.listen(this.player, 'texttrackvisibility', () => {
-        this.onCaptionStateChange_();
-      });
+      this.onCaptionStateChange_();
+    });
 
     this.eventManager.listen(this.captionButton_, 'click', () => {
-        this.onCaptionClick_();
-      });
+      this.onCaptionClick_();
+    });
 
     this.eventManager.listen(this.player, 'textchanged', () => {
-        this.updateTextLanguages_();
-      });
+      this.updateTextLanguages_();
+    });
 
     this.eventManager.listen(this.player, 'trackschanged', () => {
-        this.onTracksChange_();
-      });
+      this.onTracksChanged_();
+    });
 
     // Initialize caption state with a fake event.
     this.onCaptionStateChange_();
@@ -267,17 +267,9 @@ shaka.ui.TextSelection = class extends shaka.ui.Element {
 
 
   /** @private */
-  onTracksChange_() {
-    // TS content might have captions embedded in video stream, we can't know
-    // until we start transmuxing. So, always show the caption button if we're
-    // playing TS content.
-    if (shaka.ui.Utils.isTsContent(this.player)) {
-        shaka.ui.Utils.setDisplay(this.captionButton_, true);
-    } else {
-      const hasText = this.player.getTextTracks().length;
-      shaka.ui.Utils.setDisplay(this.captionButton_, hasText > 0);
-    }
-
+  onTracksChanged_() {
+    const hasText = this.player.getTextTracks().length > 0;
+    shaka.ui.Utils.setDisplay(this.captionButton_, hasText);
     this.updateTextLanguages_();
   }
 };

ui/ui_utils.js

@@ -51,26 +51,6 @@ shaka.ui.Utils.getDescendantIfExists = function(element, className) {
 };
 
 
-/**
- * Return true if the content is Transport Stream.
- * Used to decide if caption button is shown all the time in the demo,
- * and whether to show 'Default Text' as a Text Track option.
- *
- * @param {shaka.Player} player
- * @return {boolean}
- */
-shaka.ui.Utils.isTsContent = function(player) {
-  let activeTracks = player.getVariantTracks().filter(function(track) {
-    return track.active == true;
-  });
-  let activeTrack = activeTracks[0];
-  if (activeTrack) {
-    return activeTrack.mimeType == 'video/mp2t';
-  }
-  return false;
-};
-
-
 /**
  * Finds a descendant of |menu| that has a 'shaka-chosen-item' class
  * and focuses on its' parent.