Add "noFade" configuration to UI.

This allows users to tell the UI to stay visible at all times, even if
there are no mouse events.
This is necessary on ChromeCast, where there is no mouse, or touch
controls, or anything; without this setting, the controls just stay
transparent all the time.

Change-Id: Ie74c689f9bee9f07ffcb68dbacfd7bfe3ad066de

demo/cast_receiver/receiver_app.js

@@ -50,6 +50,7 @@ class ShakaReceiverApp {
 
     // Make sure we don't show extra UI elements we don't need on the TV.
     ui.configure({
+      noFade: true,
       controlPanelElements: [
         'play_pause',
         'time_and_duration',

ui/controls.js

@@ -363,6 +363,11 @@ shaka.ui.Controls = class extends shaka.util.FakeEventTarget {
     // Create the new layout
     this.createDOM_();
 
+    // If the controls are supposed to not fade, then they should be shown here.
+    if (config.noFade) {
+      this.setControlsOpacity_(shaka.ui.Enums.Opacity.OPAQUE);
+    }
+
     // Init the play state
     this.onPlayStateChange_();
 
@@ -1046,7 +1051,7 @@ shaka.ui.Controls = class extends shaka.util.FakeEventTarget {
 
     // Keep showing the controls if ad or video is paused or one of
     // the control menus is hovered.
-    if (adIsPaused ||
+    if (adIsPaused || this.config_.noFade ||
        (!this.ad_ && videoIsPaused) || this.overrideCssShowControls_) {
       this.setControlsOpacity_(shaka.ui.Enums.Opacity.OPAQUE);
     } else {

ui/externs/ui.js

@@ -60,7 +60,8 @@ shaka.extern.UIVolumeBarColors;
  *   clearBufferOnQualityChange: boolean,
  *   seekBarColors: shaka.extern.UISeekBarColors,
  *   volumeBarColors: shaka.extern.UIVolumeBarColors,
- *   trackLabelFormat: shaka.ui.TrackLabelFormat
+ *   trackLabelFormat: shaka.ui.TrackLabelFormat,
+ *   noFade: boolean
  * }}
  *
  * @property {!Array.<string>} controlPanelElements
@@ -97,6 +98,8 @@ shaka.extern.UIVolumeBarColors;
  *   ROLE means that only the role of the item is shown.
  *   LANGUAGE_ROLE means both are shown, or just language if there is no role.
  *   Defaults to LANGUAGE.
+ * @property {boolean} noFade
+ *   If set to true, the UI will not fade, even if the user is not mousing over.
  */
 shaka.extern.UIConfiguration;
 

ui/ui.js

@@ -210,6 +210,7 @@ shaka.ui.Overlay = class {
         level: 'rgb(255, 255, 255)',
       },
       trackLabelFormat: shaka.ui.TrackLabelFormat.LANGUAGE,
+      noFade: false,
     };
   }