[gnome-shell: 14/14] mpris: Make forward/backward insensitive when unavailable

[Florian Müllner <fmuellner src gnome org>]

commit 19816523c7e16dd8b0aef5aaf2f2b9a6e6208760
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Nov 3 18:11:54 2016 +0100

    mpris: Make forward/backward insensitive when unavailable
    
    Media notifications currently always show the forward and backward
    buttons as clickable, regardless of whether the corresponding action
    is available or not. Media players usually address this by rendering
    controls insensitive in this case, so do the same here.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=773884

 data/theme/gnome-shell-high-contrast.css |    2 ++
 data/theme/gnome-shell-sass              |    2 +-
 data/theme/gnome-shell.css               |    2 ++
 js/ui/mpris.js                           |   21 +++++++++++++++++++--
 4 files changed, 24 insertions(+), 3 deletions(-)
---
diff --git a/data/theme/gnome-shell-high-contrast.css b/data/theme/gnome-shell-high-contrast.css
index 6a3f875..b46a695 100644
--- a/data/theme/gnome-shell-high-contrast.css
+++ b/data/theme/gnome-shell-high-contrast.css
@@ -912,6 +912,8 @@ StScrollBar {
     padding-right: 18px; }
   .message-media-control:last-child:rtl {
     padding-left: 18px; }
+  .message-media-control:insensitive {
+    color: #999999; }
 
 .media-message-cover-icon {
   icon-size: 48px !important; }
diff --git a/data/theme/gnome-shell-sass b/data/theme/gnome-shell-sass
index a172894..671023a 160000
--- a/data/theme/gnome-shell-sass
+++ b/data/theme/gnome-shell-sass
@@ -1 +1 @@
-Subproject commit a172894788ec73c82be9aa6d29243809fdb0111d
+Subproject commit 671023a8b333f027d8c88fca9963b11581c10a70
diff --git a/data/theme/gnome-shell.css b/data/theme/gnome-shell.css
index 58a7656..5f2d39f 100644
--- a/data/theme/gnome-shell.css
+++ b/data/theme/gnome-shell.css
@@ -912,6 +912,8 @@ StScrollBar {
     padding-right: 18px; }
   .message-media-control:last-child:rtl {
     padding-left: 18px; }
+  .message-media-control:insensitive {
+    color: #8e8e80; }
 
 .media-message-cover-icon {
   icon-size: 48px !important; }
diff --git a/js/ui/mpris.js b/js/ui/mpris.js
index b42d9aa..a5ca66f 100644
--- a/js/ui/mpris.js
+++ b/js/ui/mpris.js
@@ -36,6 +36,8 @@ const MprisPlayerIface = '<node> \
   <method name="PlayPause" /> \
   <method name="Next" /> \
   <method name="Previous" /> \
+  <property name="CanGoNext" type="b" access="read" /> \
+  <property name="CanGoPrevious" type="b" access="read" /> \
   <property name="CanPlay" type="b" access="read" /> \
   <property name="Metadata" type="a{sv}" access="read" /> \
   <property name="PlaybackStatus" type="s" access="read" /> \
@@ -57,7 +59,7 @@ const MediaMessage = new Lang.Class({
         this._icon = new St.Icon({ style_class: 'media-message-cover-icon' });
         this.setIcon(this._icon);
 
-        this.addMediaControl('media-skip-backward-symbolic',
+        this._prevButton = this.addMediaControl('media-skip-backward-symbolic',
             Lang.bind(this, function() {
                 this._player.previous();
             }));
@@ -67,7 +69,7 @@ const MediaMessage = new Lang.Class({
                 this._player.playPause();
             }));
 
-        this.addMediaControl('media-skip-forward-symbolic',
+        this._nextButton = this.addMediaControl('media-skip-forward-symbolic',
             Lang.bind(this, function() {
                 this._player.next();
             }));
@@ -82,6 +84,10 @@ const MediaMessage = new Lang.Class({
         Main.panel.closeCalendar();
     },
 
+    _updateNavButton: function(button, sensitive) {
+        button.reactive = sensitive;
+    },
+
     _update: function() {
         this.setTitle(this._player.trackArtists.join(', '));
         this.setBody(this._player.trackTitle);
@@ -99,6 +105,9 @@ const MediaMessage = new Lang.Class({
         let iconName = isPlaying ? 'media-playback-pause-symbolic'
                                  : 'media-playback-start-symbolic';
         this._playPauseButton.child.icon_name = iconName;
+
+        this._updateNavButton(this._prevButton, this._player.canGoPrevious);
+        this._updateNavButton(this._nextButton, this._player.canGoNext);
     }
 });
 
@@ -139,10 +148,18 @@ const MprisPlayer = new Lang.Class({
         this._playerProxy.PlayPauseRemote();
     },
 
+    get canGoNext() {
+        return this._playerProxy.CanGoNext;
+    },
+
     next: function() {
         this._playerProxy.NextRemote();
     },
 
+    get canGoPrevious() {
+        return this._playerProxy.CanGoPrevious;
+    },
+
     previous: function() {
         this._playerProxy.PreviousRemote();
     },