Show message and hide controls if no player is available

Summary: Instead of showing empty controls show a message that no players are available

Test Plan: Use eyes

Reviewers: #kde_connect, apol

Reviewed By: #kde_connect, apol

Subscribers: kdeconnect

Tags: #kde_connect

Differential Revision: https://phabricator.kde.org/D12830

app/qml/mpris.qml

@@ -29,9 +29,17 @@ Kirigami.Page
     property QtObject pluginInterface
     title: i18n("Multimedia Controls")
 
+    Label {
+        id: noPlayersText
+        text: i18n("No players available")
+        anchors.centerIn: parent
+        visible: pluginInterface.playerList.length == 0
+    }
+
     ColumnLayout
     {
         anchors.fill: parent
+        visible: !noPlayersText.visible
 
         Component.onCompleted: {
             pluginInterface.requestPlayerList();