Make system tray pin persistent across sessions

applets/systemtray/package/contents/config/main.xml

@@ -50,6 +50,10 @@
       <label>Default icon size for the systray icons, it's an enum which values mean, Small, SmallMedium, Medium, Large, Huge, Enormous respectively. On low DPI systems they correspond to 16, 22, 32, 48, 64, 128 pixels. On high DPI systems those values would be scaled up, depending on the DPI.</label>
       <default>1</default>
     </entry>
+    <entry name="pin" type="Bool">
+      <label>Whether the popup should remain open when another window is activated</label>
+      <default>false</default>
+    </entry>
   </group>
 
 </kcfg>

applets/systemtray/package/contents/ui/ExpandedRepresentation.qml

@@ -31,7 +31,6 @@ Item {
     Layout.preferredWidth: Layout.minimumWidth
     Layout.preferredHeight: Layout.minimumHeight * 1.5
 
-    property bool hideOnWindowDeactivate: !pinButton.checked
     property alias activeApplet: container.activeApplet
     property alias hiddenLayout: hiddenItemsView.layout
 
@@ -41,6 +40,8 @@ Item {
         width: Math.round(units.gridUnit * 1.25)
         height: width
         checkable: true
+        checked: plasmoid.configuration.pin
+        onCheckedChanged: plasmoid.configuration.pin = checked
         iconSource: "window-pin"
         z: 2
     }

applets/systemtray/package/contents/ui/main.qml

@@ -339,7 +339,7 @@ MouseArea {
         visualParent: root
         flags: Qt.WindowStaysOnTopHint
         location: plasmoid.location
-        hideOnWindowDeactivate: expandedRepresentation.hideOnWindowDeactivate
+        hideOnWindowDeactivate: !plasmoid.configuration.pin
 
         onVisibleChanged: {
             if (!visible) {