[Device Notifier] Restore busy indicator

Summary:
This patch fixes two issues:
- the 'state' of the device now propagates correctly, that makes the busy indicator be displayed again, device emblems are also updated correctly
- there is no more delay between the moment when the device is actually mounted and the moment the device notifier says it is. The worst case used to be 5 seconds.

BUG: 354321
BUG: 399986

Reviewers: #plasma, #vdg, broulik, bruns, ngraham, davidedmundson

Reviewed By: #plasma, #vdg, ngraham, davidedmundson

Subscribers: mart, cfeck, ngraham, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D16170

applets/devicenotifier/package/contents/ui/DeviceItem.qml

@@ -119,6 +119,19 @@ MouseArea {
         }
     }
 
+    Timer {
+        id: updateStorageSpaceTimer
+        interval: 5000
+        repeat: true
+        running: mounted && plasmoid.expanded
+        triggeredOnStart: true     // Update the storage space as soon as we open the plasmoid
+        onTriggered: {
+            var service = sdSource.serviceForSource(udi);
+            var operation = service.operationDescription("updateFreespace");
+            service.startOperationCall(operation);
+        }
+    }
+
     RowLayout {
         id: row
         anchors.horizontalCenter: parent.horizontalCenter
@@ -239,8 +252,6 @@ MouseArea {
                 font.pointSize: theme.smallestFont.pointSize
                 visible: deviceItem.state != 0 || (!actionsList.visible && !deviceItem.hasMessage)
                 text: {
-                    // FIXME: state changes do not reach the plasmoid if the
-                    // device was already attached when the plasmoid was initialized
                     if (deviceItem.state == 0) {
                         if (!hpSource.data[udi]) {
                             return ""

applets/devicenotifier/package/contents/ui/devicenotifier.qml

@@ -109,7 +109,7 @@ Item {
         id: sdSource
         engine: "soliddevice"
         connectedSources: hpSource.sources
-        interval: plasmoid.expanded ? 5000 : 0
+        interval: 0
         property string last
         onSourceAdded: {
             disconnectSource(source);