[sysui, downloads] add pull down to refresh for categories

- update ToolsColumn to ListView to have Flickable component. Fix JSONModel to handle updates.
Add pull down to refresh for categories column

Fixes: AUTOSUITE-850
Change-Id: If4170c283002ea1e921582085e7ec2e50c0919be
Reviewed-by: Grigorii Zimin <gzimin@luxoft.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/apps/com.pelagicore.downloads/controls/DownloadsToolsColumn.qml b/apps/com.pelagicore.downloads/controls/DownloadsToolsColumn.qml
index 95dea832..65ab16c3 100644
--- a/apps/com.pelagicore.downloads/controls/DownloadsToolsColumn.qml
+++ b/apps/com.pelagicore.downloads/controls/DownloadsToolsColumn.qml
@@ -44,14 +44,52 @@ Item {
     property string serverUrl
 
     signal toolClicked(int index)
+    signal refresh()
+
+    BusyIndicator {
+        id: busyIndicator
+
+        running: false
+        anchors.horizontalCenter: root.horizontalCenter
+        opacity: 0.0;
+        visible: opacity > 0.0
+        width: Sizes.dp(100); height: width
+    }
 
     ToolsColumn {
         id: toolsColumn
 
+        property bool refreshRequired: false
+
+        interactive: true
         width: Sizes.dp(264)
         anchors.horizontalCenter: parent.horizontalCenter
         anchors.top: parent.top
         anchors.topMargin: Sizes.dp(53)
         onClicked: root.toolClicked(currentIndex)
+        onContentYChanged: {
+            if (atYBeginning) {
+                var d = Math.abs(contentY);
+                busyIndicator.opacity = d / busyIndicator.height;
+                if (d > busyIndicator.height) {
+                    if (!busyIndicator.running) {
+                        busyIndicator.running = true;
+                        refreshRequired = true;
+                    }
+                } else {
+                    busyIndicator.running = false;
+                    // if we drag back - no refresh
+                    if (dragging)
+                        refreshRequired = false;
+                }
+            }
+        }
+        onMovementEnded: {
+            busyIndicator.opacity = 0.0;
+            if (refreshRequired) {
+                refreshRequired = false;
+                refresh();
+            }
+        }
     }
 }