QML, ViewerPage: primitive pinch and panning

src/desktop/qml/ViewerPage.qml

@@ -10,8 +10,29 @@ Page {
 
     title: qsTr("VNC Client - Viewer")
 
-    VncOutput {
-        id: viewer
+    PinchArea {
+        property real initialScale: 1.0
+        property point initialCenter
+
         anchors.fill: parent
+        onPinchStarted: {
+            initialScale = viewer.scale
+            initialCenter = viewer.center
+        }
+        onPinchUpdated: {
+            var requestedScale = initialScale * pinch.scale
+            var diffX = (pinch.center.x - pinch.startCenter.x) /
+                requestedScale
+            var diffY = (pinch.center.y - pinch.startCenter.y) /
+                requestedScale
+            viewer.scale = requestedScale
+            viewer.center = Qt.point(initialCenter.x - diffX, initialCenter.y - diffY)
+        }
+
+        VncOutput {
+            id: viewer
+            anchors.fill: parent
+            enabled: !parent.pinch.active
+        }
     }
 }