Perf: Loaders and async loading

qgroundcontrol.qrc

@@ -88,11 +88,13 @@
         <file alias="QGroundControl/FactControls/FactPanel.qml">src/FactSystem/FactControls/FactPanel.qml</file>
         <file alias="QGroundControl/FactControls/FactTextField.qml">src/FactSystem/FactControls/FactTextField.qml</file>
         <file alias="QGroundControl/FactControls/qmldir">src/FactSystem/FactControls/qmldir</file>
+
+        <file alias="QGroundControl/FlightDisplay/qmldir">src/FlightDisplay/qmldir</file>
         <file alias="QGroundControl/FlightDisplay/FlightDisplayView.qml">src/FlightDisplay/FlightDisplayView.qml</file>
         <file alias="QGroundControl/FlightDisplay/FlightDisplayViewMap.qml">src/FlightDisplay/FlightDisplayViewMap.qml</file>
         <file alias="QGroundControl/FlightDisplay/FlightDisplayViewVideo.qml">src/FlightDisplay/FlightDisplayViewVideo.qml</file>
         <file alias="QGroundControl/FlightDisplay/FlightDisplayViewWidgets.qml">src/FlightDisplay/FlightDisplayViewWidgets.qml</file>
-        <file alias="QGroundControl/FlightDisplay/qmldir">src/FlightDisplay/qmldir</file>
+        <file alias="VirtualJoystick.qml">src/FlightDisplay/VirtualJoystick.qml</file>
 
         <file alias="QGroundControl/FlightMap/qmldir">src/FlightMap/qmldir</file>
         <file alias="QGroundControl/FlightMap/FlightMap.qml">src/FlightMap/FlightMap.qml</file>

src/FlightDisplay/FlightDisplayView.qml

@@ -231,58 +231,25 @@ QGCView {
             anchors.left:       parent.left
             anchors.bottom:     parent.bottom
             height:             availableHeight
+            asynchronous:       true
+            visible:            status == Loader.Ready
+
             property bool isBackgroundDark: root.isBackgroundDark
             property var qgcView: root
         }
 
         //-- Virtual Joystick
-        Item {
+        Loader {
             id:                         multiTouchItem
             z:                          _panel.z + 5
             width:                      parent.width  - (_flightVideoPipControl.width / 2)
-            height:                     thumbAreaHeight
+            height:                     Math.min(parent.height * 0.25, ScreenTools.defaultFontPixelWidth * 16)
             visible:                    QGroundControl.virtualTabletJoystick
             anchors.bottom:             _flightVideoPipControl.top
             anchors.bottomMargin:       ScreenTools.defaultFontPixelHeight * 2
             anchors.horizontalCenter:   parent.horizontalCenter
-
-            readonly property real thumbAreaHeight: Math.min(parent.height * 0.25, ScreenTools.defaultFontPixelWidth * 16)
-
-            QGCMapPalette { id: mapPal; lightColors: !isBackgroundDark }
-
-            Timer {
-                interval:   40  // 25Hz, same as real joystick rate
-                running:    QGroundControl.virtualTabletJoystick && _activeVehicle
-                repeat:     true
-                onTriggered: {
-                    if (_activeVehicle) {
-                        _activeVehicle.virtualTabletJoystickValue(rightStick.xAxis, rightStick.yAxis, leftStick.xAxis, leftStick.yAxis)
-                    }
-                }
-            }
-
-            JoystickThumbPad {
-                id:                     leftStick
-                anchors.leftMargin:     xPositionDelta
-                anchors.bottomMargin:   -yPositionDelta
-                anchors.left:           parent.left
-                anchors.bottom:         parent.bottom
-                width:                  parent.thumbAreaHeight
-                height:                 parent.thumbAreaHeight
-                yAxisThrottle:          true
-                lightColors:            !isBackgroundDark
-            }
-
-            JoystickThumbPad {
-                id:                     rightStick
-                anchors.rightMargin:    -xPositionDelta
-                anchors.bottomMargin:   -yPositionDelta
-                anchors.right:          parent.right
-                anchors.bottom:         parent.bottom
-                width:                  parent.thumbAreaHeight
-                height:                 parent.thumbAreaHeight
-                lightColors:            !isBackgroundDark
-            }
+            source:                     "qrc:/qml/VirtualJoystick.qml"
+            active:                     QGroundControl.virtualTabletJoystick
         }
     }
 }

src/FlightDisplay/VirtualJoystick.qml

+/*=====================================================================
+
+QGroundControl Open Source Ground Control Station
+
+(c) 2009, 2015 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
+
+This file is part of the QGROUNDCONTROL project
+
+    QGROUNDCONTROL is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    QGROUNDCONTROL is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with QGROUNDCONTROL. If not, see <http://www.gnu.org/licenses/>.
+
+======================================================================*/
+
+import QtQuick 2.5
+
+import QGroundControl               1.0
+import QGroundControl.ScreenTools   1.0
+import QGroundControl.Controls      1.0
+import QGroundControl.Palette       1.0
+import QGroundControl.Vehicle       1.0
+
+Item {
+    QGCMapPalette { id: mapPal; lightColors: !isBackgroundDark }
+
+    Timer {
+        interval:   40  // 25Hz, same as real joystick rate
+        running:    QGroundControl.virtualTabletJoystick && _activeVehicle
+        repeat:     true
+        onTriggered: {
+            if (_activeVehicle) {
+                _activeVehicle.virtualTabletJoystickValue(rightStick.xAxis, rightStick.yAxis, leftStick.xAxis, leftStick.yAxis)
+            }
+        }
+    }
+
+    JoystickThumbPad {
+        id:                     leftStick
+        anchors.leftMargin:     xPositionDelta
+        anchors.bottomMargin:   -yPositionDelta
+        anchors.left:           parent.left
+        anchors.bottom:         parent.bottom
+        width:                  parent.height
+        height:                 parent.height
+        yAxisThrottle:          true
+        lightColors:            !isBackgroundDark
+    }
+
+    JoystickThumbPad {
+        id:                     rightStick
+        anchors.rightMargin:    -xPositionDelta
+        anchors.bottomMargin:   -yPositionDelta
+        anchors.right:          parent.right
+        anchors.bottom:         parent.bottom
+        width:                  parent.height
+        height:                 parent.height
+        lightColors:            !isBackgroundDark
+    }
+}