Merge pull request #7873 from DonLakeFlyer/CorridorTools

Corridor edit toolbar

ChangeLog.md

@@ -6,6 +6,7 @@ Note: This file only contains high level features or important fixes.
 
 ### 3.6.0 - Daily Build
 
+* New Corridor editing tools ui. Includes ability to trace polyline by clicking.
 * New Polygon editing tools ui. Includes ability to trace polygon by clicking.
 * ArduCopter/Rover: Follow Me setup page
 * More performant flight path display algorithm. Mobile builds no longer show limited path length.

qgroundcontrol.qrc

@@ -101,6 +101,7 @@
         <file alias="QGroundControl/Controls/ParameterEditor.qml">src/QmlControls/ParameterEditor.qml</file>
         <file alias="QGroundControl/Controls/ParameterEditorDialog.qml">src/QmlControls/ParameterEditorDialog.qml</file>
         <file alias="QGroundControl/Controls/PIDTuning.qml">src/QmlControls/PIDTuning.qml</file>
+        <file alias="QGroundControl/Controls/PlanEditToolbar.qml">src/PlanView/PlanEditToolbar.qml</file>
         <file alias="QGroundControl/Controls/PreFlightCheckButton.qml">src/QmlControls/PreFlightCheckButton.qml</file>
         <file alias="QGroundControl/Controls/PreFlightCheckGroup.qml">src/QmlControls/PreFlightCheckGroup.qml</file>
         <file alias="QGroundControl/Controls/PreFlightCheckModel.qml">src/QmlControls/PreFlightCheckModel.qml</file>

src/MissionManager/QGCMapPolygonVisuals.qml

@@ -71,9 +71,9 @@ Item {
     }
 
 
-    function addToolVisuals() {
+    function addToolbarVisuals() {
         if (_objMgrToolVisuals.empty) {
-            _objMgrToolVisuals.createObject(editHeaderComponent, mapControl)
+            _objMgrToolVisuals.createObject(toolbarComponent, mapControl)
         }
     }
 
@@ -155,7 +155,7 @@ Item {
     function _handleInteractiveChanged() {
         if (interactive) {
             addEditingVisuals()
-            addToolVisuals()
+            addToolbarVisuals()
         } else {
             _traceMode = false
             removeEditingVisuals()
@@ -513,73 +513,53 @@ Item {
     }
 
     Component {
-        id: editHeaderComponent
+        id: toolbarComponent
 
-        Item {
-            x:          mapControl.centerViewport.left + _viewportMargins
-            y:          mapControl.centerViewport.top + _viewportMargins
-            width:      mapControl.centerViewport.width - (_viewportMargins * 2)
-            height:     editHeaderRowLayout.y + editHeaderRowLayout.height + _viewportMargins
+        PlanEditToolbar {
+            x:          mapControl.centerViewport.left + _margins
+            y:          mapControl.centerViewport.top + _margins
+            width:      mapControl.centerViewport.width - (_margins * 2)
             z:          QGroundControl.zOrderMapItems + 2
 
-            property real   _radius:            ScreenTools.defaultFontPixelWidth / 2
-            property real   _viewportMargins:   ScreenTools.defaultFontPixelWidth
+            property real   _margins: ScreenTools.defaultFontPixelWidth
 
-            Rectangle {
-                anchors.fill:    parent
-                radius:         _radius
-                color:          "white"
-                opacity:        0.75
+            QGCButton {
+                _horizontalPadding: 0
+                text:               qsTr("Basic Polygon")
+                visible:            !_traceMode
+                onClicked:          _resetPolygon()
             }
 
-            RowLayout {
-                id:                 editHeaderRowLayout
-                anchors.margins:    _viewportMargins
-                anchors.top:        parent.top
-                anchors.left:       parent.left
-                anchors.right:      parent.right
-
-                QGCButton {
-                    text:       qsTr("Basic Polygon")
-                    visible:    !_traceMode
-                    onClicked:  _resetPolygon()
-                }
-
-                QGCButton {
-                    text:       qsTr("Circular Polygon")
-                    visible:    !_traceMode
-                    onClicked:  _resetCircle()
-                }
+            QGCButton {
+                _horizontalPadding: 0
+                text:               qsTr("Circular Polygon")
+                visible:            !_traceMode
+                onClicked:          _resetCircle()
+            }
 
-                QGCButton {
-                    text:       _traceMode ? qsTr("Done Tracing") : qsTr("Trace Polygon")
-                    onClicked: {
-                        if (_traceMode) {
-                            if (mapPolygon.count < 3) {
-                                _restorePreviousVertices()
-                            }
-                            _traceMode = false
-                        } else {
-                            _saveCurrentVertices()
-                            _circleMode = false
-                            _traceMode = true
-                            mapPolygon.clear();
+            QGCButton {
+                _horizontalPadding: 0
+                text:               _traceMode ? qsTr("Done Tracing") : qsTr("Trace Polygon")
+                onClicked: {
+                    if (_traceMode) {
+                        if (mapPolygon.count < 3) {
+                            _restorePreviousVertices()
                         }
+                        _traceMode = false
+                    } else {
+                        _saveCurrentVertices()
+                        _circleMode = false
+                        _traceMode = true
+                        mapPolygon.clear();
                     }
                 }
+            }
 
-                QGCButton {
-                    text:       qsTr("Load KML/SHP...")
-                    onClicked:  kmlOrSHPLoadDialog.openForLoad()
-                    visible:    !_traceMode
-                }
-
-                QGCLabel {
-                    id:                     instructionLabel
-                    color:                  "black"
-                    text:                   _instructionText
-                    Layout.fillWidth:       true
-                }
+            QGCButton {
+                _horizontalPadding: 0
+                text:               qsTr("Load KML/SHP...")
+                onClicked:          kmlOrSHPLoadDialog.openForLoad()
+                visible:            !_traceMode
             }
         }
     }
@@ -589,7 +569,7 @@ Item {
         id:  traceMouseAreaComponent
 
         MouseArea {
-            anchors.fill:       map
+            anchors.fill:       mapControl
             preventStealing:    true
             z:                  QGroundControl.zOrderMapItems + 1   // Over item indicators
 
@@ -640,38 +620,6 @@ Item {
                     _lastRadius = radius
                 }
             }
-
-            /*
-            onItemCoordinateChanged: delayTimer.radius = mapPolygon.center.distanceTo(itemCoordinate)
-
-            onDragStart:    delayTimer.start()
-            onDragStop:     { delayTimer.stop(); delayTimer.update() }
-
-            // Use a delayed update to increase performance of redraw while dragging
-            Timer {
-                id:             delayTimer
-                interval:       100
-                repeat:         true
-
-                property real radius
-                property real _lastRadius
-
-                onRadiusChanged: console.log(radius)
-
-                function update() {
-                    // Prevent signalling re-entrancy
-                    if (!_circleRadiusDrag && radius != _lastRadius) {
-                        _circleRadiusDrag = true
-                        _createCircularPolygon(mapPolygon.center, radius)
-                        _circleRadiusDragCoord = itemCoordinate
-                        _circleRadiusDrag = false
-                        _lastRadius = radius
-                    }
-                }
-
-                onTriggered: update()
-            }
-        */
         }
     }
 

src/MissionManager/QGCMapPolyline.cc

@@ -27,6 +27,7 @@ QGCMapPolyline::QGCMapPolyline(QObject* parent)
     : QObject               (parent)
     , _dirty                (false)
     , _interactive          (false)
+    , _resetActive          (false)
 {
     _init();
 }
@@ -35,6 +36,7 @@ QGCMapPolyline::QGCMapPolyline(const QGCMapPolyline& other, QObject* parent)
     : QObject               (parent)
     , _dirty                (false)
     , _interactive          (false)
+    , _resetActive          (false)
 {
     *this = other;
 
@@ -118,6 +120,8 @@ QPointF QGCMapPolyline::_pointFFromCoord(const QGeoCoordinate& coordinate) const
 
 void QGCMapPolyline::setPath(const QList<QGeoCoordinate>& path)
 {
+    _beginResetIfNotActive();
+
     _polylinePath.clear();
     _polylineModel.clearAndDeleteContents();
     for (const QGeoCoordinate& coord: path) {
@@ -126,20 +130,22 @@ void QGCMapPolyline::setPath(const QList<QGeoCoordinate>& path)
     }
 
     setDirty(true);
-    emit pathChanged();
+
+    _endResetIfNotActive();
 }
 
 void QGCMapPolyline::setPath(const QVariantList& path)
 {
-    _polylinePath = path;
+    _beginResetIfNotActive();
 
+    _polylinePath = path;
     _polylineModel.clearAndDeleteContents();
     for (int i=0; i<_polylinePath.count(); i++) {
         _polylineModel.append(new QGCQGeoCoordinate(_polylinePath[i].value<QGeoCoordinate>(), this));
     }
-
     setDirty(true);
-    emit pathChanged();
+
+    _endResetIfNotActive();
 }
 
 
@@ -339,6 +345,8 @@ QList<QGeoCoordinate> QGCMapPolyline::offsetPolyline(double distance)
 
 bool QGCMapPolyline::loadKMLFile(const QString& kmlFile)
 {
+    _beginResetIfNotActive();
+
     QString errorString;
     QList<QGeoCoordinate> rgCoords;
     if (!KMLFileHelper::loadPolylineFromFile(kmlFile, rgCoords, errorString)) {
@@ -349,6 +357,8 @@ bool QGCMapPolyline::loadKMLFile(const QString& kmlFile)
     clear();
     appendVertices(rgCoords);
 
+    _endResetIfNotActive();
+
     return true;
 }
 
@@ -380,12 +390,41 @@ double QGCMapPolyline::length(void) const
 
 void QGCMapPolyline::appendVertices(const QList<QGeoCoordinate>& coordinates)
 {
-    QList<QObject*> objects;
+    _beginResetIfNotActive();
 
+    QList<QObject*> objects;
     for (const QGeoCoordinate& coordinate: coordinates) {
         objects.append(new QGCQGeoCoordinate(coordinate, this));
         _polylinePath.append(QVariant::fromValue(coordinate));
     }
     _polylineModel.append(objects);
+
+    _endResetIfNotActive();
+}
+
+void QGCMapPolyline::beginReset(void)
+{
+    _resetActive = true;
+    _polylineModel.beginReset();
+}
+
+void QGCMapPolyline::endReset(void)
+{
+    _resetActive = false;
+    _polylineModel.endReset();
     emit pathChanged();
 }
+
+void QGCMapPolyline::_beginResetIfNotActive(void)
+{
+    if (!_resetActive) {
+        beginReset();
+    }
+}
+
+void QGCMapPolyline::_endResetIfNotActive(void)
+{
+    if (!_resetActive) {
+        endReset();
+    }
+}

src/MissionManager/QGCMapPolyline.h

@@ -30,6 +30,8 @@ public:
     Q_PROPERTY(QmlObjectListModel*  pathModel   READ qmlPathModel                           CONSTANT)
     Q_PROPERTY(bool                 dirty       READ dirty          WRITE setDirty          NOTIFY dirtyChanged)
     Q_PROPERTY(bool                 interactive READ interactive    WRITE setInteractive    NOTIFY interactiveChanged)
+    Q_PROPERTY(bool                 isValid     READ isValid                                NOTIFY countChanged)
+    Q_PROPERTY(bool                 empty       READ empty                                  NOTIFY countChanged)
 
     Q_INVOKABLE void clear(void);
     Q_INVOKABLE void appendVertex(const QGeoCoordinate& coordinate);
@@ -52,11 +54,14 @@ public:
     /// @return true: success
     Q_INVOKABLE bool loadKMLFile(const QString& kmlFile);
 
+    Q_INVOKABLE void beginReset (void);
+    Q_INVOKABLE void endReset   (void);
+
     /// Returns the path in a list of QGeoCoordinate's format
     QList<QGeoCoordinate> coordinateList(void) const;
 
     /// Returns the QGeoCoordinate for the vertex specified
-    QGeoCoordinate vertexCoordinate(int vertex) const;
+    Q_INVOKABLE QGeoCoordinate vertexCoordinate(int vertex) const;
 
     /// Saves the polyline to the json object.
     ///     @param json Json object to save to
@@ -76,12 +81,13 @@ public:
     double length(void) const;
 
     // Property methods
-
     int             count       (void) const { return _polylinePath.count(); }
     bool            dirty       (void) const { return _dirty; }
     void            setDirty    (bool dirty);
     bool            interactive (void) const { return _interactive; }
     QVariantList    path        (void) const { return _polylinePath; }
+    bool            isValid     (void) const { return _polylineModel.count() >= 2; }
+    bool            empty       (void) const { return _polylineModel.count() == 0; }
 
     QmlObjectListModel* qmlPathModel(void) { return &_polylineModel; }
     QmlObjectListModel& pathModel   (void) { return _polylineModel; }
@@ -104,12 +110,15 @@ private slots:
     void _polylineModelDirtyChanged(bool dirty);
 
 private:
-    void _init(void);
-    QGeoCoordinate _coordFromPointF(const QPointF& point) const;
-    QPointF _pointFFromCoord(const QGeoCoordinate& coordinate) const;
+    void            _init                   (void);
+    QGeoCoordinate  _coordFromPointF        (const QPointF& point) const;
+    QPointF         _pointFFromCoord        (const QGeoCoordinate& coordinate) const;
+    void            _beginResetIfNotActive  (void);
+    void            _endResetIfNotActive    (void);
 
     QVariantList        _polylinePath;
     QmlObjectListModel  _polylineModel;
     bool                _dirty;
     bool                _interactive;
+    bool                _resetActive;
 };

src/MissionManager/QGCMapPolylineVisuals.qml

@@ -30,85 +30,92 @@ Item {
     property int    lineWidth:      3
     property color  lineColor:      "#be781c"
 
-
-    property var    _polylineComponent
     property var    _dragHandlesComponent
     property var    _splitHandlesComponent
-
-    property real _zorderDragHandle:    QGroundControl.zOrderMapItems + 3   // Highest to prevent splitting when items overlap
-    property real _zorderSplitHandle:   QGroundControl.zOrderMapItems + 2
-
-    function addVisuals() {
-        _polylineComponent = polylineComponent.createObject(mapControl)
-        mapControl.addMapItem(_polylineComponent)
-    }
-
-    function removeVisuals() {
-        _polylineComponent.destroy()
-    }
-
-    function addHandles() {
-        if (!_dragHandlesComponent) {
-            _dragHandlesComponent = dragHandlesComponent.createObject(mapControl)
-            _splitHandlesComponent = splitHandlesComponent.createObject(mapControl)
+    property bool   _traceMode:             false
+    property string _instructionText:       _corridorToolsText
+    property real   _zorderDragHandle:      QGroundControl.zOrderMapItems + 3   // Highest to prevent splitting when items overlap
+    property real   _zorderSplitHandle:     QGroundControl.zOrderMapItems + 2
+    property var    _savedVertices:         [ ]
+
+    readonly property string _corridorToolsText:    qsTr("Corridor Tools")
+    readonly property string _traceText:            qsTr("Click in the map to add vertices. Click 'Done Tracing' when finished.")
+
+    function _addCommonVisuals() {
+        if (_objMgrCommonVisuals.empty) {
+            _objMgrCommonVisuals.createObject(polylineComponent, mapControl, true)
         }
     }
 
-    function removeHandles() {
-        if (_dragHandlesComponent) {
-            _dragHandlesComponent.destroy()
-            _dragHandlesComponent = undefined
-        }
-        if (_splitHandlesComponent) {
-            _splitHandlesComponent.destroy()
-            _splitHandlesComponent = undefined
+    function _addInteractiveVisuals() {
+        if (_objMgrInteractiveVisuals.empty) {
+            _objMgrInteractiveVisuals.createObjects([ dragHandlesComponent, splitHandlesComponent, toolbarComponent ], mapControl)
         }
     }
 
     /// Calculate the default/initial polyline
-    function defaultPolylineVertices() {
-        var x = map.centerViewport.x + (map.centerViewport.width / 2)
-        var yInset = map.centerViewport.height / 4
-        var topPointCoord =     map.toCoordinate(Qt.point(x, map.centerViewport.y + yInset),                                false /* clipToViewPort */)
-        var bottomPointCoord =  map.toCoordinate(Qt.point(x, map.centerViewport.y + map.centerViewport.height - yInset),    false /* clipToViewPort */)
+    function _defaultPolylineVertices() {
+        var x = mapControl.centerViewport.x + (mapControl.centerViewport.width / 2)
+        var yInset = mapControl.centerViewport.height / 4
+        var topPointCoord =     mapControl.toCoordinate(Qt.point(x, mapControl.centerViewport.y + yInset),                                false /* clipToViewPort */)
+        var bottomPointCoord =  mapControl.toCoordinate(Qt.point(x, mapControl.centerViewport.y + mapControl.centerViewport.height - yInset),    false /* clipToViewPort */)
         return [ topPointCoord, bottomPointCoord ]
     }
 
-    /// Add an initial 2 point polyline
-    function addInitialPolyline() {
-        if (mapPolyline.count < 2) {
-            mapPolyline.clear()
-            var initialVertices = defaultPolylineVertices()
-            mapPolyline.appendVertex(initialVertices[0])
-            mapPolyline.appendVertex(initialVertices[1])
+    /// Reset polyline back to initial default
+    function _resetPolyline() {
+        mapPolyline.beginReset()
+        mapPolyline.clear()
+        var initialVertices = _defaultPolylineVertices()
+        mapPolyline.appendVertex(initialVertices[0])
+        mapPolyline.appendVertex(initialVertices[1])
+        mapPolyline.endReset()
+    }
+
+    function _saveCurrentVertices() {
+        _savedVertices = [ ]
+        for (var i=0; i<mapPolyline.count; i++) {
+            _savedVertices.push(mapPolyline.vertexCoordinate(i))
         }
     }
 
-    /// Reset polyline back to initial default
-    function resetPolyline() {
+    function _restorePreviousVertices() {
+        mapPolyline.beginReset()
         mapPolyline.clear()
-        addInitialPolyline()
+        for (var i=0; i<_savedVertices.length; i++) {
+            mapPolyline.appendVertex(_savedVertices[i])
+        }
+        mapPolyline.endReset()
     }
 
     onInteractiveChanged: {
         if (interactive) {
-            addHandles()
+            _addInteractiveVisuals()
+        } else {
+            _objMgrInteractiveVisuals.destroyObjects()
+        }
+    }
+
+    on_TraceModeChanged: {
+        if (_traceMode) {
+            _instructionText = _traceText
+            _objMgrTraceVisuals.createObject(traceMouseAreaComponent, mapControl, false)
         } else {
-            removeHandles()
+            _instructionText = _corridorToolsText
+            _objMgrTraceVisuals.destroyObjects()
         }
     }
 
     Component.onCompleted: {
-        addVisuals()
+        _addCommonVisuals()
         if (interactive) {
-            addHandles()
+            _addInteractiveVisuals()
         }
     }
 
-    Component.onDestruction: {
-        removeVisuals()
-        removeHandles()
-    }
+    QGCDynamicObjectManager { id: _objMgrCommonVisuals }
+    QGCDynamicObjectManager { id: _objMgrInteractiveVisuals }
+    QGCDynamicObjectManager { id: _objMgrTraceVisuals }
 
     QGCPalette { id: qgcPal }
 
@@ -142,19 +149,10 @@ Item {
             onTriggered:    mapPolyline.removeVertex(menu._removeVertexIndex)
         }
 
-        QGCMenuSeparator {
-            visible:        removeVertexItem.visible
-        }
-
         QGCMenuItem {
             text:           qsTr("Edit position..." )
             onTriggered:    mainWindow.showComponentDialog(editPositionDialog, qsTr("Edit Position"), mainWindow.showDialogDefaultWidth, StandardButton.Cancel)
         }
-
-        QGCMenuItem {
-            text:           qsTr("Load KML...")
-            onTriggered:    kmlLoadDialog.openForLoad()
-        }
     }
 
     Component {
@@ -311,5 +309,66 @@ Item {
             }
         }
     }
+
+    Component {
+        id: toolbarComponent
+
+        PlanEditToolbar {
+            x:          mapControl.centerViewport.left + _margins
+            y:          mapControl.centerViewport.top + _margins
+            width:      mapControl.centerViewport.width - (_margins * 2)
+            z:          QGroundControl.zOrderMapItems + 2
+
+            property real _margins: ScreenTools.defaultFontPixelWidth
+
+            QGCButton {
+                _horizontalPadding: 0
+                text:               qsTr("Basic Corridor")
+                visible:            !_traceMode
+                onClicked:          _resetPolyline()
+            }
+
+            QGCButton {
+                _horizontalPadding: 0
+                text:               _traceMode ? qsTr("Done Tracing") : qsTr("Trace Corridor")
+                onClicked: {
+                    if (_traceMode) {
+                        if (mapPolyline.count < 2) {
+                            _restorePreviousVertices()
+                        }
+                        _traceMode = false
+                    } else {
+                        _saveCurrentVertices()
+                        _traceMode = true
+                        mapPolyline.clear();
+                    }
+                }
+            }
+
+            QGCButton {
+                _horizontalPadding: 0
+                text:               qsTr("Load KML...")
+                onClicked:          kmlLoadDialog.openForLoad()
+                visible:            !_traceMode
+            }
+        }
+    }
+
+    // Mouse area to capture clicks for tracing a polyline
+    Component {
+        id:  traceMouseAreaComponent
+
+        MouseArea {
+            anchors.fill:       mapControl
+            preventStealing:    true
+            z:                  QGroundControl.zOrderMapItems + 1   // Over item indicators
+
+            onClicked: {
+                if (mouse.button === Qt.LeftButton) {
+                    mapPolyline.appendVertex(mapControl.toCoordinate(Qt.point(mouse.x, mouse.y), false /* clipToViewPort */))
+                }
+            }
+        }
+    }
 }
 

src/PlanView/CorridorScanMapVisual.qml

@@ -21,8 +21,6 @@ TransectStyleMapVisuals {
 
     property bool _currentItem: object.isCurrentItem
 
-    Component.onCompleted: mapPolylineVisuals.addInitialPolyline()
-
     QGCMapPolylineVisuals {
         id:             mapPolylineVisuals
         mapControl:     map

src/PlanView/PlanEditToolbar.qml

+/****************************************************************************
+ *
+ *   (c) 2009-2016 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
+ *
+ * QGroundControl is licensed according to the terms in the file
+ * COPYING.md in the root of the source code directory.
+ *
+ ****************************************************************************/
+
+import QtQuick              2.3
+import QtQuick.Controls     2.11
+import QtQuick.Layouts      1.2
+
+import QGroundControl               1.0
+import QGroundControl.ScreenTools   1.0
+import QGroundControl.Controls      1.0
+
+/// Toolbar used for things like Polygon editing tools
+Item {
+    height: toolsFlickable.y + toolsFlickable.height + _margins
+    z:      QGroundControl.zOrderMapItems + 2
+
+    property real   _radius:            ScreenTools.defaultFontPixelWidth / 2
+    property real   _margins:   ScreenTools.defaultFontPixelWidth / 2
+
+    Component.onCompleted: {
+        // Move the child controls from consumer into the layout control
+        var moveList = []
+        var i
+        for (i = 2; i < children.length; i++) {
+            moveList.push(children[i])
+        }
+        for (i = 0; i < moveList.length; i++) {
+            moveList[i].parent = toolsRowLayout
+        }
+        instructionComponent.createObject(toolsRowLayout)
+    }
+
+    Rectangle {
+        anchors.fill:    parent
+        radius:         _radius
+        color:          "white"
+        opacity:        0.75
+    }
+
+    QGCFlickable {
+        id:                 toolsFlickable
+        anchors.margins:    _margins
+        anchors.top:        parent.top
+        anchors.left:       parent.left
+        anchors.right:      parent.right
+        height:             toolsRowLayout.height
+        clip:               true
+        flickableDirection: Flickable.HorizontalFlick
+        contentWidth:       toolsRowLayout.width
+
+        RowLayout {
+            id:                 toolsRowLayout
+            spacing:            _margins
+        }
+    }
+
+    Component {
+        id: instructionComponent
+
+        QGCLabel {
+            id:                     instructionLabel
+            color:                  "black"
+            text:                   _instructionText
+            Layout.fillWidth:       true
+        }
+    }
+}

src/QmlControls/QGroundControl/Controls/qmldir

@@ -39,6 +39,7 @@ PageView                1.0 PageView.qml
 ParameterEditor         1.0 ParameterEditor.qml
 ParameterEditorDialog   1.0 ParameterEditorDialog.qml
 PIDTuning               1.0 PIDTuning.qml
+PlanEditToolbar         1.0 PlanEditToolbar.qml
 PreFlightCheckButton    1.0 PreFlightCheckButton.qml
 PreFlightCheckGroup     1.0 PreFlightCheckGroup.qml
 PreFlightCheckModel     1.0 PreFlightCheckModel.qml