Make option to show/hide vehicle related functions

Create new, specific button for clearing mission from vehicle
Adjust sizing of DropPanel

src/PlanView/PlanView.qml

@@ -877,32 +877,6 @@ QGCView {
                 rowSpacing:         _margin
                 columnSpacing:      ScreenTools.defaultFontPixelWidth
 
-                QGCButton {
-                    text:               qsTr("Upload")
-                    Layout.fillWidth:   true
-                    enabled:            !masterController.offline && !masterController.syncInProgress
-                    visible:            _activeVehicle
-                    onClicked: {
-                        dropPanel.hide()
-                        masterController.upload()
-                    }
-                }
-
-                QGCButton {
-                    text:               qsTr("Download")
-                    Layout.fillWidth:   true
-                    enabled:            !masterController.offline && !masterController.syncInProgress
-                    visible:            _activeVehicle
-                    onClicked: {
-                        dropPanel.hide()
-                        if (masterController.dirty) {
-                            _qgcView.showDialog(syncLoadFromVehicleOverwrite, columnHolder._overwriteText, _qgcView.showDialogDefaultWidth, StandardButton.Yes | StandardButton.Cancel)
-                        } else {
-                            masterController.loadFromVehicle()
-                        }
-                    }
-                }
-
                 QGCButton {
                     text:               qsTr("New...")
                     Layout.fillWidth:   true
@@ -977,6 +951,54 @@ QGCView {
                     }
                 }
 
+                Rectangle {
+                    width:              parent.width * 0.8
+                    height:             1
+                    color:              qgcPal.text
+                    opacity:            0.5
+                    visible:            !QGroundControl.corePlugin.options.disableVehicleConnection
+                    Layout.fillWidth:   true
+                    Layout.columnSpan:  2
+                }
+
+                QGCButton {
+                    text:               qsTr("Upload")
+                    Layout.fillWidth:   true
+                    enabled:            !masterController.offline && !masterController.syncInProgress && _visualItems.count > 1
+                    visible:            !QGroundControl.corePlugin.options.disableVehicleConnection
+                    onClicked: {
+                        dropPanel.hide()
+                        masterController.upload()
+                    }
+                }
+
+                QGCButton {
+                    text:               qsTr("Download")
+                    Layout.fillWidth:   true
+                    enabled:            !masterController.offline && !masterController.syncInProgress
+                    visible:            !QGroundControl.corePlugin.options.disableVehicleConnection
+                    onClicked: {
+                        dropPanel.hide()
+                        if (masterController.dirty) {
+                            _qgcView.showDialog(syncLoadFromVehicleOverwrite, columnHolder._overwriteText, _qgcView.showDialogDefaultWidth, StandardButton.Yes | StandardButton.Cancel)
+                        } else {
+                            masterController.loadFromVehicle()
+                        }
+                    }
+                }
+
+                QGCButton {
+                    text:               qsTr("Clear Vehicle Mission")
+                    Layout.fillWidth:   true
+                    Layout.columnSpan:  2
+                    enabled:            !masterController.offline && !masterController.syncInProgress
+                    visible:            !QGroundControl.corePlugin.options.disableVehicleConnection
+                    onClicked: {
+                        dropPanel.hide()
+                        masterController.removeAllFromVehicle()
+                    }
+                }
+
             }
         }
     }

src/QmlControls/DropPanel.qml

@@ -71,11 +71,11 @@ Item {
     }
 
     function _calcPositions() {
-        var panelComponentWidth = panelLoader.item.width
+        var panelComponentWidth  = panelLoader.item.width
         var panelComponentHeight = panelLoader.item.height
 
-        dropDownItem.width = panelComponentWidth + _dropMarginX2 + _arrowPointWidth
-        dropDownItem.height = panelComponentHeight + _dropMarginX2
+        dropDownItem.width  = panelComponentWidth  + (_dropMarginX2 * 2) + _arrowPointWidth
+        dropDownItem.height = panelComponentHeight + (_dropMarginX2 * 2)
 
         dropDownItem.x = _dropEdgeTopPoint.x + _dropMargin
         dropDownItem.y = _dropEdgeTopPoint.y -(dropDownItem.height / 2) + radius

src/api/QGCOptions.h

@@ -49,6 +49,7 @@ public:
     Q_PROPERTY(bool                     guidedActionsRequireRCRSSI      READ guidedActionsRequireRCRSSI     CONSTANT)
     Q_PROPERTY(bool                     showMissionAbsoluteAltitude     READ showMissionAbsoluteAltitude    NOTIFY showMissionAbsoluteAltitudeChanged)
     Q_PROPERTY(bool                     showSimpleMissionStart          READ showSimpleMissionStart         NOTIFY showSimpleMissionStartChanged)
+    Q_PROPERTY(bool                     disableVehicleConnection        READ disableVehicleConnection       CONSTANT)
 
     /// Should QGC hide its settings menu and colapse it into one single menu (Settings and Vehicle Setup)?
     /// @return true if QGC should consolidate both menus into one.
@@ -90,6 +91,7 @@ public:
     virtual bool    showOfflineMapImport            () const { return true; }
     virtual bool    showMissionAbsoluteAltitude     () const { return true; }
     virtual bool    showSimpleMissionStart          () const { return false; }
+    virtual bool    disableVehicleConnection        () const { return false; }  ///< true: vehicle connection is disabled
 
 #if defined(__mobile__)
     virtual bool    useMobileFileDialog             () const { return true;}