Add the LinkIndicator to the toolbar

The LinkIndicator shows the connected links and lets the user select the priority link,

qgroundcontrol.qrc

@@ -9,10 +9,11 @@
         <file alias="GPSRTKIndicator.qml">src/ui/toolbar/GPSRTKIndicator.qml</file>
         <file alias="MessageIndicator.qml">src/ui/toolbar/MessageIndicator.qml</file>
         <file alias="ModeIndicator.qml">src/ui/toolbar/ModeIndicator.qml</file>
-		<file alias="VTOLModeIndicator.qml">src/ui/toolbar/VTOLModeIndicator.qml</file>
+        <file alias="VTOLModeIndicator.qml">src/ui/toolbar/VTOLModeIndicator.qml</file>
         <file alias="RCRSSIIndicator.qml">src/ui/toolbar/RCRSSIIndicator.qml</file>
         <file alias="TelemetryRSSIIndicator.qml">src/ui/toolbar/TelemetryRSSIIndicator.qml</file>
         <file alias="JoystickIndicator.qml">src/ui/toolbar/JoystickIndicator.qml</file>
+        <file alias="LinkIndicator.qml">src/ui/toolbar/LinkIndicator.qml</file>
     </qresource>
     <qresource prefix="/qml">
         <file alias="CorridorScanEditor.qml">src/PlanView/CorridorScanEditor.qml</file>
@@ -126,7 +127,7 @@
         <file alias="QGroundControl/Controls/SliderSwitch.qml">src/QmlControls/SliderSwitch.qml</file>
         <file alias="QGroundControl/Controls/SubMenuButton.qml">src/QmlControls/SubMenuButton.qml</file>
         <file alias="QGroundControl/Controls/SurveyMapVisual.qml">src/PlanView/SurveyMapVisual.qml</file>
-		<file alias="QGroundControl/Controls/TransectStyleComplexItemStats.qml">src/PlanView/TransectStyleComplexItemStats.qml</file>
+        <file alias="QGroundControl/Controls/TransectStyleComplexItemStats.qml">src/PlanView/TransectStyleComplexItemStats.qml</file>
         <file alias="QGroundControl/Controls/ToolStrip.qml">src/QmlControls/ToolStrip.qml</file>
         <file alias="QGroundControl/Controls/VehicleRotationCal.qml">src/QmlControls/VehicleRotationCal.qml</file>
         <file alias="QGroundControl/Controls/VehicleSummaryRow.qml">src/QmlControls/VehicleSummaryRow.qml</file>
@@ -139,7 +140,7 @@
         <file alias="QGroundControl/FactControls/FactTextField.qml">src/FactSystem/FactControls/FactTextField.qml</file>
         <file alias="QGroundControl/FactControls/FactTextFieldGrid.qml">src/FactSystem/FactControls/FactTextFieldGrid.qml</file>
         <file alias="QGroundControl/FactControls/FactTextFieldRow.qml">src/FactSystem/FactControls/FactTextFieldRow.qml</file>
-		<file alias="QGroundControl/FactControls/FactValueSlider.qml">src/FactSystem/FactControls/FactValueSlider.qml</file>
+        <file alias="QGroundControl/FactControls/FactValueSlider.qml">src/FactSystem/FactControls/FactValueSlider.qml</file>
         <file alias="QGroundControl/FactControls/qmldir">src/FactSystem/FactControls/qmldir</file>
         <file alias="QGroundControl/FlightDisplay/FlightDisplayView.qml">src/FlightDisplay/FlightDisplayView.qml</file>
         <file alias="QGroundControl/FlightDisplay/FlightDisplayViewMap.qml">src/FlightDisplay/FlightDisplayViewMap.qml</file>
@@ -225,10 +226,10 @@
         <file alias="USBBoardInfo.json">src/comm/USBBoardInfo.json</file>
         <file alias="Vehicle/BatteryFact.json">src/Vehicle/BatteryFact.json</file>
         <file alias="Vehicle/ClockFact.json">src/Vehicle/ClockFact.json</file>
-		<file alias="Vehicle/DistanceSensorFact.json">src/Vehicle/DistanceSensorFact.json</file>
+        <file alias="Vehicle/DistanceSensorFact.json">src/Vehicle/DistanceSensorFact.json</file>
         <file alias="Vehicle/GPSFact.json">src/Vehicle/GPSFact.json</file>
         <file alias="Vehicle/GPSRTKFact.json">src/Vehicle/GPSRTKFact.json</file>
-		<file alias="Vehicle/SetpointFact.json">src/Vehicle/SetpointFact.json</file>
+        <file alias="Vehicle/SetpointFact.json">src/Vehicle/SetpointFact.json</file>
         <file alias="Vehicle/SubmarineFact.json">src/Vehicle/SubmarineFact.json</file>
         <file alias="Vehicle/TemperatureFact.json">src/Vehicle/TemperatureFact.json</file>
         <file alias="Vehicle/VehicleFact.json">src/Vehicle/VehicleFact.json</file>

src/FirmwarePlugin/FirmwarePlugin.cc

@@ -344,6 +344,7 @@ const QVariantList &FirmwarePlugin::toolBarIndicators(const Vehicle* vehicle)
         _toolBarIndicatorList.append(QVariant::fromValue(QUrl::fromUserInput("qrc:/toolbar/VTOLModeIndicator.qml")));
         _toolBarIndicatorList.append(QVariant::fromValue(QUrl::fromUserInput("qrc:/toolbar/ArmedIndicator.qml")));
         _toolBarIndicatorList.append(QVariant::fromValue(QUrl::fromUserInput("qrc:/toolbar/GPSRTKIndicator.qml")));
+        _toolBarIndicatorList.append(QVariant::fromValue(QUrl::fromUserInput("qrc:/toolbar/LinkIndicator.qml")));
     }
     return _toolBarIndicatorList;
 }

src/Vehicle/Vehicle.cc

@@ -1683,6 +1683,7 @@ void Vehicle::_sendMessageOnLink(LinkInterface* link, mavlink_message_t message)
 
 void Vehicle::_updatePriorityLink(void)
 {
+    emit linkNamesChanged();
     LinkInterface* newPriorityLink = NULL;
 
     // This routine specifically does not clear _priorityLink when there are no links remaining.
@@ -1747,6 +1748,7 @@ void Vehicle::_updatePriorityLink(void)
 
     _priorityLink = _toolbox->linkManager()->sharedLinkInterfacePointerForLink(newPriorityLink);
     _updateHighLatencyLink();
+    emit priorityLinkNameChanged(_priorityLink->getName());
 }
 
 void Vehicle::_updateAttitude(UASInterface*, double roll, double pitch, double yaw, quint64)
@@ -2088,6 +2090,44 @@ void Vehicle::setFlightMode(const QString& flightMode)
     }
 }
 
+QStringList Vehicle::linkNames(void) const
+{
+    QStringList names;
+
+    for (int i=0; i<_links.count(); i++) {
+        names += _links[i]->getName();
+    }
+    return names;
+}
+
+QString Vehicle::priorityLinkName(void) const
+{
+    return _priorityLink->getName();
+}
+
+void Vehicle::setPriorityLinkByName(const QString& priorityLinkName)
+{
+    if (priorityLinkName == _priorityLink->getName()) {
+        // The link did not change
+        return;
+    }
+
+    LinkInterface* newPriorityLink = NULL;
+
+
+    for (int i=0; i<_links.count(); i++) {
+        if (_links[i]->getName() == priorityLinkName) {
+            newPriorityLink = _links[i];
+        }
+    }
+
+    if (newPriorityLink) {
+        _priorityLink = _toolbox->linkManager()->sharedLinkInterfacePointerForLink(newPriorityLink);
+        _updateHighLatencyLink();
+        emit priorityLinkNameChanged(_priorityLink->getName());
+    }
+}
+
 bool Vehicle::hilMode(void)
 {
     return _base_mode & MAV_MODE_FLAG_HIL_ENABLED;

src/Vehicle/Vehicle.h

@@ -493,6 +493,8 @@ public:
     Q_PROPERTY(bool                 vtolInFwdFlight         READ vtolInFwdFlight        WRITE setVtolInFwdFlight        NOTIFY vtolInFwdFlightChanged)
     Q_PROPERTY(bool                 highLatencyLink         READ highLatencyLink                                        NOTIFY highLatencyLinkChanged)
     Q_PROPERTY(bool                 supportsTerrainFrame    READ supportsTerrainFrame                                   NOTIFY firmwareTypeChanged)
+    Q_PROPERTY(QStringList          linkNames               READ linkNames                                              NOTIFY linkNamesChanged)
+    Q_PROPERTY(QString              priorityLinkName        READ priorityLinkName       WRITE setPriorityLinkByName     NOTIFY priorityLinkNameChanged)
 
     // Vehicle state used for guided control
     Q_PROPERTY(bool flying                  READ flying NOTIFY flyingChanged)                               ///< Vehicle is flying
@@ -692,6 +694,10 @@ public:
     QString flightMode(void) const;
     void setFlightMode(const QString& flightMode);
 
+    QStringList linkNames(void) const;
+    QString priorityLinkName(void) const;
+    void setPriorityLinkByName(const QString& priorityLinkName);
+
     bool hilMode(void);
     void setHilMode(bool hilMode);
 
@@ -943,6 +949,8 @@ signals:
     void capabilityBitsChanged(uint64_t capabilityBits);
     void toolBarIndicatorsChanged(void);
     void highLatencyLinkChanged(bool highLatencyLink);
+    void linkNamesChanged(void);
+    void priorityLinkNameChanged(const QString& priorityLinkName);
 
     void messagesReceivedChanged    ();
     void messagesSentChanged        ();

src/ui/toolbar/LinkIndicator.qml

@@ -0,0 +1,75 @@
+/****************************************************************************
+ *
+ *   (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 1.2
+
+import QGroundControl                       1.0
+import QGroundControl.Controls              1.0
+import QGroundControl.MultiVehicleManager   1.0
+import QGroundControl.ScreenTools           1.0
+import QGroundControl.Palette               1.0
+
+//-------------------------------------------------------------------------
+//-- Link Indicator
+Item {
+    anchors.top:    parent.top
+    anchors.bottom: parent.bottom
+    width:          priorityLinkSelector.width
+
+    property var _activeVehicle: QGroundControl.multiVehicleManager.activeVehicle
+
+    QGCLabel {
+        id:                     priorityLinkSelector
+        text:                   _activeVehicle ? _activeVehicle.priorityLinkName : qsTr("N/A", "No data to display")
+        font.pointSize:         ScreenTools.mediumFontPointSize
+        color:                  qgcPal.buttonText
+        anchors.verticalCenter: parent.verticalCenter
+        Menu {
+            id: linkSelectionMenu
+        }
+        Component {
+            id: linkSelectionMenuItemComponent
+            MenuItem {
+                onTriggered: _activeVehicle.priorityLinkName = text
+            }
+        }
+        property var linkSelectionMenuItems: []
+        function updatelinkSelectionMenu() {
+            if (_activeVehicle) {
+                // Remove old menu items
+                for (var i = 0; i < linkSelectionMenuItems.length; i++) {
+                    linkSelectionMenu.removeItem(linkSelectionMenuItems[i])
+                }
+                linkSelectionMenuItems.length = 0
+                // Add new items
+                for (var i = 0; i < _activeVehicle.linkNames.length; i++) {
+                    var menuItem = linkSelectionMenuItemComponent.createObject(null, { "text": _activeVehicle.linkNames[i] })
+                    linkSelectionMenuItems.push(menuItem)
+                    linkSelectionMenu.insertItem(i, menuItem)
+                }
+            }
+        }
+        Component.onCompleted: priorityLinkSelector.updatelinkSelectionMenu()
+        Connections {
+            target:                 QGroundControl.multiVehicleManager
+            onActiveVehicleChanged: priorityLinkSelector.updatelinkSelectionMenu()
+        }
+        Connections {
+            target:                 _activeVehicle
+            onLinkNamesChanged:     priorityLinkSelector.updatelinkSelectionMenu()
+        }
+        MouseArea {
+            visible:        _activeVehicle
+            anchors.fill:   parent
+            onClicked:      linkSelectionMenu.popup()
+        }
+    }
+}