Support user configurable unit conversion

src/FactSystem/FactMetaData.cc

@@ -534,3 +534,47 @@ void FactMetaData::setAppSettingsTranslators(void)
         }
     }
 }
+
+const FactMetaData::AppSettingsTranslation_s* FactMetaData::_findAppSettingsDistanceUnitsTranslation(const QString& rawUnits)
+{
+    for (size_t i=0; i<sizeof(_rgAppSettingsTranslations)/sizeof(_rgAppSettingsTranslations[0]); i++) {
+        const AppSettingsTranslation_s* pAppSettingsTranslation = &_rgAppSettingsTranslations[i];
+
+        if (pAppSettingsTranslation->rawUnits == rawUnits &&
+                 (!pAppSettingsTranslation->speed && pAppSettingsTranslation->speedOrDistanceUnits == QGroundControlQmlGlobal::distanceUnits()->rawValue().toUInt())) {
+            return pAppSettingsTranslation;
+        }
+    }
+
+    return NULL;
+}
+
+QVariant FactMetaData::metersToAppSettingsDistanceUnits(const QVariant& meters)
+{
+    const AppSettingsTranslation_s* pAppSettingsTranslation = _findAppSettingsDistanceUnitsTranslation("m");
+    if (pAppSettingsTranslation) {
+        return pAppSettingsTranslation->rawTranslator(meters);
+    } else {
+        return meters;
+    }
+}
+
+QVariant FactMetaData::appSettingsDistanceUnitsToMeters(const QVariant& distance)
+{
+    const AppSettingsTranslation_s* pAppSettingsTranslation = _findAppSettingsDistanceUnitsTranslation("m");
+    if (pAppSettingsTranslation) {
+        return pAppSettingsTranslation->cookedTranslator(distance);
+    } else {
+        return distance;
+    }
+}
+
+QString FactMetaData::appSettingsDistanceUnitsString(void)
+{
+    const AppSettingsTranslation_s* pAppSettingsTranslation = _findAppSettingsDistanceUnitsTranslation("m");
+    if (pAppSettingsTranslation) {
+        return pAppSettingsTranslation->cookedUnits;
+    } else {
+        return QStringLiteral("m");
+    }
+}

src/FactSystem/FactMetaData.h

@@ -61,6 +61,15 @@ public:
 
     const FactMetaData& operator=(const FactMetaData& other);
 
+    /// Converts from meters to the user specified distance unit
+    static QVariant metersToAppSettingsDistanceUnits(const QVariant& meters);
+
+    /// Converts from user specified distance unit to meters
+    static QVariant appSettingsDistanceUnitsToMeters(const QVariant& distance);
+
+    /// Returns the string for distance units which has configued by user
+    static QString appSettingsDistanceUnitsString(void);
+
     int             decimalPlaces           (void) const { return _decimalPlaces; }
     QVariant        rawDefaultValue         (void) const;
     QVariant        cookedDefaultValue      (void) const { return _rawTranslator(rawDefaultValue()); }
@@ -154,6 +163,18 @@ private:
     static QVariant _metersPerSecondToKnots(const QVariant& metersPerSecond);
     static QVariant _knotsToMetersPerSecond(const QVariant& knots);
 
+    struct AppSettingsTranslation_s {
+        const char* rawUnits;
+        const char* cookedUnits;
+        bool        speed;
+        uint32_t    speedOrDistanceUnits;
+        Translator  rawTranslator;
+        Translator  cookedTranslator;
+
+    };
+
+    static const AppSettingsTranslation_s* _findAppSettingsDistanceUnitsTranslation(const QString& rawUnits);
+
     ValueType_t     _type;                  // must be first for correct constructor init
     int             _decimalPlaces;
     QVariant        _rawDefaultValue;
@@ -186,15 +207,6 @@ private:
     };
     static const BuiltInTranslation_s _rgBuiltInTranslations[];
 
-    struct AppSettingsTranslation_s {
-        const char* rawUnits;
-        const char* cookedUnits;
-        bool        speed;
-        uint32_t    speedOrDistanceUnits;
-        Translator  rawTranslator;
-        Translator  cookedTranslator;
-
-    };
     static const AppSettingsTranslation_s _rgAppSettingsTranslations[];
 };
 

src/FlightDisplay/FlightDisplayViewWidgets.qml

@@ -341,7 +341,7 @@ Item {
                 break;
             case confirmTakeoff:
                 altitudeSlider.visible = true
-                altitudeSlider.initialValue = 10
+                altitudeSlider.setInitialValueMeters(10)
                 _guidedModeBar.confirmText = "takeoff"
                 break;
             case confirmLand:
@@ -349,7 +349,7 @@ Item {
                 break;
             case confirmChangeAlt:
                 altitudeSlider.visible = true
-                altitudeSlider.initialValue = _activeVehicle.altitudeAMSL.value
+                altitudeSlider.setInitialValueAppSettingsDistanceUnits(_activeVehicle.altitudeAMSL.value)
                 _guidedModeBar.confirmText = "altitude change"
                 break;
             case confirmGoTo:
@@ -444,14 +444,24 @@ Item {
         opacity:            0.8
         visible:            false
 
-        property alias initialValue:    altSlider.value
+        function setInitialValueMeters(meters) {
+            altSlider.value = QGroundControl.metersToAppSettingsDistanceUnits(meters)
+        }
+
+        function setInitialValueAppSettingsDistanceUnits(height) {
+            altSlider.value = height
+        }
 
         /// Returns NaN for bad value
         function getValue() {
-            return parseFloat(altField.text)
+            var value =  parseFloat(altField.text)
+            if (!isNaN(value)) {
+                return QGroundControl.appSettingsDistanceUnitsToMeters(value);
+            } else {
+                return value;
+            }
         }
 
-
         Column {
             id:                 headerColumn
             anchors.margins:    _margins
@@ -461,12 +471,12 @@ Item {
 
             QGCLabel {
                 anchors.horizontalCenter: parent.horizontalCenter
-                text: "Altitude"
+                text: "Alt (rel)"
             }
 
             QGCLabel {
                 anchors.horizontalCenter: parent.horizontalCenter
-                text: "meters (rel)"
+                text: QGroundControl.appSettingsDistanceUnitsString
             }
 
             QGCTextField {
@@ -486,9 +496,7 @@ Item {
             anchors.right:      parent.right
             orientation:        Qt.Vertical
             minimumValue:       0
-            maximumValue:       100
-            value:              30
-            //anchors.horizontalCenter: parent.horizontalCenter
+            maximumValue:       QGroundControl.metersToAppSettingsDistanceUnits(100)
         }
     }
 }

src/MissionEditor/MissionItemStatus.qml

@@ -27,6 +27,7 @@ import QtQuick.Controls 1.3
 import QGroundControl.ScreenTools   1.0
 import QGroundControl.Controls      1.0
 import QGroundControl.Palette       1.0
+import QGroundControl               1.0
 
 Rectangle {
     property var    currentMissionItem          ///< Mission item to display status for
@@ -50,8 +51,8 @@ Rectangle {
     property real   _gradientPercent:   isNaN(_gradient) ? 0 : _gradient * 100
     property real   _azimuth:           _statusValid ? _currentMissionItem.azimuth : -1
     property bool   _statusValid:       currentMissionItem != undefined
-    property string _distanceText:      _statusValid ? _distance.toFixed(2) + " m" : ""
-    property string _altText:           _statusValid ? _altDifference.toFixed(2) + " m" : ""
+    property string _distanceText:      _statusValid ? QGroundControl.metersToAppSettingsDistanceUnits(_distance).toFixed(2) + " " + QGroundControl.appSettingsDistanceUnitsString : ""
+    property string _altText:           _statusValid ? QGroundControl.metersToAppSettingsDistanceUnits(_altDifference).toFixed(2) + " " + QGroundControl.appSettingsDistanceUnitsString : ""
     property string _gradientText:      _statusValid ? _gradientPercent.toFixed(0) + "%" : ""
     property string _azimuthText:       _statusValid ? Math.round(_azimuth) : ""
 

src/QmlControls/QGroundControlQmlGlobal.h

@@ -34,6 +34,7 @@
 #include "FlightMapSettings.h"
 #include "MissionCommands.h"
 #include "SettingsFact.h"
+#include "FactMetaData.h"
 
 #ifdef QT_DEBUG
 #include "MockLink.h"
@@ -104,6 +105,9 @@ public:
     /// @ return: true: experimental survey ip code is turned on
     Q_PROPERTY(bool experimentalSurvey READ experimentalSurvey WRITE setExperimentalSurvey NOTIFY experimentalSurveyChanged)
 
+    /// Returns the string for distance units which has configued by user
+    Q_PROPERTY(QString appSettingsDistanceUnitsString READ appSettingsDistanceUnitsString CONSTANT)
+
     Q_INVOKABLE void    saveGlobalSetting       (const QString& key, const QString& value);
     Q_INVOKABLE QString loadGlobalSetting       (const QString& key, const QString& defaultValue);
     Q_INVOKABLE void    saveBoolGlobalSetting   (const QString& key, bool value);
@@ -118,6 +122,14 @@ public:
     Q_INVOKABLE void    startAPMArduPlaneMockLink   (bool sendStatusText);
     Q_INVOKABLE void    stopAllMockLinks            (void);
 
+    /// Converts from meters to the user specified distance unit
+    Q_INVOKABLE QVariant metersToAppSettingsDistanceUnits(const QVariant& meters) const { return FactMetaData::metersToAppSettingsDistanceUnits(meters); }
+
+    /// Converts from user specified distance unit to meters
+    Q_INVOKABLE QVariant appSettingsDistanceUnitsToMeters(const QVariant& distance) const { return FactMetaData::appSettingsDistanceUnitsToMeters(distance); }
+
+    QString appSettingsDistanceUnitsString(void) const { return FactMetaData::appSettingsDistanceUnitsString(); }
+
     // Property accesors
 
     FlightMapSettings*      flightMapSettings   ()      { return _flightMapSettings; }