Validate decimal places against increment value

src/FactSystem/FactMetaData.cc

@@ -56,7 +56,7 @@ const FactMetaData::AppSettingsTranslation_s FactMetaData::_rgAppSettingsTransla
 FactMetaData::FactMetaData(QObject* parent)
     : QObject(parent)
     , _type(valueTypeInt32)
-    , _decimalPlaces(defaultDecimalPlaces)
+    , _decimalPlaces(unknownDecimalPlaces)
     , _rawDefaultValue(0)
     , _defaultValueAvailable(false)
     , _group("*Default Group")
@@ -75,7 +75,7 @@ FactMetaData::FactMetaData(QObject* parent)
 FactMetaData::FactMetaData(ValueType_t type, QObject* parent)
     : QObject(parent)
     , _type(type)
-    , _decimalPlaces(defaultDecimalPlaces)
+    , _decimalPlaces(unknownDecimalPlaces)
     , _rawDefaultValue(0)
     , _defaultValueAvailable(false)
     , _group("*Default Group")
@@ -578,3 +578,33 @@ QString FactMetaData::appSettingsDistanceUnitsString(void)
         return QStringLiteral("m");
     }
 }
+
+int FactMetaData::decimalPlaces(void) const
+{
+    int actualDecimalPlaces = defaultDecimalPlaces;
+    int incrementDecimalPlaces = unknownDecimalPlaces;
+
+    // First determine decimal places from increment
+    double increment = this->increment();
+    if (!qIsNaN(increment)) {
+        double integralPart;
+
+        // Get the fractional part only
+        increment = fabs(modf(increment, &integralPart));
+        if (increment == 0.0) {
+            // No fractional part, so no decimal places
+            incrementDecimalPlaces = 0;
+        } else {
+            incrementDecimalPlaces = -ceil(log10(increment));
+        }
+    }
+
+    // Correct decimal places is the larger of the two, increment or meta data value
+    if (incrementDecimalPlaces != unknownDecimalPlaces && _decimalPlaces == unknownDecimalPlaces) {
+        actualDecimalPlaces = incrementDecimalPlaces;
+    } else {
+        actualDecimalPlaces = qMax(_decimalPlaces, incrementDecimalPlaces);
+    }
+
+    return actualDecimalPlaces;
+}

src/FactSystem/FactMetaData.h

@@ -70,7 +70,7 @@ public:
     /// Returns the string for distance units which has configued by user
     static QString appSettingsDistanceUnitsString(void);
 
-    int             decimalPlaces           (void) const { return _decimalPlaces; }
+    int             decimalPlaces           (void) const;
     QVariant        rawDefaultValue         (void) const;
     QVariant        cookedDefaultValue      (void) const { return _rawTranslator(rawDefaultValue()); }
     bool            defaultValueAvailable   (void) const { return _defaultValueAvailable; }
@@ -139,7 +139,8 @@ public:
     /// Same as convertAndValidateRaw except for cookedValue input
     bool convertAndValidateCooked(const QVariant& cookedValue, bool convertOnly, QVariant& typedValue, QString& errorString);
 
-    static const int defaultDecimalPlaces = 3;
+    static const int defaultDecimalPlaces = 3;  ///< Default value for decimal places if not specified/known
+    static const int unknownDecimalPlaces = -1; ///< Number of decimal places to specify is not known
 
     static ValueType_t stringToType(const QString& typeString, bool& unknownType);
     static size_t typeToSize(ValueType_t type);

src/MissionManager/MissionCommandList.cc

@@ -187,7 +187,7 @@ void MissionCommandList::_loadMavCmdInfoJson(const QString& jsonFilename)
 
                 paramInfo->_label =         paramObject.value(_labelJsonKey).toString();
                 paramInfo->_defaultValue =  paramObject.value(_defaultJsonKey).toDouble(0.0);
-                paramInfo->_decimalPlaces = paramObject.value(_decimalPlacesJsonKey).toInt(FactMetaData::defaultDecimalPlaces);
+                paramInfo->_decimalPlaces = paramObject.value(_decimalPlacesJsonKey).toInt(FactMetaData::unknownDecimalPlaces);
                 paramInfo->_enumStrings =   paramObject.value(_enumStringsJsonKey).toString().split(",", QString::SkipEmptyParts);
                 paramInfo->_param =         i;
                 paramInfo->_units =         paramObject.value(_unitsJsonKey).toString();

src/MissionManager/SimpleMissionItem.cc

@@ -322,16 +322,16 @@ QString SimpleMissionItem::abbreviation() const
 void SimpleMissionItem::_clearParamMetaData(void)
 {
     _param1MetaData.setRawUnits("");
-    _param1MetaData.setDecimalPlaces(FactMetaData::defaultDecimalPlaces);
+    _param1MetaData.setDecimalPlaces(FactMetaData::unknownDecimalPlaces);
     _param1MetaData.setBuiltInTranslator();
     _param2MetaData.setRawUnits("");
-    _param2MetaData.setDecimalPlaces(FactMetaData::defaultDecimalPlaces);
+    _param2MetaData.setDecimalPlaces(FactMetaData::unknownDecimalPlaces);
     _param2MetaData.setBuiltInTranslator();
     _param3MetaData.setRawUnits("");
-    _param3MetaData.setDecimalPlaces(FactMetaData::defaultDecimalPlaces);
+    _param3MetaData.setDecimalPlaces(FactMetaData::unknownDecimalPlaces);
     _param3MetaData.setBuiltInTranslator();
     _param4MetaData.setRawUnits("");
-    _param4MetaData.setDecimalPlaces(FactMetaData::defaultDecimalPlaces);
+    _param4MetaData.setDecimalPlaces(FactMetaData::unknownDecimalPlaces);
     _param4MetaData.setBuiltInTranslator();
 }