Material: editor, get rid of duplicate unit definition

- in mat editor xml file and in FreeCAD unit system
- remove it from material editor xml file and get it from FreeCAD unit system

Author: berndhahnebach

src/Mod/Material/MatPropDict.xml

@@ -23,44 +23,44 @@
     </Group>
 
     <Group Name="Mechanical">
-        <Property Name="Density" Type="Quantity" Units="(-3, 1, 0, 0, 0, 0, 0, 0)">
+        <Property Name="Density" Type="Quantity">
             <Reference>https://en.wikipedia.org/wiki/Density</Reference>
         </Property>
-        <Property Name="YoungsModulus" Type="Quantity" Units="(-1, 1, -2, 0, 0, 0, 0, 0)">
+        <Property Name="YoungsModulus" Type="Quantity">
             <Reference>https://en.wikipedia.org/wiki/Young%27s_modulus</Reference>
         </Property>
         <Property Name="PoissonRatio" Type="Float">
             <Reference>https://en.wikipedia.org/wiki/Poisson%27s_ratio</Reference>
         </Property>
-        <Property Name="UltimateTensileStrength" Type="Quantity" Units="(-1, 1, -2, 0, 0, 0, 0, 0)">
+        <Property Name="UltimateTensileStrength" Type="Quantity">
             <Reference>https://en.wikipedia.org/wiki/Ultimate_tensile_strength</Reference>
         </Property>
-        <Property Name="CompressiveStrength" Type="Quantity" Units="(-1, 1, -2, 0, 0, 0, 0, 0)">
+        <Property Name="CompressiveStrength" Type="Quantity">
             <Reference>https://en.wikipedia.org/wiki/Compressive_strength</Reference>
         </Property>
-        <Property Name="YieldStrength" Type="Quantity" Units="(-1, 1, -2, 0, 0, 0, 0, 0)">
+        <Property Name="YieldStrength" Type="Quantity">
             <Reference>https://en.wikipedia.org/wiki/Yield_Strength</Reference>
         </Property>
         <Property Name="UltimateStrain" Type="Float">
             <Reference>https://en.wikipedia.org/wiki/Deformation_(mechanics)</Reference>
         </Property>
-        <Property Name="FractureToughness" Type="Quantity" Units="(-1, 1, -2, 0, 0, 0, 0, 0)">
+        <Property Name="FractureToughness" Type="Quantity">
             <Reference>https://en.wikipedia.org/wiki/Fracture_toughness</Reference>
         </Property>
-        <Property Name="AngleOfFriction" Type="Quantity" Units="(0, 0, 0, 0, 0, 0, 0, 1)">
+        <Property Name="AngleOfFriction" Type="Quantity">
             <Reference>https://en.wikipedia.org/wiki/Friction#Angle_of_friction</Reference>
             <Reference>https://en.m.wikipedia.org/wiki/Mohr%E2%80%93Coulomb_theory</Reference>
         </Property>
     </Group>
 
     <Group Name="Thermal">
-        <Property Name="ThermalConductivity" Type="Quantity" Units="(1, 1, -3, 0, -1, 0, 0, 0)">
+        <Property Name="ThermalConductivity" Type="Quantity">
             <Reference>https://en.wikipedia.org/wiki/Thermal_conductivity</Reference>
         </Property>
-        <Property Name="ThermalExpansionCoefficient" Type="Quantity" Units="(0, 0, 0, 0, -1, 0, 0, 0)">
+        <Property Name="ThermalExpansionCoefficient" Type="Quantity">
             <Reference>https://en.wikipedia.org/wiki/Volumetric_thermal_expansion_coefficient</Reference>
         </Property>
-        <Property Name="SpecificHeat" Type="Quantity" Units="(2, 0, -2, 0, -1, 0, 0, 0)">
+        <Property Name="SpecificHeat" Type="Quantity">
             <Reference>https://en.wikipedia.org/wiki/Heat_capacity</Reference>
         </Property>
     </Group>

src/Mod/Material/MaterialEditor.py

@@ -112,13 +112,11 @@ def implementModel(self):
         widget = self.widget
         treeView = widget.treeView
         model = treeView.model()
-        model.setHorizontalHeaderLabels(["Property", "Value",
-                                         "Type", "Units"])
+        model.setHorizontalHeaderLabels(["Property", "Value", "Type"])
 
         treeView.setColumnWidth(0, 250)
         treeView.setColumnWidth(1, 250)
         treeView.setColumnHidden(2, True)
-        treeView.setColumnHidden(3, True)
 
         tree = getMaterialAttributeStructure(True)
         MatPropDict = tree.getroot()
@@ -141,13 +139,7 @@ def implementModel(self):
                 tt = properDict['Type']
                 itType = QtGui.QStandardItem(tt)
 
-                try:
-                    uu = properDict['Units']
-                    itUnit = QtGui.QStandardItem(uu)
-                except KeyError:
-                    itUnit = QtGui.QStandardItem()
-
-                top.appendRow([item, it, itType, itUnit])
+                top.appendRow([item, it, itType])
 
             top.sortChildren(0)
 
@@ -486,24 +478,22 @@ def createEditor(self, parent, option, index):
         if column == 1:
 
             row = index.row()
+
+            PP = group.child(row, 0)
+            matproperty = PP.text().replace(" ", "")  # remove spaces
+
             TT = group.child(row, 2)
 
             if TT:
                 Type = TT.text()
-                UU = group.child(row, 3)
-                if UU:
-                    Units = UU.text()
-                else:
-                    Units = None
 
             else:
                 Type = "String"
-                Units = None
 
             VV = group.child(row, 1)
             Value = VV.text()
 
-            editor = matProperWidget(parent, Type, Units, Value)
+            editor = matProperWidget(parent, matproperty, Type, Value)
 
         elif column == 0:
 
@@ -546,7 +536,7 @@ def setEditorData(self, editor, index):
 ui = FreeCADGui.UiLoader()
 
 
-def matProperWidget(parent=None, Type="String", Units=None, Value=None,
+def matProperWidget(parent=None, matproperty=None, Type="String", Value=None,
                     minimum=None, maximum=None, stepsize=None, precision=None):
 
     '''customs widgets for the material stuff.'''
@@ -569,13 +559,12 @@ def matProperWidget(parent=None, Type="String", Units=None, Value=None,
     elif Type == "Quantity":
 
         widget = ui.createWidget("Gui::InputField")
-        if Units:
-            vv = string2tuple(Units)
-            unit = FreeCAD.Units.Unit(
-                vv[0], vv[1], vv[2], vv[3], vv[4], vv[5], vv[6], vv[7]
-            )
+        if hasattr(FreeCAD.Units, matproperty):
+            unit = getattr(FreeCAD.Units, matproperty)
             quantity = FreeCAD.Units.Quantity(1, unit)
             widget.setProperty('unit', quantity.getUserPreferred()[2])
+        else:
+            FreeCAD.Console.PrintError('Not known unit for property: ' + matproperty + '\n')
 
     elif Type == "Integer":