From 2e29b3413f180a3f6d36067573f8bb136f20c82d Mon Sep 17 00:00:00 2001
From: Bernd Hahnebach <bernd@bimstatik.org>
Date: Tue, 3 Mar 2020 21:04:41 +0100
Subject: [PATCH] FEM: use python base constraint class, material obj

---
 .../femguiobjects/_ViewProviderFemMaterial.py | 60 +++----------------
 src/Mod/Fem/femobjects/_FemMaterial.py        | 13 ++--
 2 files changed, 16 insertions(+), 57 deletions(-)

diff --git a/src/Mod/Fem/femguiobjects/_ViewProviderFemMaterial.py b/src/Mod/Fem/femguiobjects/_ViewProviderFemMaterial.py
index 8ee7910c9c..ea27cd51e6 100644
--- a/src/Mod/Fem/femguiobjects/_ViewProviderFemMaterial.py
+++ b/src/Mod/Fem/femguiobjects/_ViewProviderFemMaterial.py
@@ -30,7 +30,7 @@ __url__ = "http://www.freecadweb.org"
 
 import FreeCAD
 import FreeCADGui
-import FemGui  # needed to display the icons in TreeView
+from . import ViewProviderFemConstraint
 
 # for the panel
 from FreeCAD import Units
@@ -39,66 +39,24 @@ from PySide import QtCore
 from PySide import QtGui
 import sys
 
-False if FemGui.__name__ else True  # flake8, dummy FemGui usage
 
 if sys.version_info.major >= 3:
     unicode = str
 
 
-class _ViewProviderFemMaterial:
+class _ViewProviderFemMaterial(ViewProviderFemConstraint.ViewProxy):
     "A View Provider for the FemMaterial object"
 
-    def __init__(self, vobj):
-        vobj.Proxy = self
-
     def getIcon(self):
         return ":/icons/fem-material.svg"
 
-    def attach(self, vobj):
-        self.ViewObject = vobj
-        self.Object = vobj.Object
-
-    def updateData(self, obj, prop):
-        return
-
-    def onChanged(self, vobj, prop):
-        return
-
-    def setEdit(self, vobj, mode):
-        # hide all meshes
-        for o in FreeCAD.ActiveDocument.Objects:
-            if o.isDerivedFrom("Fem::FemMeshObject"):
-                o.ViewObject.hide()
-        # show task panel
-        taskd = _TaskPanelFemMaterial(self.Object)
-        taskd.obj = vobj.Object
-        FreeCADGui.Control.showDialog(taskd)
-        return True
-
-    def unsetEdit(self, vobj, mode):
-        FreeCADGui.Control.closeDialog()
-        return True
-
-    # overwrite the doubleClicked of material object python to make sure no other Material taskd
-    # (and thus no selection observer) is still active
-    def doubleClicked(self, vobj):
-        guidoc = FreeCADGui.getDocument(vobj.Object.Document)
-        # check if another VP is in edit mode
-        # https://forum.freecadweb.org/viewtopic.php?t=13077#p104702
-        if not guidoc.getInEdit():
-            guidoc.setEdit(vobj.Object.Name)
-        else:
-            from PySide.QtGui import QMessageBox
-            message = "Active Task Dialog found! Please close this one before opening  a new one!"
-            QMessageBox.critical(None, "Error in tree view", message)
-            FreeCAD.Console.PrintError(message + "\n")
-        return True
-
-    def __getstate__(self):
-        return None
-
-    def __setstate__(self, state):
-        return None
+    def setEdit(self, vobj, mode=0):
+        ViewProviderFemConstraint.ViewProxy.setEdit(
+            self,
+            vobj,
+            mode,
+            _TaskPanelFemMaterial
+        )
 
 
 class _TaskPanelFemMaterial:
diff --git a/src/Mod/Fem/femobjects/_FemMaterial.py b/src/Mod/Fem/femobjects/_FemMaterial.py
index eb661163f0..16fe442e08 100644
--- a/src/Mod/Fem/femobjects/_FemMaterial.py
+++ b/src/Mod/Fem/femobjects/_FemMaterial.py
@@ -27,10 +27,16 @@ __url__ = "http://www.freecadweb.org"
 #  \ingroup FEM
 #  \brief FEM material
 
+from . import FemConstraint
 
-class _FemMaterial:
+
+class _FemMaterial(FemConstraint.Proxy):
     "The FEM Material object"
+
+    Type = "Fem::Material"
+
     def __init__(self, obj):
+        super(_FemMaterial, self).__init__(obj)
         obj.addProperty(
             "App::PropertyLinkSubList",
             "References",
@@ -44,8 +50,3 @@ class _FemMaterial:
             "Material type: fluid or solid"
         )
         obj.Category = ["Solid", "Fluid"]  # used in TaskPanel
-        obj.Proxy = self
-        self.Type = "Fem::Material"
-
-    def execute(self, obj):
-        return