[FEM] fix enable editing for all solvers

- currently for Z88 nothing happens when clicking the Edit button in the solver task dialog. The reason is that opening *.txt files was never implemented
- also do this for Elmer
- for Z88 we need to open several file for a proper editing because the solver info is distributed over these files

src/Mod/Fem/Gui/AppFemGuiPy.cpp

@@ -125,11 +125,14 @@ private:
             }
         }
 
-        if (ext == QLatin1String("inp")) {
+        if ( (ext == QLatin1String("inp"))
+            || (ext == QLatin1String("sif"))
+            || (ext == QLatin1String("txt")) ) {
             Gui::TextEditor* editor = new Gui::TextEditor();
             editor->setWindowIcon(Gui::BitmapFactory().pixmap(":/icons/fem-solver-inp-editor.svg"));
             Gui::EditorView* edit = new Gui::EditorView(editor, Gui::getMainWindow());
-            editor->setSyntaxHighlighter(new FemGui::AbaqusHighlighter(editor));
+            if (ext == QLatin1String("inp"))
+                editor->setSyntaxHighlighter(new FemGui::AbaqusHighlighter(editor));
             edit->setDisplayName(Gui::EditorView::FileName);
             edit->open(fileName);
             edit->resize(400, 300);

src/Mod/Fem/femsolver/elmer/solver.py

@@ -28,6 +28,11 @@ __url__ = "https://www.freecadweb.org"
 ## \addtogroup FEM
 #  @{
 
+import glob
+import os
+
+import FreeCAD
+
 from . import tasks
 from .equations import elasticity
 from .equations import electrostatic
@@ -39,6 +44,9 @@ from .. import run
 from .. import solverbase
 from femtools import femutils
 
+if FreeCAD.GuiUp:
+    import FemGui
+
 
 def create(doc, name="ElmerSolver"):
     return femutils.createObject(
@@ -109,6 +117,15 @@ class Proxy(solverbase.Proxy):
     def isSupported(self, eqId):
         return eqId in self._EQUATIONS
 
+    def editSupported(self):
+        return True
+
+    def edit(self, directory):
+        pattern = os.path.join(directory, "case.sif")
+        FreeCAD.Console.PrintMessage("{}\n".format(pattern))
+        f = glob.glob(pattern)[0]
+        FemGui.open(f)
+
 
 class ViewProxy(solverbase.ViewProxy):
     """Proxy for FemSolverElmers View Provider."""

src/Mod/Fem/femsolver/z88/solver.py

@@ -78,7 +78,27 @@ class Proxy(solverbase.Proxy):
         return True
 
     def edit(self, directory):
-        pattern = os.path.join(directory, "*.txt")
+        pattern = os.path.join(directory, "z88i1.txt")
+        FreeCAD.Console.PrintMessage("{}\n".format(pattern))
+        f = glob.glob(pattern)[0]
+        FemGui.open(f)
+        pattern = os.path.join(directory, "z88i2.txt")
+        FreeCAD.Console.PrintMessage("{}\n".format(pattern))
+        f = glob.glob(pattern)[0]
+        FemGui.open(f)
+        pattern = os.path.join(directory, "z88i5.txt")
+        FreeCAD.Console.PrintMessage("{}\n".format(pattern))
+        f = glob.glob(pattern)[0]
+        FemGui.open(f)
+        pattern = os.path.join(directory, "z88man.txt")
+        FreeCAD.Console.PrintMessage("{}\n".format(pattern))
+        f = glob.glob(pattern)[0]
+        FemGui.open(f)
+        pattern = os.path.join(directory, "z88mat.txt")
+        FreeCAD.Console.PrintMessage("{}\n".format(pattern))
+        f = glob.glob(pattern)[0]
+        FemGui.open(f)
+        pattern = os.path.join(directory, "z88elp.txt")
         FreeCAD.Console.PrintMessage("{}\n".format(pattern))
         f = glob.glob(pattern)[0]
         FemGui.open(f)