[FEM] get Gmsh version

src/Mod/Fem/Gui/Resources/ui/MeshGmsh.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>400</width>
-    <height>413</height>
+    <height>439</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -151,9 +151,9 @@
         <property name="fieldGrowthPolicy">
          <enum>QFormLayout::AllNonFixedFieldsGrow</enum>
         </property>
-        <item row="0" column="1">
+        <item row="1" column="1">
          <layout class="QGridLayout" name="gl_actions">
-          <item row="1" column="0">
+          <item row="5" column="0">
            <widget class="QLabel" name="l_time">
             <property name="font">
              <font>
@@ -172,6 +172,32 @@
             </property>
            </widget>
           </item>
+          <item row="7" column="0">
+           <widget class="QPushButton" name="pb_get_gmsh_version">
+            <property name="sizePolicy">
+             <sizepolicy hsizetype="Minimum" vsizetype="Fixed">
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
+            </property>
+            <property name="text">
+             <string>Gmsh version</string>
+            </property>
+           </widget>
+          </item>
+          <item row="6" column="0">
+           <spacer name="verticalSpacer">
+            <property name="orientation">
+             <enum>Qt::Vertical</enum>
+            </property>
+            <property name="sizeHint" stdset="0">
+             <size>
+              <width>20</width>
+              <height>40</height>
+             </size>
+            </property>
+           </spacer>
+          </item>
          </layout>
         </item>
        </layout>

src/Mod/Fem/femmesh/gmshtools.py

@@ -30,6 +30,7 @@ __url__ = "https://www.freecadweb.org"
 import subprocess
 import sys
 import os
+import re
 
 import FreeCAD
 from FreeCAD import Console
@@ -366,6 +367,36 @@ class GmshTools():
         if self.group_elements:
             Console.PrintMessage("  {}\n".format(self.group_elements))
 
+    def get_gmsh_version(self):
+        self.get_gmsh_command()
+        if os.path.exists(self.gmsh_bin):
+            found_message = "executable found: " + self.gmsh_bin 
+            Console.PrintMessage(found_message + "\n")
+        else:
+            found_message = "executable not found: " + self.gmsh_bin
+            Console.PrintError(found_message + "\n")
+            return (None, None, None), found_message
+
+        command_list = [self.gmsh_bin, "--info"]
+        p = subprocess.Popen(
+            command_list,
+            shell=False,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            text=True
+        )
+        gmsh_stdout, gmsh_stderr = p.communicate()
+
+        Console.PrintMessage("Gmsh: StdOut:\n" + gmsh_stdout + "\n")
+        if gmsh_stderr:
+            Console.PrintError("Gmsh: StdErr:\n" + gmsh_stderr + "\n")
+
+        match = re.search("^Version\s*:\s*(\d+)\.(\d+)\.(\d+)", gmsh_stdout)
+        if match:
+            return match.group(1, 2, 3), found_message + "\n\n" + gmsh_stdout         # major, minor, patch, fullmessage
+        else:
+            return (None, None, None), found_message + "\n\n" + gmsh_stdout
+
     def get_region_data(self):
         # mesh regions
         if not self.mesh_obj.MeshRegionList:

src/Mod/Fem/femtaskpanels/task_mesh_gmsh.py

@@ -82,6 +82,11 @@ class _TaskPanel:
             QtCore.SIGNAL("timeout()"),
             self.update_timer_text
         )
+        QtCore.QObject.connect(
+            self.form.pb_get_gmsh_version,
+            QtCore.SIGNAL("clicked()"),
+            self.get_gmsh_version
+        )
 
         self.form.cb_dimension.addItems(
             mesh_gmsh.MeshGmsh.known_element_dimensions
@@ -109,6 +114,7 @@ class _TaskPanel:
     def reject(self):
         self.mesh_obj.ViewObject.Document.resetEdit()
         self.mesh_obj.Document.recompute()
+        self.Timer.stop()
         return True
 
     def clicked(self, button):
@@ -162,6 +168,15 @@ class _TaskPanel:
         self.form.cb_dimension.setCurrentIndex(index)
         self.dimension = str(self.form.cb_dimension.itemText(index))  # form returns unicode
 
+    def get_gmsh_version(self):
+        from femmesh import gmshtools
+        version, full_message = gmshtools.GmshTools(self.mesh_obj, self.analysis).get_gmsh_version()
+        QtGui.QMessageBox.information(
+            None,
+            "Gmsh - Information",
+            full_message
+        )
+
     def run_gmsh(self):
         QApplication.setOverrideCursor(Qt.WaitCursor)
         part = self.mesh_obj.Part
@@ -202,7 +217,6 @@ class _TaskPanel:
         try:
             error = gmsh_mesh.create_mesh()
         except Exception:
-            import sys
             error = sys.exc_info()[1]
             FreeCAD.Console.PrintMessage(
                 "Unexpected error when creating mesh: {}\n"