error handling, fix #2

plugin.ini

@@ -1,20 +1,20 @@
 
 #
-# plugin config settings
+# plugin settings
 #
 
 #
 # java invocation
 [java]
 
-# name of jave executable
+# name of java executable
 path = java
 
 # freerouting invocation
 [module]
 
-# time to wait for router to return, seconds
-timeout = 600
+input_ext  = dsn
+output_ext = ses
 
 #
 # jar artifact descriptor

plugin.py

@@ -3,10 +3,12 @@
 import wx.aui
 import time
 import pcbnew
+import textwrap
 import threading
 import subprocess
 import configparser
 
+
 #
 # FreeRouting round trip invocation:
 # * export board.dsn file from pcbnew
@@ -36,46 +38,244 @@ def prepare(self):
         config.read(config_path)
 
         self.java_path = config['java']['path']
-        self.module_timeout = float(config['module']['timeout'])
 
         self.module_file = config['artifact']['location']
         self.module_path = os.path.join(self.here_path, self.module_file)
 
-        self.module_input = self.board_prefix + '.dsn'
-        self.module_output = self.board_prefix + '.ses'
+        self.module_input = self.board_prefix + '.' + config['module']['input_ext']
+        self.module_output = self.board_prefix + '.' + config['module']['output_ext']
+
+        self.module_command = [self.java_path, "-jar", self.module_path, "-de", self.module_input, "-s"]
 
         if os.path.isfile(self.module_input):
             os.remove(self.module_input)
         if os.path.isfile(self.module_output):
             os.remove(self.module_output)
+
+    # export board.dsn file from pcbnew
+    def RunExport(self):
+        ok = pcbnew.ExportSpecctraDSN(self.module_input)
+        if ok and os.path.isfile(self.module_input):
+            return True
+        else:
+            wx_show_error("""
+            Failed to invoke:
+            * pcbnew.ExportSpecctraDSN
+            """)
+            return False
+
+    # auto route by invoking FreeRouting.jar
+    def RunRouter(self):
+
+        dialog = ProcessDialog(None, """
+        Complete or Terminate FreeRouting:
+        * to complete, close Java window
+        * to terminate, press Terminate here
+        """)
 
-    # run inside gui-thread-safe context
-    def invoke(self, runner):
-        wx.CallAfter(runner)
+        def on_complete():
+            wx_safe_invoke(dialog.terminate)
 
-    def RunExport(self):
-        pcbnew.ExportSpecctraDSN(self.module_input)
+        invoker = ProcessThread(self.module_command, on_complete)
 
-    def RunRouter(self):
-        command = [self.java_path, "-jar", self.module_path, "-de", self.module_input, "-s"]
-        process = subprocess.Popen(command)
-        process.wait(self.module_timeout)
+        dialog.Show()  # dialog first
+        invoker.start()  # run java process
+        result = dialog.ShowModal()  # block pcbnew here
+        dialog.Destroy()
+
+        try:
+            if result == dialog.result_button:  # return via terminate button
+                invoker.terminate()
+                return False
+            elif result == dialog.result_terminate:  # return via dialog.terminate()
+                if invoker.has_ok():
+                    return True
+                else:
+                    invoker.show_error()
+                    return False
+            else:
+                return False  # should not happen
+        finally:
+            invoker.join(10)  # prevent thread resource leak
 
+    # import generated board.ses file into pcbnew
     def RunImport(self):
-        pcbnew.ImportSpecctraSES(self.module_output)
+        ok = pcbnew.ImportSpecctraSES(self.module_output)
+        if ok and os.path.isfile(self.module_output):
+            return True
+        else:
+            wx_show_error("""
+            Failed to invoke:
+            * pcbnew.ImportSpecctraSES    
+            """)
+            return False
+
+    # invoke chain of dependent methods
+    def RunSteps(self):
+        self.prepare()
+        if not self.RunExport() :
+            return 
+        if not self.RunRouter() :
+            return
+        wx_safe_invoke(self.RunImport)
 
+    # kicad plugin action entry
     def Run(self):
-        self.prepare()
-        self.invoke(self.RunExport)
-        self.invoke(self.RunRouter)
-        self.invoke(self.RunImport)
+        if has_pcbnew_api():
+            self.RunSteps()
+        else:
+            wx_show_error("""
+            Missing required python API:
+            * pcbnew.ExportSpecctraDSN
+            * pcbnew.ImportSpecctraSES
+            ---
+            Try development nightly build:
+            * http://kicad-pcb.org/download/
+            """)
 
 
 # provision gui-thread-safe execution context
-if not wx.GetApp():
-    theApp = wx.App()
-else:
-    theApp = wx.GetApp()
+# https://git.launchpad.net/kicad/tree/pcbnew/python/kicad_pyshell/__init__.py#n89
+if 'phoenix' in wx.PlatformInfo:
+    if not wx.GetApp():
+        theApp = wx.App()
+    else:
+        theApp = wx.GetApp()
+
+
+# run functon inside gui-thread-safe context, requires wx.App on phoenix
+def wx_safe_invoke(function, *args, **kwargs):
+    wx.CallAfter(function, *args, **kwargs)
+
+
+# verify required pcbnew api is present
+def has_pcbnew_api():
+    return hasattr(pcbnew, 'ExportSpecctraDSN') and hasattr(pcbnew, 'ImportSpecctraSES')
+
+
+# message dialog style
+wx_caption = "KiCad FreeRouting Plugin"
+
+
+# display error text to the user
+def wx_show_error(text):
+    message = textwrap.dedent(text)
+    style = wx.OK | wx.ICON_ERROR
+    dialog = wx.MessageDialog(None, message=message, caption=wx_caption, style=style)
+    dialog.ShowModal()
+    dialog.Destroy()
+
+
+# prompt user to cancel pending action; allow to cancel programmatically
+class ProcessDialog (wx.Dialog):
+
+    def __init__(self, parent, text):
+
+        message = textwrap.dedent(text)
+
+        self.result_button = wx.NewId()
+        self.result_terminate = wx.NewId()
+
+        wx.Dialog.__init__ (self, parent, id=wx.ID_ANY, title=wx_caption, pos=wx.DefaultPosition, size=wx.Size(-1, -1), style=wx.CAPTION)
+
+        self.SetSizeHints(wx.DefaultSize, wx.DefaultSize)
+
+        sizer = wx.BoxSizer(wx.VERTICAL)
+
+        self.text = wx.StaticText(self, wx.ID_ANY, message, wx.DefaultPosition, wx.DefaultSize, 0)
+        self.text.Wrap(-1)
+        sizer.Add(self.text, 0, wx.ALIGN_CENTER_HORIZONTAL | wx.ALL, 10)
+
+        self.line = wx.StaticLine(self, wx.ID_ANY, wx.DefaultPosition, wx.DefaultSize, wx.LI_HORIZONTAL)
+        sizer.Add(self.line, 0, wx.EXPAND | wx.ALL, 5)
+
+        self.bttn = wx.Button(self, wx.ID_ANY, "Terminate", wx.DefaultPosition, wx.DefaultSize, 0)
+        self.bttn.SetDefault()
+        sizer.Add(self.bttn, 0, wx.ALIGN_CENTER_HORIZONTAL | wx.ALL, 5)
+
+        self.SetSizer(sizer)
+        self.Layout()
+        sizer.Fit(self)
+
+        self.Centre(wx.BOTH)
+
+        self.bttn.Bind(wx.EVT_BUTTON, self.bttn_on_click)
+
+    def __del__(self):
+        pass
+
+    def bttn_on_click(self, event):
+        self.EndModal(self.result_button)
+
+    def terminate(self):
+        self.EndModal(self.result_terminate)
+
+
+# cancelable external process invoker with completion notification
+class ProcessThread(threading.Thread):
+
+    def __init__(self, command, on_complete=None):
+        self.command = command
+        self.on_complete = on_complete
+        threading.Thread.__init__(self)
+        self.setDaemon(True)
+
+    # thread runner
+    def run(self):
+        try:
+            self.process = subprocess.Popen(self.command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+            self.stdout, self.stderr = self.process.communicate()
+        except Exception as error:
+            self.error = error
+        finally:
+            if self.on_complete is not None:
+                self.on_complete()
+
+    def has_ok(self):
+        return self.has_process() and self.process.returncode == 0
+
+    def has_code(self):
+        return self.has_process() and self.process.returncode != 0
+
+    def has_error(self):
+        return hasattr(self, "error")
+
+    def has_process(self):
+        return hasattr(self, "process")
+
+    def terminate(self):
+        if self.has_process():
+            self.process.kill()
+        else:
+            pass
+
+    def show_error(self):
+        command = " ".join(self.command)
+        if self.has_error() :
+            wx_show_error("""
+            Process failure:
+            ---
+            command:
+            %s
+            ---
+            error:
+            %s""" % (command, str(self.error)))
+        elif self.has_code():
+            wx_show_error("""
+            Program failure:
+            ---
+            command:
+            %s
+            ---
+            exit code: %d
+            --- stdout ---
+            %s
+            --- stderr  ---
+            %s
+            """ % (command, self.process.returncode, self.stdout, self.stderr))
+        else:
+            pass
+
 
 # register plugin with kicad backend
 FreeRoutingPlugin().register()