wxGUI/startup: fix terminate location download dialog download thread (…

…#832) (#873)

* wxGUI/startup: don't set message wx widget string if location download dialog is destroyed
* wxGUI/core: replace set/reset stop flag for terminate thread with traces (urlretrieve runned from thread can't terminate with stop flag)
* wxGUI/startup: avoid printing annoying wx debug message on location download dialog start-up
* wxGUI/startup: change 'Download' button label to 'Abort' after start downloading, and allow terminate download thread correctly
* wxGUI/startup: handle location download dialog urlretrieve HTTPError, URLError exception
* wxGUI/startup: add string translation function
* wxGUI/startup: set location download dialog download button mnemonic label
* wxGUI/startup: fix close location download modal dialog
* wxGUI/startup: fix location download dialog 'Cancel' and 'Download' button layout
* wxGUI/startup: centre location download modal dialog

gui/wxpython/core/gthread.py

@@ -18,6 +18,7 @@
 import time
 
 import wx
+from wx.lib.newevent import NewEvent
 
 import sys
 if sys.version_info.major == 2:
@@ -27,14 +28,21 @@
 
 from core.gconsole import EVT_CMD_DONE, wxCmdDone
 
+wxThdTerminate, EVT_THD_TERMINATE = NewEvent()
+
 
 class gThread(threading.Thread, wx.EvtHandler):
-    """Thread for various backends"""
+    """Thread for various backends
+
+    terminating thread:
+    https://www.geeksforgeeks.org/python-different-ways-to-kill-a-thread/
+    """
     requestId = 0
 
     def __init__(self, requestQ=None, resultQ=None, **kwds):
         wx.EvtHandler.__init__(self)
         self.terminate = False
+        self._terminate_evt = None
 
         threading.Thread.__init__(self, **kwds)
 
@@ -51,6 +59,7 @@ def __init__(self, requestQ=None, resultQ=None, **kwds):
         self.setDaemon(True)
 
         self.Bind(EVT_CMD_DONE, self.OnDone)
+        self.Bind(EVT_THD_TERMINATE, self.OnTerminate)
         self.start()
 
     def Run(self, *args, **kwds):
@@ -80,7 +89,7 @@ def SetId(self, id):
     def run(self):
         while True:
             requestId, args, kwds = self.requestQ.get()
-            for key in ('callable', 'ondone', 'userdata'):
+            for key in ('callable', 'ondone', 'userdata', 'onterminate'):
                 if key in kwds:
                     vars()[key] = kwds[key]
                     del kwds[key]
@@ -93,6 +102,13 @@ def run(self):
             exception = None
             time.sleep(.01)
 
+            self._terminate_evt = wxThdTerminate(
+                onterminate=vars()['onterminate'],
+                kwds=kwds,
+                args=args,
+                pid=requestId,
+            )
+
             if self.terminate:
                 return
 
@@ -123,3 +139,31 @@ def OnDone(self, event):
     def Terminate(self, terminate=True):
         """Abort command(s)"""
         self.terminate = terminate
+
+    def start(self):
+        self.__run_backup = self.run
+        self.run = self.__run
+        threading.Thread.start(self)
+
+    def __run(self):
+        sys.settrace(self.globaltrace)
+        self.__run_backup()
+        self.run = self.__run_backup
+
+    def globaltrace(self, frame, event, arg):
+        if event == 'call':
+            return self.localtrace
+        else:
+            return None
+
+    def localtrace(self, frame, event, arg):
+        if self.terminate:
+            if event == 'line':
+                # Send event
+                wx.PostEvent(self, self._terminate_evt)
+                raise SystemExit()
+        return self.localtrace
+
+    def OnTerminate(self, event):
+        if event.onterminate:
+            event.onterminate(event)

gui/wxpython/gis_set.py

@@ -33,6 +33,11 @@
 
 from core import globalvar
 import wx
+# import adv and html before wx.App is created, otherwise
+# we get annoying "Debug: Adding duplicate image handler for 'Windows bitmap file'"
+# during download location dialog start up, remove when not needed
+import wx.adv
+import wx.html
 import wx.lib.mixins.listctrl as listmix
 
 from core.gcmd import GMessage, GError, DecodeString, RunCommand
@@ -766,6 +771,7 @@ def DownloadLocation(self, event):
         from startup.locdownload import LocationDownloadDialog
 
         loc_download = LocationDownloadDialog(parent=self, database=self.gisdbase)
+        loc_download.Centre()
         loc_download.ShowModal()
         location = loc_download.GetLocation()
         if location: