Allow plugins to show error in status area asynchronously

EDMarketConnector.py

@@ -92,7 +92,7 @@ class AppWindow:
         self.w.rowconfigure(0, weight=1)
         self.w.columnconfigure(0, weight=1)
 
-        plug.load_plugins()
+        plug.load_plugins(master)
 
         if platform != 'darwin':
             if platform == 'win32':
@@ -276,6 +276,7 @@ class AppWindow:
         self.w.bind_all('<<Invoke>>', self.getandsend)		# Hotkey monitoring
         self.w.bind_all('<<JournalEvent>>', self.journal_event)	# Journal monitoring
         self.w.bind_all('<<InteractionEvent>>', self.interaction_event)	# cmdrHistory monitoring
+        self.w.bind_all('<<PluginError>>', self.plugin_error)	# Statusbar
         self.w.bind_all('<<Quit>>', self.onexit)		# Updater
 
         # Load updater after UI creation (for WinSparkle)
@@ -725,6 +726,15 @@ class AppWindow:
                 if not config.getint('hotkey_mute'):
                     hotkeymgr.play_bad()
 
+    # Display asynchronous error from plugin
+    def plugin_error(self, event=None):
+        if plug.last_error['msg']:
+            self.status['text'] = plug.last_error
+            self.w.update_idletasks()
+            if not config.getint('hotkey_mute'):
+                hotkeymgr.play_bad()
+        plug.last_error = None
+
     def shipyard_url(self, shipname=None):
 
         if not monitor.cmdr or not monitor.mode:

PLUGINS.md

@@ -155,6 +155,12 @@ def cmdr_data(data, is_beta):
 
 The data is a dictionary and full of lots of wonderful stuff!
 
+## Error messages
+
+You can display an error in EDMC's status area by returning a string from your `journal_entry()`, `interaction()` or `cmdr_data()` function, or asynchronously (e.g. from a "worker" thread that is performing a long running operation) by calling `plug.show_error()`. Either method will cause the "bad" sound to be played (unless the user has muted sound).
+
+The status area is shared between EDMC itself and all other plugins, so your message won't be displayed for very long. Create a dedicated widget if you need to display routine status information.
+
 # Distributing a Plugin
 
 To package your plugin for distribution simply create a `.zip` archive of your plugin's folder:

plug.py

@@ -17,6 +17,12 @@ from config import config, appname
 # List of loaded Plugins
 PLUGINS = []
 
+# For asynchronous error display
+last_error = {
+    'msg':  None,
+    'root': None,
+}
+
 
 class Plugin(object):
 
@@ -95,11 +101,13 @@ class Plugin(object):
         return None
 
 
-def load_plugins():
+def load_plugins(master):
     """
     Find and load all plugins
     :return:
     """
+    last_error['root'] = master
+
     imp.acquire_lock()
 
     internal = []
@@ -283,3 +291,14 @@ def notify_newdata(data, is_beta):
             except:
                 print_exc()
     return error
+
+
+def show_error(err):
+    """
+    Display an error message in the status line of the main window.
+    :param err:
+    versionadded:: 2.3.7
+    """
+    if err and last_error['root']:
+        last_error['msg'] = unicode(err)
+        last_error['root'].event_generate('<<PluginError>>', when="tail")