PluginManager: retry loading trayicon plugin when service is missing

safeeyes/model.py

@@ -425,6 +425,7 @@ def build(cls, name, icon_path, icon_id, action):
 class PluginDependency:
     message: str
     link: str|None = None
+    retryable: bool = False
 
 class RequiredPluginException(Exception):
     def __init__(self, plugin_id, plugin_name: str, message: str|PluginDependency):

safeeyes/plugin_manager.py

@@ -57,14 +57,13 @@
 import sys
 
 from safeeyes import utility
-from safeeyes.model import RequiredPluginException
+from safeeyes.model import PluginDependency, RequiredPluginException
 
 sys.path.append(os.path.abspath(utility.SYSTEM_PLUGINS_DIR))
 sys.path.append(os.path.abspath(utility.USER_PLUGINS_DIR))
 
 HORIZONTAL_LINE_LENGTH = 64
 
-
 class PluginManager:
     """
     Imports the Safe Eyes plugins and calls the methods defined in those plugins.
@@ -99,6 +98,27 @@ def init(self, context, config):
             plugin.init_plugin(context, config)
         return True
 
+    def needs_retry(self):
+        return self.get_retryable_error() is not None
+
+    def get_retryable_error(self):
+        for plugin in self.__plugins.values():
+            if plugin.required_plugin and plugin.errored and plugin.enabled:
+                if isinstance(plugin.last_error, PluginDependency) and plugin.last_error.retryable:
+                    return RequiredPluginException(
+                        plugin.id,
+                        plugin.get_name(),
+                        plugin.last_error
+                    )
+
+        return None
+
+    def retry_errored_plugins(self):
+        for plugin in self.__plugins.values():
+            if plugin.required_plugin and plugin.errored and plugin.enabled:
+                if isinstance(plugin.last_error, PluginDependency) and plugin.last_error.retryable:
+                    plugin.reload_errored()
+
     def start(self):
         """
         Execute the on_start() function of plugins.
@@ -235,7 +255,8 @@ def __init__(self, plugin):
 
             if message:
                 self.errored = True
-                if self.required_plugin:
+                self.last_error = message
+                if self.required_plugin and not (isinstance(message, PluginDependency) and message.retryable):
                     raise RequiredPluginException(
                         plugin['id'],
                         plugin_config['meta']['name'],
@@ -262,9 +283,9 @@ def reload_config(self, plugin):
         if self.enabled or self.break_override_allowed:
             plugin_path = os.path.join(self.plugin_dir, self.id)
             message = utility.check_plugin_dependencies(
-                plugin['id'],
+                self.id,
                 self.plugin_config,
-                plugin.get('settings', {}),
+                self.config,
                 plugin_path
             )
 
@@ -279,6 +300,35 @@ def reload_config(self, plugin):
                 # No longer errored, import the module now
                 self._import_plugin()
 
+
+    def reload_errored(self):
+        if not self.errored:
+            return
+
+        if self.enabled or self.break_override_allowed:
+            plugin_path = os.path.join(self.plugin_dir, self.id)
+            message = utility.check_plugin_dependencies(
+                self.id,
+                self.plugin_config,
+                self.config,
+                plugin_path
+            )
+
+            if message:
+                self.errored = True
+                self.last_error = message
+            elif self.errored:
+                self.errored = False
+                self.last_error = None
+
+            if not self.errored and self.module is None:
+                # No longer errored, import the module now
+                self._import_plugin()
+
+
+    def get_name(self):
+        return self.plugin_config['meta']['name']
+
     def _import_plugin(self):
         if self.errored:
             # do not try to import errored plugin

safeeyes/plugins/trayicon/dependency_checker.py

@@ -39,7 +39,8 @@ def validate(plugin_config, plugin_settings):
     else:
         return PluginDependency(
             message=_("Please install service providing tray icons for your desktop environment."),
-            link="https://github.com/slgobinath/SafeEyes/wiki/How-to-install-backend-for-Safe-Eyes-tray-icon"
+            link="https://github.com/slgobinath/SafeEyes/wiki/How-to-install-backend-for-Safe-Eyes-tray-icon",
+            retryable=True
         )
 
     command = None

safeeyes/safeeyes.py

@@ -37,7 +37,7 @@
 from safeeyes.ui.settings_dialog import SettingsDialog
 
 gi.require_version('Gtk', '3.0')
-from gi.repository import Gtk, Gio
+from gi.repository import Gtk, Gio, GLib
 
 SAFE_EYES_VERSION = "2.2.2"
 
@@ -48,6 +48,7 @@ class SafeEyes(Gtk.Application):
     """
 
     required_plugin_dialog_active = False
+    retry_errored_plugins_count = 0
 
     def __init__(self, system_locale, config, cli_args):
         super().__init__(
@@ -119,8 +120,7 @@ def do_startup(self):
         try:
             self.plugins_manager.init(self.context, self.config)
         except RequiredPluginException as e:
-            self.show_required_plugin_dialog(e.get_plugin_id(), e.get_plugin_name(), e.get_message())
-            self.required_plugin_dialog_active = True
+            self.show_required_plugin_dialog(e)
 
         self.hold()
 
@@ -129,7 +129,7 @@ def do_startup(self):
         if self.config.get('use_rpc_server', True):
             self.__start_rpc_server()
 
-        if not self.required_plugin_dialog_active and self.safe_eyes_core.has_breaks():
+        if not self.plugins_manager.needs_retry() and not self.required_plugin_dialog_active and self.safe_eyes_core.has_breaks():
             self.active = True
             self.context['state'] = State.START
             self.plugins_manager.start()		# Call the start method of all plugins
@@ -139,6 +139,9 @@ def do_startup(self):
     def do_activate(self):
         logging.info('Application activated')
 
+        if self.plugins_manager.needs_retry():
+            GLib.timeout_add_seconds(1, self._retry_errored_plugins)
+
         if self.cli_args.about:
             self.show_about()
         elif self.cli_args.disable:
@@ -150,6 +153,32 @@ def do_activate(self):
         elif self.cli_args.take_break:
             self.take_break()
 
+
+    def _retry_errored_plugins(self):
+        if not self.plugins_manager.needs_retry():
+            return
+
+        logging.info(f"Retry loading errored plugin")
+        self.plugins_manager.retry_errored_plugins()
+
+        error = self.plugins_manager.get_retryable_error()
+
+        if error is None:
+            # success
+            self.restart(self.config, set_active=True)
+            return
+
+        # errored again
+        if self.retry_errored_plugins_count >= 3:
+            self.show_required_plugin_dialog(error)
+            return
+
+        timeout = pow(2, self.retry_errored_plugins_count)
+        self.retry_errored_plugins_count += 1
+
+        GLib.timeout_add_seconds(timeout, self._retry_errored_plugins)
+
+
     def show_settings(self):
         """
         Listen to tray icon Settings action and send the signal to Settings dialog.
@@ -161,12 +190,14 @@ def show_settings(self):
                 self.config.clone(), self.save_settings)
             settings_dialog.show()
 
-    def show_required_plugin_dialog(self, plugin_id, plugin_name, message):
+    def show_required_plugin_dialog(self, error: RequiredPluginException):
+        self.required_plugin_dialog_active = True
+
         logging.info("Show RequiredPlugin dialog")
         dialog = RequiredPluginDialog(
-            plugin_id,
-            plugin_name,
-            message,
+            error.get_plugin_id(),
+            error.get_plugin_name(),
+            error.get_message(),
             self.quit,
             lambda: self.disable_plugin(plugin_id)
         )
@@ -306,8 +337,7 @@ def restart(self, config, set_active=False):
         try:
             self.plugins_manager.init(self.context, self.config)
         except RequiredPluginException as e:
-            self.show_required_plugin_dialog(e.get_plugin_id(), e.get_plugin_name(), e.get_message())
-            self.required_plugin_dialog_active = True
+            self.show_required_plugin_dialog(e)
             return
 
         if set_active: