Simplify calling commands with an instance.

We used to use a signal and a function in app.py which executes the command
handler. Now we instead use QCoreApplication.instance() which makes everything
a lot easier and cleaner.

qutebrowser/app.py

@@ -49,7 +49,6 @@ import qutebrowser.config.config as config
 import qutebrowser.network.qutescheme as qutescheme
 import qutebrowser.config.websettings as websettings
 import qutebrowser.network.proxy as proxy
-import qutebrowser.utils.message as message
 import qutebrowser.browser.quickmarks as quickmarks
 from qutebrowser.network.networkmanager import NetworkManager
 from qutebrowser.config.config import ConfigManager
@@ -60,13 +59,11 @@ from qutebrowser.keyinput.modeparsers import (NormalKeyParser, HintKeyParser,
                                               PromptKeyParser)
 from qutebrowser.keyinput.keyparser import PassthroughKeyParser
 from qutebrowser.commands.managers import CommandManager, SearchManager
-from qutebrowser.commands.exceptions import CommandError
 from qutebrowser.config.iniparsers import ReadWriteConfigParser
 from qutebrowser.config.lineparser import LineConfigParser
 from qutebrowser.browser.cookies import CookieJar
 from qutebrowser.utils.message import MessageBridge
-from qutebrowser.utils.misc import (dotted_getattr, get_standard_dir,
+from qutebrowser.utils.misc import get_standard_dir, actute_warning
-                                    actute_warning)
 from qutebrowser.utils.readline import ReadlineBridge
 from qutebrowser.utils.debug import set_trace  # pylint: disable=unused-import
 
@@ -142,7 +139,6 @@ class QuteBrowser(QApplication):
         self.networkmanager = NetworkManager(self.cookiejar)
         self.commandmanager = CommandManager()
         self.searchmanager = SearchManager()
-        self._init_cmds()
         self.mainwindow = MainWindow()
 
         self.modeman.mainwindow = self.mainwindow
@@ -310,20 +306,6 @@ class QuteBrowser(QApplication):
             # pylint: disable=no-member
             faulthandler.register(signal.SIGUSR1)
 
-    def _init_cmds(self):
-        """Initialisation of the qutebrowser commands.
-
-        Registers all commands and connects their signals.
-        """
-        for key, cmd in sorted(cmdutils.cmd_dict.items()):
-            cmd.signal.connect(self.command_handler)
-            if cmd.instance is not None:
-                func = '.'.join([cmd.instance if cmd.instance else 'app',
-                                 cmd.handler.__name__])
-            else:
-                func = cmd.handler.__name__
-            logging.debug("Registered command: {} -> {}".format(key, func))
-
     def _process_init_args(self):
         """Process initial positional args.
 
@@ -672,30 +654,3 @@ class QuteBrowser(QApplication):
         """
         logging.debug("Shutdown complete, quitting.")
         self.quit()
-
-    @pyqtSlot(tuple)
-    def command_handler(self, tpl):
-        """Handle commands which need an instance..
-
-        Args:
-            tpl: An (instance, func, count, args) tuple.
-                instance: How to get the current instance of the target object
-                          from app.py, as a dotted string, e.g.
-                          'mainwindow.tabs.cur'.
-                func:     The function name to be called (as string).
-                count:    The count given to the command, or None.
-                args:     A list of arguments given to the command.
-        """
-        (instance, func, count, args) = tpl
-        if instance == '':
-            obj = self
-        else:
-            obj = dotted_getattr(self, instance)
-        handler = getattr(obj, func)
-        try:
-            if count is not None:
-                handler(*args, count=count)
-            else:
-                handler(*args)
-        except CommandError as e:
-            message.error(e)

qutebrowser/commands/_command.py

@@ -21,12 +21,13 @@ import logging
 
 from qutebrowser.commands.exceptions import (ArgumentCountError,
                                              PrerequisitesError)
+from qutebrowser.utils.misc import dotted_getattr
 
-from PyQt5.QtCore import pyqtSignal, QObject, QCoreApplication
+from PyQt5.QtCore import QCoreApplication
 from PyQt5.QtWebKit import QWebSettings
 
 
-class Command(QObject):
+class Command:
 
     """Base skeleton for a command.
 
@@ -42,18 +43,12 @@ class Command(QObject):
         handler: The handler function to call.
         completion: Completions to use for arguments, as a list of strings.
         needs_js: Whether the command needs javascript enabled
-
-    Signals:
-        signal: Gets emitted when something should be called via handle_command
-                from the app.py context.
     """
 
     # TODO:
     # we should probably have some kind of typing / argument casting for args
     # this might be combined with help texts or so as well
 
-    signal = pyqtSignal(tuple)
-
     def __init__(self, name, split, hide, nargs, count, desc, instance,
                  handler, completion, modes, not_modes, needs_js):
         # I really don't know how to solve this in a better way, I tried.
@@ -119,10 +114,6 @@ class Command(QObject):
         Args:
             args: Arguments to the command.
             count: Command repetition count.
-
-        Emit:
-            signal: When the command has an instance and should be handled from
-                    the app.py context.
         """
         dbgout = ["command called:", self.name]
         if args:
@@ -131,13 +122,18 @@ class Command(QObject):
             dbgout.append("(count={})".format(count))
         logging.debug(' '.join(dbgout))
 
-        if self.instance is not None and self.count and count is not None:
+        kwargs = {}
-            self.signal.emit((self.instance, self.handler.__name__, count,
+        app = QCoreApplication.instance()
-                              args))
+
-        elif self.instance is not None:
+        if self.instance is not None:
-            self.signal.emit((self.instance, self.handler.__name__, None,
+            # Add the 'self' parameter.
-                              args))
+            if self.instance == '':
-        elif count is not None and self.count:
+                obj = app
-            self.handler(*args, count=count)
+            else:
-        else:
+                obj = dotted_getattr(app, self.instance)
-            self.handler(*args)
+            args.insert(0, obj)
+
+        if count is not None and self.count:
+            kwargs = {'count': count}
+
+        self.handler(*args, **kwargs)