From 1b1872e46430061eac70ee70cad0ea58ddbba7e7 Mon Sep 17 00:00:00 2001
From: Florian Bruhin <me@the-compiler.org>
Date: Mon, 10 Dec 2018 14:53:42 +0100
Subject: [PATCH] Expose a config_changed signal to extensions

---
 qutebrowser/app.py                |  1 +
 qutebrowser/components/adblock.py |  7 +++----
 qutebrowser/extensions/loader.py  | 24 +++++++++++++++++++++++-
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/qutebrowser/app.py b/qutebrowser/app.py
index 9c1ce9991..2b6896b76 100644
--- a/qutebrowser/app.py
+++ b/qutebrowser/app.py
@@ -165,6 +165,7 @@ def init(args, crash_handler):
     qApp.setQuitOnLastWindowClosed(False)
     _init_icon()
 
+    loader.init()
     loader.load_components()
     try:
         _init_modules(args, crash_handler)
diff --git a/qutebrowser/components/adblock.py b/qutebrowser/components/adblock.py
index e9d171f26..77e7a7694 100644
--- a/qutebrowser/components/adblock.py
+++ b/qutebrowser/components/adblock.py
@@ -104,12 +104,10 @@ class HostBlocker:
         self._done_count = 0
 
         self._local_hosts_file = str(data_dir / 'blocked-hosts')
-        self._update_files()
+        self.update_files()
 
         self._config_hosts_file = str(config_dir / 'blocked-hosts')
 
-        config.instance.changed.connect(self._update_files)
-
     def is_blocked(self, url, first_party_url=None):
         """Check if the given URL (as QUrl) is blocked."""
         if first_party_url is not None and not first_party_url.isValid():
@@ -296,7 +294,7 @@ class HostBlocker:
                 len(self._blocked_hosts), self._done_count))
 
     @config.change_filter('content.host_blocking.lists')
-    def _update_files(self):
+    def update_files(self):
         """Update files when the config changed."""
         if not config.val.content.host_blocking.lists:
             try:
@@ -331,4 +329,5 @@ def init(context):
     host_blocker = HostBlocker(data_dir=context.data_dir,
                                config_dir=context.config_dir,
                                args=context.args)
+    context.signals.config_changed.connect(host_blocker.update_files)
     host_blocker.read_hosts()
diff --git a/qutebrowser/extensions/loader.py b/qutebrowser/extensions/loader.py
index 303eda213..e7b93967b 100644
--- a/qutebrowser/extensions/loader.py
+++ b/qutebrowser/extensions/loader.py
@@ -28,7 +28,10 @@ import pathlib
 
 import attr
 
+from PyQt5.QtCore import pyqtSignal, QObject
+
 from qutebrowser import components
+from qutebrowser.config import config
 from qutebrowser.utils import log, standarddir, objreg
 
 
@@ -40,6 +43,14 @@ class InitContext:
     data_dir = attr.ib()  # type: pathlib.Path
     config_dir = attr.ib()  # type: pathlib.Path
     args = attr.ib()  # type: argparse.Namespace
+    signals = attr.ib()  # type: ExtensionSignals
+
+
+class ExtensionSignals(QObject):
+
+    """Signals exposed to an extension."""
+
+    config_changed = pyqtSignal(str)
 
 
 @attr.s
@@ -61,6 +72,12 @@ class ExtensionInfo:
     name = attr.ib()  # type: str
 
 
+# Global extension signals, shared between all extensions.
+# At some point we might want to make this per-extension, but then we'll need
+# to find out what to set as its Qt parent so it's kept alive.
+_extension_signals = ExtensionSignals()
+
+
 def add_module_info(module: types.ModuleType) -> ModuleInfo:
     """Add ModuleInfo to a module (if not added yet)."""
     # pylint: disable=protected-access
@@ -121,7 +138,8 @@ def _get_init_context() -> InitContext:
     """Get an InitContext object."""
     return InitContext(data_dir=pathlib.Path(standarddir.data()),
                        config_dir=pathlib.Path(standarddir.config()),
-                       args=objreg.get('args'))
+                       args=objreg.get('args'),
+                       signals=_extension_signals)
 
 
 def _load_component(info: ExtensionInfo) -> types.ModuleType:
@@ -136,3 +154,7 @@ def _load_component(info: ExtensionInfo) -> types.ModuleType:
         mod_info.init_hook(_get_init_context())
 
     return mod
+
+
+def init() -> None:
+    config.instance.changed.connect(_extension_signals.config_changed)