[gnome-tweak-tool] Support installation and management of Shell extensions

[John Stowers <jstowers src gnome org>]

commit 2a694fe50085fee44bcb7576f34a6b7b048112b4
Author: John Stowers <john stowers gmail com>
Date:   Wed May 11 09:35:36 2011 +1200

    Support installation and management of Shell extensions
    
    	* Can install extensions from zip files
    	* Can enable/disable active extensions
    
    Some code contributed by Loïc Faure-Lacroix

 NEWS                                    |    1 +
 gtweak/tweaks/tweak_shell_extensions.py |  159 +++++++++++++++++++++++++++++++
 2 files changed, 160 insertions(+), 0 deletions(-)
---
diff --git a/NEWS b/NEWS
index 40dd177..7c48c5e 100644
--- a/NEWS
+++ b/NEWS
@@ -4,6 +4,7 @@
    * A themeing specification for shell themes has been developed and agreed upon
      by a number of theme authors. If installing a theme matching this specification
      show the appropriate name
+   * Support installation and management of Shell extensions
 
 3.0.3
    * Autostart nautilus at login if it is configured to show
diff --git a/gtweak/tweaks/tweak_shell_extensions.py b/gtweak/tweaks/tweak_shell_extensions.py
new file mode 100644
index 0000000..e90f3e6
--- /dev/null
+++ b/gtweak/tweaks/tweak_shell_extensions.py
@@ -0,0 +1,159 @@
+import os.path
+import shutil
+import zipfile
+import tempfile
+import logging
+import json
+
+from gi.repository import Gtk
+from gi.repository import GLib
+
+from gtweak.utils import extract_zip_file
+from gtweak.gsettings import GSettingsSetting
+from gtweak.gshellwrapper import GnomeShell
+from gtweak.tweakmodel import Tweak, TweakGroup
+from gtweak.widgets import ZipFileChooserButton, build_label_beside_widget, build_horizontal_sizegroup
+
+class _ShellExtensionTweak(Tweak):
+
+    EXTENSION_DISABLED_KEY = "disabled-extensions"
+
+    def __init__(self, shell, ext, settings, **options):
+        Tweak.__init__(self, ext["name"], ext.get("description",""), **options)
+
+        self._shell = shell
+        self._settings = settings
+
+        sw = Gtk.Switch()
+        state = ext.get("state")
+        sw.set_active(
+                state == 1 and \
+                not self._settings.setting_is_in_list(self.EXTENSION_DISABLED_KEY, ext["uuid"])
+        )
+        sw.set_sensitive(state in (1,2))
+        sw.connect('notify::active', self._on_extension_toggled, ext["uuid"])
+
+        self.widget = build_label_beside_widget(
+                        "%s Extension" % ext["name"],
+                        sw)
+        self.widget_for_size_group = sw
+
+    def _on_extension_toggled(self, sw, active, uuid):
+        if not sw.get_active():
+            self._settings.setting_add_to_list(self.EXTENSION_DISABLED_KEY, uuid)
+        else:
+            self._settings.setting_remove_from_list(self.EXTENSION_DISABLED_KEY, uuid)
+
+        self.notify_action_required(
+            "The shell must be restarted for changes to take effect",
+            "Restart",
+            lambda: self._shell.restart())
+
+class _ShellExtensionInstallerTweak(Tweak):
+
+    EXTENSION_DIR = os.path.join(GLib.get_user_data_dir(), "gnome-shell", "extensions")
+
+    def __init__(self, shell, **options):
+        Tweak.__init__(self, "Install shell extension", "", **options)
+
+        self._shell = shell
+
+        chooser = ZipFileChooserButton("Select a theme file")
+        chooser.connect("file-set", self._on_file_set)
+
+        self.widget = build_label_beside_widget(self.name, chooser)
+        self.widget_for_size_group = chooser
+
+    def _on_file_set(self, chooser):
+        f = chooser.get_filename()
+
+        with zipfile.ZipFile(f, 'r') as z:
+            try:
+                fragment = ()
+                file_extension = None
+                file_metadata = None
+                for n in z.namelist():
+                    if n.endswith("metadata.json"):
+                        fragment = n.split("/")[0:-1]
+                        file_metadata = n
+                    if n.endswith("extension.js"):
+                        extension = True
+                        file_extension = n
+
+                if not file_metadata:
+                    raise Exception("Could not find metadata.json")
+                if not file_extension:
+                    raise Exception("Could not find extension.js")
+
+                #extract the extension uuid
+                extension_uuid = None
+                tmp = tempfile.mkdtemp()
+                z.extract(file_metadata, tmp)
+                with open(os.path.join(tmp,file_metadata)) as f:
+                    try:
+                        extension_uuid = json.load(f)["uuid"]
+                    except:
+                        logging.warning("Invalid extension format", exc_info=True)
+
+                ok = False
+                if extension_uuid:
+                    ok, updated = extract_zip_file(
+                                    z,
+                                    "/".join(fragment),
+                                    os.path.join(self.EXTENSION_DIR, extension_uuid))
+
+                if ok:
+                    if updated:
+                        verb = "%s extension updated successfully" % extension_uuid
+                    else:
+                        verb = "%s extension installed successfully" % extension_uuid
+
+                    self.notify_action_required(
+                        verb,
+                        "Restart",
+                        lambda: self._shell.restart())
+
+                else:
+                    self.notify_error("Error installing extension")
+
+
+            except:
+                #does not look like a valid theme
+                self.notify_error("Invalid extension file")
+                logging.warning("Error parsing theme zip", exc_info=True)
+
+        #set button back to default state
+        chooser.unselect_all()
+
+class ShellExtensionTweakGroup(TweakGroup):
+    def __init__(self):
+        extension_tweaks = []
+        sg = build_horizontal_sizegroup()
+
+        #check the shell is running
+        try:
+            shell = GnomeShell()
+
+            #add the extension installer
+            extension_tweaks.append(
+                _ShellExtensionInstallerTweak(shell, size_group=sg))
+
+            try:
+                settings = GSettingsSetting("org.gnome.shell")
+                #add a tweak for each installed extension
+                for extension in shell.list_extensions().values():
+                    try:
+                        extension_tweaks.append(
+                            _ShellExtensionTweak(shell, extension, settings, size_group=sg))
+                    except:
+                        logging.warning("Invalid extension", exc_info=True)
+            except:
+                logging.warning("Error listing extensions", exc_info=True)
+        except:
+            logging.warning("Error detecting shell")
+
+        TweakGroup.__init__(self, "Shell Extensions", *extension_tweaks)
+
+TWEAK_GROUPS = (
+        ShellExtensionTweakGroup(),
+)