dbusServices/extensions: Take over prefs dialog from app

As outlined earlier, in order to turn the Extensions app into a properly
sandboxed application, we need to split out the extension prefs dialog
and move it elsewhere.

With "elsewhere" being the new Extensions D-Bus service, effectively
turning it into a shell extensions portal.

https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1106

js/dbusServices/extensions/extensionsService.js

@@ -1,7 +1,9 @@
 // -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
 /* exported ExtensionsService */
 
-const { Gio, GLib } = imports.gi;
+const { Gdk, Gio, GLib, GObject, Gtk } = imports.gi;
+
+const ExtensionUtils = imports.misc.extensionUtils;
 
 const { loadInterfaceXML } = imports.misc.fileUtils;
 const { ServiceImplementation } = imports.dbusService;
@@ -108,10 +110,25 @@ var ExtensionsService = class extends ServiceImplementation {
     }
 
     OpenExtensionPrefsAsync(params, invocation) {
-        this._proxy.OpenExtensionPrefsRemote(...params, (res, error) => {
+        const [uuid, parentWindow_, options] = params;
+
+        this._proxy.GetExtensionInfoRemote(uuid, (res, error) => {
             if (this._handleError(invocation, error))
                 return;
 
+            const [serialized] = res;
+            const extension = ExtensionUtils.deserializeExtension(serialized);
+
+            const window = new ExtensionPrefsDialog(extension);
+
+            if (options.modal)
+                window.modal = options.modal.get_boolean();
+
+            window.connect('destroy', () => this.release());
+            this.hold();
+
+            window.show();
+
             invocation.return_value(null);
         });
     }
@@ -125,3 +142,124 @@ var ExtensionsService = class extends ServiceImplementation {
         });
     }
 };
+
+var ExtensionPrefsDialog = GObject.registerClass({
+    GTypeName: 'ExtensionPrefsDialog',
+    Template: 'resource:///org/gnome/Shell/Extensions/ui/extension-prefs-dialog.ui',
+    InternalChildren: [
+        'headerBar',
+        'stack',
+        'expander',
+        'expanderArrow',
+        'revealer',
+        'errorView',
+    ],
+}, class ExtensionPrefsDialog extends Gtk.Window {
+    _init(extension) {
+        super._init();
+
+        this._uuid = extension.uuid;
+        this._url = extension.metadata.url || '';
+
+        this._headerBar.title = extension.metadata.name;
+
+        this._actionGroup = new Gio.SimpleActionGroup();
+        this.insert_action_group('win', this._actionGroup);
+
+        this._initActions();
+        this._addCustomStylesheet();
+
+        this._gesture = new Gtk.GestureMultiPress({
+            widget: this._expander,
+            button: 0,
+            exclusive: true,
+        });
+
+        this._gesture.connect('released', (gesture, nPress) => {
+            if (nPress === 1)
+                this._revealer.reveal_child = !this._revealer.reveal_child;
+        });
+
+        this._revealer.connect('notify::reveal-child', () => {
+            this._expanderArrow.icon_name = this._revealer.reveal_child
+                ? 'pan-down-symbolic'
+                : 'pan-end-symbolic';
+        });
+
+        try {
+            ExtensionUtils.installImporter(extension);
+
+            // give extension prefs access to their own extension object
+            ExtensionUtils.getCurrentExtension = () => extension;
+
+            const prefsModule = extension.imports.prefs;
+            prefsModule.init(extension.metadata);
+
+            const widget = prefsModule.buildPrefsWidget();
+            this._stack.add(widget);
+            this._stack.visible_child = widget;
+        } catch (e) {
+            this._setError(e);
+        }
+    }
+
+    _setError(exc) {
+        this._errorView.buffer.text = `${exc}\n\nStack trace:\n`;
+        // Indent stack trace.
+        this._errorView.buffer.text +=
+            exc.stack.split('\n').map(line => `  ${line}`).join('\n');
+
+        // markdown for pasting in gitlab issues
+        let lines = [
+            `The settings of extension ${this._uuid} had an error:`,
+            '```',
+            `${exc}`,
+            '```',
+            '',
+            'Stack trace:',
+            '```',
+            exc.stack.replace(/\n$/, ''), // stack without trailing newline
+            '```',
+            '',
+        ];
+        this._errorMarkdown = lines.join('\n');
+        this._actionGroup.lookup('copy-error').enabled = true;
+    }
+
+    _initActions() {
+        let action;
+
+        action = new Gio.SimpleAction({
+            name: 'copy-error',
+            enabled: false,
+        });
+        action.connect('activate', () => {
+            const clipboard = Gtk.Clipboard.get_default(this.get_display());
+            clipboard.set_text(this._errorMarkdown, -1);
+        });
+        this._actionGroup.add_action(action);
+
+        action = new Gio.SimpleAction({
+            name: 'show-url',
+            enabled: this._url !== '',
+        });
+        action.connect('activate', () => {
+            Gio.AppInfo.launch_default_for_uri(this._url,
+                this.get_display().get_app_launch_context());
+        });
+        this._actionGroup.add_action(action);
+    }
+
+    _addCustomStylesheet() {
+        let provider = new Gtk.CssProvider();
+        let uri = 'resource:///org/gnome/Shell/Extensions/css/application.css';
+        try {
+            provider.load_from_file(Gio.File.new_for_uri(uri));
+        } catch (e) {
+            logError(e, 'Failed to add application style');
+        }
+        Gtk.StyleContext.add_provider_for_screen(Gdk.Screen.get_default(),
+            provider,
+            Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);
+    }
+});