feature: add settings UI for control. how to affect an items visibility

Add settings UI for controlling how the extension should affect a top
bar items visibility (whether to try to forcefully hide or show an item
or not affect its visibility at all).

src/prefsModules/PrefsBoxOrderItemOptionsDialog.ts

@@ -0,0 +1,58 @@
+"use strict";
+
+import GObject from "gi://GObject";
+import Adw from "gi://Adw";
+import GLib from "gi://GLib";
+import type Gio from "gi://Gio";
+import type Gtk from "gi://Gtk";
+
+import { ExtensionPreferences } from "resource:///org/gnome/Shell/Extensions/js/extensions/prefs.js";
+
+export default class PrefsBoxOrderItemOptionsDialog extends Adw.Dialog {
+    static {
+        GObject.registerClass({
+            GTypeName: "PrefsBoxOrderItemOptionsDialog",
+            Template: GLib.uri_resolve_relative(import.meta.url, "../ui/prefs-box-order-item-options-dialog.ui", GLib.UriFlags.NONE),
+            InternalChildren: [
+                "visibility-row",
+            ],
+        }, this);
+    }
+
+    declare _visibility_row: Adw.ComboRow;
+    #settings: Gio.Settings;
+    item: string;
+
+    constructor(params = {}, item: string) {
+        super(params);
+
+        // Associate `this` with an item.
+        this.item = item;
+        // Load the settings.
+        this.#settings = ExtensionPreferences.lookupByURL(import.meta.url)!.getSettings();
+    }
+
+    onVisibilityRowSelectionChanged(): void {
+        const visibility = (this._visibility_row.get_selected_item() as Gtk.StringObject).get_string();
+        const itemsToHide = new Set(this.#settings.get_strv("hide"));
+        const itemsToShow = new Set(this.#settings.get_strv("show"));
+
+        switch (visibility) {
+            case "Forcefully Hide":
+                itemsToHide.add(this.item)
+                itemsToShow.delete(this.item);
+                break;
+            case "Forcefully Show":
+                itemsToHide.delete(this.item)
+                itemsToShow.add(this.item);
+                break;
+            case "Default":
+                itemsToHide.delete(this.item)
+                itemsToShow.delete(this.item);
+                break;
+        }
+
+        this.#settings.set_strv("hide", Array.from(itemsToHide));
+        this.#settings.set_strv("show", Array.from(itemsToShow));
+    }
+}