Refactor: Setup Drag Source and Drop Targets in UI files

data/ui/prefs-box-order-item-row.ui

@@ -24,5 +24,20 @@
                 </style>
             </object>
         </child>
+        <child>
+            <object class="GtkDragSource">
+                <property name="actions">move</property>
+                <signal name="prepare" handler="onDragPrepare"/>
+                <signal name="drag-begin" handler="onDragBegin"/>
+                <signal name="drag-end" handler="onDragEnd"/>
+            </object>
+        </child>
+        <child>
+            <object class="GtkDropTarget">
+                <property name="actions">move</property>
+                <property name="formats">PrefsBoxOrderItemRow</property>
+                <signal name="drop" handler="onDrop"/>
+            </object>
+        </child>
     </template>
 </interface>

data/ui/prefs-box-order-list-empty-placeholder.ui

@@ -19,5 +19,12 @@
                 </child>
             </object>
         </child>
+        <child>
+            <object class="GtkDropTarget">
+                <property name="actions">move</property>
+                <property name="formats">PrefsBoxOrderItemRow</property>
+                <signal name="drop" handler="onDrop"/>
+            </object>
+        </child>
     </template>
 </interface>

src/prefsModules/PrefsBoxOrderItemRow.js

@@ -23,21 +23,53 @@ var PrefsBoxOrderItemRow = GObject.registerClass({
 
         this._associateItem(item);
         this._configureMenu();
+    }
+
+    /**
+     * Associate `this` with an item.
+     * @param {String} item
+     */
+    _associateItem(item) {
+        this.item = item;
+
+        // Set `this._item_name_display_label` to something nicer, if the
+        // associated item is an AppIndicator/KStatusNotifierItem item.
+        if (item.startsWith("appindicator-kstatusnotifieritem-")) this._item_name_display_label.set_label(item.replace("appindicator-kstatusnotifieritem-", ""));
+        // Otherwise just set it to `item`.
+        else this._item_name_display_label.set_label(item);
+    }
+
+    /**
+     * Configure the menu.
+     */
+    _configureMenu() {
+        let menu = new Gio.Menu();
+        menu.append("Forget", `prefsBoxOrderItemRow-${this.item}.forget`);
+        this._menu_button.set_menu_model(menu);
+
+        const forgetAction = new Gio.SimpleAction({ name: "forget" });
+        forgetAction.connect("activate", () => {
+            const parentListBox = this.get_parent();
+            parentListBox.remove(this);
+            parentListBox.saveBoxOrderToSettings();
+        });
+
+        const actionGroup = new Gio.SimpleActionGroup();
+        actionGroup.add_action(forgetAction);
+        this.insert_action_group(`prefsBoxOrderItemRow-${this.item}`, actionGroup);
+    }
+
+    onDragPrepare(_source, x, y) {
+        const value = new GObject.Value();
+        value.init(PrefsBoxOrderItemRow);
+        value.set_object(this);
 
-        // Make `this` draggable by creating a drag source and adding it to
-        // `this`.
-        let dragSource = new Gtk.DragSource();
-        dragSource.set_actions(Gdk.DragAction.MOVE);
-        dragSource.connect("prepare", (source, x, y) => {
         this._drag_starting_point_x = x;
         this._drag_starting_point_y = y;
-            return Gdk.ContentProvider.new_for_value(this);
+        return Gdk.ContentProvider.new_for_value(value);
-        });
+    }
-        // Stop all scrolling, which is due to this DND operation.
+
-        dragSource.connect("drag-end", () => {
+    onDragBegin(_source, drag) {
-            scrollManager.stopScrollAll();
-        });
-        dragSource.connect("drag-begin", (source, drag) => {
         let dragWidget = new Gtk.ListBox();
         let allocation = this.get_allocation();
         dragWidget.set_size_request(allocation.width, allocation.height);
@@ -49,17 +81,16 @@ var PrefsBoxOrderItemRow = GObject.registerClass({
         let currentDragIcon = Gtk.DragIcon.get_for_drag(drag);
         currentDragIcon.set_child(dragWidget);
         drag.set_hotspot(this._drag_starting_point_x, this._drag_starting_point_y);
-        });
+    }
-        this.add_controller(dragSource);
+
+    onDragEnd() {
+        // Stop all scrolling, which is due to this DND operation.
+        scrollManager.stopScrollAll();
+    }
 
-        /// Make `this` accept drops by creating a drop target and adding it to
-        /// `this`.
-        let dropTarget = new Gtk.DropTarget();
-        dropTarget.set_gtypes([this.constructor.$gtype]);
-        dropTarget.set_actions(Gdk.DragAction.MOVE);
     // Handle a new drop on `this` properly.
     // `value` is the thing getting dropped.
-        dropTarget.connect("drop", (target, value) => {
+    onDrop(_target, value, _x, _y) {
         // If `this` got dropped onto itself, do nothing.
         if (value === this) {
             return;
@@ -110,41 +141,5 @@ var PrefsBoxOrderItemRow = GObject.registerClass({
         // save an updated box order for the list were the drop value was in
         // as well.
         if (ownListBox !== valueListBox) valueListBox.saveBoxOrderToSettings();
-        });
-        this.add_controller(dropTarget);
-    }
-
-    /**
-     * Associate `this` with an item.
-     * @param {String} item
-     */
-    _associateItem(item) {
-        this.item = item;
-
-        // Set `this._item_name_display_label` to something nicer, if the
-        // associated item is an AppIndicator/KStatusNotifierItem item.
-        if (item.startsWith("appindicator-kstatusnotifieritem-")) this._item_name_display_label.set_label(item.replace("appindicator-kstatusnotifieritem-", ""));
-        // Otherwise just set it to `item`.
-        else this._item_name_display_label.set_label(item);
-    }
-
-    /**
-     * Configure the menu.
-     */
-    _configureMenu() {
-        let menu = new Gio.Menu();
-        menu.append("Forget", `prefsBoxOrderItemRow-${this.item}.forget`);
-        this._menu_button.set_menu_model(menu);
-
-        const forgetAction = new Gio.SimpleAction({ name: "forget" });
-        forgetAction.connect("activate", () => {
-            const parentListBox = this.get_parent();
-            parentListBox.remove(this);
-            parentListBox.saveBoxOrderToSettings();
-        });
-
-        const actionGroup = new Gio.SimpleActionGroup();
-        actionGroup.add_action(forgetAction);
-        this.insert_action_group(`prefsBoxOrderItemRow-${this.item}`, actionGroup);
     }
 });

src/prefsModules/PrefsBoxOrderListEmptyPlaceholder.js

@@ -14,15 +14,11 @@ var PrefsBoxOrderListEmptyPlaceholder = GObject.registerClass({
 }, class PrefsBoxOrderListEmptyPlaceholder extends Gtk.Box {
     constructor(params = {}) {
         super(params);
+    }
 
-        /// Make `this` accept drops by creating a drop target and adding it to
-        /// `this`.
-        let dropTarget = new Gtk.DropTarget();
-        dropTarget.set_gtypes([GObject.type_from_name("PrefsBoxOrderItemRow")]);
-        dropTarget.set_actions(Gdk.DragAction.MOVE);
     // Handle a new drop on `this` properly.
     // `value` is the thing getting dropped.
-        dropTarget.connect("drop", (target, value) => {
+    onDrop(_target, value, _x, _y) {
         // Get the GtkListBoxes of `this` and the drop value.
         const ownListBox = this.get_parent();
         const valueListBox = value.get_parent();
@@ -47,7 +43,5 @@ var PrefsBoxOrderListEmptyPlaceholder = GObject.registerClass({
             updatedBoxOrder.push(item);
         }
         settings.set_strv(valueListBox.boxOrder, updatedBoxOrder);
-        });
-        this.add_controller(dropTarget);
     }
 });