From cc9f949b653d7a21ad0f1c77d830222b845f41f5 Mon Sep 17 00:00:00 2001
From: Georges Basile Stavracas Neto <georges.stavracas@gmail.com>
Date: Fri, 28 Jun 2019 19:47:32 -0300
Subject: [PATCH] folderIcon: Allow dropping application icons

Connect to the overview signals related to Drag n' Drop, and
allow dropping application icons in it. Dropping an icon
appends the application id to the folder's GSettings key.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/603
---
 js/ui/appDisplay.js | 46 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index 94a7c7474..f62b94176 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -1221,6 +1221,11 @@ var FolderIcon = class FolderIcon {
 
         this.view = new FolderView(this._folder, parentView);
 
+        Main.overview.connect('item-drag-begin',
+                              this._onDragBegin.bind(this));
+        Main.overview.connect('item-drag-end',
+                              this._onDragEnd.bind(this));
+
         this.actor.connect('clicked', this.open.bind(this));
         this.actor.connect('destroy', this.onDestroy.bind(this));
         this.actor.connect('notify::mapped', () => {
@@ -1254,6 +1259,47 @@ var FolderIcon = class FolderIcon {
         return this.view.getAllItems().map(item => item.id);
     }
 
+    _onDragBegin() {
+        this._parentView.inhibitEventBlocker();
+    }
+
+    _onDragEnd() {
+        this._parentView.uninhibitEventBlocker();
+    }
+
+    _canDropAt(source) {
+        if (!(source instanceof AppIcon))
+            return false;
+
+        if (!global.settings.is_writable('favorite-apps'))
+            return false;
+
+        if (this._folder.get_strv('apps').includes(source.id))
+            return false
+
+        return true;
+    }
+
+    handleDragOver(source, actor, x, y, time) {
+        if (!this._canDropAt(source))
+            return DND.DragMotionResult.NO_DROP;
+
+        return DND.DragMotionResult.MOVE_DROP;
+    }
+
+    acceptDrop(source, actor, x, y, time) {
+        if (!this._canDropAt(source))
+            return true;
+
+        let app = source.app;
+        let folderApps = this._folder.get_strv('apps');
+        folderApps.push(app.id);
+
+        this._folder.set_strv('apps', folderApps);
+
+        return true;
+    }
+
     _updateName() {
         let name = _getFolderName(this._folder);
         if (this.name == name)