[gnome-shell] appDisplay: Handle dropped app favorites

[Marge Bot <marge-bot src gnome org>]

commit 55439713f40485f5d7fd60ee022d68f40569ccdb
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue Jan 26 11:33:54 2021 +0100

    appDisplay: Handle dropped app favorites
    
    Now that apps either appear in the dash or the app grid, it makes
    sense to allow DND between the two components to add and remove
    favorites.
    
    Currently this only works for adding items to the dash, update the
    app grid code to also accept drops from the dash.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1594>

 js/ui/appDisplay.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index c891de9665..6abe25e9bf 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -1325,7 +1325,8 @@ class AppDisplay extends BaseAppView {
         // exist in AppDisplay. We work around that by adding a placeholder
         // icon that is either destroyed on cancel, or becomes the effective
         // new icon when dropped.
-        if (_getViewFromIcon(source) instanceof FolderView)
+        if (_getViewFromIcon(source) instanceof FolderView ||
+            this._appFavorites.isFavorite(source.id))
             this._ensurePlaceholder(source);
     }
 
@@ -1363,6 +1364,9 @@ class AppDisplay extends BaseAppView {
         if (this._currentDialog)
             this._currentDialog.popdown();
 
+        if (this._appFavorites.isFavorite(source.id))
+            this._appFavorites.removeFavorite(source.id);
+
         return true;
     }