[gnome-shell/gbsneto/icon-grid-dnd: 1/2] appIcon: Hide itself when starting drag

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 9ed4772248f65e88e4c82e0d910f0df188bfa19b
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Thu Jul 4 18:39:13 2019 -0300

    appIcon: Hide itself when starting drag
    
    As per design direction, hide the app icon when starting
    dragging it, and show it again if the drop is accepted.
    Clutter takes care of animating the rest of icon positions
    through implicit animations.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/603

 js/ui/appDisplay.js | 37 ++++++++++++++++++++++++-------------
 1 file changed, 24 insertions(+), 13 deletions(-)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index c061f549b..5fb007557 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -838,10 +838,6 @@ var AllView = class AllView extends BaseAppView {
     handleDragOver(source, actor, x, y, time) {
         [x, y] = this._transformToGridCoordinates(x, y);
 
-        let sourceIndex = -1;
-        if (source.parentView == this)
-            sourceIndex = this._allItems.indexOf(source);
-
         let [index, dragLocation] = this.canDropAt(x, y);
 
         this.removeNudges();
@@ -849,9 +845,7 @@ var AllView = class AllView extends BaseAppView {
             this._schedulePopdown();
 
         if (index != -1) {
-            if (sourceIndex == -1 || (index != sourceIndex && index != sourceIndex + 1))
-                this.nudgeItemsAtIndex(index, dragLocation);
-
+            this.nudgeItemsAtIndex(index, dragLocation);
             return DND.DragMotionResult.MOVE_DROP;
         }
 
@@ -871,6 +865,15 @@ var AllView = class AllView extends BaseAppView {
             source = this._items[source.id];
         }
 
+        // AppIcon hides itself, show it again
+        source.actor.show();
+
+        // When moving to a position forward, the index will be misadjusted by
+        // one, because the original actor is hidden. Adjust it back.
+        let sourceIndex = this._allItems.indexOf(source);
+        if (sourceIndex != -1 && index > sourceIndex)
+            index++;
+
         this.moveItem(source, index);
         this.removeNudges();
         return true;
@@ -1329,8 +1332,7 @@ var FolderView = class FolderView extends BaseAppView {
 
         this._folderIcon._parentView.removeNudges();
         this.removeNudges();
-        if (index != -1 && index != sourceIndex && index != sourceIndex + 1)
-            this.nudgeItemsAtIndex(index, dragLocation);
+        this.nudgeItemsAtIndex(index, dragLocation);
 
         return DND.DragMotionResult.MOVE_DROP;
     }
@@ -1339,8 +1341,17 @@ var FolderView = class FolderView extends BaseAppView {
         [x, y] = this._transformToGridCoordinates(x, y);
 
         let [index, dragLocation] = this.canDropAt(x, y);
+        let sourceIndex = this._allItems.indexOf(source);
         let success = index != -1;
 
+        // AppIcon hides itself, show it again
+        source.actor.show();
+
+        // When moving to a position forward, the index will be misadjusted by
+        // one, because the original actor is hidden. Adjust it back.
+        if (sourceIndex != -1 && index > sourceIndex)
+            index++;
+
         if (success)
             this.moveItem(source, index);
 
@@ -1895,18 +1906,18 @@ var AppIcon = class AppIcon {
             this._draggable = DND.makeDraggable(this.actor);
             this._draggable.connect('drag-begin', () => {
                 this._dragging = true;
-                this.actor.opacity = 0;
+                this.actor.hide();
                 this._removeMenuTimeout();
                 Main.overview.beginItemDrag(this);
             });
             this._draggable.connect('drag-cancelled', () => {
                 this._dragging = false;
-                this.actor.opacity = 255;
                 Main.overview.cancelledItemDrag(this);
             });
-            this._draggable.connect('drag-end', () => {
+            this._draggable.connect('drag-end', (source, time, success) => {
                 this._dragging = false;
-                this.actor.opacity = 255;
+                if (!success)
+                    this.actor.show();
                 Main.overview.endItemDrag(this);
             });
         }