[gnome-shell/gbsneto/icon-grid-dnd: 37/41] allView, folderView: Always operate on grid coordinates

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

commit 821c016c077d632603883aaa31efce8e0019b8f4
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Thu Jul 4 14:54:20 2019 -0300

    allView, folderView: Always operate on grid coordinates
    
    Passing the actor coordinates is problematic because they do not
    match the grid coordinates at all.
    
    Transform coordinates passed by the DND handlers to the grid
    coordinates.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/603

 js/ui/appDisplay.js | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index 1b44131b3..e86198823 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -257,6 +257,21 @@ class BaseAppView {
         Tweener.addTween(this._grid, params);
     }
 
+    _transformToGridCoordinates(x, y) {
+        let point = new Clutter.Vertex();
+        point.x = x;
+        point.y = y;
+        point.z = 0.0;
+
+        point = this.actor.apply_transform_to_point(point);
+
+        let [ok, gridX, gridY] = this._grid.transform_stage_point(point.x, point.y);
+        if (!ok)
+            return [-1, -1];
+
+        return [gridX, gridY];
+    }
+
     canDropAt(x, y) {
         return this._grid.canDropAt(x, y);
     }
@@ -799,6 +814,8 @@ 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);
@@ -820,6 +837,8 @@ var AllView = class AllView extends BaseAppView {
     }
 
     acceptDrop(source, actor, x, y, time) {
+        [x, y] = this._transformToGridCoordinates(x, y);
+
         let [index, dragLocation] = this.canDropAt(x, y);
 
         if (index == -1)
@@ -1281,6 +1300,8 @@ var FolderView = class FolderView extends BaseAppView {
     }
 
     handleDragOver(source, actor, x, y, time) {
+        [x, y] = this._transformToGridCoordinates(x, y);
+
         let [index, dragLocation] = this.canDropAt(x, y);
         let sourceIndex = this._allItems.indexOf(source);
 
@@ -1293,6 +1314,8 @@ var FolderView = class FolderView extends BaseAppView {
     }
 
     acceptDrop(source, actor, x, y, time) {
+        [x, y] = this._transformToGridCoordinates(x, y);
+
         let [index, dragLocation] = this.canDropAt(x, y);
         let success = index != -1;