[gnome-shell/eos3.8: 104/255] appDisplay: Add moveItem()

[Matthew Leeds <mwleeds src gnome org>]

commit ddca9b4e0d42d02f46bb0e7bd2fe3a4cb2c0dd18
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Tue Jul 2 17:41:15 2019 -0300

    appDisplay: Add moveItem()
    
    This is a handy function to implement changing an icon's position
    in the grid.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/603

 js/ui/appDisplay.js | 30 ++++++++++++++++++++++++++++++
 js/ui/iconGrid.js   | 16 ++++++++++++++++
 2 files changed, 46 insertions(+)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index e1ca87eeef..5714af6676 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -213,6 +213,36 @@ var BaseAppView = GObject.registerClass({
         return a.name.localeCompare(b.name);
     }
 
+    moveItem(item, newPosition) {
+        let visibleItems = this._orderedItems.filter(item => item.visible);
+
+        // Avoid overflow
+        if (newPosition >= visibleItems.length)
+            return -1;
+
+        let targetId = visibleItems[newPosition].id;
+
+        let visibleIndex = visibleItems.indexOf(item);
+        if (newPosition > visibleIndex)
+            newPosition -= 1;
+
+        // Remove from the old position
+        let itemIndex = this._orderedItems.indexOf(item);
+
+        let realPosition = -1;
+        if (itemIndex != -1) {
+            this._orderedItems.splice(itemIndex, 1);
+            realPosition = this._grid.moveItem(item, newPosition);
+            this._orderedItems.splice(realPosition, 0, item);
+        } else {
+            realPosition = this._orderedItems.indexOf(targetId);
+        }
+
+        this._iconGridLayout.repositionIcon(item.id, targetId, this.id);
+
+        return realPosition;
+    }
+
     _selectAppInternal(id) {
         if (this._items.has(id))
             this._items.get(id).navigate_focus(null, St.DirectionType.TAB_FORWARD, false);
diff --git a/js/ui/iconGrid.js b/js/ui/iconGrid.js
index 7c87f224bf..1f9aa1d4f8 100644
--- a/js/ui/iconGrid.js
+++ b/js/ui/iconGrid.js
@@ -664,6 +664,22 @@ var IconGrid = GObject.registerClass({
             this.add_actor(item);
     }
 
+    moveItem(item, newPosition) {
+        if (!this.contains(item)) {
+            log('Cannot move item not contained by the IconGrid');
+            return;
+        }
+
+        let children = this.get_children();
+        let visibleChildren = children.filter(c => c.is_visible());
+        let visibleChildAtPosition = visibleChildren[newPosition];
+        let realPosition = children.indexOf(visibleChildAtPosition);
+
+        this.set_child_at_index(item, realPosition);
+
+        return realPosition;
+    }
+
     removeItem(item) {
         this.remove_child(item);
     }