[gnome-shell] iconGrid/iconGrid: Hook page-padding with CSS

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

commit 4ad32ab66260e5a3547895a05723cf58e459d299
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Wed Nov 25 18:42:03 2020 -0300

    iconGrid/iconGrid: Hook page-padding with CSS
    
    Add support for setting the page padding of the icon grid
    through CSS. Unfortunately, each side needs to be specificied
    manually, since it's not a regular padding property.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1510>

 js/ui/iconGrid.js | 7 +++++++
 1 file changed, 7 insertions(+)
---
diff --git a/js/ui/iconGrid.js b/js/ui/iconGrid.js
index 4095299504..51157a311c 100644
--- a/js/ui/iconGrid.js
+++ b/js/ui/iconGrid.js
@@ -1311,6 +1311,7 @@ var IconGrid = GObject.registerClass({
             columns_per_page: 6,
             rows_per_page: 4,
             page_halign: Clutter.ActorAlign.CENTER,
+            page_padding: new Clutter.Margin(),
             page_valign: Clutter.ActorAlign.CENTER,
             last_row_align: Clutter.ActorAlign.START,
             column_spacing: 0,
@@ -1442,6 +1443,12 @@ var IconGrid = GObject.registerClass({
 
         [found, value] = node.lookup_length('max-row-spacing', false);
         this.layout_manager.max_row_spacing = found ? value : -1;
+
+        const padding = new Clutter.Margin();
+        ['top', 'right', 'bottom', 'left'].forEach(side => {
+            padding[side] = node.get_length(`page-padding-${side}`);
+        });
+        this.layout_manager.page_padding = padding;
     }
 
     /**