Ticket #33228: 33228.2.patch

src/wp-admin/css/common.css

@@ -164 +164 @@
         display: none;
 }
 
+/* hide UI sections and allow inner sections to be visible */
+.hidden-visibility {
+        visibility: hidden;
+}
+
+.visible-visibility {
+        visibility: visible;
+}
+
 /* @todo: Take a second look. Large chunks of shared color, from the colors.css merge */
 .widget-top,
 .menu-item-handle,

src/wp-admin/js/customize-controls.js

@@ -3041 +3041 @@
                         return;
                 }
 
-                var parent, topFocus,
+                var parent,
                         body = $( document.body ),
                         overlay = body.children( '.wp-full-overlay' ),
                         title = $( '#customize-info .panel-title.site-title' ),
@@ -3555 +3555 @@
 
                 api.trigger( 'ready' );
 
-                // Make sure left column gets focus
-                topFocus = closeBtn;
-                topFocus.focus();
-                setTimeout(function () {
-                        topFocus.focus();
-                }, 200);
-
         });
 
 })( wp, jQuery );

src/wp-includes/js/customize-loader.js

@@ -208 +208 @@
                                 document.title = this.originalDocumentTitle;
                         }
 
+                        Loader.body.removeClass( 'hidden-visibility' );
+
                         // Return focus to link that was originally clicked.
                         if ( this.link ) {
                                 this.link.focus();
@@ -231 +233 @@
                  * Callback for the `load` event on the Customizer iframe.
                  */
                 loaded: function() {
-                        Loader.body.removeClass('customize-loading');
+                        // Make the overlay the only visible and focusable content.
+                        Loader.body.removeClass( 'customize-loading' ).addClass( 'hidden-visibility' );
+                        Loader.element.addClass( 'visible-visibility' );
                 },
 
                 /**