Customize: Improve flow from menu locations to editing a menu.

Adds an Edit button beside the menu location to allow users to switch to the selected menu for further edits.

Props celloexpressions.
Fixes #36795.

git-svn-id: https://develop.svn.wordpress.org/trunk@37901 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/css/customize-nav-menus.css

@@ -16,6 +16,10 @@
 	color: #555;
 }
 
+.customize-control-nav_menu_location .edit-menu {
+	margin-top: 1px;
+}
+
 .wp-customizer .menu-item-bar .menu-item-handle,
 .wp-customizer .menu-item-settings,
 .wp-customizer .menu-item-settings .description-thin {

src/wp-admin/js/customize-nav-menus.js

@@ -926,6 +926,19 @@
 				return parseInt( value, 10 );
 			};
 
+			// Edit menu button.
+			control.container.find( '.edit-menu' ).on( 'click', function() {
+				var menuId = control.setting();
+				api.section( 'nav_menu[' + menuId + ']' ).focus();
+			});
+			control.setting.bind( 'change', function() {
+				if ( 0 === control.setting() ) {
+					control.container.find( '.edit-menu' ).addClass( 'hidden' );
+				} else {
+					control.container.find( '.edit-menu' ).removeClass( 'hidden' );
+				}
+			});
+
 			// Add/remove menus from the available options when they are added and removed.
 			api.bind( 'add', function( setting ) {
 				var option, menuId, matches = setting.id.match( navMenuIdRegex );

src/wp-includes/customize/class-wp-customize-nav-menu-location-control.php

@@ -77,6 +77,7 @@ class WP_Customize_Nav_Menu_Location_Control extends WP_Customize_Control {
 				?>
 			</select>
 		</label>
+		<button type="button" class="button edit-menu<?php if ( ! $this->value() ) { echo ' hidden'; } ?>"><?php _e( 'Edit' ); ?></button>
 		<?php
 	}
 }