From e11cc3ec4fb65db545e8e50db35420550b3e24fe Mon Sep 17 00:00:00 2001
From: koopersmith <koopersmith@1a063a9b-81f0-0310-95a4-ce76da25c4cd>
Date: Mon, 16 Apr 2012 23:07:23 +0000
Subject: [PATCH] Theme Customizer: Integrate with browser history. Use
 window.history by default, with window.onhashchange as a fallback. fixes
 #20337, see #19910.

git-svn-id: http://svn.automattic.com/wordpress/trunk@20488 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/js/customize-loader.dev.js | 58 ++++++++++++++++++++++++--
 wp-includes/theme.php                  |  1 +
 2 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/wp-includes/js/customize-loader.dev.js b/wp-includes/js/customize-loader.dev.js
index 1e1032765..c2e92a639 100644
--- a/wp-includes/js/customize-loader.dev.js
+++ b/wp-includes/js/customize-loader.dev.js
@@ -6,9 +6,15 @@ if ( typeof wp === 'undefined' )
 		Loader;
 
 	Loader = {
+		supports: {
+			history:  !! ( window.history && history.pushState ),
+			hashchange: ('onhashchange' in window) && (document.documentMode === undefined || document.documentMode > 7)
+		},
+
 		initialize: function() {
-			this.body      = $( document.body ).addClass('customize-support');
-			this.element   = $( '<div id="customize-container" class="wp-full-overlay" />' ).appendTo( this.body );
+			this.body    = $( document.body ).addClass('customize-support');
+			this.window  = $( window );
+			this.element = $( '<div id="customize-container" class="wp-full-overlay" />' ).appendTo( this.body );
 
 			$('#wpbody').on( 'click', '.load-customize', function( event ) {
 				event.preventDefault();
@@ -16,8 +22,35 @@ if ( typeof wp === 'undefined' )
 				// Load the theme.
 				Loader.open( $(this).attr('href') );
 			});
+
+			// Add navigation listeners.
+			if ( this.supports.history )
+				this.window.on( 'popstate', Loader.popstate );
+
+			if ( this.supports.hashchange )
+				this.window.on( 'hashchange', Loader.hashchange );
+		},
+		popstate: function( e ) {
+			var state = e.originalEvent.state;
+			if ( state && state.customize )
+				Loader.open( state.customize );
+			else if ( Loader.active )
+				Loader.close();
+		},
+		hashchange: function( e ) {
+			var hash = window.location.toString().split('#')[1];
+
+			if ( hash && 0 === hash.indexOf( 'customize=on' ) )
+				Loader.open( wpCustomizeLoaderL10n.url + '?' + hash );
+
+			if ( ! hash )
+				Loader.close();
 		},
 		open: function( src ) {
+			if ( this.active )
+				return;
+			this.active = true;
+
 			this.iframe = $( '<iframe />', { src: src }).appendTo( this.element );
 
 			// Create a postMessage connection with the iframe.
@@ -29,14 +62,31 @@ if ( typeof wp === 'undefined' )
 			});
 
 			this.messenger.bind( 'close', function() {
-				Loader.close();
+				if ( Loader.supports.history )
+					history.back();
+				else if ( Loader.supports.hashchange )
+					window.location.hash = '';
+				else
+					Loader.close();
 			});
 
 			this.element.fadeIn( 200, function() {
+				var hash = src.split('?')[1];
+
 				Loader.body.addClass( 'customize-active full-overlay-active' );
+
+				// Ensure we don't call pushState if the user hit the forward button.
+				if ( Loader.supports.history && window.location.href !== src )
+					history.pushState( { customize: src }, '', src );
+				else if ( Loader.supports.hashchange && hash )
+					window.location.hash = hash;
 			});
 		},
 		close: function() {
+			if ( ! this.active )
+				return;
+			this.active = false;
+
 			this.element.fadeOut( 200, function() {
 				Loader.iframe.remove();
 				Loader.iframe    = null;
@@ -47,7 +97,7 @@ if ( typeof wp === 'undefined' )
 	};
 
 	$( function() {
-		if ( !! window.postMessage )
+		if ( window.postMessage )
 			Loader.initialize();
 	});
 
diff --git a/wp-includes/theme.php b/wp-includes/theme.php
index 5a6785a8a..ce9bb55f5 100644
--- a/wp-includes/theme.php
+++ b/wp-includes/theme.php
@@ -1590,6 +1590,7 @@ add_action( 'plugins_loaded', '_wp_customize_include' );
 function _wp_customize_loader_localize() {
 	wp_localize_script( 'customize-loader', 'wpCustomizeLoaderL10n', array(
 		'back' => sprintf( __( '&larr; Return to %s' ), get_admin_page_title() ),
+		'url'  => admin_url( 'admin.php' ),
 	) );
 }
 add_action( 'admin_enqueue_scripts', '_wp_customize_loader_localize' );