From c552d86639c2aa26ce9deaf923939db93ff70531 Mon Sep 17 00:00:00 2001
From: Richard Davey <rdavey@gmail.com>
Date: Thu, 5 Sep 2013 02:11:54 +0100
Subject: [PATCH] Added swapChildren to Phaser.World

---
 examples/bringToTop.php | 15 +-------
 src/core/World.js       | 81 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+), 13 deletions(-)

diff --git a/examples/bringToTop.php b/examples/bringToTop.php
index 09f98eb06..26c663be2 100644
--- a/examples/bringToTop.php
+++ b/examples/bringToTop.php
@@ -71,10 +71,9 @@
 
 	function changeOrder (node1, node2) {
 
-		// if (node1 === node2 || node1.parent !== node2.parent)
-		if (node1 === node2)
+		if (node1 === node2 || !node1.parent || !node2.parent)
 		{
-			console.warn("You cannot swap a node with itself or re-parent");
+			console.warn("You cannot swap a node with itself or swap un-parented nodes");
 			return;
 		}
 
@@ -88,12 +87,8 @@
 			//	Cache the node values
 			var node1Prev = node1._iPrev;
 			var node1Next = node1._iNext;
-			// var node1First = node1.first;
-			// var node1Last = node1.last;
 			var node2Prev = node2._iPrev;
 			var node2Next = node2._iNext;
-			// var node2First = node2.first;
-			// var node2Last = node2.last;
 
 			//	Now deep scan search and replace
 			var currentNode = game.world._stage;
@@ -103,29 +98,23 @@
 			
 			do	
 			{
-				// console.log('Checking', currentNode.name, currentNode.first.name, currentNode.last.name);
-
 				if (currentNode !== node1 && currentNode !== node2)
 				{
 					if (currentNode.first === node1)
 					{
-						console.log('F1');
 						currentNode.first = node2;
 					}
 					else if (currentNode.first === node2)
 					{
-						console.log('F2');
 						currentNode.first = node1;
 					}
 
 					if (currentNode.last === node1)
 					{
-						console.log('L1');
 						currentNode.last = node2;
 					}
 					else if (currentNode.last === node2)
 					{
-						console.log('L2');
 						currentNode.last = node1;
 					}
 				}
diff --git a/src/core/World.js b/src/core/World.js
index 988cd5423..08e0012d4 100644
--- a/src/core/World.js
+++ b/src/core/World.js
@@ -105,6 +105,87 @@ Phaser.World.prototype = {
 
 	},
 
+	swapChildren: function (stage, node1, node2) {
+
+		if (node1 === node2 || !node1.parent || !node2.parent)
+		{
+			console.warn('You cannot swap a node with itself or swap un-parented nodes');
+			return;
+		}
+
+		//	Cache the node values
+		var node1Prev = node1._iPrev;
+		var node1Next = node1._iNext;
+		var node2Prev = node2._iPrev;
+		var node2Next = node2._iNext;
+
+		var endNode = stage.last._iNext;
+		var currentNode = stage.first;
+			
+		do	
+		{
+			if (currentNode !== node1 && currentNode !== node2)
+			{
+				if (currentNode.first === node1)
+				{
+					currentNode.first = node2;
+				}
+				else if (currentNode.first === node2)
+				{
+					currentNode.first = node1;
+				}
+
+				if (currentNode.last === node1)
+				{
+					currentNode.last = node2;
+				}
+				else if (currentNode.last === node2)
+				{
+					currentNode.last = node1;
+				}
+			}
+
+			currentNode = currentNode._iNext;
+		}
+		while (currentNode != endNode)
+
+		if (node1._iNext == node2)
+		{
+			//	This is an A-B neighbour swap
+			node1._iNext = node2Next;
+			node1._iPrev = node2;
+			node2._iNext = node1;
+			node2._iPrev = node1Prev;
+
+			if (node1Prev) { node1Prev._iNext = node2; }
+			if (node2Next) { node2Next._iPrev = node1; }
+		}
+		else if (node2._iNext == node1)
+		{
+			//	This is a B-A neighbour swap
+			node1._iNext = node2;
+			node1._iPrev = node2Prev;
+			node2._iNext = node1Next;
+			node2._iPrev = node1;
+
+			if (node2Prev) { node2Prev._iNext = node1; }
+			if (node1Next) { node2Next._iPrev = node2; }
+		}
+		else
+		{
+			//	Nodes are far apart
+			node1._iNext = node2Next;
+			node1._iPrev = node2Prev;
+			node2._iNext = node1Next;
+			node2._iPrev = node1Prev;
+
+			if (node1Prev) { node1Prev._iNext = node2; }
+			if (node1Next) { node1Next._iPrev = node2; }
+			if (node2Prev) { node2Prev._iNext = node1; }
+			if (node2Next) { node2Next._iPrev = node1; }
+		}
+	}
+
 };
 
 //	Getters / Setters