From f6f3c89dc822da00800434408e89d45cd197883e Mon Sep 17 00:00:00 2001
From: Loz Calver <lozcalver@bigfork.co.uk>
Date: Tue, 22 Dec 2015 14:59:04 +0000
Subject: [PATCH] Add SSViewer_Scope constants to make it easier to work with
 item stacks

---
 view/SSViewer.php | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/view/SSViewer.php b/view/SSViewer.php
index 970c0a882..34c3b7148 100644
--- a/view/SSViewer.php
+++ b/view/SSViewer.php
@@ -24,8 +24,16 @@
  */
 class SSViewer_Scope {
 
+	const ITEM = 0;
+	const ITEM_ITERATOR = 1;
+	const ITEM_ITERATOR_TOTAL = 2;
+	const POP_INDEX = 3;
+	const UP_INDEX = 4;
+	const CURRENT_INDEX = 5;
+	const ITEM_OVERLAY = 6;
+	
 	// The stack of previous "global" items
-	// And array of item, itemIterator, itemIteratorTotal, pop_index, up_index, current_index, parent_overlay
+	// An indexed array of item, item iterator, item iterator total, pop index, up index, current index & parent overlay
 	private $itemStack = array(); 
 
 	// The current "global" item (the one any lookup starts from)
@@ -135,12 +143,12 @@ class SSViewer_Scope {
 	public function pushScope(){
 		$newLocalIndex = count($this->itemStack)-1;
 
-		$this->popIndex = $this->itemStack[$newLocalIndex][3] = $this->localIndex;
+		$this->popIndex = $this->itemStack[$newLocalIndex][SSViewer_Scope::POP_INDEX] = $this->localIndex;
 		$this->localIndex = $newLocalIndex;
 
 		// We normally keep any previous itemIterator around, so local $Up calls reference the right element. But
 		// once we enter a new global scope, we need to make sure we use a new one
-		$this->itemIterator = $this->itemStack[$newLocalIndex][1] = null;
+		$this->itemIterator = $this->itemStack[$newLocalIndex][SSViewer_Scope::ITEM_ITERATOR] = null;
 
 		return $this;
 	}
@@ -159,9 +167,9 @@ class SSViewer_Scope {
 			if (is_array($this->item)) $this->itemIterator = new ArrayIterator($this->item);
 			else $this->itemIterator = $this->item->getIterator();
 
-			$this->itemStack[$this->localIndex][1] = $this->itemIterator;
+			$this->itemStack[$this->localIndex][SSViewer_Scope::ITEM_ITERATOR] = $this->itemIterator;
 			$this->itemIteratorTotal = iterator_count($this->itemIterator); //count the total number of items
-			$this->itemStack[$this->localIndex][2] = $this->itemIteratorTotal;
+			$this->itemStack[$this->localIndex][SSViewer_Scope::ITEM_ITERATOR_TOTAL] = $this->itemIteratorTotal;
 			$this->itemIterator->rewind();
 		}
 		else {
@@ -552,7 +560,7 @@ class SSViewer_DataPresenter extends SSViewer_Scope {
 		$scope = parent::pushScope();
 
 		$itemStack = $this->getItemStack();
-		$itemStack[$this->getUpIndex()][6] = $this->overlay;
+		$itemStack[$this->getUpIndex()][SSViewer_Scope::ITEM_OVERLAY] = $this->overlay;
 
 		$this->setItemStack($itemStack);
 		$this->overlay = array();
@@ -568,7 +576,7 @@ class SSViewer_DataPresenter extends SSViewer_Scope {
 	 */
 	public function popScope() {
 		$itemStack = $this->getItemStack();
-		$this->overlay = $itemStack[$this->getUpIndex()][6];
+		$this->overlay = $itemStack[$this->getUpIndex()][SSViewer_Scope::ITEM_OVERLAY];
 
 		return parent::popScope();
 	}
@@ -596,8 +604,8 @@ class SSViewer_DataPresenter extends SSViewer_Scope {
 
 		if ($overlayIndex !== false) {
 			$itemStack = $this->getItemStack();
-			if (!$this->overlay && isset($itemStack[$overlayIndex][6])) {
-				$this->overlay = $itemStack[$overlayIndex][6];
+			if (!$this->overlay && isset($itemStack[$overlayIndex][SSViewer_Scope::ITEM_OVERLAY])) {
+				$this->overlay = $itemStack[$overlayIndex][SSViewer_Scope::ITEM_OVERLAY];
 			}
 		}