Shuffle & Cleanup Stuff (#3080)

Source/Private/ASDisplayNodeLayout.h

@@ -0,0 +1,59 @@
+//
+//  ASDisplayNodeLayout.h
+//  AsyncDisplayKit
+//
+//  Created by Michael Schneider on 08/26/16.
+//
+//  Copyright (c) 2014-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under the BSD-style license found in the
+//  LICENSE file in the root directory of this source tree. An additional grant
+//  of patent rights can be found in the PATENTS file in the same directory.
+//
+
+#pragma once
+
+#import <AsyncDisplayKit/ASDimension.h>
+
+@class ASLayout;
+
+/*
+ * Represents a connection between an ASLayout and a ASDisplayNode
+ * ASDisplayNode uses this to store additional information that are necessary besides the layout
+ */
+struct ASDisplayNodeLayout {
+  ASLayout *layout;
+  ASSizeRange constrainedSize;
+  CGSize parentSize;
+  BOOL requestedLayoutFromAbove;
+  BOOL _dirty;
+  
+  /*
+   * Create a new display node layout with
+   * @param layout The layout to associate, usually returned from a call to -layoutThatFits:parentSize:
+   * @param constrainedSize Constrained size used to create the layout
+   * @param parentSize Parent size used to create the layout
+   */
+  ASDisplayNodeLayout(ASLayout *layout, ASSizeRange constrainedSize, CGSize parentSize)
+  : layout(layout), constrainedSize(constrainedSize), parentSize(parentSize), requestedLayoutFromAbove(NO), _dirty(NO) {};
+  
+  /*
+   * Creates a layout without any layout associated. By default this display node layout is dirty.
+   */
+  ASDisplayNodeLayout()
+  : layout(nil), constrainedSize({{0, 0}, {0, 0}}), parentSize({0, 0}), requestedLayoutFromAbove(NO), _dirty(YES) {};
+  
+  /**
+   * Returns if the display node layout is dirty as it was invalidated or it was created without a layout.
+   */
+  BOOL isDirty();
+  
+  /**
+   * Returns if ASDisplayNode is still valid for a given constrained and parent size
+   */
+  BOOL isValidForConstrainedSizeParentSize(ASSizeRange constrainedSize, CGSize parentSize);
+  
+  /**
+   * Invalidate the display node layout
+   */
+  void invalidate();
+};