Merge commit '7621e2f8dec938cf48181c8b10afc9b01f444e68' into beta

submodules/AsyncDisplayKit/Source/ASScrollDirection.mm

@@ -0,0 +1,64 @@
+//
+//  ASScrollDirection.mm
+//  Texture
+//
+//  Copyright (c) Facebook, Inc. and its affiliates.  All rights reserved.
+//  Changes after 4/13/2017 are: Copyright (c) Pinterest, Inc.  All rights reserved.
+//  Licensed under Apache 2.0: http://www.apache.org/licenses/LICENSE-2.0
+//
+
+#import <AsyncDisplayKit/ASScrollDirection.h>
+
+const ASScrollDirection ASScrollDirectionHorizontalDirections = ASScrollDirectionLeft | ASScrollDirectionRight;
+const ASScrollDirection ASScrollDirectionVerticalDirections = ASScrollDirectionUp | ASScrollDirectionDown;
+
+BOOL ASScrollDirectionContainsVerticalDirection(ASScrollDirection scrollDirection) {
+  return (scrollDirection & ASScrollDirectionVerticalDirections) != 0;
+}
+
+BOOL ASScrollDirectionContainsHorizontalDirection(ASScrollDirection scrollDirection) {
+  return (scrollDirection & ASScrollDirectionHorizontalDirections) != 0;
+}
+
+BOOL ASScrollDirectionContainsRight(ASScrollDirection scrollDirection) {
+  return (scrollDirection & ASScrollDirectionRight) != 0;
+}
+
+BOOL ASScrollDirectionContainsLeft(ASScrollDirection scrollDirection) {
+  return (scrollDirection & ASScrollDirectionLeft) != 0;
+}
+
+BOOL ASScrollDirectionContainsUp(ASScrollDirection scrollDirection) {
+  return (scrollDirection & ASScrollDirectionUp) != 0;
+}
+
+BOOL ASScrollDirectionContainsDown(ASScrollDirection scrollDirection) {
+  return (scrollDirection & ASScrollDirectionDown) != 0;
+}
+
+ASScrollDirection ASScrollDirectionInvertHorizontally(ASScrollDirection scrollDirection) {
+  if (scrollDirection == ASScrollDirectionRight) {
+    return ASScrollDirectionLeft;
+  } else if (scrollDirection == ASScrollDirectionLeft) {
+    return ASScrollDirectionRight;
+  }
+  return scrollDirection;
+}
+
+ASScrollDirection ASScrollDirectionInvertVertically(ASScrollDirection scrollDirection) {
+  if (scrollDirection == ASScrollDirectionUp) {
+    return ASScrollDirectionDown;
+  } else if (scrollDirection == ASScrollDirectionDown) {
+    return ASScrollDirectionUp;
+  }
+  return scrollDirection;
+}
+
+ASScrollDirection ASScrollDirectionApplyTransform(ASScrollDirection scrollDirection, CGAffineTransform transform) {
+  if ((transform.a < 0) && ASScrollDirectionContainsHorizontalDirection(scrollDirection)) {
+    return ASScrollDirectionInvertHorizontally(scrollDirection);
+  } else if ((transform.d < 0) && ASScrollDirectionContainsVerticalDirection(scrollDirection)) {
+    return ASScrollDirectionInvertVertically(scrollDirection);
+  }
+  return scrollDirection;
+}