Huy Nguyen 2149d44990 Fix naming convetion:
- "Layout node" is changed to "layout spec".
- Update tests.
- Update Kittens sample.
2015-07-01 18:13:44 +07:00

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/*
* 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.
*
*/
#import "ASLayout.h"
#import "ASAssert.h"
#import "ASLayoutSpecUtilities.h"
#import <stack>
CGPoint const CGPointNull = {NAN, NAN};
extern BOOL CGPointIsNull(CGPoint point)
{
return isnan(point.x) && isnan(point.y);
}
@implementation ASLayout
+ (instancetype)newWithLayoutableObject:(id<ASLayoutable>)layoutableObject
size:(CGSize)size
position:(CGPoint)position
children:(NSArray *)children
{
ASDisplayNodeAssert(layoutableObject, @"layoutableObject is required.");
for (ASLayout *child in children) {
ASDisplayNodeAssert(!CGPointIsNull(child.position), @"Invalid position is not allowed in children.");
}
ASLayout *l = [super new];
if (l) {
l->_layoutableObject = layoutableObject;
l->_size = size;
l->_position = position;
l->_children = [children copy];
}
return l;
}
+ (instancetype)newWithLayoutableObject:(id<ASLayoutable>)layoutableObject
size:(CGSize)size
children:(NSArray *)children
{
return [self newWithLayoutableObject:layoutableObject size:size position:CGPointNull children:children];
}
+ (instancetype)newWithLayoutableObject:(id<ASLayoutable>)layoutableObject size:(CGSize)size
{
return [self newWithLayoutableObject:layoutableObject size:size children:nil];
}
- (void)setPosition:(CGPoint)position
{
ASDisplayNodeAssert(CGPointIsNull(_position), @"Position can be set once and only once.");
ASDisplayNodeAssert(!CGPointIsNull(position), @"Position must not be set to null.");
_position = position;
}
- (ASLayout *)flattenedLayoutUsingPredicateBlock:(BOOL (^)(ASLayout *))predicateBlock
{
NSMutableArray *flattenedChildren = [NSMutableArray array];
struct Context {
ASLayout *layout;
CGPoint absolutePosition;
BOOL visited;
};
// Stack of Contexts, used to keep track of sublayouts while traversing this layout in a DFS fashion.
std::stack<Context> stack;
stack.push({self, CGPointMake(0, 0), NO});
while (!stack.empty()) {
Context &context = stack.top();
if (context.visited) {
stack.pop();
} else {
context.visited = YES;
if (predicateBlock(context.layout)) {
[flattenedChildren addObject:[ASLayout newWithLayoutableObject:context.layout.layoutableObject
size:context.layout.size
position:context.absolutePosition
children:nil]];
}
for (ASLayout *child in context.layout.children) {
stack.push({child, context.absolutePosition + child.position, NO});
}
}
}
return [ASLayout newWithLayoutableObject:_layoutableObject size:_size children:flattenedChildren];
}
@end