Swiftgram/AsyncDisplayKit/Layout/ASLayoutSpec.mm

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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 "ASLayoutSpec.h"
#import "ASAssert.h"
#import "ASBaseDefines.h"
#import "ASInternalHelpers.h"
#import "ASLayout.h"
#import "ASLayoutOptions.h"
#import "ASLayoutOptionsPrivate.h"
#import <objc/runtime.h>
static NSString * const kDefaultChildKey = @"kDefaultChildKey";
static NSString * const kDefaultChildrenKey = @"kDefaultChildrenKey";
@interface ASLayoutSpec()
@property (nonatomic, strong) NSMutableDictionary *layoutChildren;
@end
@implementation ASLayoutSpec
@dynamic spacingAfter, spacingBefore, flexGrow, flexShrink, flexBasis, alignSelf, ascender, descender, sizeRange, layoutPosition, layoutOptions;
@synthesize layoutChildren = _layoutChildren;
@synthesize isFinalLayoutable = _isFinalLayoutable;
- (instancetype)init
{
if (!(self = [super init])) {
return nil;
}
_layoutChildren = [NSMutableDictionary dictionary];
_isMutable = YES;
return self;
}
#pragma mark - Layout
- (ASLayout *)measureWithSizeRange:(ASSizeRange)constrainedSize
{
return [ASLayout layoutWithLayoutableObject:self size:constrainedSize.min];
}
- (id<ASLayoutable>)finalLayoutable
{
return self;
}
- (void)setChild:(id<ASLayoutable>)child;
{
[self setChild:child forIdentifier:kDefaultChildKey];
}
- (id<ASLayoutable>)layoutableToAddFromLayoutable:(id<ASLayoutable>)child
{
if (self.isFinalLayoutable == NO) {
// If you are getting recursion crashes here after implementing finalLayoutable, make sure
// that you are setting isFinalLayoutable flag to YES BEFORE adding a child to the new ASLayoutable.
//
// For example:
//- (id<ASLayoutable>)finalLayoutable
//{
// ASInsetLayoutSpec *insetSpec = [[ASInsetLayoutSpec alloc] init];
// insetSpec.insets = UIEdgeInsetsMake(10,10,10,10);
// insetSpec.isFinalLayoutable = YES;
// [insetSpec setChild:self];
// return insetSpec;
//}
id<ASLayoutable> finalLayoutable = [child finalLayoutable];
if (finalLayoutable != child) {
ASLayoutOptions *layoutOptions = [child layoutOptions];
[layoutOptions copyIntoOptions:finalLayoutable.layoutOptions];
return finalLayoutable;
}
}
return child;
}
- (void)setChild:(id<ASLayoutable>)child forIdentifier:(NSString *)identifier
{
ASDisplayNodeAssert(self.isMutable, @"Cannot set properties when layout spec is not mutable");
self.layoutChildren[identifier] = [self layoutableToAddFromLayoutable:child];;
}
- (void)setChildren:(NSArray *)children
{
ASDisplayNodeAssert(self.isMutable, @"Cannot set properties when layout spec is not mutable");
NSMutableArray *finalChildren = [NSMutableArray arrayWithCapacity:children.count];
for (id<ASLayoutable> child in children) {
[finalChildren addObject:[self layoutableToAddFromLayoutable:child]];
}
self.layoutChildren[kDefaultChildrenKey] = [NSArray arrayWithArray:finalChildren];
}
- (id<ASLayoutable>)childForIdentifier:(NSString *)identifier
{
return self.layoutChildren[identifier];
}
- (id<ASLayoutable>)child
{
return self.layoutChildren[kDefaultChildKey];
}
- (NSArray *)children
{
return self.layoutChildren[kDefaultChildrenKey];
}
@end