Swiftgram/AsyncDisplayKit/Layout/ASLayoutOptions.m

121 lines
3.4 KiB
Objective-C

//
// ASLayoutOptions.m
// AsyncDisplayKit
//
// Created by Ricky Cancro on 8/27/15.
// Copyright (c) 2015 Facebook. All rights reserved.
//
#import "ASLayoutOptions.h"
#import <AsyncDisplayKit/ASAssert.h>
#import <AsyncDisplayKit/ASTextNode.h>
#import "ASInternalHelpers.h"
#import <objc/runtime.h>
@implementation ASLayoutOptions
- (instancetype)initWithLayoutable:(id<ASLayoutable>)layoutable;
{
self = [super init];
if (self) {
[self setupDefaults];
[self setValuesFromLayoutable:layoutable];
#if DEBUG
[self addObserver:self forKeyPath:@"changeMonitor"
options:NSKeyValueObservingOptionNew
context:nil];
#endif
}
return self;
}
#if DEBUG
+ (NSSet *)keyPathsForValuesAffectingChangeMonitor
{
NSMutableSet *keys = [NSMutableSet set];
unsigned int count;
objc_property_t *properties = class_copyPropertyList([self class], &count);
for (size_t i = 0; i < count; ++i) {
NSString *property = [NSString stringWithCString:property_getName(properties[i]) encoding:NSASCIIStringEncoding];
if ([property isEqualToString: @"observableSelf"] == NO) {
[keys addObject: property];
}
}
free(properties);
return keys;
}
#endif
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
#if DEBUG
if ([keyPath isEqualToString:@"changeMonitor"]) {
ASDisplayNodeAssert(self.isMutable, @"You cannot alter this class once it is marked as immutable");
} else
#endif
{
[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
}
}
#pragma mark - NSCopying
- (id)copyWithZone:(NSZone *)zone
{
ASLayoutOptions *copy = [[[self class] alloc] init];
copy.flexBasis = self.flexBasis;
copy.spacingAfter = self.spacingAfter;
copy.spacingBefore = self.spacingBefore;
copy.flexGrow = self.flexGrow;
copy.flexShrink = self.flexShrink;
copy.ascender = self.ascender;
copy.descender = self.descender;
copy.sizeRange = self.sizeRange;
copy.position = self.position;
return copy;
}
#pragma mark - Defaults
- (void)setupDefaults
{
_flexBasis = ASRelativeDimensionUnconstrained;
_spacingBefore = 0;
_spacingAfter = 0;
_flexGrow = NO;
_flexShrink = NO;
_alignSelf = ASStackLayoutAlignSelfAuto;
_ascender = 0;
_descender = 0;
_sizeRange = ASRelativeSizeRangeMake(ASRelativeSizeMakeWithCGSize(CGSizeZero), ASRelativeSizeMakeWithCGSize(CGSizeZero));
_position = CGPointZero;
}
// Do this here instead of in Node/Spec subclasses so that custom specs can set default values
- (void)setValuesFromLayoutable:(id<ASLayoutable>)layoutable
{
if ([layoutable isKindOfClass:[ASTextNode class]]) {
ASTextNode *textNode = (ASTextNode *)layoutable;
self.ascender = round([[textNode.attributedString attribute:NSFontAttributeName atIndex:0 effectiveRange:NULL] ascender] * ASScreenScale())/ASScreenScale();
self.descender = round([[textNode.attributedString attribute:NSFontAttributeName atIndex:textNode.attributedString.length - 1 effectiveRange:NULL] descender] * ASScreenScale())/ASScreenScale();
}
if ([layoutable isKindOfClass:[ASDisplayNode class]]) {
ASDisplayNode *displayNode = (ASDisplayNode *)layoutable;
self.sizeRange = ASRelativeSizeRangeMake(ASRelativeSizeMakeWithCGSize(displayNode.preferredFrameSize), ASRelativeSizeMakeWithCGSize(displayNode.preferredFrameSize));
self.position = displayNode.frame.origin;
}
}
@end