Ryan Nystrom d27c8859c7 Node placeholder API
ASDisplayNodes now have an overidable method -placeholderImage that lets you provide a custom UIImage to display while a node is displaying asyncronously. The default implementation of this method returns nil and thus does nothing. A provided example project also demonstrates using the placeholder API.
2014-12-15 17:23:52 -08:00

150 lines
6.7 KiB
Objective-C

/* This file provided by Facebook is for non-commercial testing and evaluation
* purposes only. Facebook reserves all rights not expressly granted.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#import "KittenNode.h"
#import <AsyncDisplayKit/ASDisplayNode+Subclasses.h>
static const CGFloat kImageSize = 80.0f;
static const CGFloat kOuterPadding = 16.0f;
static const CGFloat kInnerPadding = 10.0f;
@interface KittenNode ()
{
CGSize _kittenSize;
ASNetworkImageNode *_imageNode;
ASTextNode *_textNode;
ASDisplayNode *_divider;
}
@end
@implementation KittenNode
// lorem ipsum text courtesy http://kittyipsum.com/ <3
+ (NSArray *)placeholders
{
static NSArray *placeholders = nil;
static dispatch_once_t once;
dispatch_once(&once, ^{
placeholders = @[
@"Kitty ipsum dolor sit amet, purr sleep on your face lay down in your way biting, sniff tincidunt a etiam fluffy fur judging you stuck in a tree kittens.",
@"Lick tincidunt a biting eat the grass, egestas enim ut lick leap puking climb the curtains lick.",
@"Lick quis nunc toss the mousie vel, tortor pellentesque sunbathe orci turpis non tail flick suscipit sleep in the sink.",
@"Orci turpis litter box et stuck in a tree, egestas ac tempus et aliquam elit.",
@"Hairball iaculis dolor dolor neque, nibh adipiscing vehicula egestas dolor aliquam.",
@"Sunbathe fluffy fur tortor faucibus pharetra jump, enim jump on the table I don't like that food catnip toss the mousie scratched.",
@"Quis nunc nam sleep in the sink quis nunc purr faucibus, chase the red dot consectetur bat sagittis.",
@"Lick tail flick jump on the table stretching purr amet, rhoncus scratched jump on the table run.",
@"Suspendisse aliquam vulputate feed me sleep on your keyboard, rip the couch faucibus sleep on your keyboard tristique give me fish dolor.",
@"Rip the couch hiss attack your ankles biting pellentesque puking, enim suspendisse enim mauris a.",
@"Sollicitudin iaculis vestibulum toss the mousie biting attack your ankles, puking nunc jump adipiscing in viverra.",
@"Nam zzz amet neque, bat tincidunt a iaculis sniff hiss bibendum leap nibh.",
@"Chase the red dot enim puking chuf, tristique et egestas sniff sollicitudin pharetra enim ut mauris a.",
@"Sagittis scratched et lick, hairball leap attack adipiscing catnip tail flick iaculis lick.",
@"Neque neque sleep in the sink neque sleep on your face, climb the curtains chuf tail flick sniff tortor non.",
@"Ac etiam kittens claw toss the mousie jump, pellentesque rhoncus litter box give me fish adipiscing mauris a.",
@"Pharetra egestas sunbathe faucibus ac fluffy fur, hiss feed me give me fish accumsan.",
@"Tortor leap tristique accumsan rutrum sleep in the sink, amet sollicitudin adipiscing dolor chase the red dot.",
@"Knock over the lamp pharetra vehicula sleep on your face rhoncus, jump elit cras nec quis quis nunc nam.",
@"Sollicitudin feed me et ac in viverra catnip, nunc eat I don't like that food iaculis give me fish.",
];
});
return placeholders;
}
- (instancetype)initWithKittenOfSize:(CGSize)size
{
if (!(self = [super init]))
return nil;
_kittenSize = size;
// kitten image, with a purple background colour serving as placeholder
_imageNode = [[ASNetworkImageNode alloc] init];
_imageNode.backgroundColor = ASDisplayNodeDefaultPlaceholderColor();
_imageNode.URL = [NSURL URLWithString:[NSString stringWithFormat:@"http://placekitten.com/%zd/%zd",
(NSInteger)roundl(_kittenSize.width),
(NSInteger)roundl(_kittenSize.height)]];
// _imageNode.contentMode = UIViewContentModeCenter;
[self addSubnode:_imageNode];
// lorem ipsum text, plus some nice styling
_textNode = [[ASTextNode alloc] init];
_textNode.attributedString = [[NSAttributedString alloc] initWithString:[self kittyIpsum]
attributes:[self textStyle]];
[self addSubnode:_textNode];
// hairline cell separator
_divider = [[ASDisplayNode alloc] init];
_divider.backgroundColor = [UIColor lightGrayColor];
[self addSubnode:_divider];
return self;
}
- (NSString *)kittyIpsum
{
NSArray *placeholders = [KittenNode placeholders];
u_int32_t ipsumCount = (u_int32_t)[placeholders count];
u_int32_t location = arc4random_uniform(ipsumCount);
u_int32_t length = arc4random_uniform(ipsumCount - location);
NSMutableString *string = [placeholders[location] mutableCopy];
for (u_int32_t i = location + 1; i < location + length; i++) {
[string appendString:(i % 2 == 0) ? @"\n" : @" "];
[string appendString:placeholders[i]];
}
return string;
}
- (NSDictionary *)textStyle
{
UIFont *font = [UIFont fontWithName:@"HelveticaNeue" size:12.0f];
NSMutableParagraphStyle *style = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
style.paragraphSpacing = 0.5 * font.lineHeight;
style.hyphenationFactor = 1.0;
return @{ NSFontAttributeName: font,
NSParagraphStyleAttributeName: style };
}
- (CGSize)calculateSizeThatFits:(CGSize)constrainedSize
{
CGSize imageSize = CGSizeMake(kImageSize, kImageSize);
CGSize textSize = [_textNode measure:CGSizeMake(constrainedSize.width - kImageSize - 2 * kOuterPadding - kInnerPadding,
constrainedSize.height)];
// ensure there's room for the text
CGFloat requiredHeight = MAX(textSize.height, imageSize.height);
return CGSizeMake(constrainedSize.width, requiredHeight + 2 * kOuterPadding);
}
- (void)layout
{
CGFloat pixelHeight = 1.0f / [[UIScreen mainScreen] scale];
_divider.frame = CGRectMake(0.0f, 0.0f, self.calculatedSize.width, pixelHeight);
_imageNode.frame = CGRectMake(kOuterPadding, kOuterPadding, kImageSize, kImageSize);
CGSize textSize = _textNode.calculatedSize;
_textNode.frame = CGRectMake(kOuterPadding + kImageSize + kInnerPadding, kOuterPadding, textSize.width, textSize.height);
}
@end