Swiftgram/examples/Placeholders/Sample/SlowpokeImageNode.m
Ryan Nystrom 912bc9d460 Fade out placeholders
Added an API to fade out a node's placeholder when it is finished rendering.

fixes #156
2014-12-18 12:53:15 -08:00

70 lines
2.1 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
* FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* 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 "SlowpokeImageNode.h"
#import <AsyncDisplayKit/ASDisplayNode+Subclasses.h>
static CGFloat const kASDKLogoAspectRatio = 2.79;
@implementation SlowpokeImageNode
+ (UIImage *)displayWithParameters:(id<NSObject>)parameters isCancelled:(asdisplaynode_iscancelled_block_t)isCancelledBlock
{
usleep( (long)(0.5 * USEC_PER_SEC) ); // artificial delay of 0.5s
return [super displayWithParameters:parameters isCancelled:isCancelledBlock];
}
- (instancetype)init
{
if (self = [super init]) {
self.placeholderEnabled = YES;
self.fadeOutPlaceholder = YES;
}
return self;
}
- (CGSize)calculateSizeThatFits:(CGSize)constrainedSize
{
if (constrainedSize.width > 0.0) {
return CGSizeMake(constrainedSize.width, constrainedSize.width / kASDKLogoAspectRatio);
} else if (constrainedSize.height > 0.0) {
return CGSizeMake(constrainedSize.height * kASDKLogoAspectRatio, constrainedSize.height);
}
return CGSizeZero;
}
- (UIImage *)placeholderImage
{
CGSize size = self.calculatedSize;
UIGraphicsBeginImageContext(size);
[[UIColor whiteColor] setFill];
[[UIColor colorWithWhite:0.9 alpha:1] setStroke];
UIRectFill((CGRect){CGPointZero, size});
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointZero];
[path addLineToPoint:(CGPoint){size.width, size.height}];
[path stroke];
[path moveToPoint:(CGPoint){size.width, 0.0}];
[path addLineToPoint:(CGPoint){0.0, size.height}];
[path stroke];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
@end