Add functioning header/footer supplementary view support to example

examples/ASCollectionView/Sample/SupplementaryNode.h

@@ -0,0 +1,18 @@
+/* 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 <AsyncDisplayKit/AsyncDisplayKit.h>
+
+@interface SupplementaryNode : ASDisplayNode
+
+- (instancetype)initWithText:(NSString *)text;
+
+@end

examples/ASCollectionView/Sample/SupplementaryNode.m

@@ -0,0 +1,54 @@
+/* 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 "SupplementaryNode.h"
+
+#import <AsyncDisplayKit/ASDisplayNode+Subclasses.h>
+#import <AsyncDisplayKit/ASInsetLayoutSpec.h>
+#import <AsyncDisplayKit/ASCenterLayoutSpec.h>
+
+static CGFloat kInsets = 15.0;
+
+@implementation SupplementaryNode {
+  ASTextNode *_textNode;
+}
+
+- (instancetype)initWithText:(NSString *)text
+{
+  self = [super init];
+  if (self != nil) {
+    _textNode = [[ASTextNode alloc] init];
+    _textNode.attributedString = [[NSAttributedString alloc] initWithString:text
+                                                                 attributes:[self textAttributes]];
+    [self addSubnode:_textNode];
+  }
+  return self;
+}
+
+- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
+{
+  ASCenterLayoutSpec *center = [[ASCenterLayoutSpec alloc] init];
+  center.child = _textNode;
+  UIEdgeInsets insets = UIEdgeInsetsMake(kInsets, kInsets, kInsets, kInsets);
+  return [ASInsetLayoutSpec insetLayoutSpecWithInsets:insets child:center];
+}
+
+#pragma mark - Text Formatting
+
+- (NSDictionary *)textAttributes
+{
+  return @{
+           NSFontAttributeName: [UIFont systemFontOfSize:18.0],
+           NSForegroundColorAttributeName: [UIColor whiteColor],
+           };
+}
+
+@end

examples/ASCollectionView/Sample/ViewController.m

@@ -12,6 +12,7 @@
 #import "ViewController.h"
 
 #import <AsyncDisplayKit/AsyncDisplayKit.h>
+#import "SupplementaryNode.h"
 
 @interface ViewController () <ASCollectionViewDataSource, ASCollectionViewDelegateFlowLayout>
 {
@@ -32,8 +33,8 @@
     return nil;
   
   UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
-  layout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
   layout.headerReferenceSize = CGSizeMake(50.0, 50.0);
+  layout.footerReferenceSize = CGSizeMake(50.0, 50.0);
   
   _collectionView = [[ASCollectionView alloc] initWithFrame:CGRectZero collectionViewLayout:layout asyncDataFetching:YES];
   _collectionView.asyncDataSource = self;
@@ -79,7 +80,8 @@
 
 - (ASDisplayNode *)collectionView:(ASCollectionView *)collectionView nodeForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
 {
-  ASDisplayNode *node = [[ASDisplayNode alloc] init];
+  NSString *text = [kind isEqualToString:UICollectionElementKindSectionHeader] ? @"Header" : @"Footer";
+  SupplementaryNode *node = [[SupplementaryNode alloc] initWithText:text];
   if ([kind isEqualToString:UICollectionElementKindSectionHeader]) {
     node.backgroundColor = [UIColor blueColor];
   } else {