Improve PagerNode sample project

examples/PagerNode/Sample/ViewController.h

@@ -11,6 +11,6 @@
 
 #import <AsyncDisplayKit/AsyncDisplayKit.h>
 
-@interface ViewController : ASViewController
+@interface ViewController : ASViewController<ASPagerNode *>
 
 @end

examples/PagerNode/Sample/ViewController.m

@@ -15,9 +15,14 @@
 
 #import "PageNode.h"
 
-@interface ViewController () <ASPagerNodeDataSource>
+static UIColor *randomColor() {
+  CGFloat hue = ( arc4random() % 256 / 256.0 );  //  0.0 to 1.0
+  CGFloat saturation = ( arc4random() % 128 / 256.0 ) + 0.5;  //  0.5 to 1.0, away from white
+  CGFloat brightness = ( arc4random() % 128 / 256.0 ) + 0.5;  //  0.5 to 1.0, away from black
+  return [UIColor colorWithHue:hue saturation:saturation brightness:brightness alpha:1];
+}
 
-- (ASPagerNode *)node;
+@interface ViewController () <ASPagerNodeDataSource>
 
 @end
 
@@ -25,19 +30,30 @@
 
 - (instancetype)init
 {
-  if (!(self = [super initWithNode:[[ASPagerNode alloc] init]]))
-    return nil;
+  self = [super initWithNode:[[ASPagerNode alloc] init]];
+  if (self == nil) {
+    return self;
+  }
 
-  [self node].dataSource = self;
-  
   self.title = @"Pages";
+  self.node.dataSource = self;
+  
+  self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Next" style:UIBarButtonItemStylePlain target:self action:@selector(scrollToNextPage:)];
+  self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Previous" style:UIBarButtonItemStylePlain target:self action:@selector(scrollToPreviousPage:)];
 
   return self;
 }
 
-- (ASPagerNode *)node
+#pragma mark - Actions
+
+- (void)scrollToNextPage:(id)sender
 {
-  return (ASPagerNode *)[super node];
+  [self.node scrollToPageAtIndex:self.node.currentPageIndex+1 animated:YES];
+}
+
+- (void)scrollToPreviousPage:(id)sender
+{
+  [self.node scrollToPageAtIndex:self.node.currentPageIndex-1 animated:YES];
 }
 
 #pragma mark - ASPagerNodeDataSource
@@ -47,11 +63,13 @@
   return 5;
 }
 
-- (ASCellNode *)pagerNode:(ASPagerNode *)pagerNode nodeAtIndex:(NSInteger)index
+- (ASCellNodeBlock)pagerNode:(ASPagerNode *)pagerNode nodeBlockAtIndex:(NSInteger)index
 {
-  PageNode *page = [[PageNode alloc] init];
-  page.backgroundColor = [UIColor blueColor];
-  return page;
+  return ^{
+    PageNode *page = [[PageNode alloc] init];
+    page.backgroundColor = randomColor();
+    return page;
+  };
 }
 
 @end