Implement sizeToFit:

AsyncDisplayKit/ASDisplayNode.h

@@ -269,6 +269,7 @@ extern NSInteger const ASDefaultDrawingPriority;
 
 @property (nonatomic, readwrite, weak, nullable) id<ASDisplayNodeSizingDelegate> sizingDelegate;
 - (void)invalidateSize;
+- (void)sizeToFit;
 
 - (CGSize)sizeThatFits:(CGSize)size;
 

AsyncDisplayKit/ASDisplayNode.mm

@@ -730,6 +730,36 @@ static ASDisplayNodeMethodOverrides GetASDisplayNodeMethodOverrides(Class c)
   __instanceLock__.unlock();
 }
 
+- (void)sizeToFit
+{
+  ASDisplayNodeAssertThreadAffinity(self);
+  
+  __instanceLock__.lock();
+  
+  [self setNeedsLayout];
+  
+  CGSize maxSize = _supernode ? _supernode.bounds.size : CGSizeMake(CGFLOAT_MAX, CGFLOAT_MAX);
+  CGSize size = [self sizeThatFits:maxSize];
+  
+  CGRect oldBounds = self.bounds;
+  CGSize oldSize = oldBounds.size;
+  CGSize newSize = _calculatedDisplayNodeLayout->layout.size;
+  
+  if (! CGSizeEqualToSize(oldSize, newSize)) {
+    self.bounds = (CGRect){ oldBounds.origin, newSize };
+    
+    // Frame's origin must be preserved. Since it is computed from bounds size, anchorPoint
+    // and position (see frame setter in ASDisplayNode+UIViewBridge), position needs to be adjusted.
+    CGPoint anchorPoint = self.anchorPoint;
+    CGPoint oldPosition = self.position;
+    CGFloat xDelta = (newSize.width - oldSize.width) * anchorPoint.x;
+    CGFloat yDelta = (newSize.height - oldSize.height) * anchorPoint.y;
+    self.position = CGPointMake(oldPosition.x + xDelta, oldPosition.y + yDelta);
+  }
+  
+  __instanceLock__.unlock();
+}
+
 - (CGSize)sizeThatFits:(CGSize)size
 {
   return [self layoutThatFits:ASSizeRangeMake(CGSizeZero, size)].size;

examples/ASViewController/Sample/DetailViewController.m

@@ -74,7 +74,6 @@
     // Initial size of sizing node
     //self.sizingNode.frame = CGRectMake(100, 100, 50, 50);
     
-    self.buttonNode.frame = CGRectMake(100, 100, 200, 10);
     [self displayNodeDidInvalidateSize:self.buttonNode];
     
     // Initial size for image node
@@ -95,19 +94,32 @@
 {
     [super viewDidLayoutSubviews];
     
+    [self updateButtonNodeLayout];
+    
     // Update the sizing node layout
     [self updateNodeLayout];
 }
 
 #pragma mark - Update the node based on the new size
 
+- (void)updateButtonNodeLayout
+{
+    [self.buttonNode sizeToFit];
+    self.buttonNode.frame = CGRectMake((self.view.bounds.size.width - self.buttonNode.bounds.size.width) / 2.0,
+                                       100,
+                                       self.buttonNode.bounds.size.width,
+                                       self.buttonNode.bounds.size.height);
+
+    //CGSize s = [self.buttonNode sizeThatFits:CGSizeMake(CGFLOAT_MAX, CGFLOAT_MAX)];
+    //self.buttonNode.frame = CGRectMake(100, 100, s.width, s.height);
+}
+
 // The sizing delegate will get callbacks if the size did invalidate of the display node. It's the job of the delegate
 // to get the new size from the display node and update the frame based on the returned size
 - (void)displayNodeDidInvalidateSize:(ASDisplayNode *)displayNode
 {
     if (displayNode == self.buttonNode) {
-        CGSize s = [self.buttonNode sizeThatFits:CGSizeMake(CGFLOAT_MAX, CGFLOAT_MAX)];
-        self.buttonNode.frame = CGRectMake(100, 100, s.width, s.height);
+        [self updateButtonNodeLayout];
         return;
     }