[ASTextNode] Fix edge case where text truncator may not run (manually hosted nodes that are lacking the expected call to -measure).

This fixes the scenario described in https://github.com/facebook/AsyncDisplayKit/issues/1295

AsyncDisplayKit/TextKit/ASTextKitRenderer.mm

@@ -189,9 +189,10 @@ static NSCharacterSet *_defaultAvoidTruncationCharacterSet()
   // We add an assertion so we can track the rare conditions where a graphics context is not present
   ASDisplayNodeAssertNotNil(context, @"This is no good without a context.");
   
-  // This renderer may not be the one that did the sizing. If that is the case its _currentScaleFactor will not be set, so we should compute it now
-  if (_sizeIsCalculated == NO && isinf(_constrainedSize.width) == NO && [_attributes.pointSizeScaleFactors count] > 0) {
-    _currentScaleFactor = [[self fontSizeAdjuster] scaleFactor];
+  // This renderer may not be the one that did the sizing. If that is the case its truncation and currentScaleFactor may not have been evaluated.
+  // If there's any possibility we need to truncate or scale (e.g. width is not infinite, perform the size calculation.
+  if (_sizeIsCalculated == NO && isinf(_constrainedSize.width) == NO) {
+    [self _calculateSize];
   }
 
   CGRect shadowInsetBounds = [[self shadower] insetRectWithConstrainedRect:bounds];

examples/EditableText/Sample.xcworkspace/contents.xcworkspacedata

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "group:Sample.xcodeproj">
+   </FileRef>
+   <FileRef
+      location = "group:Pods/Pods.xcodeproj">
+   </FileRef>
+</Workspace>

examples/EditableText/Sample/ViewController.m

@@ -17,6 +17,10 @@
 @interface ViewController () <ASEditableTextNodeDelegate>
 {
   ASEditableTextNode *_textNode;
+  
+  // These elements are a test case for ASTextNode truncation.
+  UILabel *_label;
+  ASTextNode *_node;
 }
 
 @end
@@ -45,6 +49,24 @@
   // the usual delegate methods are available; see ASEditableTextNodeDelegate
   _textNode.delegate = self;
   
+  
+  // Do any additional setup after loading the view, typically from a nib.
+  NSDictionary *attrs = @{ NSFontAttributeName: [UIFont fontWithName:@"HelveticaNeue" size:12.0f] };
+  NSAttributedString *string = [[NSAttributedString alloc] initWithString:@"1\n2\n3\n4\n5" attributes:attrs];
+  
+  _label = [[UILabel alloc] init];
+  _label.attributedText = string;
+  _label.backgroundColor = [UIColor lightGrayColor];
+  _label.numberOfLines = 3;
+  _label.frame = CGRectMake(20, 400, 40, 100);
+  
+  _node = [[ASTextNode alloc] init];
+  _node.maximumNumberOfLines = 3;
+  _node.backgroundColor = [UIColor lightGrayColor];
+  _node.attributedString = string;
+  _node.frame = CGRectMake(70, 400, 40, 100);
+//  [_node measure:CGSizeMake(40, 50)];  No longer needed now that https://github.com/facebook/AsyncDisplayKit/issues/1295 is fixed.
+
   return self;
 }
 
@@ -53,6 +75,8 @@
   [super viewDidLoad];
 
   [self.view addSubnode:_textNode];
+  [self.view addSubnode:_node];
+  [self.view addSubview:_label];
 
   [self.view addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap:)]];
 }