[Playground] Update Measure

FlexboxPlayground.playground/Pages/Measure.xcplaygroundpage/Contents.swift

@@ -4,27 +4,99 @@ import Flexbox
 
 let config = Config()
 
+//----------------------------------------
+// Example 1
+//----------------------------------------
+
+example(
+    "measure (fixed size)",
+    Node(
+        size: config.flexContainerSize,
+        children: [
+            Node(minSize: CGSize(width: 20, height: 10)),
+            Node(minSize: CGSize(width: 40, height: 40)),
+            Node(
+                measure: { size in
+                    print("measure size = \(size)")
+                    return CGSize(width: 200, height: 80)
+                }
+            )
+        ],
+        alignItems: .center
+    )
+)
+
+//----------------------------------------
+// Example 2
+//----------------------------------------
+
+let attrText = NSAttributedString(string: "Hello World! Hello World! Hello World!")
+let font = UIFont.systemFont(ofSize: 24)
+
+extension NSAttributedString
+{
+    func fitSize(font: UIFont, maxSize: CGSize) -> CGSize
+    {
+        let fontAttribute = [NSFontAttributeName: font]
+        let attributedTextWithFont = NSMutableAttributedString(string: self.string, attributes: fontAttribute)
+        let fullRange = NSMakeRange(0, (self.string as NSString).length)
+        attributedTextWithFont.beginEditing()
+        self.enumerateAttributes(in: fullRange, options: .longestEffectiveRangeNotRequired, using: { (attributes, range, _) in
+            attributedTextWithFont.addAttributes(attributes, range: range)
+        })
+        attributedTextWithFont.endEditing()
+
+        let options: NSStringDrawingOptions = [.usesLineFragmentOrigin]
+        let size = attributedTextWithFont.boundingRect(with: maxSize, options: options, context: nil).size
+        return size
+    }
+}
+
+let maxLabelWidth = config.flexContainerSize.width - 20 - 40
+
 example(
-    "measure",
+    "measure (NSAttributedString)",
     Node(
         size: config.flexContainerSize,
         children: [
             Node(size: CGSize(width: 20, height: 10)),
             Node(size: CGSize(width: 40, height: 40)),
             Node(
+                maxSize: CGSize(width: maxLabelWidth, height: CGFloat.greatestFiniteMagnitude), // required
                 measure: { size in
                     print("measure size = \(size)")
-                    var size = size
-                    size.height -= 20
-                    return size
+
+                    let fitSize = attrText.fitSize(font: font, maxSize: size)
+                    print("attrText.fitSize = \(fitSize)")
+                    return fitSize
                 }
             )
         ],
         alignItems: .center
     )
 )
 
+//----------------------------------------
+
 let (rootView, contentView) = setup(config: config)
 PlaygroundPage.current.liveView = rootView
 
 Screenshot.save(contentView, "Measure.png")
+
+// Tweak UI after `setup`.
+if true {
+    let label = UILabel()
+    label.layer.borderColor = UIColor.red.cgColor
+    label.layer.borderWidth = 2
+    label.attributedText = attrText
+    label.font = font
+    label.lineBreakMode = .byWordWrapping
+    label.numberOfLines = 0
+    label.frame.size.width = maxLabelWidth  // set frame before `sizeToFit`
+    label.sizeToFit()
+    let targetView = contentView.subviews[2].subviews[2]
+    targetView.addSubview(label)
+
+    print("targetView.frame = \(targetView.frame)")
+    print("label.frame = \(label.frame)")
+}