Expose minContentWidth/maxContentWidth and a callback for computing them.

sky/tests/layout/custom.sky

Index: sky/tests/layout/custom.sky
diff --git a/sky/tests/layout/custom.sky b/sky/tests/layout/custom.sky
index e212a6e7a018ada1a43069f829e278291f24bdbf..538fa7544138f993dd4464df44e031b24b8130db 100644
--- a/sky/tests/layout/custom.sky
+++ b/sky/tests/layout/custom.sky
@@ -7,6 +7,12 @@
   </parent>
 </root>
 
+<intrinsic-container>
+  <intrinsic>
+    <intrinsic-child style="width: 10px; height: 10px; background-color: lightblue;" />
+  </intrinsic>
+</intrinsic-container>
+
 <script>
 import "../resources/third_party/unittest/unittest.dart";
 import "../resources/unit.dart";
@@ -17,60 +23,60 @@ import 'dart:sky';
 void main() {
   initUnit();
 
-  var first = true;
-
-  var parent = document.querySelector('parent');
-  var firstChild = parent.firstElementChild;
-  var secondChild = parent.lastElementChild;
-  var grandChild = document.querySelector('grandchild');
-
-  parent.setLayoutManager(() {
-    if (first) {
-      parent.width = 200.0;
-    } else {
-      parent.width = 150.0;
-    }
-
-    firstChild.width = 100.0;
-    firstChild.layout();
-    firstChild.x = 100.0;
-    firstChild.y = 50.0;
-    firstChild.height = 50.0;
-
-    // The second element correctly gets it's width from it's container.
-    // TODO(ojan): Change the layout method to take in availableWidth
-    // so code doesn't need to mess with setNeedsLayout dirty bits
-    // in the middle of layout and so the parent and child don't need
-    // to coordinate as much about expectations.
-    secondChild.setNeedsLayout();
-    secondChild.layout();
-
-    parent.height = 100.0;
-  });
-
-  void assertNonChangingValues() {
-    expect(parent.offsetHeight, equals(100));
-    expect(parent.offsetTop, equals(0));
-    expect(parent.offsetLeft, equals(0));
-
-    expect(firstChild.offsetWidth, equals(100));
-    expect(firstChild.offsetHeight, equals(50));
-    expect(firstChild.offsetTop, equals(50));
-    expect(firstChild.offsetLeft, equals(100));
-
-    expect(secondChild.offsetHeight, equals(25));
-    expect(secondChild.offsetTop, equals(0));
-    expect(secondChild.offsetLeft, equals(0));
-
-    expect(grandChild.offsetWidth, equals(25));
-    expect(grandChild.offsetHeight, equals(25));
-    expect(secondChild.offsetTop, equals(0));
-    expect(secondChild.offsetLeft, equals(0));
-  };
-
   test("should have the right sizes after layout", () {
     Completer completer = new Completer();
 
+    var first = true;
+
+    var parent = document.querySelector('parent');
+    var firstChild = parent.firstElementChild;
+    var secondChild = parent.lastElementChild;
+    var grandChild = document.querySelector('grandchild');
+
+    parent.setLayoutManager(() {
+      if (first) {
+        parent.width = 200.0;
+      } else {
+        parent.width = 150.0;
+      }
+
+      firstChild.width = 100.0;
+      firstChild.layout();
+      firstChild.x = 100.0;
+      firstChild.y = 50.0;
+      firstChild.height = 50.0;
+
+      // The second element correctly gets it's width from it's container.
+      // TODO(ojan): Change the layout method to take in availableWidth
+      // so code doesn't need to mess with setNeedsLayout dirty bits
+      // in the middle of layout and so the parent and child don't need
+      // to coordinate as much about expectations.
+      secondChild.setNeedsLayout();
+      secondChild.layout();
+
+      parent.height = 100.0;
+    }, () {});
+
+    void assertNonChangingValues() {
+      expect(parent.offsetHeight, equals(100));
+      expect(parent.offsetTop, equals(0));
+      expect(parent.offsetLeft, equals(0));
+
+      expect(firstChild.offsetWidth, equals(100));
+      expect(firstChild.offsetHeight, equals(50));
+      expect(firstChild.offsetTop, equals(50));
+      expect(firstChild.offsetLeft, equals(100));
+
+      expect(secondChild.offsetHeight, equals(25));
+      expect(secondChild.offsetTop, equals(0));
+      expect(secondChild.offsetLeft, equals(0));
+
+      expect(grandChild.offsetWidth, equals(25));
+      expect(grandChild.offsetHeight, equals(25));
+      expect(secondChild.offsetTop, equals(0));
+      expect(secondChild.offsetLeft, equals(0));
+    };
+
     window.requestAnimationFrame((_) {
       expect(parent.offsetWidth, equals(200));
       expect(secondChild.offsetWidth, equals(200));
@@ -86,13 +92,13 @@ void main() {
 
         parent.setLayoutManager(() {
           parent.width = 250.0;
-        });
+        }, () {});
 
         window.requestAnimationFrame((_) {
           expect(parent.offsetWidth, equals(250));
           assertNonChangingValues();
 
-          parent.setLayoutManager(null);
+          parent.setLayoutManager(null, null);
 
           window.requestAnimationFrame((_) {
             expect(parent.offsetWidth, equals(300));
@@ -123,5 +129,30 @@ void main() {
 
     return completer.future;
   });
+
+  test("intrinsic sizes should apply", () {
+    Completer completer = new Completer();
+
+    var intrinsic = document.querySelector('intrinsic');
+    var intrinsicChild = document.querySelector('intrinsic-child');
+
+    intrinsic.setLayoutManager(() {
+      intrinsicChild.layout();
+    }, () {
+      intrinsic.minContentWidth = intrinsicChild.minContentWidth + 5;
+      intrinsic.maxContentWidth = intrinsicChild.maxContentWidth + 7;
+    });
+
+    window.requestAnimationFrame((_) {
+      var container = document.querySelector('intrinsic-container');
+      container.style['width'] = '-webkit-min-content';
+      expect(container.offsetWidth, equals(15));
+      container.style['width'] = '-webkit-max-content';
+      expect(container.offsetWidth, equals(17));
+      completer.complete();
+    });
+
+    return completer.future;
+  });
 }
 </script>