Split getIntrinsicDimensions into four pieces

sky/sdk/lib/framework/rendering/box.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import 'dart:math' as math;
 import 'dart:sky' as sky;
 import 'dart:typed_data';
 import 'object.dart';
 import 'package:vector_math/vector_math.dart';
 import 'package:sky/framework/net/image_cache.dart' as image_cache;
@@ skipping 109 matching lines @@
   String toString() => 'position=$position';
 }
 
 abstract class RenderBox extends RenderObject {
 
   void setParentData(RenderObject child) {
     if (child.parentData is! BoxParentData)
       child.parentData = new BoxParentData();
   }
 
-  // override this to report what dimensions you would have if you
-  // were laid out with the given constraints this can walk the tree
-  // if it must, but it should be as cheap as possible; just get the
-  // dimensions and nothing else (e.g. don't calculate hypothetical
-  // child positions if they're not needed to determine dimensions)
-  Size getIntrinsicDimensions(BoxConstraints constraints) {
-    return constraints.constrain(Size.zero);
+  double getMinIntrinsicWidth(BoxConstraints constraints) {

[Hixie, 2015/06/08 21:35:32]

Let's define these here.

// getMinIntrinsicWidth() should return the minimum width that this box could 
// be without failing to render its contents within itself.

+    return constraints.constrainWidth(0.0);
+  }
+
+  double getMaxIntrinsicWidth(BoxConstraints constraints) {

[Hixie, 2015/06/08 21:35:32]

// getMaxIntrinsicWidth() should return the smallest width beyond which 
// increasing the width never decreases the height.

+    return constraints.constrainWidth(0.0);
+  }
+
+  double getMinIntrinsicHeight(BoxConstraints constraints) {

[Hixie, 2015/06/08 21:35:32]

// getMinIntrinsicHeight() should return the minimum height that this box could 
// be without failing to render its contents within itself.

+    return constraints.constrainHeight(0.0);
+  }
+
+  double getMaxIntrinsicHeight(BoxConstraints constraints) {

[Hixie, 2015/06/08 21:35:32]

// getMaxIntrinsicHeight should return the smallest height beyond which
// increasing the height never decreases the width.
// If the layout algorithm used is width-in-height-out, i.e. the height
// depends on the width and not vice versa, then this will return the same
// as getMinIntrinsicHeight().

+    return constraints.constrainHeight(0.0);
   }
 
   BoxConstraints get constraints => super.constraints as BoxConstraints;
   void performResize() {
     // default behaviour for subclasses that have sizedByParent = true
     size = constraints.constrain(Size.zero);
     assert(size.height < double.INFINITY);
     assert(size.width < double.INFINITY);
   }
   void performLayout() {
@@ skipping 13 matching lines @@
   Size size = Size.zero;
 
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}size: ${size}\n';
 }
 
 abstract class RenderProxyBox extends RenderBox with RenderObjectWithChildMixin<RenderBox> {
   RenderProxyBox(RenderBox child) {
     this.child = child;
   }
 
-  Size getIntrinsicDimensions(BoxConstraints constraints) {
+  double getMinIntrinsicWidth(BoxConstraints constraints) {
     if (child != null)
-      return child.getIntrinsicDimensions(constraints);
-    return super.getIntrinsicDimensions(constraints);
+      return child.getMinIntrinsicWidth(constraints);
+    return super.getMinIntrinsicWidth(constraints);
+  }
+
+  double getMaxIntrinsicWidth(BoxConstraints constraints) {
+    if (child != null)
+      return child.getMaxIntrinsicWidth(constraints);
+    return super.getMaxIntrinsicWidth(constraints);
+  }
+
+  double getMinIntrinsicHeight(BoxConstraints constraints) {
+    if (child != null)
+      return child.getMinIntrinsicHeight(constraints);
+    return super.getMinIntrinsicHeight(constraints);
+  }
+
+  double getMaxIntrinsicHeight(BoxConstraints constraints) {
+    if (child != null)
+      return child.getMaxIntrinsicHeight(constraints);
+    return super.getMaxIntrinsicHeight(constraints);
   }
 
   void performLayout() {
     if (child != null) {
       child.layout(constraints, parentUsesSize: true);
       size = child.size;
     } else {
       performResize();
     }
   }
@@ skipping 23 matching lines @@
   Size _desiredSize;
   Size get desiredSize => _desiredSize;
   void set desiredSize (Size value) {
     assert(value != null);
     if (_desiredSize == value)
       return;
     _desiredSize = value;
     markNeedsLayout();
   }
 
-  Size getIntrinsicDimensions(BoxConstraints constraints) {
-    return constraints.constrain(_desiredSize);
+  double getMinIntrinsicWidth(BoxConstraints constraints) {
+    return constraints.constrain(_desiredSize.width);
+  }
+
+  double getMaxIntrinsicWidth(BoxConstraints constraints) {
+    return constraints.constrain(_desiredSize.width);
+  }
+
+  double getMinIntrinsicHeight(BoxConstraints constraints) {
+    return constraints.constrain(_desiredSize.height);
+  }
+
+  double getMaxIntrinsicHeight(BoxConstraints constraints) {
+    return constraints.constrain(_desiredSize.height);
   }
 
   void performLayout() {
     size = constraints.constrain(_desiredSize);
     if (child != null)
       child.layout(new BoxConstraints.tight(size));
   }
 
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}desiredSize: ${desiredSize}\n';
 }
 
 class RenderConstrainedBox extends RenderProxyBox {
   RenderConstrainedBox({
     RenderBox child,
     BoxConstraints additionalConstraints
   }) : super(child), _additionalConstraints = additionalConstraints {
     assert(additionalConstraints != null);
   }
 
   BoxConstraints _additionalConstraints;
   BoxConstraints get additionalConstraints => _additionalConstraints;
   void set additionalConstraints (BoxConstraints value) {
     assert(value != null);
     if (_additionalConstraints == value)
       return;
     _additionalConstraints = value;
     markNeedsLayout();
   }
 
-  Size getIntrinsicDimensions(BoxConstraints constraints) {
-    if (child == null)
-      return constraints.constrain(Size.zero);
-    return child.getIntrinsicDimensions(constraints.apply(_additionalConstraints));
+  double getMinIntrinsicWidth(BoxConstraints constraints) {
+    if (child != null)
+      return child.getMinIntrinsicWidth(constraints.apply(_additionalConstraints));
+    return constraints.constrainWidth(0.0);
+  }
+
+  double getMaxIntrinsicWidth(BoxConstraints constraints) {
+    if (child != null)
+      return child.getMaxIntrinsicWidth(constraints.apply(_additionalConstraints));
+    return constraints.constrainWidth(0.0);
+  }
+
+  double getMinIntrinsicHeight(BoxConstraints constraints) {
+    if (child != null)
+      return child.getMinIntrinsicHeight(constraints.apply(_additionalConstraints));
+    return constraints.constrainHeight(0.0);
+  }
+
+  double getMaxIntrinsicHeight(BoxConstraints constraints) {
+    if (child != null)
+      return child.getMaxIntrinsicHeight(constraints.apply(_additionalConstraints));
+    return constraints.constrainHeight(0.0);
   }
 
   void performLayout() {
     if (child != null) {
       child.layout(constraints.apply(_additionalConstraints));
       size = child.size;
     } else {
       performResize();
     }
   }
@@ skipping 25 matching lines @@
   EdgeDims _padding;
   EdgeDims get padding => _padding;
   void set padding (EdgeDims value) {
     assert(value != null);
     if (_padding == value)
       return;
     _padding = value;
     markNeedsLayout();
   }
 
-  Size getIntrinsicDimensions(BoxConstraints constraints) {
-    assert(padding != null);
-    constraints = constraints.deflate(padding);
-    if (child == null)
-      return super.getIntrinsicDimensions(constraints);
-    return child.getIntrinsicDimensions(constraints);
+  double getMinIntrinsicWidth(BoxConstraints constraints) {
+    if (child != null)
+      return child.getMinIntrinsicWidth(constraints.deflate(padding));
+    return constraints.constrainWidth(padding.left + padding.right);
+  }
+
+  double getMaxIntrinsicWidth(BoxConstraints constraints) {
+    if (child != null)
+      return child.getMaxIntrinsicWidth(constraints.deflate(padding));
+    return constraints.constrainWidth(padding.left + padding.right);
+  }
+
+  double getMinIntrinsicHeight(BoxConstraints constraints) {
+    if (child != null)
+      return child.getMinIntrinsicHeight(constraints.deflate(padding));
+    return constraints.constrainHeight(padding.top + padding.bottom);
+  }
+
+  double getMaxIntrinsicHeight(BoxConstraints constraints) {
+    if (child != null)
+      return child.getMaxIntrinsicHeight(constraints.deflate(padding));
+    return constraints.constrainHeight(padding.top + padding.bottom);
   }
 
   void performLayout() {
     assert(padding != null);
     BoxConstraints innerConstraints = constraints.deflate(padding);
     if (child == null) {
       size = innerConstraints.constrain(
           new Size(padding.left + padding.right, padding.top + padding.bottom));
       return;
     }
@@ skipping 529 matching lines @@
 
   void defaultPaint(RenderObjectDisplayList canvas) {
     RenderBox child = firstChild;
     while (child != null) {
       assert(child.parentData is ParentDataType);
       canvas.paintChild(child, child.parentData.position);
       child = child.parentData.nextSibling;
     }
   }
 }