Rename rendering/render_*.dart to rendering/*.dart

sky/sdk/lib/framework/rendering/render_flex.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:sky' as sky;
-import 'render_box.dart';
-import 'render_node.dart';
-
-class FlexBoxParentData extends BoxParentData with ContainerParentDataMixin<RenderBox> {
-  int flex;
-  void merge(FlexBoxParentData other) {
-    if (other.flex != null)
-      flex = other.flex;
-    super.merge(other);
-  }
-}
-
-enum FlexDirection { Horizontal, Vertical }
-
-class RenderFlex extends RenderBox with ContainerRenderNodeMixin<RenderBox, FlexBoxParentData>,
-                                        RenderBoxContainerDefaultsMixin<RenderBox, FlexBoxParentData> {
-  // lays out RenderBox children using flexible layout
-
-  RenderFlex({
-    FlexDirection direction: FlexDirection.Horizontal
-  }) : _direction = direction;
-
-  FlexDirection _direction;
-  FlexDirection get direction => _direction;
-  void set direction (FlexDirection value) {
-    if (_direction != value) {
-      _direction = value;
-      markNeedsLayout();
-    }
-  }
-
-  void setParentData(RenderBox child) {
-    if (child.parentData is! FlexBoxParentData)
-      child.parentData = new FlexBoxParentData();
-  }
-
-  bool get sizedByParent => true;
-  void performResize() {
-    size = constraints.constrain(new sky.Size(constraints.maxWidth, constraints.maxHeight));
-    assert(size.height < double.INFINITY);
-    assert(size.width < double.INFINITY);
-  }
-
-  int _getFlex(RenderBox child) {
-    assert(child.parentData is FlexBoxParentData);
-    return child.parentData.flex != null ? child.parentData.flex : 0;
-  }
-
-  void performLayout() {
-    // Based on http://www.w3.org/TR/css-flexbox-1/ Section 9.7 Resolving Flexible Lengths
-    // Steps 1-3. Determine used flex factor, size inflexible items, calculate free space
-    int totalFlex = 0;
-    assert(constraints != null);
-    double freeSpace = (_direction == FlexDirection.Horizontal) ? constraints.maxWidth : constraints.maxHeight;
-    RenderBox child = firstChild;
-    while (child != null) {
-      int flex = _getFlex(child);
-      if (flex > 0) {
-        totalFlex += child.parentData.flex;
-      } else {
-        BoxConstraints innerConstraints = new BoxConstraints(maxHeight: constraints.maxHeight,
-                                                             maxWidth: constraints.maxWidth);
-        child.layout(innerConstraints, parentUsesSize: true);
-        freeSpace -= (_direction == FlexDirection.Horizontal) ? child.size.width : child.size.height;
-      }
-      child = child.parentData.nextSibling;
-    }
-
-    // Steps 4-5. Distribute remaining space to flexible children.
-    double spacePerFlex = totalFlex > 0 ? (freeSpace / totalFlex) : 0.0;
-    double usedSpace = 0.0;
-    child = firstChild;
-    while (child != null) {
-      int flex = _getFlex(child);
-      if (flex > 0) {
-        double spaceForChild = spacePerFlex * flex;
-        BoxConstraints innerConstraints;
-        switch (_direction) {
-          case FlexDirection.Horizontal:
-            innerConstraints = new BoxConstraints(maxHeight: constraints.maxHeight,
-                                                  minWidth: spaceForChild,
-                                                  maxWidth: spaceForChild);
-            break;
-          case FlexDirection.Vertical:
-            innerConstraints = new BoxConstraints(minHeight: spaceForChild,
-                                                  maxHeight: spaceForChild,
-                                                  maxWidth: constraints.maxWidth);
-            break;
-        }
-        child.layout(innerConstraints, parentUsesSize: true);
-      }
-
-      // For now, center the flex items in the cross direction
-      switch (_direction) {
-        case FlexDirection.Horizontal:
-          child.parentData.position = new sky.Point(usedSpace, size.height / 2.0 - child.size.height / 2.0);
-          usedSpace += child.size.width;
-          break;
-        case FlexDirection.Vertical:
-          child.parentData.position = new sky.Point(size.width / 2.0 - child.size.width / 2.0, usedSpace);
-          usedSpace += child.size.height;
-          break;
-      }
-      child = child.parentData.nextSibling;
-    }
-  }
-
-  void hitTestChildren(HitTestResult result, { sky.Point position }) {
-    defaultHitTestChildren(result, position: position);
-  }
-
-  void paint(RenderNodeDisplayList canvas) {
-    defaultPaint(canvas);
-  }
-}