Rationalize Dart mojo and sky package structure

sky/framework/layout.dart

-library layout;
-
-import 'node.dart';
-import 'dart:sky' as sky;
-import 'dart:collection';
-
-// UTILS
-
-// Bridge to legacy CSS-like style specification
-// Eventually we'll replace this with something else
-class Style {
-  final String _className;
-  static final Map<String, Style> _cache = new HashMap<String, Style>();
-
-  static int _nextStyleId = 1;
-
-  static String _getNextClassName() { return "style${_nextStyleId++}"; }
-
-  Style extend(Style other) {
-    var className = "$_className ${other._className}";
-
-    return _cache.putIfAbsent(className, () {
-      return new Style._internal(className);
-    });
-  }
-
-  factory Style(String styles) {
-    return _cache.putIfAbsent(styles, () {
-      var className = _getNextClassName();
-      sky.Element styleNode = sky.document.createElement('style');
-      styleNode.setChild(new sky.Text(".$className { $styles }"));
-      sky.document.appendChild(styleNode);
-      return new Style._internal(className);
-    });
-  }
-
-  Style._internal(this._className);
-}
-
-class Rect {
-  const Rect(this.x, this.y, this.width, this.height);
-  final double x;
-  final double y;
-  final double width;
-  final double height;
-}
-
-
-// ABSTRACT LAYOUT
-
-class ParentData {
-  void detach() {
-    detachSiblings();
-  }
-  void detachSiblings() { } // workaround for lack of inter-class mixins in Dart
-  void merge(ParentData other) {
-    // override this in subclasses to merge in data from other into this
-    assert(other.runtimeType == this.runtimeType);
-  }
-}
-
-abstract class RenderNode extends Node {
-
-  // LAYOUT
-
-  // parentData is only for use by the RenderNode that actually lays this
-  // node out, and any other nodes who happen to know exactly what
-  // kind of node that is.
-  ParentData parentData;
-  void setupPos(RenderNode child) {
-    // override this to setup .parentData correctly for your class
-    if (child.parentData is! ParentData)
-      child.parentData = new ParentData();
-  }
-
-  void setAsChild(RenderNode child) { // only for use by subclasses
-    // call this whenever you decide a node is a child
-    assert(child != null);
-    setupPos(child);
-    super.setAsChild(child);
-  }
-  void dropChild(RenderNode child) { // only for use by subclasses
-    assert(child != null);
-    assert(child.parentData != null);
-    child.parentData.detach();
-    super.dropChild(child);
-  }
-
-}
-
-abstract class RenderBox extends RenderNode { }
-
-
-// GENERIC MIXIN FOR RENDER NODES THAT TAKE A LIST OF CHILDREN
-
-abstract class ContainerParentDataMixin<ChildType extends RenderNode> {
-  ChildType previousSibling;
-  ChildType nextSibling;
-  void detachSiblings() {
-    if (previousSibling != null) {
-      assert(previousSibling.parentData is ContainerParentDataMixin<ChildType>);
-      assert(previousSibling != this);
-      assert(previousSibling.parentData.nextSibling == this);
-      previousSibling.parentData.nextSibling = nextSibling;
-    }
-    if (nextSibling != null) {
-      assert(nextSibling.parentData is ContainerParentDataMixin<ChildType>);
-      assert(nextSibling != this);
-      assert(nextSibling.parentData.previousSibling == this);
-      nextSibling.parentData.previousSibling = previousSibling;
-    }
-    previousSibling = null;
-    nextSibling = null;
-  }
-}
-
-abstract class ContainerRenderNodeMixin<ChildType extends RenderNode, ParentDataType extends ContainerParentDataMixin<ChildType>> implements RenderNode {
-  // abstract class that has only InlineNode children
-
-  bool _debugUltimatePreviousSiblingOf(ChildType child, { ChildType equals }) {
-    assert(child.parentData is ParentDataType);
-    while (child.parentData.previousSibling != null) {
-      assert(child.parentData.previousSibling != child);
-      child = child.parentData.previousSibling;
-      assert(child.parentData is ParentDataType);
-    }
-    return child == equals;
-  }
-  bool _debugUltimateNextSiblingOf(ChildType child, { ChildType equals }) {
-    assert(child.parentData is ParentDataType);
-    while (child.parentData.nextSibling != null) {
-      assert(child.parentData.nextSibling != child);
-      child = child.parentData.nextSibling;
-      assert(child.parentData is ParentDataType);
-    }
-    return child == equals;
-  }
-
-  ChildType _firstChild;
-  ChildType _lastChild;
-  void add(ChildType child, { ChildType before }) {
-    assert(child != this);
-    assert(before != this);
-    assert(child != before);
-    assert(child != _firstChild);
-    assert(child != _lastChild);
-    setAsChild(child);
-    assert(child.parentData is ParentDataType);
-    assert(child.parentData.nextSibling == null);
-    assert(child.parentData.previousSibling == null);
-    if (before == null) {
-      // append at the end (_lastChild)
-      child.parentData.previousSibling = _lastChild;
-      if (_lastChild != null) {
-        assert(_lastChild.parentData is ParentDataType);
-        _lastChild.parentData.nextSibling = child;
-      }
-      _lastChild = child;
-      if (_firstChild == null)
-        _firstChild = child;
-    } else {
-      assert(_firstChild != null);
-      assert(_lastChild != null);
-      assert(_debugUltimatePreviousSiblingOf(before, equals: _firstChild));
-      assert(_debugUltimateNextSiblingOf(before, equals: _lastChild));
-      assert(before.parentData is ParentDataType);
-      if (before.parentData.previousSibling == null) {
-        // insert at the start (_firstChild); we'll end up with two or more children
-        assert(before == _firstChild);
-        child.parentData.nextSibling = before;
-        before.parentData.previousSibling = child;
-        _firstChild = child;
-      } else {
-        // insert in the middle; we'll end up with three or more children
-        // set up links from child to siblings
-        child.parentData.previousSibling = before.parentData.previousSibling;
-        child.parentData.nextSibling = before;
-        // set up links from siblings to child
-        assert(child.parentData.previousSibling.parentData is ParentDataType);
-        assert(child.parentData.nextSibling.parentData is ParentDataType);
-        child.parentData.previousSibling.parentData.nextSibling = child;
-        child.parentData.nextSibling.parentData.previousSibling = child;
-        assert(before.parentData.previousSibling == child);
-      }
-    }
-    markNeedsLayout();
-  }
-  void remove(ChildType child) {
-    assert(child.parentData is ParentDataType);
-    assert(_debugUltimatePreviousSiblingOf(child, equals: _firstChild));
-    assert(_debugUltimateNextSiblingOf(child, equals: _lastChild));
-    if (child.parentData.previousSibling == null) {
-      assert(_firstChild == child);
-      _firstChild = child.parentData.nextSibling;
-    } else {
-      assert(child.parentData.previousSibling.parentData is ParentDataType);
-      child.parentData.previousSibling.parentData.nextSibling = child.parentData.nextSibling;
-    }
-    if (child.parentData.nextSibling == null) {
-      assert(_lastChild == child);
-      _lastChild = child.parentData.previousSibling;
-    } else {
-      assert(child.parentData.nextSibling.parentData is ParentDataType);
-      child.parentData.nextSibling.parentData.previousSibling = child.parentData.previousSibling;
-    }
-    child.parentData.previousSibling = null;
-    child.parentData.nextSibling = null;
-    dropChild(child);
-    markNeedsLayout();
-  }
-  void redepthChildren() {
-    ChildType child = _firstChild;
-    while (child != null) {
-      redepthChild(child);
-      assert(child.parentData is ParentDataType);
-      child = child.parentData.nextSibling;
-    }
-  }
-  void attachChildren() {
-    ChildType child = _firstChild;
-    while (child != null) {
-      child.attach();
-      assert(child.parentData is ParentDataType);
-      child = child.parentData.nextSibling;
-    }
-  }
-  void detachChildren() {
-    ChildType child = _firstChild;
-    while (child != null) {
-      child.detach();
-      assert(child.parentData is ParentDataType);
-      child = child.parentData.nextSibling;
-    }
-  }
-
-  ChildType get firstChild => _firstChild;
-  ChildType get lastChild => _lastChild;
-  ChildType childAfter(ChildType child) {
-    assert(child.parentData is ParentDataType);
-    return child.parentData.nextSibling;
-  }
-
-}
-
-
-// CSS SHIMS
-
-abstract class RenderCSS extends RenderBox {
-
-  dynamic debug;
-  sky.Element _skyElement;
-
-  RenderCSS(this.debug) {
-    _skyElement = createSkyElement();
-    registerEventTarget(_skyElement, this);
-  }
-
-  sky.Element createSkyElement();
-
-  void updateStyles(List<Style> styles) {
-    _skyElement.setAttribute('class', stylesToClasses(styles));
-  }
-
-  String stylesToClasses(List<Style> styles) {
-    return styles.map((s) => s._className).join(' ');
-  }
-
-  String _inlineStyles = '';
-  String _additionalStylesFromParent = ''; // used internally to propagate parentData settings to the child
-
-  void updateInlineStyle(String newStyle) {
-    _inlineStyles = newStyle != null ? newStyle : '';
-    _updateInlineStyleAttribute();
-  }
-
-  void _updateInlineStyleAttribute() {
-    if ((_inlineStyles != '') && (_additionalStylesFromParent != ''))
-      _skyElement.setAttribute('style', "$_inlineStyles;$_additionalStylesFromParent");
-    else
-      _skyElement.setAttribute('style', "$_inlineStyles$_additionalStylesFromParent");
-  }
-
-  double get width {
-    sky.ClientRect rect = _skyElement.getBoundingClientRect();
-    return rect.width;
-  }
-
-  double get height {
-    sky.ClientRect rect = _skyElement.getBoundingClientRect();
-    return rect.height;
-  }
-
-  Rect get rect {
-    sky.ClientRect rect = _skyElement.getBoundingClientRect();
-    return new Rect(rect.left, rect.top, rect.width, rect.height);
-  }
-
-}
-
-class CSSParentData extends ParentData with ContainerParentDataMixin<RenderCSS> { }
-
-class RenderCSSContainer extends RenderCSS with ContainerRenderNodeMixin<RenderCSS, CSSParentData> {
-
-  RenderCSSContainer(debug) : super(debug);
-
-  void setupPos(RenderNode child) {
-    if (child.parentData is! CSSParentData)
-      child.parentData = new CSSParentData();
-  }
-
-  sky.Element createSkyElement() => sky.document.createElement('div')
-                                               ..setAttribute('debug', debug.toString());
-
-  void markNeedsLayout() { }
-
-  void add(RenderCSS child, { RenderCSS before }) {
-    if (before != null) {
-      assert(before._skyElement.parentNode != null);
-      assert(before._skyElement.parentNode == _skyElement);
-    }
-    super.add(child, before: before);
-    if (before != null) {
-      before._skyElement.insertBefore([child._skyElement]);
-      assert(child._skyElement.parentNode != null);
-      assert(child._skyElement.parentNode == _skyElement);
-      assert(child._skyElement.parentNode == before._skyElement.parentNode);
-    } else {
-      _skyElement.appendChild(child._skyElement);
-    }    
-  }
-  void remove(RenderCSS child) {
-    child._skyElement.remove();
-    super.remove(child);
-  }
-
-}
-
-class FlexBoxParentData extends CSSParentData {
-  int flex;
-  void merge(FlexBoxParentData other) {
-    if (other.flex != null)
-      flex = other.flex;
-    super.merge(other);
-  }
-}
-
-enum FlexDirection { Row, Column }
-
-class RenderCSSFlex extends RenderCSSContainer {
-
-  RenderCSSFlex(debug, FlexDirection direction) : _direction = direction, super(debug);
-
-  FlexDirection _direction;
-  FlexDirection get direction => _direction;
-  void set direction (FlexDirection value) {
-    _direction = value;
-    markNeedsLayout();
-  }
-
-  void setupPos(RenderNode child) {
-    if (child.parentData is! FlexBoxParentData)
-      child.parentData = new FlexBoxParentData();
-  }
-
-  static final Style _displayFlex = new Style('display:flex');
-  static final Style _displayFlexRow = new Style('flex-direction:row');
-  static final Style _displayFlexColumn = new Style('flex-direction:column');
-
-  String stylesToClasses(List<Style> styles) {
-    var settings = _displayFlex._className;
-    switch (_direction) {
-      case FlexDirection.Row: settings += ' ' + _displayFlexRow._className; break;
-      case FlexDirection.Column: settings += ' ' + _displayFlexColumn._className; break;
-    }
-    return super.stylesToClasses(styles) + ' ' + settings;
-  }
-
-  void markNeedsLayout() {
-    super.markNeedsLayout();
-
-    // pretend we did the layout:
-    RenderCSS child = _firstChild;
-    while (child != null) {
-      assert(child.parentData is FlexBoxParentData);
-      if (child.parentData.flex != null) {
-        child._additionalStylesFromParent = 'flex:${child.parentData.flex}';
-        child._updateInlineStyleAttribute();
-      }
-      child = child.parentData.nextSibling;
-    }
-  }
-
-}
-
-class RenderCSSParagraph extends RenderCSSContainer {
-
-  RenderCSSParagraph(debug) : super(debug);
-
-  static final Style _displayParagraph = new Style('display:paragraph');
-
-  String stylesToClasses(List<Style> styles) {
-    return super.stylesToClasses(styles) + ' ' + _displayParagraph._className;
-  }
-
-}
-
-class RenderCSSInline extends RenderCSS {
-
-  RenderCSSInline(debug, String newData) : super(debug) {
-    data = newData;
-  }
-
-  static final Style _displayInline = new Style('display:inline');
-
-  String stylesToClasses(List<Style> styles) {
-    return super.stylesToClasses(styles) + ' ' + _displayInline._className;
-  }
-
-  sky.Element createSkyElement() {
-    return sky.document.createElement('div')
-                      ..setChild(new sky.Text())
-                      ..setAttribute('debug', debug.toString());
-  }
-
-  void set data (String value) {
-    (_skyElement.firstChild as sky.Text).data = value;
-  }
-
-}
-
-class RenderCSSImage extends RenderCSS {
-
-  RenderCSSImage(debug, String src, num width, num height) : super(debug) {
-    configure(src, width, height);
-  }
-
-  sky.Element createSkyElement() {
-    return sky.document.createElement('img')
-                      ..setAttribute('debug', debug.toString());
-  }
-
-  void configure(String src, num width, num height) {
-    if (_skyElement.getAttribute('src') != src)
-      _skyElement.setAttribute('src', src);
-    _skyElement.style['width'] = '${width}px';
-    _skyElement.style['height'] = '${height}px';
-  }
-
-}
-
-class RenderCSSRoot extends RenderCSSContainer {
-  RenderCSSRoot(debug) : super(debug);
-  sky.Element createSkyElement() {
-    var result = super.createSkyElement();
-    assert(result != null);
-    sky.document.appendChild(result);
-    return result;
-  }
-}
-
-
-// legacy tools
-Map<sky.EventTarget, RenderNode> _eventTargetRegistry = {};
-void registerEventTarget(sky.EventTarget e, RenderNode n) {
-  _eventTargetRegistry[e] = n;
-}
-RenderNode bridgeEventTargetToRenderNode(sky.EventTarget e) {
-  return _eventTargetRegistry[e];
-}
-
-
-
-
-String _attributes(node) {
-  if (node is! sky.Element) return '';
-  var result = '';
-  var attrs = node.getAttributes();
-  for (var attr in attrs)
-    result += ' ${attr.name}="${attr.value}"';
-  return result;
-}
-
-void _serialiseDOM(node, [String prefix = '']) {
-  if (node is sky.Text) {
-    print(prefix + 'text: "' + node.data.replaceAll('\n', '\\n') + '"');
-    return;
-  }
-  print(prefix + node.toString() + _attributes(node));
-  var children = node.getChildNodes();
-  prefix = prefix + '  ';
-  for (var child in children)
-    _serialiseDOM(child, prefix);
-}
-
-void dumpState() {
-  _serialiseDOM(sky.document);
-}