Add support for text styles - Work In Progress

sky/sdk/lib/framework/rendering/paragraph.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 'box.dart';
 import 'object.dart';
 
 class RenderInline extends RenderObject {
   RenderInline(this.data);
   String data;
 }
 
+class TextStyle {
+  final Color color;

[Hixie, 2015/06/11 17:39:28]

constructor then fields (see sky/specs/style-guide.md)

+  final String fontSize;

[Hixie, 2015/06/11 17:39:27]

fontSize should be a double (pixels).

+  final String fontWeight;

[Hixie, 2015/06/11 17:39:27]

fontWeight should be an enum.

+
+  const TextStyle({
+    this.color,
+    this.fontSize,
+    this.fontWeight
+  });
+
+  bool operator ==(other) => other is TextStyle &&

[Hixie, 2015/06/11 17:39:28]

If you have an operator ==, you need a hashCode function.

Also, only use => if it fits on one line.

+    color == other.color &&
+    fontSize == other.fontSize &&
+    fontWeight == other.fontWeight;
+}
+
 // Unfortunately, using full precision floating point here causes bad layouts
 // because floating point math isn't associative. If we add and subtract
 // padding, for example, we'll get different values when we estimate sizes and
 // when we actually compute layout because the operations will end up associated
 // differently. To work around this problem for now, we round fractional pixel
 // values up to the nearest whole pixel value. The right long-term fix is to do
 // layout using fixed precision arithmetic.
 double _applyFloatingPointHack(double layoutValue) {
   return layoutValue.ceilToDouble();
 }
 
 class RenderParagraph extends RenderBox {
 
   RenderParagraph({
     String text,
-    Color color
-  }) : _color = color {
+    Color color,
+    TextStyle style
+  }) : _color = color, _style = style {
     _layoutRoot.rootElement = _document.createElement('p');
     this.text = text;
   }
 
   final sky.Document _document = new sky.Document();
   final sky.LayoutRoot _layoutRoot = new sky.LayoutRoot();
 
   String get text => (_layoutRoot.rootElement.firstChild as sky.Text).data;
   void set text (String value) {
     _layoutRoot.rootElement.setChild(_document.createText(value));
     markNeedsLayout();
   }
 
+  // TODO(hansmuller): remove this
   Color _color = const Color(0xFF000000);
   Color get color => _color;
   void set color (Color value) {
     if (_color != value) {
       _color = value;
       markNeedsPaint();
     }
   }
 
+  TextStyle _style;
+  TextStyle get style => _style;
+  void set style (TextStyle value) {
+    if (_style != value) {
+      _style = value;
+      // TODO(hansmuller): decide if a new layout or paint is needed
+      markNeedsLayout();
+    }
+  }
+
   BoxConstraints _constraintsForCurrentLayout;
 
   sky.Element _layout(BoxConstraints constraints) {
     _layoutRoot.maxWidth = constraints.maxWidth;
     _layoutRoot.minWidth = constraints.minWidth;
     _layoutRoot.minHeight = constraints.minHeight;
     _layoutRoot.maxHeight = constraints.maxHeight;
     _layoutRoot.layout();
     _constraintsForCurrentLayout = constraints;
   }
@@ skipping 36 matching lines @@
     // Ideally we could compute the min/max intrinsic width/height with a
     // non-destructive operation. However, currently, computing these values
     // will destroy state inside the layout root. If that happens, we need to
     // get back the correct state by calling _layout again.
     //
     // TODO(abarth): Make computing the min/max intrinsic width/height a
     //               non-destructive operation.
     if (_constraintsForCurrentLayout != constraints && constraints != null)
       _layout(constraints);
 
-    if (_color != null) {
+    if (style != null && style.color != null) {
+      Color color = style.color;
       _layoutRoot.rootElement.style['color'] =
-          'rgba(${_color.red}, ${_color.green}, ${_color.blue}, ${_color.alpha / 255.0 })';
+          'rgba(${color.red}, ${color.green}, ${color.blue}, ${color.alpha / 255.0 })';
     }
     _layoutRoot.paint(canvas);
   }
 
   // we should probably expose a way to do precise (inter-glpyh) hit testing
 
   String debugDescribeSettings(String prefix) => '${super.debugDescribeSettings(prefix)}${prefix}color: ${color}\n${prefix}text: ${text}\n';
 }