update text widgets.

Assets/UIWidgets/Tests/Widgets.cs

 
         double _offsetY = 0.0;
         int _index = -1;
-        
+
         Widget _buildHeader(BuildContext context) {
             return new Container(
                 padding: EdgeInsets.only(left: 16.0, right: 8.0),
                 )
             );
         }
-        
+
-                    setState(() => {
-                        _offsetY = pixels / 2.0;
-                    });
+                    setState(() => { _offsetY = pixels / 2.0; });
-                    setState(() => {
-                        _offsetY = 0.0;
-                    });
+                    setState(() => { _offsetY = 0.0; });
+
             return true;
         }
 

Assets/UIWidgets/foundation/diagnostics.cs

         }
     }
 
-    public class FlagProperty : DiagnosticsProperty<bool> {
-        public FlagProperty(String name,
-            bool value,
+    public class FlagProperty : DiagnosticsProperty<bool?> {
+        public FlagProperty(string name,
+            bool? value,
             string ifTrue = null,
             string ifFalse = null,
             bool showName = false,
         public readonly string ifFalse;
 
         protected override string valueToString(TextTreeConfiguration parentConfiguration = null) {
-            if (this.value) {
+            if (this.value == true) {
-            } else if (!this.value) {
+            } else if (this.value == false) {
                 if (this.ifFalse != null) {
                     return this.ifFalse;
                 }
 
         public override bool showName {
             get {
-                if (this.value && this.ifTrue == null || !this.value == false && this.ifFalse == null) {
+                if (this.value == null || this.value == true && this.ifTrue == null || this.value == false && this.ifFalse == null) {
                     return true;
                 }
 
 
         public override DiagnosticLevel level {
             get {
-                if (this.value) {
+                if (this.value == true) {
-                if (!this.value) {
+                if (this.value == false) {
                     if (this.ifFalse == null) {
                         return DiagnosticLevel.hidden;
                     }
         );
 
         internal static readonly _NoDefaultValue kNoDefaultValue = new _NoDefaultValue();
-        internal static readonly _NullDefaultValue kNullDefaultValue = new _NullDefaultValue();
+        
+        public static readonly object kNullDefaultValue = new _NullDefaultValue();
 
         public static string shortHash(object o) {
             return (o.GetHashCode() & 0xFFFFF).ToString("X").PadLeft(5, '0');

Assets/UIWidgets/painting/text_style.cs

             base.debugFillProperties(properties);
 
             List<DiagnosticsNode> styles = new List<DiagnosticsNode>();
-            styles.Add(new DiagnosticsProperty<Color>("color", color, defaultValue: null));
-            styles.Add(new StringProperty("family", fontFamily, defaultValue: null, quoted: false));
-            styles.Add(new DiagnosticsProperty<double?>("size", fontSize, defaultValue: null));
+            styles.Add(new DiagnosticsProperty<Color>("color", color, defaultValue: Diagnostics.kNullDefaultValue));
+            styles.Add(new StringProperty("family", fontFamily, defaultValue: Diagnostics.kNullDefaultValue, quoted: false));
+            styles.Add(new DiagnosticsProperty<double?>("size", fontSize, defaultValue: Diagnostics.kNullDefaultValue));
             string weightDescription = "";
             if (fontWeight != null)
             {
                 "weight",
                 fontWeight,
                 description: weightDescription,
-                defaultValue: null
+                defaultValue: Diagnostics.kNullDefaultValue
-            styles.Add(new EnumProperty<FontStyle?>("style", fontStyle, defaultValue: null));
-            styles.Add(new DiagnosticsProperty<double?>("letterSpacing", letterSpacing, defaultValue: null));
-            styles.Add(new DiagnosticsProperty<double?>("wordSpacing", wordSpacing, defaultValue: null));
-            styles.Add(new EnumProperty<TextBaseline?>("baseline", textBaseline, defaultValue: null));
-            styles.Add(new DiagnosticsProperty<double?>("height", height, defaultValue: null));
-            styles.Add(new StringProperty("background", background == null ? null : background.ToString(), defaultValue: null, quoted: false));
+            styles.Add(new EnumProperty<FontStyle?>("style", fontStyle, defaultValue: Diagnostics.kNullDefaultValue));
+            styles.Add(new DiagnosticsProperty<double?>("letterSpacing", letterSpacing, defaultValue: Diagnostics.kNullDefaultValue));
+            styles.Add(new DiagnosticsProperty<double?>("wordSpacing", wordSpacing, defaultValue: Diagnostics.kNullDefaultValue));
+            styles.Add(new EnumProperty<TextBaseline?>("baseline", textBaseline, defaultValue: Diagnostics.kNullDefaultValue));
+            styles.Add(new DiagnosticsProperty<double?>("height", height, defaultValue: Diagnostics.kNullDefaultValue));
+            styles.Add(new StringProperty("background", background == null ? null : background.ToString(), defaultValue: Diagnostics.kNullDefaultValue, quoted: false));
             if (decoration != null)
             {
                 List<string> decorationDescription = new List<string>();
                 }
                 
-                styles.Add(new DiagnosticsProperty<Color>("decorationColor", decorationColor, defaultValue: null, 
+                styles.Add(new DiagnosticsProperty<Color>("decorationColor", decorationColor, defaultValue: Diagnostics.kNullDefaultValue, 
                     level: DiagnosticLevel.fine));
                 if (decorationColor != null)
                 {
-                styles.Add(new DiagnosticsProperty<TextDecoration>("decoration", decoration, defaultValue: null,
+                styles.Add(new DiagnosticsProperty<TextDecoration>("decoration", decoration, defaultValue: Diagnostics.kNullDefaultValue,
                     level: DiagnosticLevel.hidden));
                 if (decoration != null)
                     decorationDescription.Add("$decoration");

Assets/UIWidgets/ui/text.cs

 {
     public enum FontStyle
     {
-        /// Use the upright glyphs
-
-        /// Use glyphs designed for slanting
         italic,
     }
 
 
     public enum TextAlign
     {
-        /// Align the text on the left edge of the container.
-
-        /// Align the text on the right edge of the container.
-
-        /// Align the text in the center of the container.
-
-        /// Stretch lines of text that end with a soft line break to fill the width of
-        /// the container.
-        ///
-        /// Lines that end with hard line breaks are aligned towards the [start] edge.
         justify,
     }
 

Assets/UIWidgets/widgets/basic.cs

         }
     }
 
-    public class Flexible : ParentDataWidget {
+    public class Flexible : ParentDataWidget<Flex> {
         public Flexible(
             Key key = null,
             int flex = 1,

Assets/UIWidgets/widgets/editable_text.cs

             {
                 style.debugFillProperties(properties);
             }
-            properties.add(new EnumProperty<TextAlign>("textAlign", textAlign, defaultValue: null));
-            properties.add(new EnumProperty<TextDirection?>("textDirection", textDirection, defaultValue: null));
-            properties.add(new DiagnosticsProperty<double>("textScaleFactor", textScaleFactor, defaultValue: null));
+            properties.add(new EnumProperty<TextAlign>("textAlign", textAlign, defaultValue: Diagnostics.kNullDefaultValue));
+            properties.add(new EnumProperty<TextDirection?>("textDirection", textDirection, defaultValue: Diagnostics.kNullDefaultValue));
+            properties.add(new DiagnosticsProperty<double>("textScaleFactor", textScaleFactor, defaultValue: Diagnostics.kNullDefaultValue));
             properties.add(new DiagnosticsProperty<int>("maxLines", maxLines, defaultValue: 1));
             properties.add(new DiagnosticsProperty<bool>("autofocus", autofocus, defaultValue: false));
         }

Assets/UIWidgets/widgets/framework.cs

             : base(key: key, child: child) {
         }
 
+        public abstract bool debugIsValidAncestor(RenderObjectWidget ancestor);
+
+        public abstract string debugDescribeInvalidAncestorChain(
+            string description = null,
+            string ownershipChain = null,
+            bool foundValidAncestor = false,
+            IEnumerable<Widget> badAncestors = null
+        );
+
+        public abstract void applyParentData(RenderObject renderObject);
+
+        public virtual bool debugCanApplyOutOfTurn() {
+            return false;
+        }
+    }
+
+    public abstract class ParentDataWidget<T> : ParentDataWidget where T : RenderObjectWidget {
+        public ParentDataWidget(Key key = null, Widget child = null)
+            : base(key: key, child: child) {
+        }
+
-        public virtual bool debugIsValidAncestor(RenderObjectWidget ancestor) {
-            return ancestor is RenderObjectWidget;
+        public override bool debugIsValidAncestor(RenderObjectWidget ancestor) {
+            D.assert(typeof(T) != typeof(RenderObjectWidget));            
+            return ancestor is T;
-        public virtual string debugDescribeInvalidAncestorChain(
-            String description = null, String ownershipChain = null, bool foundValidAncestor = false,
+        public override string debugDescribeInvalidAncestorChain(
+            string description = null,
+            string ownershipChain = null,
+            bool foundValidAncestor = false,
-            String result;
+            D.assert(typeof(T) != typeof(RenderObjectWidget));            
+
+            string result;
-                result = string.Format("{0} widgets must be placed inside {1} widgets.\n" +
-                                       "{2} has no {1} ancestor at all.\n", this.GetType(), typeof(RenderObjectWidget), description);
+                result = string.Format(
+                    "{0} widgets must be placed inside {1} widgets.\n" +
+                                       "{2} has no {1} ancestor at all.\n", this.GetType(), typeof(T), description);
-                result = string.Format("{0} widgets must be placed directly inside {1} widgets.\n" +
+                result = string.Format(
+                    "{0} widgets must be placed directly inside {1} widgets.\n" +
-                    this.GetType(), typeof(RenderObjectWidget), description);
+                    this.GetType(), typeof(T), description);
 
                 foreach (Widget ancestor in badAncestors) {
                     if (ancestor.GetType() == this.GetType()) {
                     }
                 }
 
-                result += "These widgets cannot come between a " + this.GetType() + " and its " + typeof(RenderObjectWidget) + ".\n";
+                result += "These widgets cannot come between a " + this.GetType() + " and its " + typeof(T) + ".\n";
             }
 
             result += "The ownership chain for the parent of the offending "
-
-        public abstract void applyParentData(RenderObject renderObject);
-
-        public virtual bool debugCanApplyOutOfTurn() {
-            return false;
-        }
-
 
     public abstract class InheritedWidget : ProxyWidget {
         protected InheritedWidget(Key key = null, Widget child = null) : base(key, child) {

Assets/UIWidgets/widgets/sliver.cs

         }
     }
 
-    public class KeepAlive : ParentDataWidget{
+    public class KeepAlive : ParentDataWidget<SliverMultiBoxAdaptorWidget> {
         public KeepAlive(
             Key key = null,
             bool keepAlive = true,

Assets/UIWidgets/widgets/text.cs

 using UIWidgets.ui;
 using TextStyle = UIWidgets.painting.TextStyle;
 
-namespace UIWidgets.widgets
-{
-    public class DefaultTextStyle : InheritedWidget
-    {
-        public DefaultTextStyle(TextStyle style, Widget child,
-            TextAlign textAlign, int maxLines = 0,
+namespace UIWidgets.widgets {
+    public class DefaultTextStyle : InheritedWidget {
+        public DefaultTextStyle(
+            Key key = null,
+            TextStyle style = null,
+            TextAlign? textAlign = null,
-            TextOverflow overflow = TextOverflow.clip, Key key = null) : base(key, child)
-        {
+            TextOverflow overflow = TextOverflow.clip,
+            int? maxLines = null,
+            Widget child = null
+        ) : base(key, child) {
+            D.assert(maxLines == null || maxLines > 0);
+            
+            this.overflow = overflow;
-            this.overflow = overflow;
+        }
+
+        private DefaultTextStyle() {
+            this.style = new TextStyle();
+            this.textAlign = null;
+            this.softWrap = true;
+            this.overflow = TextOverflow.clip;
+            this.maxLines = null;
-        public static DefaultTextStyle fallback()
-        {
-            return new DefaultTextStyle(new TextStyle(), null, TextAlign.left, 0, true,
-                TextOverflow.clip, null);
+        public static DefaultTextStyle fallback() {
+            return new DefaultTextStyle();
-        public static Widget merge(Key key, TextStyle style, TextAlign? textAlign,
-            bool? softWrap, TextOverflow? overflow, int? maxLines, Widget child)
-        {
+        public static Widget merge(
+            Key key = null,
+            TextStyle style = null,
+            TextAlign? textAlign = null,
+            bool? softWrap = null,
+            TextOverflow? overflow = null,
+            int? maxLines = null,
+            Widget child = null
+        ) {
-            return new Builder(builder: (context =>
-            {
+            return new Builder(builder: (context => {
                 var parent = DefaultTextStyle.of(context);
                 return new DefaultTextStyle(
                     key: key,
         }
 
         public readonly TextStyle style;
-        public readonly TextAlign textAlign;
+        public readonly TextAlign? textAlign;
-        public readonly int maxLines;
+        public readonly int? maxLines;
-        public static DefaultTextStyle of(BuildContext context)
-        {
+        public static DefaultTextStyle of(BuildContext context) {
-        public override bool updateShouldNotify(InheritedWidget w)
-        {
+        public override bool updateShouldNotify(InheritedWidget w) {
-            return style != oldWidget.style ||
-                   textAlign != oldWidget.textAlign ||
-                   softWrap != oldWidget.softWrap ||
-                   overflow != oldWidget.overflow ||
-                   maxLines != oldWidget.maxLines;
+            return this.style != oldWidget.style ||
+                   this.textAlign != oldWidget.textAlign ||
+                   this.softWrap != oldWidget.softWrap ||
+                   this.overflow != oldWidget.overflow ||
+                   this.maxLines != oldWidget.maxLines;
-        public override void debugFillProperties(DiagnosticPropertiesBuilder properties)
-        {
+        public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
-            if (style != null)
-            {
-                style.debugFillProperties(properties);
+            if (this.style != null) {
+                this.style.debugFillProperties(properties);
-            properties.add(new EnumProperty<TextAlign>("textAlign", textAlign, defaultValue: null));
-            properties.add(new FlagProperty("softWrap", value: softWrap, ifTrue: "wrapping at box width",
+            properties.add(new EnumProperty<TextAlign?>("textAlign", this.textAlign,
+                defaultValue: Diagnostics.kNullDefaultValue));
+            properties.add(new FlagProperty("softWrap", value: this.softWrap, ifTrue: "wrapping at box width",
-            properties.add(new EnumProperty<TextOverflow>("overflow", overflow, defaultValue: null));
-            properties.add(new IntProperty("maxLines", maxLines, defaultValue: null));
+            properties.add(new EnumProperty<TextOverflow>("overflow", this.overflow,
+                defaultValue: Diagnostics.kNullDefaultValue));
+            properties.add(new IntProperty("maxLines", this.maxLines,
+                defaultValue: Diagnostics.kNullDefaultValue));
-    public class Text : StatelessWidget
-    {
-        public Text(string data, Key key = null, TextStyle style = null,
-            TextAlign? textAlign = null, bool? softWrap = null,
-            TextOverflow? overflow = null, double? textScaleFactor = null, int? maxLines = null) : base(key)
-        {
+    public class Text : StatelessWidget {
+        public Text(string data,
+            Key key = null, 
+            TextStyle style = null,
+            TextAlign? textAlign = null, 
+            bool? softWrap = null,
+            TextOverflow? overflow = null,
+            double? textScaleFactor = null,
+            int? maxLines = null) : base(key) {
             D.assert(data != null);
             this.textSpan = null;
             this.data = data;
             this.maxLines = maxLines;
         }
 
-        public Text(TextSpan textSpan, Key key = null, TextStyle style = null,
-            TextAlign? textAlign = null, bool? softWrap = null,
-            TextOverflow? overflow = null, double? textScaleFactor = null, int? maxLines = null) : base(key)
-        {
+        private Text(TextSpan textSpan, 
+            Key key = null, 
+            TextStyle style = null,
+            TextAlign? textAlign = null,
+            bool? softWrap = null,
+            TextOverflow? overflow = null,
+            double? textScaleFactor = null, 
+            int? maxLines = null) : base(key) {
             D.assert(textSpan != null);
             this.textSpan = textSpan;
             this.data = null;
             this.maxLines = maxLines;
         }
 
+        public static Text rich(TextSpan textSpan,
+            Key key = null,
+            TextStyle style = null,
+            TextAlign? textAlign = null,
+            bool? softWrap = null,
+            TextOverflow? overflow = null,
+            double? textScaleFactor = null,
+            int? maxLines = null) {
+            return new Text(
+                textSpan, key,
+                style,
+                textAlign,
+                softWrap,
+                overflow,
+                textScaleFactor,
+                maxLines);
+        }
+
         public readonly string data;
 
         public readonly TextSpan textSpan;
         public readonly TextAlign? textAlign;
 
-        public readonly TextDirection? textDirection;
-
         public readonly bool? softWrap;
 
         public readonly TextOverflow? overflow;
         public readonly int? maxLines;
 
-        public override Widget build(BuildContext context)
-        {
+        public override Widget build(BuildContext context) {
-            TextStyle effectiveTextStyle = style;
-            if (style == null || style.inherit)
-            {
-                effectiveTextStyle = defaultTextStyle.style.merge(style);
+            TextStyle effectiveTextStyle = this.style;
+            if (this.style == null || this.style.inherit) {
+                effectiveTextStyle = defaultTextStyle.style.merge(this.style);
-                textAlign: textAlign ?? defaultTextStyle.textAlign,
-                softWrap: softWrap ?? defaultTextStyle.softWrap,
-                overflow: overflow ?? defaultTextStyle.overflow,
-                textScaleFactor: textScaleFactor ?? 1.0, // MediaQuery.textScaleFactorOf(context), todo
-                maxLines: maxLines ?? defaultTextStyle.maxLines,
+                textAlign: this.textAlign ?? defaultTextStyle.textAlign ??  TextAlign.left,
+                softWrap: this.softWrap ?? defaultTextStyle.softWrap,
+                overflow: this.overflow ?? defaultTextStyle.overflow,
+                textScaleFactor: this.textScaleFactor ?? 1.0, // MediaQuery.textScaleFactorOf(context), todo
+                maxLines: this.maxLines ?? defaultTextStyle.maxLines,
-                    text: data,
-                    children: textSpan != null ? new List<TextSpan>() {textSpan} : null
+                    text: this.data,
+                    children: this.textSpan != null ? new List<TextSpan> {this.textSpan} : null
-
-        public override void debugFillProperties(DiagnosticPropertiesBuilder properties)
-        {
+        public override void debugFillProperties(DiagnosticPropertiesBuilder properties) {
-            properties.add(new StringProperty("data", data, showName: false));
-            if (textSpan != null)
-            {
-                properties.add(textSpan.toDiagnosticsNode(name: "textSpan", style: DiagnosticsTreeStyle.transition));
+            properties.add(new StringProperty("data", this.data, showName: false));
+            if (this.textSpan != null) {
+                properties.add(this.textSpan.toDiagnosticsNode(name: "textSpan", style: DiagnosticsTreeStyle.transition));
-            if (style != null)
-            {
-                style.debugFillProperties(properties);
+            if (this.style != null) {
+                this.style.debugFillProperties(properties);
-            properties.add(new EnumProperty<TextAlign?>("textAlign", textAlign, defaultValue: null));
-            properties.add(new EnumProperty<TextDirection?>("textDirection", textDirection, defaultValue: null));
-            properties.add(new FlagProperty("softWrap", value: softWrap ?? false, ifTrue: "wrapping at box width",
-                ifFalse: "no wrapping except at line break characters", showName: true)); // todo ObjectFlagProperty
-            properties.add(new EnumProperty<TextOverflow?>("overflow", overflow, defaultValue: null));
-            properties.add(new DoubleProperty("textScaleFactor", textScaleFactor, defaultValue: null));
-            properties.add(new IntProperty("maxLines", maxLines, defaultValue: null));
+            properties.add(new EnumProperty<TextAlign?>("textAlign", this.textAlign,
+                defaultValue: Diagnostics.kNullDefaultValue));
+            properties.add(new FlagProperty("softWrap", value: this.softWrap, ifTrue: "wrapping at box width",
+                ifFalse: "no wrapping except at line break characters", showName: true));
+            properties.add(new EnumProperty<TextOverflow?>("overflow", this.overflow,
+                defaultValue: Diagnostics.kNullDefaultValue));
+            properties.add(new DoubleProperty("textScaleFactor", this.textScaleFactor,
+                defaultValue: Diagnostics.kNullDefaultValue));
+            properties.add(new IntProperty("maxLines", this.maxLines, defaultValue: Diagnostics.kNullDefaultValue));
         }
     }
 }