Pre-nullsafety changes

Author: tneotia

lib/flutter_html.dart

@@ -36,13 +36,13 @@ class Html extends StatelessWidget {
     Key key,
     @required this.data,
     this.onLinkTap,
-    this.customRender,
+    this.customRender = const {},
     this.customImageRenders = const {},
     this.onImageError,
     this.shrinkWrap = false,
     this.onImageTap,
     this.blacklistedElements = const [],
-    this.style,
+    this.style = const {},
     this.navigationDelegateForIframe,
   }) : super(key: key);
 

lib/html_parser.dart

@@ -39,15 +39,15 @@ class HtmlParser extends StatelessWidget {
 
   HtmlParser({
     @required this.htmlData,
-    this.onLinkTap,
-    this.onImageTap,
-    this.onImageError,
-    this.shrinkWrap,
-    this.style,
-    this.customRender,
-    this.imageRenders,
-    this.blacklistedElements,
-    this.navigationDelegateForIframe,
+    @required this.onLinkTap,
+    @required this.onImageTap,
+    @required this.onImageError,
+    @required this.shrinkWrap,
+    @required this.style,
+    @required this.customRender,
+    @required this.imageRenders,
+    @required this.blacklistedElements,
+    @required this.navigationDelegateForIframe,
   });
 
   @override
@@ -108,8 +108,9 @@ class HtmlParser extends StatelessWidget {
   ) {
     StyledElement tree = StyledElement(
       name: "[Tree Root]",
-      children: new List<StyledElement>(),
+      children: <StyledElement>[],
       node: html.documentElement,
+      style: Style(),
     );
 
     html.nodes.forEach((node) {
@@ -134,7 +135,7 @@ class HtmlParser extends StatelessWidget {
     List<String> blacklistedElements,
     NavigationDelegate navigationDelegateForIframe,
   ) {
-    List<StyledElement> children = List<StyledElement>();
+    List<StyledElement> children = <StyledElement>[];
 
     node.nodes.forEach((childNode) {
       children.add(_recursiveLexer(
@@ -168,7 +169,7 @@ class HtmlParser extends StatelessWidget {
         return EmptyContentElement();
       }
     } else if (node is dom.Text) {
-      return TextContentElement(text: node.text);
+      return TextContentElement(text: node.text, style: Style());
     } else {
       return EmptyContentElement();
     }
@@ -667,7 +668,7 @@ class HtmlParser extends StatelessWidget {
   /// or any block-level [TextContentElement] that contains only whitespace and doesn't follow
   /// a block element or a line break.
   static StyledElement _removeEmptyElements(StyledElement tree) {
-    List<StyledElement> toRemove = new List<StyledElement>();
+    List<StyledElement> toRemove = <StyledElement>[];
     bool lastChildBlock = true;
     tree.children?.forEach((child) {
       if (child is EmptyContentElement || child is EmptyLayoutElement) {
@@ -723,9 +724,9 @@ class RenderContext {
   final Style style;
 
   RenderContext({
-    this.buildContext,
-    this.parser,
-    this.style,
+    @required this.buildContext,
+    @required this.parser,
+    @required this.style,
   });
 }
 
@@ -743,8 +744,8 @@ class ContainerSpan extends StatelessWidget {
   ContainerSpan({
     this.child,
     this.children,
-    this.style,
-    this.newContext,
+    @required this.style,
+    @required this.newContext,
     this.shrinkWrap = false,
   });
 
@@ -780,10 +781,10 @@ class StyledText extends StatelessWidget {
   final RenderContext renderContext;
 
   const StyledText({
-    this.textSpan,
-    this.style,
+    @required this.textSpan,
+    @required this.style,
     this.textScaleFactor = 1.0,
-    this.renderContext,
+    @required this.renderContext,
   });
 
   @override

lib/src/css_parser.dart

@@ -91,7 +91,7 @@ class DeclarationVisitor extends css.Visitor {
   @override
   void visitDeclaration(css.Declaration node) {
     _currentProperty = node.property;
-    _result[_currentProperty] = new List<css.Expression>();
+    _result[_currentProperty] = <css.Expression>[];
     node.expression.visit(this);
   }
 

lib/src/interactable_element.dart

@@ -8,11 +8,11 @@ class InteractableElement extends StyledElement {
   String href;
 
   InteractableElement({
-    String name,
-    List<StyledElement> children,
-    Style style,
-    this.href,
-    dom.Node node,
+    @required String name,
+    @required List<StyledElement> children,
+    @required Style style,
+    @required this.href,
+    @required dom.Node node,
   }) : super(name: name, children: children, style: style, node: node);
 }
 
@@ -23,21 +23,26 @@ enum Gesture {
 
 InteractableElement parseInteractableElement(
     dom.Element element, List<StyledElement> children) {
-  InteractableElement interactableElement = InteractableElement(
-    name: element.localName,
-    children: children,
-    node: element,
-  );
-
   switch (element.localName) {
     case "a":
-      interactableElement.href = element.attributes['href'];
-      interactableElement.style = Style(
-        color: Colors.blue,
-        textDecoration: TextDecoration.underline,
+      return InteractableElement(
+        name: element.localName,
+        children: children,
+        href: element.attributes['href'],
+        style: Style(
+          color: Colors.blue,
+          textDecoration: TextDecoration.underline,
+        ),
+        node: element,
+      );
+    /// will never be called, just to suppress missing return warning
+    default:
+      return InteractableElement(
+        name: element.localName,
+        children: children,
+        node: element,
+        href: '',
+        style: Style(),
       );
-      break;
   }
-
-  return interactableElement;
 }

lib/src/layout_element.dart

@@ -12,22 +12,20 @@ import 'package:html/dom.dart' as dom;
 /// an html document with a more complex layout. LayoutElements handle
 abstract class LayoutElement extends StyledElement {
   LayoutElement({
-    String name,
-    List<StyledElement> children,
-    Style style,
+    String name = "[[No Name]]",
+    @required List<StyledElement> children,
     dom.Element node,
-  }) : super(name: name, children: children, style: style, node: node);
+  }) : super(name: name, children: children, style: Style(), node: node);
 
   Widget toWidget(RenderContext context);
 }
 
 class TableLayoutElement extends LayoutElement {
   TableLayoutElement({
-    String name,
-    Style style,
+    @required String name,
     @required List<StyledElement> children,
-    dom.Element node,
-  }) : super(name: name, style: style, children: children, node: node);
+    @required dom.Element node,
+  }) : super(name: name, children: children, node: node);
 
   @override
   Widget toWidget(RenderContext context) {
@@ -51,8 +49,7 @@ class TableLayoutElement extends LayoutElement {
         columnSizes = child.children
             .where((c) => c.name == "col")
             .map((c) {
-              final span =
-                  int.parse(c.attributes["span"] ?? "1", onError: (_) => 1);
+              final span = int.tryParse(c.attributes["span"] ?? "1") ?? 1;
               final colWidth = c.attributes["width"];
               return List.generate(span, (index) {
                 if (colWidth != null && colWidth.endsWith("%")) {
@@ -145,16 +142,16 @@ class TableLayoutElement extends LayoutElement {
 
     return LayoutGrid(
       gridFit: GridFit.loose,
-      templateColumnSizes: finalColumnSizes,
-      templateRowSizes: rowSizes,
+      columnSizes: finalColumnSizes,
+      rowSizes: rowSizes,
       children: cells,
     );
   }
 }
 
 class TableSectionLayoutElement extends LayoutElement {
   TableSectionLayoutElement({
-    String name,
+    @required String name,
     @required List<StyledElement> children,
   }) : super(name: name, children: children);
 
@@ -167,9 +164,9 @@ class TableSectionLayoutElement extends LayoutElement {
 
 class TableRowLayoutElement extends LayoutElement {
   TableRowLayoutElement({
-    String name,
+    @required String name,
     @required List<StyledElement> children,
-    dom.Element node,
+    @required dom.Element node,
   }) : super(name: name, children: children, node: node);
 
   @override
@@ -184,12 +181,12 @@ class TableCellElement extends StyledElement {
   int rowspan = 1;
 
   TableCellElement({
-    String name,
-    String elementId,
-    List<String> elementClasses,
+    @required String name,
+    @required String elementId,
+    @required List<String> elementClasses,
     @required List<StyledElement> children,
-    Style style,
-    dom.Element node,
+    @required Style style,
+    @required dom.Element node,
   }) : super(
             name: name,
             elementId: elementId,
@@ -217,6 +214,7 @@ TableCellElement parseTableCellElement(
     elementClasses: element.classes.toList(),
     children: children,
     node: element,
+    style: Style(),
   );
   if (element.localName == "th") {
     cell.style = Style(
@@ -228,10 +226,10 @@ TableCellElement parseTableCellElement(
 
 class TableStyleElement extends StyledElement {
   TableStyleElement({
-    String name,
-    List<StyledElement> children,
-    Style style,
-    dom.Element node,
+    @required String name,
+    @required List<StyledElement> children,
+    @required Style style,
+    @required dom.Element node,
   }) : super(name: name, children: children, style: style, node: node);
 }
 
@@ -246,20 +244,26 @@ TableStyleElement parseTableDefinitionElement(
         name: element.localName,
         children: children,
         node: element,
+        style: Style(),
       );
     default:
-      return TableStyleElement();
+      return TableStyleElement(
+        name: "[[No Name]]",
+        children: children,
+        node: element,
+        style: Style(),
+      );
   }
 }
 
 class DetailsContentElement extends LayoutElement {
   List<dom.Element> elementList;
 
   DetailsContentElement({
-    String name,
-    List<StyledElement> children,
-    dom.Element node,
-    this.elementList,
+    @required String name,
+    @required List<StyledElement> children,
+    @required dom.Element node,
+    @required this.elementList,
   }) : super(name: name, node: node, children: children);
 
   @override
@@ -311,7 +315,7 @@ class DetailsContentElement extends LayoutElement {
 }
 
 class EmptyLayoutElement extends LayoutElement {
-  EmptyLayoutElement({String name = "empty"}) : super(name: name);
+  EmptyLayoutElement({@required String name}) : super(name: name, children: []);
 
   @override
   Widget toWidget(_) => null;
@@ -324,7 +328,7 @@ LayoutElement parseLayoutElement(
   switch (element.localName) {
     case "details":
       if (children?.isEmpty ?? false) {
-        return EmptyLayoutElement();
+        return EmptyLayoutElement(name: "empty");
       }
       return DetailsContentElement(
           node: element,
@@ -355,6 +359,10 @@ LayoutElement parseLayoutElement(
       );
       break;
     default:
-      return TableLayoutElement(children: children);
+      return TableLayoutElement(
+          children: children,
+          name: "[[No Name]]",
+          node: element
+      );
   }
 }