Add possibility to overwrite anchor links

Author: DFelten

lib/flutter_html.dart

@@ -65,6 +65,7 @@ class Html extends StatelessWidget {
     GlobalKey? anchorKey,
     required this.data,
     this.onLinkTap,
+    this.onAnchorTap,
     this.customRender = const {},
     this.customImageRenders = const {},
     this.onCssParseError,
@@ -85,6 +86,7 @@ class Html extends StatelessWidget {
     GlobalKey? anchorKey,
     @required this.document,
     this.onLinkTap,
+    this.onAnchorTap,
     this.customRender = const {},
     this.customImageRenders = const {},
     this.onCssParseError,
@@ -112,6 +114,10 @@ class Html extends StatelessWidget {
   /// A function that defines what to do when a link is tapped
   final OnTap? onLinkTap;
 
+  /// A function that defines what to do when an anchor link is tapped. When this value is set,
+  /// the default anchor behaviour is overwritten.
+  final OnTap? onAnchorTap;
+
   /// An API that allows you to customize the entire process of image rendering.
   /// See the README for more details.
   final Map<ImageSourceMatcher, ImageRender> customImageRenders;
@@ -167,6 +173,7 @@ class Html extends StatelessWidget {
         key: _anchorKey,
         htmlData: doc,
         onLinkTap: onLinkTap,
+        onAnchorTap: onAnchorTap,
         onImageTap: onImageTap,
         onCssParseError: onCssParseError,
         onImageError: onImageError,

lib/html_parser.dart

@@ -41,6 +41,7 @@ class HtmlParser extends StatelessWidget {
   final Key? key;
   final dom.Document htmlData;
   final OnTap? onLinkTap;
+  final OnTap? onAnchorTap;
   final OnTap? onImageTap;
   final OnCssParseError? onCssParseError;
   final ImageErrorListener? onImageError;
@@ -58,6 +59,7 @@ class HtmlParser extends StatelessWidget {
     required this.key,
     required this.htmlData,
     required this.onLinkTap,
+    required this.onAnchorTap,
     required this.onImageTap,
     required this.onCssParseError,
     required this.onImageError,
@@ -68,7 +70,12 @@ class HtmlParser extends StatelessWidget {
     required this.imageRenders,
     required this.tagsList,
     required this.navigationDelegateForIframe,
-  }): this._onAnchorTap = key != null ? _handleAnchorTap(key, onLinkTap): null, super(key: key);
+  })  : this._onAnchorTap = onAnchorTap != null
+          ? onAnchorTap
+          : key != null
+              ? _handleAnchorTap(key, onLinkTap)
+              : null,
+        super(key: key);
 
   @override
   Widget build(BuildContext context) {