[flutter_markdown] Add horizontal scroll for markdown table (#6983)

Add horizontal scroll for markdown table when using `tableColumnWidth: FixedColumnWidth(width)`

Fix [flutter/flutter#129052](flutter/flutter#129052)

packages/flutter_markdown/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.7.3
+
+* Adds horizontal scrolling for table when using `tableColumnWidth: FixedColumnWidth(width)`.
+
 ## 0.7.2+1
 
 * Fixes a crash caused by text selection when `selectable` is true and `onSelectionChanged` is null.

packages/flutter_markdown/lib/src/builder.dart

@@ -438,12 +438,20 @@ class MarkdownBuilder implements md.NodeVisitor {
           );
         }
       } else if (tag == 'table') {
-        child = Table(
-          defaultColumnWidth: styleSheet.tableColumnWidth!,
-          defaultVerticalAlignment: styleSheet.tableVerticalAlignment,
-          border: styleSheet.tableBorder,
-          children: _tables.removeLast().rows,
-        );
+        if (styleSheet.tableColumnWidth is FixedColumnWidth) {
+          final ScrollController tableScrollController = ScrollController();
+          child = Scrollbar(
+            controller: tableScrollController,
+            child: SingleChildScrollView(
+              controller: tableScrollController,
+              scrollDirection: Axis.horizontal,
+              padding: styleSheet.tablePadding,
+              child: _buildTable(),
+            ),
+          );
+        } else {
+          child = _buildTable();
+        }
       } else if (tag == 'blockquote') {
         _isInBlockquote = false;
         child = DecoratedBox(
@@ -558,6 +566,15 @@ class MarkdownBuilder implements md.NodeVisitor {
     _lastVisitedTag = tag;
   }
 
+  Table _buildTable() {
+    return Table(
+      defaultColumnWidth: styleSheet.tableColumnWidth!,
+      defaultVerticalAlignment: styleSheet.tableVerticalAlignment,
+      border: styleSheet.tableBorder,
+      children: _tables.removeLast().rows,
+    );
+  }
+
   Widget _buildImage(String src, String? title, String? alt) {
     final List<String> parts = src.split('#');
     if (parts.isEmpty) {

packages/flutter_markdown/lib/src/style_sheet.dart

@@ -38,6 +38,7 @@ class MarkdownStyleSheet {
     this.tableHead,
     this.tableBody,
     this.tableHeadAlign,
+    this.tablePadding,
     this.tableBorder,
     this.tableColumnWidth,
     this.tableCellsPadding,
@@ -134,6 +135,7 @@ class MarkdownStyleSheet {
       tableHead: const TextStyle(fontWeight: FontWeight.w600),
       tableBody: theme.textTheme.bodyMedium,
       tableHeadAlign: TextAlign.center,
+      tablePadding: const EdgeInsets.only(bottom: 4.0),
       tableBorder: TableBorder.all(
         color: theme.dividerColor,
       ),
@@ -231,6 +233,7 @@ class MarkdownStyleSheet {
       ),
       tableBody: theme.textTheme.textStyle,
       tableHeadAlign: TextAlign.center,
+      tablePadding: const EdgeInsets.only(bottom: 8),
       tableBorder: TableBorder.all(color: CupertinoColors.separator, width: 0),
       tableColumnWidth: const FlexColumnWidth(),
       tableCellsPadding: const EdgeInsets.fromLTRB(16, 8, 16, 8),
@@ -312,6 +315,7 @@ class MarkdownStyleSheet {
       tableHead: const TextStyle(fontWeight: FontWeight.w600),
       tableBody: theme.textTheme.bodyMedium,
       tableHeadAlign: TextAlign.center,
+      tablePadding: const EdgeInsets.only(bottom: 4.0),
       tableBorder: TableBorder.all(
         color: theme.dividerColor,
       ),
@@ -371,6 +375,7 @@ class MarkdownStyleSheet {
     TextStyle? tableHead,
     TextStyle? tableBody,
     TextAlign? tableHeadAlign,
+    EdgeInsets? tablePadding,
     TableBorder? tableBorder,
     TableColumnWidth? tableColumnWidth,
     EdgeInsets? tableCellsPadding,
@@ -436,6 +441,7 @@ class MarkdownStyleSheet {
       tableHead: tableHead ?? this.tableHead,
       tableBody: tableBody ?? this.tableBody,
       tableHeadAlign: tableHeadAlign ?? this.tableHeadAlign,
+      tablePadding: tablePadding ?? this.tablePadding,
       tableBorder: tableBorder ?? this.tableBorder,
       tableColumnWidth: tableColumnWidth ?? this.tableColumnWidth,
       tableCellsPadding: tableCellsPadding ?? this.tableCellsPadding,
@@ -502,6 +508,7 @@ class MarkdownStyleSheet {
       tableHead: tableHead!.merge(other.tableHead),
       tableBody: tableBody!.merge(other.tableBody),
       tableHeadAlign: other.tableHeadAlign,
+      tablePadding: other.tablePadding,
       tableBorder: other.tableBorder,
       tableColumnWidth: other.tableColumnWidth,
       tableCellsPadding: other.tableCellsPadding,
@@ -620,6 +627,9 @@ class MarkdownStyleSheet {
   /// The [TextAlign] to use for `th` elements.
   final TextAlign? tableHeadAlign;
 
+  /// The padding to use for `table` elements.
+  final EdgeInsets? tablePadding;
+
   /// The [TableBorder] to use for `table` elements.
   final TableBorder? tableBorder;
 
@@ -740,6 +750,7 @@ class MarkdownStyleSheet {
         other.tableHead == tableHead &&
         other.tableBody == tableBody &&
         other.tableHeadAlign == tableHeadAlign &&
+        other.tablePadding == tablePadding &&
         other.tableBorder == tableBorder &&
         other.tableColumnWidth == tableColumnWidth &&
         other.tableCellsPadding == tableCellsPadding &&
@@ -798,6 +809,7 @@ class MarkdownStyleSheet {
       tableHead,
       tableBody,
       tableHeadAlign,
+      tablePadding,
       tableBorder,
       tableColumnWidth,
       tableCellsPadding,

packages/flutter_markdown/pubspec.yaml

@@ -4,7 +4,7 @@ description: A Markdown renderer for Flutter. Create rich text output,
   formatted with simple Markdown tags.
 repository: https://github.com/flutter/packages/tree/main/packages/flutter_markdown
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+flutter_markdown%22
-version: 0.7.2+1
+version: 0.7.3
 
 environment:
   sdk: ^3.3.0

packages/flutter_markdown/test/scrollable_test.dart

@@ -110,5 +110,69 @@ void defineTests() {
         ]);
       },
     );
+
+    testWidgets(
+      'table',
+      (WidgetTester tester) async {
+        const String data = '|Header 1|Header 2|Header 3|'
+            '\n|-----|-----|-----|'
+            '\n|Col 1|Col 2|Col 3|';
+        await tester.pumpWidget(
+          boilerplate(
+            MediaQuery(
+              data: const MediaQueryData(),
+              child: MarkdownBody(
+                data: data,
+                styleSheet: MarkdownStyleSheet(
+                  tableColumnWidth: const FixedColumnWidth(150),
+                ),
+              ),
+            ),
+          ),
+        );
+
+        final Iterable<Widget> widgets = tester.allWidgets;
+        final Iterable<SingleChildScrollView> scrollViews =
+            widgets.whereType<SingleChildScrollView>();
+        expect(scrollViews, isNotEmpty);
+        expect(scrollViews.first.controller, isNotNull);
+      },
+    );
+
+    testWidgets(
+      'two tables use different scroll controllers',
+      (WidgetTester tester) async {
+        const String data = '|Header 1|Header 2|Header 3|'
+            '\n|-----|-----|-----|'
+            '\n|Col 1|Col 2|Col 3|'
+            '\n'
+            '\n|Header 1|Header 2|Header 3|'
+            '\n|-----|-----|-----|'
+            '\n|Col 1|Col 2|Col 3|';
+
+        await tester.pumpWidget(
+          boilerplate(
+            MediaQuery(
+              data: const MediaQueryData(),
+              child: MarkdownBody(
+                data: data,
+                styleSheet: MarkdownStyleSheet(
+                  tableColumnWidth: const FixedColumnWidth(150),
+                ),
+              ),
+            ),
+          ),
+        );
+
+        final Iterable<Widget> widgets = tester.allWidgets;
+        final Iterable<SingleChildScrollView> scrollViews =
+            widgets.whereType<SingleChildScrollView>();
+        expect(scrollViews, hasLength(2));
+        expect(scrollViews.first.controller, isNotNull);
+        expect(scrollViews.last.controller, isNotNull);
+        expect(scrollViews.first.controller,
+            isNot(equals(scrollViews.last.controller)));
+      },
+    );
   });
 }