[two_dimensional_scrollables] Merged cells for TableView

packages/two_dimensional_scrollables/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.1.0
+
+* [Breaking change] Adds support for merged cells in the TableView.
+
 ## 0.0.6
 
 * Fixes an error in TableSpanDecoration when one or both axes are reversed.

packages/two_dimensional_scrollables/example/lib/main.dart

@@ -44,6 +44,28 @@ class _TableExampleState extends State<TableExample> {
   late final ScrollController _verticalController = ScrollController();
   int _rowCount = 20;
 
+  final Map<TableVicinity, ({int start, int span})> mergedRows =
+      <TableVicinity, ({int start, int span})>{
+    TableVicinity.zero: (start: 0, span: 2),
+    TableVicinity.zero.copyWith(row: 1): (start: 0, span: 2),
+  };
+
+  final Map<TableVicinity, ({int start, int span})> mergedColumns =
+      <TableVicinity, ({int start, int span})>{
+    const TableVicinity(row: 0, column: 1): (start: 1, span: 2),
+    const TableVicinity(row: 0, column: 2): (start: 1, span: 2),
+  };
+
+  // If a merged square is along the identity matrix, the values are the same
+  // for row merge and column merge data.
+  final Map<TableVicinity, ({int start, int span})> mergedIdentitySquares =
+      <TableVicinity, ({int start, int span})>{
+    const TableVicinity(row: 1, column: 1): (start: 1, span: 2),
+    const TableVicinity(row: 1, column: 2): (start: 1, span: 2),
+    const TableVicinity(row: 2, column: 1): (start: 1, span: 2),
+    const TableVicinity(row: 2, column: 2): (start: 1, span: 2),
+  };
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -53,44 +75,43 @@ class _TableExampleState extends State<TableExample> {
       body: Padding(
         padding: const EdgeInsets.symmetric(horizontal: 50),
         child: TableView.builder(
-          verticalDetails:
-              ScrollableDetails.vertical(controller: _verticalController),
+          verticalDetails: ScrollableDetails.vertical(
+            controller: _verticalController,
+          ),
           cellBuilder: _buildCell,
           columnCount: 20,
-          columnBuilder: _buildColumnSpan,
           rowCount: _rowCount,
+          columnBuilder: _buildColumnSpan,
           rowBuilder: _buildRowSpan,
         ),
       ),
-      persistentFooterButtons: <Widget>[
-        TextButton(
-          onPressed: () {
-            _verticalController.jumpTo(0);
-          },
-          child: const Text('Jump to Top'),
-        ),
-        TextButton(
-          onPressed: () {
-            _verticalController
-                .jumpTo(_verticalController.position.maxScrollExtent);
-          },
-          child: const Text('Jump to Bottom'),
-        ),
-        TextButton(
-          onPressed: () {
-            setState(() {
-              _rowCount += 10;
-            });
-          },
-          child: const Text('Add 10 Rows'),
-        ),
-      ],
     );
   }
 
-  Widget _buildCell(BuildContext context, TableVicinity vicinity) {
-    return Center(
-      child: Text('Tile c: ${vicinity.column}, r: ${vicinity.row}'),
+  TableViewCell _buildCell(BuildContext context, TableVicinity vicinity) {
+    final bool mergedCell = mergedRows.keys.contains(vicinity) ||
+        mergedColumns.keys.contains(vicinity) ||
+        mergedIdentitySquares.keys.contains(vicinity);
+    if (mergedCell) {
+      return TableViewCell(
+        rowMergeStart: mergedIdentitySquares[vicinity]?.start ??
+            mergedRows[vicinity]?.start,
+        rowMergeSpan:
+            mergedIdentitySquares[vicinity]?.span ?? mergedRows[vicinity]?.span,
+        columnMergeStart: mergedIdentitySquares[vicinity]?.start ??
+            mergedColumns[vicinity]?.start,
+        columnMergeSpan: mergedIdentitySquares[vicinity]?.span ??
+            mergedColumns[vicinity]?.span,
+        child: const Center(
+          child: Text('Merged'),
+        ),
+      );
+    }
+
+    return TableViewCell(
+      child: Center(
+        child: Text('(${vicinity.row}, ${vicinity.column})'),
+      ),
     );
   }
 
@@ -148,7 +169,7 @@ class _TableExampleState extends State<TableExample> {
 
   TableSpan _buildRowSpan(int index) {
     final TableSpanDecoration decoration = TableSpanDecoration(
-      color: index.isEven ? Colors.purple[100] : null,
+      color: index.isEven ? Colors.blueAccent[100] : null,
       border: const TableSpanBorder(
         trailing: BorderSide(
           width: 3,

packages/two_dimensional_scrollables/example/macos/Runner.xcodeproj/project.pbxproj

@@ -227,7 +227,7 @@
 			isa = PBXProject;
 			attributes = {
 				LastSwiftUpdateCheck = 0920;
-				LastUpgradeCheck = 1430;
+				LastUpgradeCheck = 1510;
 				ORGANIZATIONNAME = "";
 				TargetAttributes = {
 					331C80D4294CF70F00263BE5 = {

packages/two_dimensional_scrollables/example/macos/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1430"
+   LastUpgradeVersion = "1510"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"