Add flutter_web samples (#75)

web/charts/flutter/test/behaviors/legend/legend_layout_test.dart

@@ -0,0 +1,116 @@
+// Copyright 2018 the Charts project authors. Please see the AUTHORS file
+// for details.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import 'package:flutter_web/material.dart';
+import 'package:mockito/mockito.dart';
+import 'package:test/test.dart';
+
+import 'package:charts_flutter/src/behaviors/legend/legend_layout.dart';
+
+class MockContext extends Mock implements BuildContext {}
+
+void main() {
+  BuildContext context;
+
+  setUp(() {
+    context = new MockContext();
+  });
+
+  group('TabularLegendLayoutBuilder', () {
+    test('builds horizontally', () {
+      final builder = new TabularLegendLayout.horizontalFirst();
+      final widgets = <Widget>[new Text('1'), new Text('2'), new Text('3')];
+
+      final Table layout = builder.build(context, widgets);
+      expect(layout.children.length, 1);
+      expect(layout.children.first.children.length, 3);
+    });
+
+    test('does not build extra columns if max columns exceed widget count', () {
+      final builder =
+          new TabularLegendLayout.horizontalFirst(desiredMaxColumns: 10);
+      final widgets = <Widget>[new Text('1'), new Text('2'), new Text('3')];
+
+      final Table layout = builder.build(context, widgets);
+      expect(layout.children.length, 1);
+      expect(layout.children.first.children.length, 3);
+    });
+
+    test('builds horizontally until max column exceeded', () {
+      final builder =
+          new TabularLegendLayout.horizontalFirst(desiredMaxColumns: 2);
+
+      final widgets = new List<Widget>.generate(
+          7, (int index) => new Text(index.toString()));
+
+      final Table layout = builder.build(context, widgets);
+      expect(layout.children.length, 4);
+
+      expect(layout.children[0].children[0], equals(widgets[0]));
+      expect(layout.children[0].children[1], equals(widgets[1]));
+
+      expect(layout.children[1].children[0], equals(widgets[2]));
+      expect(layout.children[1].children[1], equals(widgets[3]));
+
+      expect(layout.children[2].children[0], equals(widgets[4]));
+      expect(layout.children[2].children[1], equals(widgets[5]));
+
+      expect(layout.children[3].children[0], equals(widgets[6]));
+    });
+
+    test('builds vertically', () {
+      final builder = new TabularLegendLayout.verticalFirst();
+      final widgets = <Widget>[new Text('1'), new Text('2'), new Text('3')];
+
+      final Table layout = builder.build(context, widgets);
+      expect(layout.children.length, 3);
+      expect(layout.children[0].children.length, 1);
+      expect(layout.children[1].children.length, 1);
+      expect(layout.children[2].children.length, 1);
+    });
+
+    test('does not build extra rows if max rows exceed widget count', () {
+      final builder = new TabularLegendLayout.verticalFirst(desiredMaxRows: 10);
+      final widgets = <Widget>[new Text('1'), new Text('2'), new Text('3')];
+
+      final Table layout = builder.build(context, widgets);
+      expect(layout.children.length, 3);
+      expect(layout.children[0].children.length, 1);
+      expect(layout.children[1].children.length, 1);
+      expect(layout.children[2].children.length, 1);
+    });
+
+    test('builds vertically until max column exceeded', () {
+      final builder = new TabularLegendLayout.verticalFirst(desiredMaxRows: 2);
+
+      final widgets = new List<Widget>.generate(
+          7, (int index) => new Text(index.toString()));
+
+      final Table layout = builder.build(context, widgets);
+      expect(layout.children.length, 2);
+
+      expect(layout.children[0].children[0], equals(widgets[0]));
+      expect(layout.children[1].children[0], equals(widgets[1]));
+
+      expect(layout.children[0].children[1], equals(widgets[2]));
+      expect(layout.children[1].children[1], equals(widgets[3]));
+
+      expect(layout.children[0].children[2], equals(widgets[4]));
+      expect(layout.children[1].children[2], equals(widgets[5]));
+
+      expect(layout.children[0].children[3], equals(widgets[6]));
+    });
+  });
+}