[WIP] Refactoring - Separate and Test Header

lib/flutter_calendar_carousel.dart

@@ -6,13 +6,13 @@ import 'package:date_utils/date_utils.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_calendar_carousel/classes/event_list.dart';
 import 'package:flutter_calendar_carousel/src/default_styles.dart';
+import 'package:flutter_calendar_carousel/src/calendar_header.dart';
 import 'package:intl/date_symbol_data_local.dart';
 import 'package:intl/intl.dart' show DateFormat;
 
 typedef MarkedDateIconBuilder<T> = Widget Function(T event);
 
 class CalendarCarousel<T> extends StatefulWidget {
-
   final double viewportFraction;
   final TextStyle prevDaysTextStyle;
   final TextStyle daysTextStyle;
@@ -188,16 +188,6 @@ class _CalendarState<T> extends State<CalendarCarousel<T>> {
 
   @override
   Widget build(BuildContext context) {
-    Widget headerText = DefaultTextStyle(
-        style: TextStyle(fontSize: 16.0, color: Colors.black),
-        child: widget.headerText != null
-            ? widget.headerText
-            : Text(
-                widget.weekFormat
-                    ? '${_localeDate.format(_weeks[1].first)}'
-                    : '${_localeDate.format(this._dates[1])}',
-                style: widget.headerTextStyle,
-              ));
     if (_isReloadSelectedDate) {
       if (widget.selectedDateTime != null)
         _selectedDate = widget.selectedDateTime;
@@ -210,42 +200,22 @@ class _CalendarState<T> extends State<CalendarCarousel<T>> {
       height: widget.height,
       child: Column(
         children: <Widget>[
-          widget.showHeader
-              ? Container(
-                  margin: widget.headerMargin,
-                  child: DefaultTextStyle(
-                      style: widget.headerTextStyle != null
-                          ? widget.headerTextStyle
-                          : defaultHeaderTextStyle,
-                      child: Row(
-                          mainAxisAlignment: MainAxisAlignment.spaceBetween,
-                          children: <Widget>[
-                            widget.showHeaderButton
-                                ? IconButton(
-                                    onPressed: () => _setDate(0),
-                                    icon: Icon(Icons.chevron_left,
-                                        color: widget.iconColor),
-                                  )
-                                : Container(),
-                            widget.headerTitleTouchable
-                                ? FlatButton(
-                                    onPressed:
-                                        widget.onHeaderTitlePressed != null
-                                            ? widget.onHeaderTitlePressed
-                                            : () => _selectDateFromPicker(),
-                                    child: headerText,
-                                  )
-                                : headerText,
-                            widget.showHeaderButton
-                                ? IconButton(
-                                    onPressed: () => _setDate(2),
-                                    icon: Icon(Icons.chevron_right,
-                                        color: widget.iconColor),
-                                  )
-                                : Container(),
-                          ])),
-                )
-              : Container(),
+          CalendarHeader(
+            showHeader: widget.showHeader,
+            headerMargin: widget.headerMargin,
+            headerTitle: widget.weekFormat
+                ? '${_localeDate.format(_weeks[1].first)}'
+                : '${_localeDate.format(this._dates[1])}',
+            headerTextStyle: widget.headerTextStyle,
+            showHeaderButtons: widget.showHeaderButton,
+            headerIconColor: widget.iconColor,
+            onLeftButtonPressed: () => _setDate(0),
+            onRightButtonPressed: () => _setDate(2),
+            isTitleTouchable: widget.headerTitleTouchable,
+            onHeaderTitlePressed: widget.onHeaderTitlePressed != null
+                ? widget.onHeaderTitlePressed
+                : () => _selectDateFromPicker(),
+          ),
           Container(
             child: !widget.showWeekDays
                 ? Container()
@@ -965,28 +935,21 @@ class _CalendarState<T> extends State<CalendarCarousel<T>> {
             );
           }
         } else {
-
-
           //max 5 dots
-          if(event_index < 5) {
+          if (event_index < 5) {
             if (widget.markedDateIconBuilder != null) {
               tmp.add(widget.markedDateIconBuilder(event));
-            }
-            else {
+            } else {
               if (widget.markedDateWidget != null) {
                 tmp.add(widget.markedDateWidget);
               } else {
                 tmp.add(defaultMarkedDateWidget);
               }
             }
           }
-
-
-
         }
 
         event_index++;
-
       });
       return tmp;
     }

lib/src/calendar_header.dart

@@ -0,0 +1,63 @@
+import 'package:flutter/material.dart';
+import 'default_styles.dart' show defaultHeaderTextStyle;
+
+class CalendarHeader extends StatelessWidget {
+  CalendarHeader(
+      {@required this.headerTitle,
+      this.headerMargin,
+      this.showHeader,
+      this.headerTextStyle,
+      this.showHeaderButtons,
+      this.headerIconColor,
+      @required this.onLeftButtonPressed,
+      @required this.onRightButtonPressed,
+      this.isTitleTouchable,
+      @required this.onHeaderTitlePressed});
+
+  final String headerTitle;
+  final EdgeInsetsGeometry headerMargin;
+  final bool showHeader;
+  final TextStyle headerTextStyle;
+  final bool showHeaderButtons;
+  final Color headerIconColor;
+  final VoidCallback onLeftButtonPressed;
+  final VoidCallback onRightButtonPressed;
+  final bool isTitleTouchable;
+  final VoidCallback onHeaderTitlePressed;
+
+  TextStyle get getTextStyle =>
+      headerTextStyle != null ? headerTextStyle : defaultHeaderTextStyle;
+
+  Widget _leftButton() => IconButton(
+        onPressed: onLeftButtonPressed,
+        icon: Icon(Icons.chevron_left, color: headerIconColor),
+      );
+
+  Widget _rightButton() => IconButton(
+        onPressed: onRightButtonPressed,
+        icon: Icon(Icons.chevron_right, color: headerIconColor),
+      );
+
+  Widget _headerTouchable() => FlatButton(
+        onPressed: onHeaderTitlePressed,
+        child: Text(headerTitle, style: getTextStyle),
+      );
+
+  @override
+  Widget build(BuildContext context) => showHeader
+      ? Container(
+          margin: headerMargin,
+          child: DefaultTextStyle(
+              style: getTextStyle,
+              child: Row(
+                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                  children: <Widget>[
+                    showHeaderButtons ? _leftButton() : Container(),
+                    isTitleTouchable
+                        ? _headerTouchable()
+                        : Text(headerTitle, style: getTextStyle),
+                    showHeaderButtons ? _rightButton() : Container(),
+                  ])),
+        )
+      : Container();
+}

test/src/header_test.dart

@@ -0,0 +1,101 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:flutter_calendar_carousel/src/calendar_header.dart';
+
+import 'package:flutter/material.dart';
+
+void main() {
+  final title = "Test title";
+  final margin = const EdgeInsets.symmetric(vertical: 16.0);
+  final iconColor = Colors.blueAccent;
+
+  testWidgets('Verify Header Defaults', (WidgetTester tester) async {
+    var headerTapped = false;
+    var leftPressed = false;
+    var rightPressed = false;
+
+    await tester.pumpWidget(wrapped(CalendarHeader(
+      headerTitle: title,
+      headerMargin: margin,
+      showHeader: true,
+      showHeaderButtons: true,
+      headerIconColor: iconColor,
+      onHeaderTitlePressed: () => headerTapped = true,
+      onRightButtonPressed: () => rightPressed = true,
+      onLeftButtonPressed: () => leftPressed = true,
+      isTitleTouchable: true,
+    )));
+
+    expect(find.text(title), findsOneWidget);
+
+    await tester.tap(find.byType(FlatButton));
+
+    await tester.pump();
+
+    expect(headerTapped, equals(true));
+
+    await tester.tap(find.widgetWithIcon(IconButton, Icons.chevron_right));
+
+    await tester.pump();
+
+    expect(rightPressed, equals(true));
+
+    await tester.tap(find.widgetWithIcon(IconButton, Icons.chevron_left));
+
+    await tester.pump();
+
+    expect(leftPressed, equals(true));
+  });
+
+  testWidgets('Verify No header Renders', (WidgetTester tester) async {
+    final noHeaderEmpty = CalendarHeader(showHeader: false);
+
+    await tester.pumpWidget(Container(child: noHeaderEmpty));
+
+    expect(find.byWidget(noHeaderEmpty), findsOneWidget);
+  });
+
+  testWidgets('Verify Header Is Not Touchable', (WidgetTester tester) async {
+    await tester.pumpWidget(wrapped(CalendarHeader(
+      headerTitle: title,
+      headerMargin: margin,
+      showHeader: true,
+      showHeaderButtons: true,
+      headerIconColor: iconColor,
+      onHeaderTitlePressed: () {},
+      onRightButtonPressed: () {},
+      onLeftButtonPressed: () {},
+      isTitleTouchable: false,
+    )));
+
+    // the header FlatButton Should not render
+    final touchableHeader = find.byType(FlatButton);
+
+    expect(touchableHeader, findsNothing);
+  });
+
+  testWidgets('Verify No Header Buttons', (WidgetTester tester) async {
+    await tester.pumpWidget(wrapped(CalendarHeader(
+      headerTitle: title,
+      headerMargin: margin,
+      showHeader: true,
+      showHeaderButtons: false,
+      headerIconColor: iconColor,
+      onHeaderTitlePressed: () {},
+      onRightButtonPressed: () {},
+      onLeftButtonPressed: () {},
+      isTitleTouchable: true,
+    )));
+
+    // the header IconButtons Should not render
+    final headerButton = find.byType(IconButton);
+
+    expect(headerButton, findsNothing);
+  });
+}
+
+// header uses Row which requires MaterialApp as an ancestor
+Widget wrapped(Widget widget) => MaterialApp(
+      home: Container(
+        child: Material(child: widget),
+      ),
+    );