Handling gestures

lib/main.dart

@@ -1,73 +1,65 @@
 import 'package:flutter/material.dart';
 
-class MyAppBar extends StatelessWidget {
-  MyAppBar({this.title});
-
-  // Fields in a Widget subclass are always marked "final".
-
-  final Widget title;
+void main() {
+  runApp(MaterialApp(
+    title: 'Flutter Tutorial',
+    home: TutorialHome(),
+  ));
+}
 
+class TutorialHome extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
-    return Container(
-      height: 56.0, // in logical pixels
-      padding: const EdgeInsets.symmetric(horizontal: 8.0),
-      decoration: BoxDecoration(color: Colors.blue[500]),
-      // Row is a horizontal, linear layout.
-      child: Row(
-        // <Widget> is the type of items in the list.
-        children: <Widget>[
-          IconButton(
-            icon: Icon(Icons.menu),
-            tooltip: 'Navigation menu',
-            onPressed: null, // null disables the button
-          ),
-          // Expanded expands its child to fill the available space.
-          Expanded(
-            child: title,
-          ),
+    // Scaffold is a layout for the major Material Components.
+    return Scaffold(
+      appBar: AppBar(
+        leading: IconButton(
+          icon: Icon(Icons.menu),
+          tooltip: 'Navigation menu',
+          onPressed: null,
+        ),
+        title: Text('Example title'),
+        actions: <Widget>[
           IconButton(
             icon: Icon(Icons.search),
             tooltip: 'Search',
             onPressed: null,
           ),
         ],
       ),
+      // body is the majority of the screen.
+      body: Center(
+        child: MyButton(),
+      ),
+      floatingActionButton: FloatingActionButton(
+        tooltip: 'Add', // used by assistive technologies
+        child: Icon(Icons.add),
+        onPressed: null,
+      ),
     );
   }
 }
 
-class MyScaffold extends StatelessWidget {
+
+class MyButton extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
-    // Material is a conceptual piece of paper on which the UI appears.
-    return Material(
-      // Column is a vertical, linear layout.
-      child: Column(
-        children: <Widget>[
-          MyAppBar(
-            title: Text(
-              'Example title',
-              style: Theme
-                  .of(context)
-                  .primaryTextTheme
-                  .headline6,
-            ),
-          ),
-          Expanded(
-            child: Center(
-              child: Text('Hello, world!'),
-            ),
-          ),
-        ],
+    return GestureDetector(
+      onTap: () {
+        print('MyButton was tapped!');
+      },
+      child: Container(
+        height: 36.0,
+        padding: const EdgeInsets.all(8.0),
+        margin: const EdgeInsets.symmetric(horizontal: 8.0),
+        decoration: BoxDecoration(
+          borderRadius: BorderRadius.circular(5.0),
+          color: Colors.lightGreen[500],
+        ),
+        child: Center(
+          child: Text('Engage'),
+        ),
       ),
     );
   }
-}
-
-void main() {
-  runApp(MaterialApp(
-    title: 'My app', // used by the OS task switcher
-    home: MyScaffold(),
-  ));
-}
+}