Flutter Playground – Part 2: Login screen

In this post, we will implement this Login screen for both Android and iOS. We will cover a bit on assets, layouts(Stack, Container, Column), and widgets(Text, TextField, MaterialButton).

Layouts and Widgets

To realize this screen, we will work with the below layouts/containers and widgets. All this will be done by using dart. For now, we will not concentrate on modularising the code. That means all layouts, widgets, and styling will be done inline. Later, we can work on extracting parts of the layout into separate classes and styles into an application theme.

The Scaffold holds the basic material design visual layout structure which can directly host other widgets like an AppBar, BottomAppBar, FloatingActionButton, Drawer, BottomSheet etc.

The AppBar acts as the toolbar for your application.

appBar: AppBar(
  title: Text(widget.title),
),

The body parameter of the Scaffold specifies its primary content. This is displayed below the AppBar, behind the FloatingActionButton and Drawers if present.

@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(
      title: Text(widget.title),
    ),
    body: Stack(
      children: <Widget>[
      ],
    )
  );
}

The Stack is a container where you can place containers or widgets on top of each other. A stack contains an array of widgets.

The first child for the stack is an image, which fills the whole screen and is at the bottom of the stack.

Container(
  decoration: BoxDecoration(
      image: DecorationImage(
          image: AssetImage("images/bg.jpg"), fit: BoxFit.cover)),
),

This draws the bg.jpg placed in the images folder of the root project. To be able to access this image, an entry for this folder is required in the pubspec.yaml file.

flutter:
  assets:
    - images/

Let’s define the next child as a Column since we have to display widgets one below the other. The column will need 4 containers for the following:

1. Text: “Login to your account”
2. TextField: For entering your email
3. TextField: For entering your password
4. MaterialButton: Login button

We will also be adding some paddings and alignments to the containers, which you can check out in the source code. That would be too much of details for this post.

Container(
  padding: EdgeInsets.only(top: 40, left: 20, right: 20),
  child: Text(
    "Login to your account",
    style: TextStyle(fontSize: 25, color: Colors.limeAccent, fontStyle: FontStyle.italic),
  ),
)

Container(
  padding: EdgeInsets.only(left: 20, right: 20),
  child: TextField(
    style: TextStyle(
      color: Colors.white,
      fontSize: 20,
    ),
    decoration: InputDecoration(
      hintText: "Email",
      hintStyle: TextStyle(
        color: Colors.white30
      ),
    ),
  ),
)

Container(
  padding: EdgeInsets.only(left: 20, right: 20),
  child: TextField(
    style: TextStyle(
      color: Colors.white,
      fontSize: 20,
    ),
    decoration: InputDecoration(
      hintText: "Password",
      hintStyle: TextStyle(
        color: Colors.white30
      )
    ),
  ),
)

Container(
  alignment: AlignmentDirectional.bottomEnd,
  padding: EdgeInsets.only(left: 20, right: 20, top: 10),
  child: MaterialButton(
    child: Text(
        "Login",
      style: TextStyle(
        fontSize: 20,
        color: Colors.limeAccent
      ),
    ),
    onPressed: login,
  ),
)

That’s it. You should be able to see the screens on both Android and iOS.

Source @Github: flutter-playground

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