How to Create Cupertino Styled Forms in Flutter

Creating iOS-style forms in Flutter can elevate your app’s user experience, especially when targeting Apple users. In this guide, we’ll explore how to build elegant Cupertino-styled forms that feel right at home on iOS devices.

Understanding Cupertino Widgets

Before diving into form creation, let’s understand what makes Cupertino widgets special. These widgets are Flutter’s implementation of Apple’s iOS design language, offering native-like appearance and behavior that iOS users are familiar with.

Essential Form Components

CupertinoTextField

The CupertinoTextField is the cornerstone of iOS-style input fields. Here’s how to create one:

CupertinoTextField(
  placeholder: "Enter your name",
  padding: EdgeInsets.all(12.0),
  decoration: BoxDecoration(
    border: Border(bottom: BorderSide(width: 0.0, color: CupertinoColors.systemGrey4))
  ),
)

CupertinoFormSection

To group related fields together, wrap them in a CupertinoFormSection:

CupertinoFormSection(
  header: Text('Personal Information'),
  children: [
    CupertinoTextFormFieldRow(
      prefix: Text('Name'),
      placeholder: 'Enter your full name',
    ),
    CupertinoTextFormFieldRow(
      prefix: Text('Email'),
      placeholder: 'your@email.com',
      keyboardType: TextInputType.emailAddress,
    ),
  ],
)

Adding Interactive Elements

CupertinoPicker

For selection inputs, the CupertinoPicker provides a native iOS-style wheel picker:

CupertinoPicker(
  itemExtent: 32.0,
  onSelectedItemChanged: (int index) {
    // Handle selection
  },
  children: List<Widget>.generate(3, (int index) {
    return Center(child: Text('Option ${index + 1}'));
  }),
)

CupertinoSwitch

For toggle options, use the CupertinoSwitch:

CupertinoSwitch(
  value: switchValue,
  onChanged: (bool value) {
    setState(() {
      switchValue = value;
    });
  },
)

Form Validation and Submission

Remember to implement proper validation and error handling:

final _formKey = GlobalKey<FormState>();

CupertinoFormSection(
  key: _formKey,
  header: Text('Validation Example'),
  children: [
    CupertinoTextFormFieldRow(
      validator: (value) {
        if (value == null || value.isEmpty) {
          return 'Please enter some text';
        }
        return null;
      },
    ),
  ],
)

Best Practices

1. Maintain consistency with iOS design guidelines
2. Use appropriate keyboard types for different input fields
3. Implement proper error handling and validation
4. Consider accessibility features
5. Test on both iOS and Android devices

Conclusion

Building Cupertino-styled forms in Flutter doesn’t have to be complicated. By following these guidelines and utilizing Flutter’s built-in Cupertino widgets, you can create forms that feel natural to iOS users while maintaining cross-platform compatibility.