manual_camera_view

A lightweight Flutter plugin for embedding a native camera preview inside a Flutter screen.

Features

• Embed a native camera preview with ManualCameraView
• Tap the preview to focus and meter exposure
• Adjust brightness with setNormalizedExposure(-1.0 ~ 1.0)
• Set JPEG quality with setImageQuality(1~100)
• Capture a photo and receive JPEG bytes as Uint8List
• Use the same Dart API on Android and iOS

Use Cases

This plugin is a good fit when you want to:

• place a native camera preview directly in a Flutter page
• build custom Flutter capture buttons, sliders, and overlays
• upload, save, compress, or display captured bytes in your own app flow

Installation

Add the package to your Flutter project:

dependencies:
  manual_camera_view: ^0.1.0

Then run:

flutter pub get

For local development inside this repository, the example app can keep the path dependency as path: ../.

Permissions

Android

Add camera permission to AndroidManifest.xml:

<uses-permission android:name="android.permission.CAMERA" />

iOS

Add a camera usage description to Info.plist:

<key>NSCameraUsageDescription</key>
<string>This app needs camera access to capture photos.</string>

Basic Usage

Import the package:

import 'package:manual_camera_view/manual_camera.dart';

Create a ManualCameraController and pass it to ManualCameraView:

final ManualCameraController controller = ManualCameraController();

ManualCameraView(
  controller: controller,
  onViewCreated: () {
    debugPrint('camera view ready');
  },
)

Notes:

• The controller must be owned by your Flutter widget
• The controller is ready only after onViewCreated is called
• Calling capture or exposure APIs too early throws a StateError

Exposure

Slider(
  min: -1.0,
  max: 1.0,
  value: _exposure,
  onChanged: (value) {
    setState(() => _exposure = value);
    _controller.setNormalizedExposure(value);
  },
)

• -1.0: darker
• 0.0: default exposure
• 1.0: brighter

Tap To Focus

ManualCameraView supports tap to focus out of the box. You can also call:

await _controller.setFocusPoint(0.5, 0.5);

Capture

await _controller.setImageQuality(90);
final bytes = await _controller.takePicture();
debugPrint('image bytes: ${bytes.length}');

The returned value is a JPEG Uint8List that you can upload, save, or display.

Example

A complete runnable example is available in example/lib/main.dart.

Public API

• ManualCameraController.isReady
• ManualCameraController.setNormalizedExposure()
• ManualCameraController.setImageQuality()
• ManualCameraController.setFocusPoint()
• ManualCameraController.takePicture()
• ManualCameraView

Notes

• Android and iOS use different native implementations, but the Dart API stays consistent
• takePicture() returns in-memory JPEG bytes instead of a file path
• Saving to the photo library, uploading, and post-processing are handled by your app