flutter_multi_screenshot

A Flutter plugin for capturing screenshots on Linux. This plugin supports capturing single or multiple screens and saving them as files or Base64-encoded strings, making it easy to integrate screenshot functionality into Flutter desktop apps.

📌 Features

• ✅ Capture a single screen and save it as a file.
• ✅ Capture a single screen and return a Base64 string.
• ✅ Capture all connected screens and save them as files.
• ✅ Capture all connected screens and return multiple Base64 strings.
• ✅ Automatically selects the best available screenshot tool on Linux (scrot, gnome-screenshot, flameshot, etc.).
• ✅ Works on X11 (Wayland may need additional configuration).

---

🚀 Installation

1️⃣ Add Dependency

Add this plugin to your pubspec.yaml:

dependencies:
  flutter_multi_screenshot: ^1.0.2

2️⃣ Install Packages

Run:

flutter pub get

---

🖼️ Usage

Import the Plugin

import 'package:flutter_multi_screenshot/flutter_multi_screenshot.dart';

📸 Capture a Single Screen as a File

String filePath = await FlutterMultiScreenshot.captureToFile();
print("Screenshot saved at: $filePath");

📸 Capture a Single Screen as Base64

String base64Image = await FlutterMultiScreenshot.captureAsBase64();
String cleanBase64 = base64Image.replaceAll('\n', '').replaceAll('\r', '');
Uint8List imageBytes = base64Decode(cleanBase64);
print("Screenshot captured as Base64.");

📸 Capture All Screens as Files

List<String> filePaths = await FlutterMultiScreenshot.captureAllToFile();
print("Screenshots saved at: $filePaths");

📸 Capture All Screens as Base64

List<String> base64Images = await FlutterMultiScreenshot.captureAllAsBase64();
List<Uint8List> decodedImages = base64Images.map((base64) {
  String cleanBase64 = base64.replaceAll('\n', '').replaceAll('\r', '');
  return base64Decode(cleanBase64);
}).toList();
print("All Screenshots captured as Base64.");

---

🎯 Example App

Here’s a full example with buttons to capture and display screenshots:

import 'package:flutter/material.dart';
import 'package:flutter_multi_screenshot/flutter_multi_screenshot.dart';
import 'dart:io';
import 'dart:convert';
import 'dart:typed_data';

void main() {
  runApp(MaterialApp(home: ScreenshotTestApp()));
}

class ScreenshotTestApp extends StatefulWidget {
  @override
  _ScreenshotTestAppState createState() => _ScreenshotTestAppState();
}

class _ScreenshotTestAppState extends State<ScreenshotTestApp> {
  List<String>? screenshotPaths;
  List<Uint8List>? base64Screenshots;
  String? singleScreenshotPath;
  Uint8List? singleScreenshotBase64;

  Future<void> captureSingleScreenToFile() async {
    String filePath = await FlutterMultiScreenshot.captureToFile();
    setState(() {
      singleScreenshotPath = filePath;
      singleScreenshotBase64 = null;
    });
  }

  Future<void> captureSingleScreenAsBase64() async {
    String base64Image = await FlutterMultiScreenshot.captureAsBase64();
    String cleanBase64 = base64Image.replaceAll('\n', '').replaceAll('\r', '');
    setState(() {
      singleScreenshotBase64 = base64Decode(cleanBase64);
      singleScreenshotPath = null;
    });
  }

  Future<void> captureAllScreenshotsToFile() async {
    List<String> filePaths = await FlutterMultiScreenshot.captureAllToFile();
    setState(() {
      screenshotPaths = filePaths;
      base64Screenshots = null;
    });
  }

  Future<void> captureAllScreenshotsAsBase64() async {
    List<String> base64Images = await FlutterMultiScreenshot.captureAllAsBase64();
    List<Uint8List> decodedImages = base64Images.map((base64) {
      String cleanBase64 = base64.replaceAll('\n', '').replaceAll('\r', '');
      return base64Decode(cleanBase64);
    }).toList();
    setState(() {
      base64Screenshots = decodedImages;
      screenshotPaths = null;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("Multi-Screen Screenshot Test")),
      body: SingleChildScrollView(
        child: Column(
          children: [
            if (singleScreenshotPath != null) ...[
              Text("Single Screenshot File:"),
              Image.file(File(singleScreenshotPath!), width: 200, height: 200),
            ],
            if (singleScreenshotBase64 != null) ...[
              Text("Single Screenshot Base64 Preview:"),
              Image.memory(singleScreenshotBase64!, width: 200, height: 200),
            ],
            if (screenshotPaths != null) ...[
              Text("All Screenshots as Files:"),
              for (var path in screenshotPaths!)
                Image.file(File(path), width: 200, height: 200),
            ],
            if (base64Screenshots != null) ...[
              Text("All Screenshots as Base64:"),
              for (var image in base64Screenshots!)
                Image.memory(image, width: 200, height: 200),
            ],
            SizedBox(height: 20),
            ElevatedButton(onPressed: captureSingleScreenToFile, child: Text("Capture Single Screen (File)")),
            ElevatedButton(onPressed: captureSingleScreenAsBase64, child: Text("Capture Single Screen (Base64)")),
            ElevatedButton(onPressed: captureAllScreenshotsToFile, child: Text("Capture All Screens (Files)")),
            ElevatedButton(onPressed: captureAllScreenshotsAsBase64, child: Text("Capture All Screens (Base64)")),
          ],
        ),
      ),
    );
  }
}

---

🛠️ Supported Screenshot Tools

This plugin automatically detects and uses one of the following tools:

• 🖼 gnome-screenshot (Default for Ubuntu GNOME)
• 🖼 scrot (Lightweight CLI alternative)
• 🖼 flameshot (Modern screenshot tool)
• 🖼 maim (Alternative to scrot)
• 🖼 import (ImageMagick)

📌 Install a Screenshot Tool (If Missing)

sudo apt install gnome-screenshot scrot flameshot maim imagemagick

---

❌ Troubleshooting

1️⃣ Screenshots are black/empty?

If running on Wayland, switch to X11:

export GDK_BACKEND=x11
flutter run -d linux

2️⃣ Plugin not found?

flutter doctor -v
flutter pub get
flutter build linux

3️⃣ Check if the plugin is built correctly

ls build/linux/x64/debug/bundle/libflutter_multi_screenshot.so

If the file doesn’t exist, rebuild the plugin:

flutter clean
flutter build linux

---

📄 License

This plugin is licensed under the MIT License.

---

👨‍💻 Contributing

Pull requests are welcome! If you find a bug or have suggestions, open an issue.

---