flutter-quill/flutter_quill_extensions/lib/services/clipboard/super_clipboard_service.dart

import 'dart:async' show Completer;
import 'dart:convert' show utf8;

import 'package:flutter/foundation.dart';
// ignore: implementation_imports
import 'package:flutter_quill/src/editor_toolbar_controller_shared/clipboard/clipboard_service.dart';

import 'package:super_clipboard/super_clipboard.dart';

/// Implementation based on https://pub.dev/packages/super_clipboard
class SuperClipboardService implements ClipboardService {
  /// Null if the Clipboard API is not supported on this platform
  /// https://pub.dev/packages/super_clipboard#usage
  SystemClipboard? _getSuperClipboard() {
    return SystemClipboard.instance;
  }

  SystemClipboard _getSuperClipboardOrThrow() {
    final clipboard = _getSuperClipboard();
    if (clipboard == null) {
      // To avoid getting this exception, use _canProvide()
      throw UnsupportedError(
        'Clipboard API is not supported on this platform.',
      );
    }
    return clipboard;
  }

  Future<bool> _canProvide({required DataFormat format}) async {
    final clipboard = _getSuperClipboard();
    if (clipboard == null) {
      return false;
    }
    final reader = await clipboard.read();
    return reader.canProvide(format);
  }

  Future<Uint8List> _provideFileAsBytes({
    required SimpleFileFormat format,
  }) async {
    final clipboard = _getSuperClipboardOrThrow();
    final reader = await clipboard.read();
    final completer = Completer<Uint8List>();

    reader.getFile(
      format,
      (file) async {
        final bytes = await file.readAll();
        completer.complete(bytes);
      },
      onError: completer.completeError,
    );
    final bytes = await completer.future;
    return bytes;
  }

  Future<String> _provideFileAsString({
    required SimpleFileFormat format,
  }) async {
    final fileBytes = await _provideFileAsBytes(format: format);
    final fileText = utf8.decode(fileBytes);
    return fileText;
  }

  /// According to super_clipboard docs, will return `null` if the value
  /// is not available or the data is virtual (macOS and Windows)
  Future<String?> _provideSimpleValueFormatAsString({
    required SimpleValueFormat<String> format,
  }) async {
    final clipboard = _getSuperClipboardOrThrow();
    final reader = await clipboard.read();
    final value = await reader.readValue<String>(format);
    return value;
  }

  @override
  Future<bool> canProvideHtmlText() {
    return _canProvide(format: Formats.htmlText);
  }

  @override
  Future<String?> getHtmlText() {
    return _provideSimpleValueFormatAsString(format: Formats.htmlText);
  }

  @override
  Future<bool> canProvideHtmlTextFromFile() {
    return _canProvide(format: Formats.htmlFile);
  }

  @override
  Future<String?> getHtmlTextFromFile() {
    return _provideFileAsString(format: Formats.htmlFile);
  }

  @override
  Future<bool> canProvideMarkdownText() async {
    // Formats.markdownText or Formats.mdText does not exist yet in super_clipboard
    return false;
  }

  @override
  Future<String?> getMarkdownText() async {
    // Formats.markdownText or Formats.mdText does not exist yet in super_clipboard
    throw UnsupportedError(
      'SuperClipboardService does not support retrieving image files.',
    );
  }

  @override
  Future<bool> canProvideMarkdownTextFromFile() async {
    // Formats.md is for markdown files
    return _canProvide(format: Formats.md);
  }

  @override
  Future<String?> getMarkdownTextFromFile() async {
    // Formats.md is for markdown files
    return _provideFileAsString(format: Formats.md);
  }

  @override
  Future<bool> canProvidePlainText() {
    return _canProvide(format: Formats.plainText);
  }

  @override
  Future<String?> getPlainText() {
    return _provideSimpleValueFormatAsString(format: Formats.plainText);
  }

  /// This will need to be updated if [getImageFileAsBytes] updated.
  /// Notice that even if the copied image is JPEG, it still can be provided
  /// as PNG, will handle JPEG check in case this info is incorrect.
  @override
  Future<bool> canProvideImageFile() async {
    final canProvidePngFile = await _canProvide(format: Formats.png);
    if (canProvidePngFile) {
      return true;
    }
    final canProvideJpegFile = await _canProvide(format: Formats.jpeg);
    if (canProvideJpegFile) {
      return true;
    }
    return false;
  }

  /// This will need to be updated if [canProvideImageFile] updated.
  @override
  Future<Uint8List> getImageFileAsBytes() async {
    final canProvidePngFile = await _canProvide(format: Formats.png);
    if (canProvidePngFile) {
      return _provideFileAsBytes(format: Formats.png);
    }
    return _provideFileAsBytes(format: Formats.jpeg);
  }

  @override
  Future<bool> canProvideGifFile() {
    return _canProvide(format: Formats.gif);
  }

  @override
  Future<Uint8List> getGifFileAsBytes() {
    return _provideFileAsBytes(format: Formats.gif);
  }

  @override
  Future<bool> canPaste() async {
    final clipboard = _getSuperClipboard();
    if (clipboard == null) {
      return false;
    }
    final reader = await clipboard.read();
    final availablePlatformFormats = reader.platformFormats;
    return availablePlatformFormats.isNotEmpty;
  }
}