solar-marsh-4778

readme.md

solar-marsh-4778

Created with <3 with dartpad.dev.

main.dart

import 'dart:async';
import 'dart:ui' as ui;

Future<void> main() async {
  // This completer is only used to make the test wait until the frame is done.
  var frameCompleter = Completer<void>();

  // The concept of "dispatcher" is likely irrelevant to the WebText proposal.
  // It's just part of Flutter's structure of the rendering API.
  var dispatcher = ui.PlatformDispatcher.instance;

  // The onDrawFrame callback is Flutter's requestAnimationFrame, on top of
  // which it is implemented. All semantics of the requestAnimationFrame are
  // preserved. In particular, note that the callback is synchronous. Any
  // asynchrony would cause a miss in the frame.
  dispatcher.onDrawFrame = () {
    // The paragraph-level style that sets paragraph-level properties, such
    // as maximum number of lines, ellipsis, etc, but also a subset of text
    // styling properties that will apply to all in the paragraph by default.
    //
    // Full API: https://api.flutter.dev/flutter/dart-ui/ParagraphStyle/ParagraphStyle.html
    var paragraphStyle = ui.ParagraphStyle(
      fontFamily: 'Roboto',
      textDirection: ui.TextDirection.ltr,
      maxLines: 10,
    );

    // Flutter uses a builder pattern for creating paragraphs of text.
    //
    // Full API: https://api.flutter.dev/flutter/dart-ui/ParagraphBuilder-class.html
    var paragraphBuilder = ui.ParagraphBuilder(paragraphStyle);
    paragraphBuilder.addText('Hello, World!');

    // Create the paragraph object that can be laid out, rendered, and
    // inspected (for various metrics).
    //
    // Full API: https://api.flutter.dev/flutter/dart-ui/Paragraph-class.html
    var paragraph = paragraphBuilder.build();
    paragraph.layout(const ui.ParagraphConstraints(
      width: 200,
    ));

    // Flutter's rendering API
    var recorder = ui.PictureRecorder();
    var canvas = ui.Canvas(recorder);
    canvas.drawColor(const ui.Color(0xFFFFFFFF), ui.BlendMode.dstOver);
    canvas.drawParagraph(paragraph, const ui.Offset(10, 10));
    var picture = recorder.endRecording();

    var sb = ui.SceneBuilder();
    sb.pushOffset(0, 0);
    sb.addPicture(ui.Offset.zero, picture);
    var scene = sb.build();
    dispatcher.implicitView!.render(scene);
    frameCompleter.complete();
  };

  ui.PlatformDispatcher.instance.scheduleFrame();

  await frameCompleter.future;
  print('>>> done');
}