Last active
May 22, 2017 21:55
-
-
Save rxlabz/21bd3bb06ee5f53d4b5b34b11557e86e to your computer and use it in GitHub Desktop.
FRP with flutter ?
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import 'dart:async'; | |
import 'dart:ui'; | |
final double devicePixelRatio = window.devicePixelRatio; | |
final Size logicalSize = window.physicalSize / devicePixelRatio; | |
final Rect physicalBounds = Offset.zero & (logicalSize * devicePixelRatio); | |
void main() { | |
final time$ = new Stream.periodic( new Duration(seconds: 1), (value) => value); | |
final value$ = time$.map((t)=>"Counter : $t"); | |
value$.map(buildView).listen((view) { | |
window.render(view); | |
window.scheduleFrame(); | |
}); | |
} | |
Scene buildView(String text) => render(draw(buildParagraph(text))); | |
Scene render(Picture view) { | |
final sceneBuilder = new SceneBuilder() | |
..pushClipRect(physicalBounds) | |
..addPicture(Offset.zero, view) | |
..pop(); | |
return sceneBuilder.build(); | |
} | |
Picture draw(Paragraph p) { | |
final recorder = new PictureRecorder(); | |
final canvas = new Canvas(recorder, physicalBounds); | |
canvas.scale(devicePixelRatio, devicePixelRatio); | |
canvas.drawParagraph(p, new Offset(100.0, 100.0)); | |
return recorder.endRecording(); | |
} | |
Paragraph buildParagraph(String text) { | |
final paragraphBuilder = new ParagraphBuilder(new ParagraphStyle()) | |
..addText('$text'); | |
final p = paragraphBuilder.build() | |
..layout(new ParagraphConstraints(width: logicalSize.width)); | |
return p; | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment