// Copyright 2015 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. import 'dart:sky'; Picture draw(int a, int r, int g, int b) { Size size = new Size(view.width, view.height); PictureRecorder recorder = new PictureRecorder(); final double devicePixelRatio = view.devicePixelRatio; Canvas canvas = new Canvas(recorder, Point.origin & (size * devicePixelRatio)); canvas.scale(devicePixelRatio, devicePixelRatio); double radius = size.shortestSide * 0.45; Paint paint = new Paint()..color = new Color.fromARGB(a, r, g, b); canvas.drawCircle(size.center(Point.origin), radius, paint); return recorder.endRecording(); } bool handleEvent(Event event) { if (event.type == "pointerdown") { view.picture = draw(255, 0, 0, 255); view.scheduleFrame(); return true; } if (event.type == "pointerup") { view.picture = draw(255, 0, 255, 0); view.scheduleFrame(); return true; } if (event.type == "back") { print("Pressed back button."); return true; } return false; } void main() { print("Hello, world"); view.picture = draw(255, 0, 255, 0); view.scheduleFrame(); view.setEventCallback(handleEvent); }