| // 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'; |
| |
| PaintingNode paintingNode = null; |
| Picture draw(int a, int r, int g, int b) { |
| final double devicePixelRatio = view.devicePixelRatio; |
| Size size = new Size(view.width, view.height); |
| |
| PictureRecorder recorder = new PictureRecorder(); |
| Canvas canvas = new Canvas(recorder, new Rect.fromLTRB(0.0, 0.0, view.width * devicePixelRatio, view.height * 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); |
| |
| if (paintingNode == null) { |
| paintingNode = new PaintingNode(); |
| Paint innerPaint = new Paint()..color = new Color.fromARGB(a, 255 - r, 255 - g, 255 - b); |
| PictureRecorder innerRecorder = new PictureRecorder(); |
| Canvas innerCanvas = new Canvas(innerRecorder, Point.origin & size); |
| innerCanvas.drawCircle(size.center(Point.origin), radius * 0.5, innerPaint); |
| |
| paintingNode.setBackingDrawable(innerRecorder.endRecordingAsDrawable()); |
| } |
| canvas.drawPaintingNode(paintingNode, Point.origin); |
| |
| 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; |
| } |
| |
| return false; |
| } |
| |
| void main() { |
| view.picture = draw(255, 0, 255, 0); |
| view.scheduleFrame(); |
| |
| view.setEventCallback(handleEvent); |
| } |