/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package websocket.drawboard; import java.awt.BasicStroke; import java.awt.Color; import java.awt.Graphics2D; import java.awt.geom.Arc2D; import java.awt.geom.Line2D; import java.awt.geom.Rectangle2D; /** * A message that represents a drawing action. * Note that we use primitive types instead of Point, Color etc. * to reduce object allocation.<br><br> * * TODO: But a Color objects needs to be created anyway for drawing this * onto a Graphics2D object, so this probably does not save much. */ public final class DrawMessage { private int type; private byte colorR, colorG, colorB, colorA; private double thickness; private double x1, y1, x2, y2; /** * The type. * * @return 1: Brush<br>2: Line<br>3: Rectangle<br>4: Ellipse */ public int getType() { return type; } public void setType(int type) { this.type = type; } public double getThickness() { return thickness; } public void setThickness(double thickness) { this.thickness = thickness; } public byte getColorR() { return colorR; } public void setColorR(byte colorR) { this.colorR = colorR; } public byte getColorG() { return colorG; } public void setColorG(byte colorG) { this.colorG = colorG; } public byte getColorB() { return colorB; } public void setColorB(byte colorB) { this.colorB = colorB; } public byte getColorA() { return colorA; } public void setColorA(byte colorA) { this.colorA = colorA; } public double getX1() { return x1; } public void setX1(double x1) { this.x1 = x1; } public double getX2() { return x2; } public void setX2(double x2) { this.x2 = x2; } public double getY1() { return y1; } public void setY1(double y1) { this.y1 = y1; } public double getY2() { return y2; } public void setY2(double y2) { this.y2 = y2; } public DrawMessage(int type, byte colorR, byte colorG, byte colorB, byte colorA, double thickness, double x1, double x2, double y1, double y2) { this.type = type; this.colorR = colorR; this.colorG = colorG; this.colorB = colorB; this.colorA = colorA; this.thickness = thickness; this.x1 = x1; this.x2 = x2; this.y1 = y1; this.y2 = y2; } /** * Draws this DrawMessage onto the given Graphics2D. * * @param g The target for the DrawMessage */ public void draw(Graphics2D g) { g.setStroke(new BasicStroke((float) thickness, BasicStroke.CAP_ROUND, BasicStroke.JOIN_MITER)); g.setColor(new Color(colorR & 0xFF, colorG & 0xFF, colorB & 0xFF, colorA & 0xFF)); if (x1 == x2 && y1 == y2) { // Always draw as arc to meet the behavior in the HTML5 Canvas. Arc2D arc = new Arc2D.Double(x1, y1, 0, 0, 0d, 360d, Arc2D.OPEN); g.draw(arc); } else if (type == 1 || type == 2) { // Draw a line. Line2D line = new Line2D.Double(x1, y1, x2, y2); g.draw(line); } else if (type == 3 || type == 4) { double x1 = this.x1, x2 = this.x2, y1 = this.y1, y2 = this.y2; if (x1 > x2) { x1 = this.x2; x2 = this.x1; } if (y1 > y2) { y1 = this.y2; y2 = this.y1; } // TODO: If (x1 == x2 || y1 == y2) draw as line. if (type == 3) { // Draw a rectangle. Rectangle2D rect = new Rectangle2D.Double(x1, y1, x2 - x1, y2 - y1); g.draw(rect); } else if (type == 4) { // Draw an ellipse. Arc2D arc = new Arc2D.Double(x1, y1, x2 - x1, y2 - y1, 0d, 360d, Arc2D.OPEN); g.draw(arc); } } } /** * Converts this message into a String representation that * can be sent over WebSocket.<br> * Since a DrawMessage consists only of numbers, * we concatenate those numbers with a ",". */ @Override public String toString() { return type + "," + (colorR & 0xFF) + "," + (colorG & 0xFF) + "," + (colorB & 0xFF) + "," + (colorA & 0xFF) + "," + thickness + "," + x1 + "," + y1 + "," + x2 + "," + y2; } public static DrawMessage parseFromString(String str) throws ParseException { int type; byte[] colors = new byte[4]; double thickness; double[] coords = new double[4]; try { String[] elements = str.split(","); type = Integer.parseInt(elements[0]); if (!(type >= 1 && type <= 4)) throw new ParseException("Invalid type: " + type); for (int i = 0; i < colors.length; i++) { colors[i] = (byte) Integer.parseInt(elements[1 + i]); } thickness = Double.parseDouble(elements[5]); if (Double.isNaN(thickness) || thickness < 0 || thickness > 100) throw new ParseException("Invalid thickness: " + thickness); for (int i = 0; i < coords.length; i++) { coords[i] = Double.parseDouble(elements[6 + i]); if (Double.isNaN(coords[i])) throw new ParseException("Invalid coordinate: " + coords[i]); } } catch (RuntimeException ex) { throw new ParseException(ex); } DrawMessage m = new DrawMessage(type, colors[0], colors[1], colors[2], colors[3], thickness, coords[0], coords[2], coords[1], coords[3]); return m; } public static class ParseException extends Exception { private static final long serialVersionUID = -6651972769789842960L; public ParseException(Throwable root) { super(root); } public ParseException(String message) { super(message); } } }