3 * Guacamole - Clientless Remote Desktop
4 * Copyright (C) 2010 Michael Jumper
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU Affero General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU Affero General Public License for more details.
16 * You should have received a copy of the GNU Affero General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 function Layer(width, height) {
23 var display = document.createElement("canvas");
24 var displayContext = display.getContext("2d");
26 function resize(newWidth, newHeight) {
27 display.style.position = "absolute";
28 display.style.left = "0px";
29 display.style.top = "0px";
31 display.width = newWidth;
32 display.height = newHeight;
38 display.resize = function(newWidth, newHeight) {
39 if (newWidth != width || newHeight != height)
40 resize(newWidth, newHeight);
43 function fitRect(x, y, w, h) {
49 // Determine max width
52 resizeWidth = opBoundX;
56 // Determine max height
58 if (opBoundY > height)
59 resizeHeight = opBoundY;
61 resizeHeight = height;
63 // Resize if necessary
64 if (resizeWidth != width || resizeHeight != height)
65 resize(resizeWidth, resizeHeight);
69 resize(width, height);
71 var updates = new Array();
74 function Update(updateHandler) {
76 this.setHandler = function(handler) {
77 updateHandler = handler;
80 this.hasHandler = function() {
81 return updateHandler != null;
84 this.handle = function() {
90 display.setAutosize = function(flag) {
94 function reserveJob(handler) {
96 // If no pending updates, just call (if available) and exit
97 if (display.isReady() && handler != null) {
102 // If updates are pending/executing, schedule a pending update
103 // and return a reference to it.
104 var update = new Update(handler);
105 updates.push(update);
110 function handlePendingUpdates() {
112 // Draw all pending updates.
114 while ((update = updates[0]) != null && update.hasHandler()) {
121 display.isReady = function() {
122 return updates.length == 0;
126 display.drawImage = function(x, y, image) {
127 reserveJob(function() {
128 if (autosize != 0) fitRect(x, y, image.width, image.height);
129 displayContext.drawImage(image, x, y);
134 display.draw = function(x, y, url) {
135 var update = reserveJob(null);
137 var image = new Image();
138 image.onload = function() {
140 update.setHandler(function() {
141 if (autosize != 0) fitRect(x, y, image.width, image.height);
142 displayContext.drawImage(image, x, y);
145 // As this update originally had no handler and may have blocked
146 // other updates, handle any blocked updates.
147 handlePendingUpdates();
154 // Run arbitrary function as soon as currently pending operations complete.
155 // Future operations will not block this function from being called (unlike
156 // the ready handler, which requires no pending updates)
157 display.sync = function(handler) {
161 display.copyRect = function(srcLayer, srcx, srcy, w, h, x, y) {
163 function doCopyRect() {
164 if (autosize != 0) fitRect(x, y, w, h);
165 displayContext.drawImage(srcLayer, srcx, srcy, w, h, x, y, w, h);
168 // If we ARE the source layer, no need to sync.
169 // Syncing would result in deadlock.
170 if (display === srcLayer)
171 reserveJob(doCopyRect);
173 // Otherwise synchronize copy operation with source layer
175 var update = reserveJob(null);
176 srcLayer.sync(function() {
178 update.setHandler(doCopyRect);
180 // As this update originally had no handler and may have blocked
181 // other updates, handle any blocked updates.
182 handlePendingUpdates();
189 display.clearRect = function(x, y, w, h) {
190 reserveJob(function() {
191 if (autosize != 0) fitRect(x, y, w, h);
192 displayContext.clearRect(x, y, w, h);
196 display.filter = function(filter) {
197 reserveJob(function() {
198 var imageData = displayContext.getImageData(0, 0, width, height);
199 filter(imageData.data, width, height);
200 displayContext.putImageData(imageData, 0, 0);
204 var compositeOperation = {
205 /* 0x0 NOT IMPLEMENTED */
206 0x1: "destination-in",
207 0x2: "destination-out",
208 /* 0x3 NOT IMPLEMENTED */
210 /* 0x5 NOT IMPLEMENTED */
212 /* 0x7 NOT IMPLEMENTED */
214 0x9: "destination-atop",
216 0xB: "destination-over",
218 /* 0xD NOT IMPLEMENTED */
223 display.setChannelMask = function(mask) {
224 reserveJob(function() {
225 displayContext.globalCompositeOperation = compositeOperation[mask];