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 busyHandler = null;
72 var readyHandler = null;
74 var updates = new Array();
77 function Update(updateHandler) {
79 this.setHandler = function(handler) {
80 updateHandler = handler;
83 this.hasHandler = function() {
84 return updateHandler != null;
87 this.handle = function() {
93 display.setAutosize = function(flag) {
97 function reserveJob(handler) {
99 // If no pending updates, just call (if available) and exit
100 if (display.isReady() && handler != null) {
105 // If updates are pending/executing, schedule a pending update
106 // and return a reference to it.
107 var update = new Update(handler);
108 updates.push(update);
113 function handlePendingUpdates() {
115 // Draw all pending updates.
117 while ((update = updates[0]) != null && update.hasHandler()) {
122 // If done with updates, call ready handler
123 if (display.isReady() && readyHandler != null)
128 display.isReady = function() {
129 return updates.length == 0;
132 display.setReadyHandler = function(handler) {
133 readyHandler = handler;
136 display.setBusyHandler = function(handler) {
137 busyHandler = handler;
141 display.drawImage = function(x, y, image) {
142 reserveJob(function() {
143 if (autosize != 0) fitRect(x, y, image.width, image.height);
144 displayContext.drawImage(image, x, y);
149 display.draw = function(x, y, url) {
151 // If about to become busy, call busy handler
152 if (display.isReady() && busyHandler != null)
155 var update = reserveJob(null);
157 var image = new Image();
158 image.onload = function() {
160 update.setHandler(function() {
161 if (autosize != 0) fitRect(x, y, image.width, image.height);
162 displayContext.drawImage(image, x, y);
165 // As this update originally had no handler and may have blocked
166 // other updates, handle any blocked updates.
167 handlePendingUpdates();
174 // Run arbitrary function as soon as currently pending operations complete.
175 // Future operations will not block this function from being called (unlike
176 // the ready handler, which requires no pending updates)
177 display.sync = function(handler) {
181 display.copyRect = function(srcLayer, srcx, srcy, w, h, x, y) {
183 function scheduleCopyRect() {
184 reserveJob(function() {
185 if (autosize != 0) fitRect(x, y, w, h);
186 displayContext.drawImage(srcLayer, srcx, srcy, w, h, x, y, w, h);
190 // If we ARE the source layer, no need to sync.
191 // Syncing would result in deadlock.
192 if (display === srcLayer)
195 // Otherwise synchronize copy operation with source layer
197 srcLayer.sync(scheduleCopyRect);
201 display.clearRect = function(x, y, w, h) {
202 reserveJob(function() {
203 if (autosize != 0) fitRect(x, y, w, h);
204 displayContext.clearRect(x, y, w, h);
208 display.filter = function(filter) {
209 reserveJob(function() {
210 var imageData = displayContext.getImageData(0, 0, width, height);
211 filter(imageData.data, width, height);
212 displayContext.putImageData(imageData, 0, 0);