Merge pull request #269 from glyptodon/image-handshake

GUAC-1305: Add image mimetypes to Guacamole protocol handshake.

guacamole-common/src/main/java/org/glyptodon/guacamole/protocol/ConfiguredGuacamoleSocket.java

@@ -183,6 +183,13 @@ public class ConfiguredGuacamoleSocket implements GuacamoleSocket {
                     info.getVideoMimetypes().toArray(new String[0])
                 ));
 
+        // Send supported image formats
+        writer.writeInstruction(
+                new GuacamoleInstruction(
+                    "image",
+                    info.getImageMimetypes().toArray(new String[0])
+                ));
+
         // Send args
         writer.writeInstruction(new GuacamoleInstruction("connect", arg_values));
 

guacamole-common/src/main/java/org/glyptodon/guacamole/protocol/GuacamoleClientInformation.java

@@ -55,10 +55,15 @@ public class GuacamoleClientInformation {
     private final List<String> audioMimetypes = new ArrayList<String>();
 
     /**
-     * The list of audio mimetypes reported by the client to be supported.
+     * The list of video mimetypes reported by the client to be supported.
      */
     private final List<String> videoMimetypes = new ArrayList<String>();
 
+    /**
+     * The list of image mimetypes reported by the client to be supported.
+     */
+    private final List<String> imageMimetypes = new ArrayList<String>();
+
     /**
      * Returns the optimal screen width requested by the client, in pixels.
      * @return The optimal screen width requested by the client, in pixels.
@@ -133,4 +138,16 @@ public class GuacamoleClientInformation {
         return videoMimetypes;
     }
 
+    /**
+     * Returns the list of image mimetypes supported by the client. To add or
+     * removed supported mimetypes, the list returned by this function can be
+     * modified.
+     *
+     * @return
+     *     The set of image mimetypes supported by the client.
+     */
+    public List<String> getImageMimetypes() {
+        return imageMimetypes;
+    }
+
 }

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/TunnelRequest.java

@@ -92,6 +92,13 @@ public abstract class TunnelRequest {
      */
     public static final String VIDEO_PARAMETER = "GUAC_VIDEO";
 
+    /**
+     * The name of the parameter specifying one supported image mimetype. This
+     * will normally appear multiple times within a single tunnel request -
+     * once for each mimetype.
+     */
+    public static final String IMAGE_PARAMETER = "GUAC_IMAGE";
+
     /**
      * All supported object types that can be used as the destination of a
      * tunnel.
@@ -350,4 +357,16 @@ public abstract class TunnelRequest {
         return getParameterValues(VIDEO_PARAMETER);
     }
 
+    /**
+     * Returns a list of all image mimetypes declared as supported within the
+     * tunnel request.
+     *
+     * @return
+     *     A list of all image mimetypes declared as supported within the
+     *     tunnel request, or null if no mimetypes were specified.
+     */
+    public List<String> getImageMimetypes() {
+        return getParameterValues(IMAGE_PARAMETER);
+    }
+
 }

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/TunnelRequestService.java

@@ -114,6 +114,11 @@ public class TunnelRequestService {
         if (videoMimetypes != null)
             info.getVideoMimetypes().addAll(videoMimetypes);
 
+        // Add image mimetypes
+        List<String> imageMimetypes = request.getImageMimetypes();
+        if (imageMimetypes != null)
+            info.getImageMimetypes().addAll(imageMimetypes);
+
         return info;
     }
 

guacamole/src/main/webapp/app/client/services/guacImage.js

@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2015 Glyptodon LLC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ * A service for checking browser image support.
+ */
+angular.module('client').factory('guacImage', ['$injector', function guacImage($injector) {
+
+    // Required services
+    var $q = $injector.get('$q');
+
+    var service = {};
+
+    /**
+     * Map of possibly-supported image mimetypes to corresponding test images
+     * encoded with base64. If the image is correctly decoded, it will be a
+     * single pixel (1x1) image.
+     *
+     * @type Object.<String, String>
+     */
+    var testImages = {
+
+        /**
+         * Test JPEG image, encoded as base64.
+         */
+        'image/jpeg' :
+            '/9j/4AAQSkZJRgABAQEASABIAAD/2wBDAAMCAgMCAgMDAwMEAwMEBQgFBQQEBQoH'
+          + 'BwYIDAoMDAsKCwsNDhIQDQ4RDgsLEBYQERMUFRUVDA8XGBYUGBIUFRT/2wBDAQME'
+          + 'BAUEBQkFBQkUDQsNFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQU'
+          + 'FBQUFBQUFBQUFBQUFBT/wAARCAABAAEDAREAAhEBAxEB/8QAFAABAAAAAAAAAAA'
+          + 'AAAAAAAAACf/EABQQAQAAAAAAAAAAAAAAAAAAAAD/xAAUAQEAAAAAAAAAAAAAAA'
+          + 'AAAAAA/8QAFBEBAAAAAAAAAAAAAAAAAAAAAP/aAAwDAQACEQMRAD8AVMH/2Q==',
+
+        /**
+         * Test PNG image, encoded as base64.
+         */
+        'image/png' :
+            'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAA1BMVEX///+nxBvI'
+          + 'AAAACklEQVQI12NgAAAAAgAB4iG8MwAAAABJRU5ErkJggg=='
+
+    };
+
+    /**
+     * Return a promise which resolves with to an array of image mimetypes
+     * supported by the browser, once those mimetypes are known. The returned
+     * promise is guaranteed to resolve successfully.
+     *
+     * @returns {Promise.<String[]>}
+     *     A promise which resolves with an array of image mimetypes supported
+     *     by the browser.
+     */
+    service.getSupportedMimetypes = function getSupportedMimetypes() {
+
+        var deferred = $q.defer();
+
+        var supported = [];
+        var pendingTests = [];
+
+        // Test each possibly-supported image
+        angular.forEach(testImages, function testImageSupport(data, mimetype) {
+
+            // Add promise for current image test
+            var imageTest = $q.defer();
+            pendingTests.push(imageTest.promise);
+
+            // Attempt to load image
+            var image = new Image();
+            image.src = 'data:' + mimetype + ';base64,' + data;
+
+            // Store as supported depending on whether load was successful
+            image.onload = image.onerror = function imageTestComplete() {
+
+                // Image format is supported if successfully decoded
+                if (image.width === 1 && image.height === 1)
+                    supported.push(mimetype);
+
+                // Test is complete
+                imageTest.resolve();
+
+            };
+
+        });
+
+        // When all image tests are complete, resolve promise with list of
+        // supported formats
+        $q.all(pendingTests).then(function imageTestsCompleted() {
+            deferred.resolve(supported);
+        });
+
+        return deferred.promise;
+
+    };
+
+    return service;
+
+}]);

guacamole/src/main/webapp/app/client/types/ManagedClient.js

@@ -36,13 +36,15 @@ angular.module('client').factory('ManagedClient', ['$rootScope', '$injector',
     var ManagedFileUpload    = $injector.get('ManagedFileUpload');
 
     // Required services
-    var $window                = $injector.get('$window');
     var $document              = $injector.get('$document');
+    var $q                     = $injector.get('$q');
+    var $window                = $injector.get('$window');
     var authenticationService  = $injector.get('authenticationService');
     var connectionGroupService = $injector.get('connectionGroupService');
     var connectionService      = $injector.get('connectionService');
     var guacAudio              = $injector.get('guacAudio');
     var guacHistory            = $injector.get('guacHistory');
+    var guacImage              = $injector.get('guacImage');
     var guacVideo              = $injector.get('guacVideo');
         
     /**
@@ -149,10 +151,11 @@ angular.module('client').factory('ManagedClient', ['$rootScope', '$injector',
     };
 
     /**
-     * Returns the string of connection parameters to be passed to the
+     * Returns a promise which resolves with the string of connection
-     * Guacamole client during connection. This string generally contains the
+     * parameters to be passed to the Guacamole client during connection. This
-     * desired connection ID, display resolution, and supported audio/video
+     * string generally contains the desired connection ID, display resolution,
-     * codecs.
+     * and supported audio/video/image formats. The returned promise is
+     * guaranteed to resolve successfully.
      *
      * @param {ClientIdentifier} identifier
      *     The identifier representing the connection or group to connect to.
@@ -160,12 +163,14 @@ angular.module('client').factory('ManagedClient', ['$rootScope', '$injector',
      * @param {String} [connectionParameters]
      *     Any additional HTTP parameters to pass while connecting.
      * 
-     * @returns {String}
+     * @returns {Promise.<String>}
-     *     The string of connection parameters to be passed to the Guacamole
+     *     A promise which resolves with the string of connection parameters to
-     *     client.
+     *     be passed to the Guacamole client, once the string is ready.
      */
     var getConnectString = function getConnectString(identifier, connectionParameters) {
 
+        var deferred = $q.defer();
+
         // Calculate optimal width/height for display
         var pixel_density = $window.devicePixelRatio || 1;
         var optimal_dpi = pixel_density * 96;
@@ -183,17 +188,30 @@ angular.module('client').factory('ManagedClient', ['$rootScope', '$injector',
             + "&GUAC_DPI="         + Math.floor(optimal_dpi)
             + (connectionParameters ? '&' + connectionParameters : '');
 
-        // Add audio mimetypes to connect_string
+        // Add audio mimetypes to connect string
         guacAudio.supported.forEach(function(mimetype) {
             connectString += "&GUAC_AUDIO=" + encodeURIComponent(mimetype);
         });
 
-        // Add video mimetypes to connect_string
+        // Add video mimetypes to connect string
         guacVideo.supported.forEach(function(mimetype) {
             connectString += "&GUAC_VIDEO=" + encodeURIComponent(mimetype);
         });
 
-        return connectString;
+        // Add image mimetypes to connect string
+        guacImage.getSupportedMimetypes().then(function supportedMimetypesKnown(mimetypes) {
+
+            // Add each image mimetype
+            angular.forEach(mimetypes, function addImageMimetype(mimetype) {
+                connectString += "&GUAC_IMAGE=" + encodeURIComponent(mimetype);
+            });
+
+            // Connect string is now ready - nothing else is deferred
+            deferred.resolve(connectString);
+
+        });
+
+        return deferred.promise;
 
     };
 
@@ -411,7 +429,10 @@ angular.module('client').factory('ManagedClient', ['$rootScope', '$injector',
         var clientIdentifier = ClientIdentifier.fromString(id);
 
         // Connect the Guacamole client
-        client.connect(getConnectString(clientIdentifier, connectionParameters));
+        getConnectString(clientIdentifier, connectionParameters)
+        .then(function connectClient(connectString) {
+            client.connect(connectString);
+        });
 
         // If using a connection, pull connection name
         if (clientIdentifier.type === ClientIdentifier.Types.CONNECTION) {