GUACAMOLE-55: Move clipboard handling to own module. Represent clipboard contents with ClipboardData type.

guacamole/src/main/webapp/app/clipboard/services/clipboardService.js

@@ -0,0 +1,160 @@
+/*
+ * 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.
+ */
+
+/**
+ * A service for accessing local clipboard data.
+ */
+angular.module('clipboard').factory('clipboardService', ['$injector',
+        function clipboardService($injector) {
+
+    // Get required services
+    var $q = $injector.get('$q');
+
+    var service = {};
+
+    /**
+     * A div which is used to hide the clipboard textarea and remove it from
+     * document flow.
+     *
+     * @type Element
+     */
+    var clipElement = document.createElement('div');
+
+    /**
+     * The textarea that will be used to hold the local clipboard contents.
+     *
+     * @type Element
+     */
+    var clipboardContent = document.createElement('textarea');
+
+    // Ensure textarea is selectable but not visible
+    clipElement.appendChild(clipboardContent);
+    clipElement.style.position = 'fixed';
+    clipElement.style.width    = '1px';
+    clipElement.style.height   = '1px';
+    clipElement.style.left     = '-1px';
+    clipElement.style.top      = '-1px';
+    clipElement.style.overflow = 'hidden';
+
+    // Add textarea to DOM
+    document.body.appendChild(clipElement);
+
+    /**
+     * Sets the local clipboard, if possible, to the given text.
+     *
+     * @param {ClipboardData} data
+     *     The data to assign to the local clipboard should be set.
+     *
+     * @return {Promise}
+     *     A promise that will resolve if setting the clipboard was successful,
+     *     and will reject if it failed.
+     */
+    service.setLocalClipboard = function setLocalClipboard(data) {
+
+        var deferred = $q.defer();
+
+        // Track the originally-focused element prior to changing focus
+        var originalElement = document.activeElement;
+
+        // Copy the given value into the clipboard DOM element
+        clipboardContent.value = 'X';
+        clipboardContent.select();
+
+        // Override copied contents of clipboard with the provided value
+        clipboardContent.oncopy = function overrideContent(e) {
+
+            // Override the contents of the clipboard
+            e.preventDefault();
+
+            // Remove anything already present within the clipboard
+            var items = e.clipboardData.items;
+            items.clear();
+
+            // If the provided data is a string, add it as such
+            if (typeof data.data === 'string')
+                items.add(data.data, data.type);
+
+            // Otherwise, add as a File
+            else
+                items.add(new File([data.data], 'data', { type : data.type }));
+
+        };
+
+        // Attempt to copy data from clipboard element into local clipboard
+        if (document.execCommand('copy'))
+            deferred.resolve();
+        else
+            deferred.reject();
+
+        // Unfocus the clipboard DOM event to avoid mobile keyboard opening,
+        // restoring whichever element was originally focused
+        clipboardContent.blur();
+        originalElement.focus();
+
+        return deferred.promise;
+    };
+
+    /**
+     * Get the current value of the local clipboard.
+     *
+     * @return {Promise.<ClipboardData>}
+     *     A promise that will resolve with the contents of the local clipboard
+     *     if getting the clipboard was successful, and will reject if it
+     *     failed.
+     */
+    service.getLocalClipboard = function getLocalClipboard() {
+
+        var deferred = $q.defer();
+
+        // Wait for the next event queue run before attempting to read
+        // clipboard data (in case the copy/cut has not yet completed)
+        window.setTimeout(function deferredClipboardRead() {
+
+            // Track the originally-focused element prior to changing focus
+            var originalElement = document.activeElement;
+
+            // Clear and select the clipboard DOM element
+            clipboardContent.value = '';
+            clipboardContent.focus();
+            clipboardContent.select();
+
+            // FIXME: Only handling text data
+
+            // Attempt paste local clipboard into clipboard DOM element
+            if (document.activeElement === clipboardContent && document.execCommand('paste'))
+                deferred.resolve(new ClipboardData({
+                    type : 'text/plain',
+                    data : clipboardContent.value
+                }));
+            else
+                deferred.reject();
+
+            // Unfocus the clipboard DOM event to avoid mobile keyboard opening,
+            // restoring whichever element was originally focused
+            clipboardContent.blur();
+            originalElement.focus();
+
+        }, 100);
+
+        return deferred.promise;
+    };
+
+    return service;
+
+}]);