GUACAMOLE-310: Wait until clipboard target is actually focused before attempting paste.

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

@@ -398,53 +398,81 @@ angular.module('clipboard').factory('clipboardService', ['$injector',
             var originalElement = document.activeElement;
             pushSelection();
 
+            /**
+             * Attempts to paste the clipboard contents into the
+             * currently-focused element. The promise related to the current
+             * attempt to read the clipboard will be resolved or rejected
+             * depending on whether the attempt to paste succeeds.
+             */
+            var performPaste = function performPaste() {
+
+                // Attempt paste local clipboard into clipboard DOM element
+                if (document.execCommand('paste')) {
+
+                    // If the pasted data is a single image, resolve with a blob
+                    // containing that image
+                    var currentImage = service.getImageContent(clipboardContent);
+                    if (currentImage) {
+
+                        // Convert the image's data URL into a blob
+                        var blob = service.parseDataURL(currentImage);
+                        if (blob) {
+                            deferred.resolve(new ClipboardData({
+                                type : blob.type,
+                                data : blob
+                            }));
+                        }
+
+                        // Reject if conversion fails
+                        else
+                            deferred.reject();
+
+                    } // end if clipboard is an image
+
+                    // Otherwise, assume the clipboard contains plain text
+                    else
+                        deferred.resolve(new ClipboardData({
+                            type : 'text/plain',
+                            data : clipboardContent.value
+                        }));
+
+                }
+
+                // Otherwise, reading from the clipboard has failed
+                else
+                    deferred.reject();
+
+            };
+
+            // Clean up event listener and selection once the paste attempt has
+            // completed
+            deferred.promise['finally'](function cleanupReadAttempt() {
+
+                // Do not use future changes in focus
+                clipboardContent.removeEventListener('focus', performPaste);
+
+                // Unfocus the clipboard DOM event to avoid mobile keyboard opening,
+                // restoring whichever element was originally focused
+                clipboardContent.blur();
+                originalElement.focus();
+                popSelection();
+
+            });
+
+            // Ensure clipboard element is blurred (and that the "focus" event
+            // will fire)
+            clipboardContent.blur();
+            clipboardContent.addEventListener('focus', performPaste);
+
             // Clear and select the clipboard DOM element
             clipboardContent.value = '';
             clipboardContent.focus();
             selectAll(clipboardContent);
 
-            // Attempt paste local clipboard into clipboard DOM element
+            // If focus failed to be set, we cannot read the clipboard
-            if (document.activeElement === clipboardContent && document.execCommand('paste')) {
+            if (document.activeElement !== clipboardContent)
-
-                // If the pasted data is a single image, resolve with a blob
-                // containing that image
-                var currentImage = service.getImageContent(clipboardContent);
-                if (currentImage) {
-
-                    // Convert the image's data URL into a blob
-                    var blob = service.parseDataURL(currentImage);
-                    if (blob) {
-                        deferred.resolve(new ClipboardData({
-                            type : blob.type,
-                            data : blob
-                        }));
-                    }
-
-                    // Reject if conversion fails
-                    else
-                        deferred.reject();
-
-                } // end if clipboard is an image
-
-                // Otherwise, assume the clipboard contains plain text
-                else
-                    deferred.resolve(new ClipboardData({
-                        type : 'text/plain',
-                        data : clipboardContent.value
-                    }));
-
-            }
-
-            // Otherwise, reading from the clipboard has failed
-            else
                 deferred.reject();
 
-            // Unfocus the clipboard DOM event to avoid mobile keyboard opening,
-            // restoring whichever element was originally focused
-            clipboardContent.blur();
-            originalElement.focus();
-            popSelection();
-
         }, CLIPBOARD_READ_DELAY);
 
         return deferred.promise;