/*
* 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.
*/
var Guacamole = Guacamole || {};
/**
* A hidden input field which attempts to keep itself focused at all times,
* except when another input field has been intentionally focused, whether
* programatically or by the user. The actual underlying input field, returned
* by getElement(), may be used as a reliable source of keyboard-related events,
* particularly composition and input events which may require a focused input
* field to be dispatched at all.
*
* @constructor
*/
Guacamole.InputSink = function InputSink() {
/**
* Reference to this instance of Guacamole.InputSink.
*
* @private
* @type {Guacamole.InputSink}
*/
var sink = this;
/**
* The underlying input field, styled to be invisible.
*
* @private
* @type {Element}
*/
var field = document.createElement('textarea');
field.style.position = 'fixed';
field.style.outline = 'none';
field.style.border = 'none';
field.style.margin = '0';
field.style.padding = '0';
field.style.height = '0';
field.style.width = '0';
field.style.left = '0';
field.style.bottom = '0';
field.style.resize = 'none';
field.style.background = 'transparent';
field.style.color = 'transparent';
// Keep field clear when modified via normal keypresses
field.addEventListener("keypress", function clearKeypress(e) {
field.value = '';
}, false);
// Keep field clear when modofied via composition events
field.addEventListener("compositionend", function clearCompletedComposition(e) {
if (e.data)
field.value = '';
}, false);
// Keep field clear when modofied via input events
field.addEventListener("input", function clearCompletedInput(e) {
if (e.data && !e.isComposing)
field.value = '';
}, false);
// Whenever focus is gained, automatically click to ensure cursor is
// actually placed within the field (the field may simply be highlighted or
// outlined otherwise)
field.addEventListener("focus", function focusReceived() {
window.setTimeout(function deferRefocus() {
field.click();
field.select();
}, 0);
}, true);
/**
* Attempts to focus the underlying input field. The focus attempt occurs
* asynchronously, and may silently fail depending on browser restrictions.
*/
this.focus = function focus() {
window.setTimeout(function deferRefocus() {
field.focus(); // Focus must be deferred to work reliably across browsers
}, 0);
};
/**
* Returns the underlying input field. This input field MUST be manually
* added to the DOM for the Guacamole.InputSink to have any effect.
*
* @returns {Element}
*/
this.getElement = function getElement() {
return field;
};
// Automatically refocus input sink if part of DOM
document.addEventListener("keydown", function refocusSink(e) {
// Do not refocus if focus is on an input field
var focused = document.activeElement;
if (focused && focused !== document.body) {
// Only consider focused input fields which are actually visible
var rect = focused.getBoundingClientRect();
if (rect.left + rect.width > 0 && rect.top + rect.height > 0)
return;
}
// Refocus input sink instead of handling click
sink.focus();
}, true);
};