node-webodf
Version:
WebODF - JavaScript Document Engine http://webodf.org/
151 lines (139 loc) • 4.81 kB
JavaScript
/**
* Copyright (C) 2010-2014 KO GmbH <copyright@kogmbh.com>
*
* @licstart
* This file is part of WebODF.
*
* WebODF is free software: you can redistribute it and/or modify it
* under the terms of the GNU Affero General Public License (GNU AGPL)
* as published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* WebODF is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with WebODF. If not, see <http://www.gnu.org/licenses/>.
* @licend
*
* @source: http://www.webodf.org/
* @source: https://github.com/kogmbh/WebODF/
*/
/*global core, runtime*/
(function() {
"use strict";
/** @type {!RedrawTasks} */
var redrawTasks;
/**
* FF doesn't execute requestAnimationFrame requests before it's next repaint,
* causing flickering when performing some types of updates (e.g., recomputing Style2CSS).
* To workaround this, sometimes we force animation callbacks to redraw ourselves
* at certain points.
*
* This object collects animation frame requests and provides
* a safe way of executing any outstanding requests
*
* @constructor
*/
function RedrawTasks() {
var callbacks = {};
/**
* Schedule a callback to be invoked on the next animation frame, or
* when performRedraw is called.
*
* @param {!function():undefined} callback
* @return {!number}
*/
this.requestRedrawTask = function(callback) {
var id = runtime.requestAnimationFrame(function() {
callback();
delete callbacks[id];
});
callbacks[id] = callback;
return id;
};
/**
* Execute any pending animation frame callbacks and cancel their
* browser animation frame request.
*
* @return {undefined}
*/
this.performRedraw = function() {
Object.keys(callbacks).forEach(function(id) {
callbacks[id]();
runtime.cancelAnimationFrame(parseInt(id, 10));
});
callbacks = {};
};
/**
* Cancel a pending animation frame callback
* @param {!number} id
* @return {undefined}
*/
this.cancelRedrawTask = function(id) {
runtime.cancelAnimationFrame(id);
delete callbacks[id];
};
}
/**
* @type {!Object}
*/
core.Task = {};
/**
* Disable manually processing of tasks when core.Task.processTasks is called.
* This is only used during benchmarks to prevent caret redraws from skewing
* the resulting numbers
* @type {!boolean}
*/
core.Task.SUPPRESS_MANUAL_PROCESSING = false;
/**
* Process any outstanding redraw tasks that may be queued up
* waiting for an animation frame
*
* @return {undefined}
*/
core.Task.processTasks = function() {
if (!core.Task.SUPPRESS_MANUAL_PROCESSING) {
redrawTasks.performRedraw();
}
};
/**
* Creates a new task that will execute the specified callback once
* when redrawing the next animation frame. Triggering the task multiple
* times before the execution occurs will still only result in a single
* call being made.
*
* @param {!Function} callback
* @return {!core.ScheduledTask}
*/
core.Task.createRedrawTask = function (callback) {
return new core.ScheduledTask(callback,
redrawTasks.requestRedrawTask,
redrawTasks.cancelRedrawTask
);
};
/**
* Creates a new task that will execute the specified callback once
* within the specified delay period. Triggering the task multiple
* times before the execution occurs will still only result in a single
* call being made.
*
* @param {!Function} callback
* @param {!number} delay
* @return {!core.ScheduledTask}
*/
core.Task.createTimeoutTask = function (callback, delay) {
return new core.ScheduledTask(callback,
function(callback) {
return runtime.setTimeout(callback, delay);
},
runtime.clearTimeout
);
};
function init() {
redrawTasks = new RedrawTasks();
}
init();
}());