rx-player
Version:
Canal+ HTML5 Video Player
80 lines (79 loc) • 2.85 kB
JavaScript
/**
* Copyright 2015 CANAL+ Group
*
* Licensed 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.
*/
import log from "../../../log";
import arrayFindIndex from "../../../utils/array_find_index";
import arrayIncludes from "../../../utils/array_includes";
import objectAssign from "../../../utils/object_assign";
/**
* Transform all styles inheriting from other styles to the same styles but with
* the inheritance removed (by resolving those inheritance here).
*
* Note that the original style object is directly mutated with every
* inheritance they had resolved and removed.
*
* To make a pseudo-code analogy this would be equivalent to transform those
* two classes:
* ```
* class A {
* methodA() {}
* }
*
* class B extends A {
* method B() {}
* }
* ```
* into the same two classes without inheritance:
* ```
* class A {
* methodA() {}
* }
* class B {
* methodA() {} // inherited from class A
* methodB() {}
* }
* ```
*
* Doing this here allows to simplify further treatment of those styles.
* @param {Array.<Object>} styles
*/
export default function resolveStylesInheritance(styles) {
// keep track of all the indexes parsed to avoid infinite loops
const recursivelyBrowsedIndexes = [];
function resolveStyleInheritance(styleElt, index) {
recursivelyBrowsedIndexes.push(index);
for (const extendedStyleID of styleElt.extendsStyles) {
const extendedStyleIndex = arrayFindIndex(styles, (x) => x.id === extendedStyleID);
if (extendedStyleIndex < 0) {
log.warn("TTML Parser: unknown style inheritance: " + extendedStyleID);
}
else {
const extendedStyle = styles[extendedStyleIndex];
if (arrayIncludes(recursivelyBrowsedIndexes, extendedStyleIndex)) {
log.warn("TTML Parser: infinite style inheritance loop avoided");
}
else {
resolveStyleInheritance(extendedStyle, extendedStyleIndex);
}
styleElt.style = objectAssign({}, extendedStyle.style, styleElt.style);
}
}
styleElt.extendsStyles.length = 0;
}
for (let i = 0; i < styles.length; i++) {
resolveStyleInheritance(styles[i], i);
recursivelyBrowsedIndexes.length = 0; // reset
}
}