react-native/Libraries/StyleSheet/StyleSheetRegistry.js

45 lines
1.0 KiB
JavaScript

/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
* @providesModule StyleSheetRegistry
* @flow
*/
'use strict';
var styles = {};
var uniqueID = 1;
var emptyStyle = {};
class StyleSheetRegistry {
static registerStyle(style: Object): number {
var id = ++uniqueID;
if (__DEV__) {
Object.freeze(style);
}
styles[id] = style;
return id;
}
static getStyleByID(id: number): Object {
if (!id) {
// Used in the style={[condition && id]} pattern,
// we want it to be a no-op when the value is false or null
return emptyStyle;
}
var style = styles[id];
if (!style) {
console.warn('Invalid style with id `' + id + '`. Skipping ...');
return emptyStyle;
}
return style;
}
}
module.exports = StyleSheetRegistry;