react-native/Libraries/ReactIOS/InspectorOverlay/resolveBoxStyle.js

60 lines
1.3 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 resolveBoxStyle
* @flow
*/
'use strict';
/**
* Resolve a style property into it's component parts, e.g.
*
* resolveProperties('margin', {margin: 5, marginBottom: 10})
* ->
* {top: 5, left: 5, right: 5, bottom: 10}
*
* If none are set, returns false.
*/
function resolveBoxStyle(prefix: String, style: Object): ?Object {
var res = {};
var subs = ['top', 'left', 'bottom', 'right'];
var set = false;
subs.forEach(sub => {
res[sub] = style[prefix] || 0;
});
if (style[prefix]) {
set = true;
}
if (style[prefix + 'Vertical']) {
res.top = res.bottom = style[prefix + 'Vertical'];
set = true;
}
if (style[prefix + 'Horizontal']) {
res.left = res.right = style[prefix + 'Horizontal'];
set = true;
}
subs.forEach(sub => {
var val = style[prefix + capFirst(sub)];
if (val) {
res[sub] = val;
set = true;
}
});
if (!set) {
return;
}
return res;
}
function capFirst(text) {
return text[0].toUpperCase() + text.slice(1);
}
module.exports = resolveBoxStyle;