Files

98 lines
3.0 KiB
JavaScript

'use strict';
var removeRule = require('./vcssom/removeRule').removeRule;
exports.addon = function (renderer) {
// VCSSOM support only browser environment.
if (!renderer.client) return;
if (process.env.NODE_ENV !== 'production') {
require('./__dev__/warnOnMissingDependencies')('cssom', renderer, ['createRule']); // cssom
}
var kebab = renderer.kebab;
function VRule (selector, prelude) {
this.rule = renderer.createRule(selector, prelude);
this.decl = {};
}
VRule.prototype.diff = function (newDecl) {
var oldDecl = this.decl;
var style = this.rule.style;
var property;
for (property in oldDecl)
if (newDecl[property] === undefined)
style.removeProperty(property);
for (property in newDecl)
if (newDecl[property] !== oldDecl[property])
style.setProperty(kebab(property), newDecl[property]);
this.decl = newDecl;
};
VRule.prototype.del = function () {
removeRule(this.rule);
};
function VSheet () {
/**
* {
* '<at-rule-prelude>': {
* '<selector>': {
* color: 'red
* }
* }
* }
*/
this.tree = {};
}
VSheet.prototype.diff = function (newTree) {
var oldTree = this.tree;
// Remove media queries not present in new tree.
for (var prelude in oldTree) {
if (newTree[prelude] === undefined) {
var rules = oldTree[prelude];
for (var selector in rules)
rules[selector].del();
}
}
for (var prelude in newTree) {
if (oldTree[prelude] === undefined) {
// Whole media query is new.
for (var selector in newTree[prelude]) {
var rule = new VRule(selector, prelude);
rule.diff(newTree[prelude][selector]);
newTree[prelude][selector] = rule;
}
} else {
// Old tree already has rules with this media query.
var oldRules = oldTree[prelude];
var newRules = newTree[prelude];
// Remove rules not present in new tree.
for (var selector in oldRules)
if (!newRules[selector])
oldRules[selector].del();
// Apply new rules.
for (var selector in newRules) {
var rule = oldRules[selector];
if (rule) {
rule.diff(newRules[selector]);
newRules[selector] = rule;
} else {
rule = new VRule(selector, prelude);
rule.diff(newRules[selector]);
newRules[selector] = rule;
}
}
}
}
this.tree = newTree;
};
renderer.VRule = VRule;
renderer.VSheet = VSheet;
};