cione-comp-lib
Version:
`$ yarn add cione-comp-lib` 或者 `$ npm i cione-comp-lib -S`
104 lines (103 loc) • 3.6 kB
JavaScript
import { ASTWalker } from "./parsers.mjs";
/* @license
* Copyright 2019 Google LLC. All Rights Reserved.
* 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.
*/
var _a, _b, _c, _d;
const $instances = Symbol("instances");
const $activateListener = Symbol("activateListener");
const $deactivateListener = Symbol("deactivateListener");
const $notifyInstances = Symbol("notifyInstances");
const $notify = Symbol("notify");
const $scrollCallback = Symbol("callback");
class ScrollObserver {
constructor(callback) {
this[$scrollCallback] = callback;
}
static [$notifyInstances]() {
for (const instance of ScrollObserver[$instances]) {
instance[$notify]();
}
}
static [(_a = $instances, $activateListener)]() {
window.addEventListener("scroll", this[$notifyInstances], { passive: true });
}
static [$deactivateListener]() {
window.removeEventListener("scroll", this[$notifyInstances]);
}
observe() {
if (ScrollObserver[$instances].size === 0) {
ScrollObserver[$activateListener]();
}
ScrollObserver[$instances].add(this);
}
disconnect() {
ScrollObserver[$instances].delete(this);
if (ScrollObserver[$instances].size === 0) {
ScrollObserver[$deactivateListener]();
}
}
[$notify]() {
this[$scrollCallback]();
}
}
ScrollObserver[_a] = /* @__PURE__ */ new Set();
const $computeStyleCallback = Symbol("computeStyleCallback");
const $astWalker = Symbol("astWalker");
const $dependencies = Symbol("dependencies");
const $onScroll = Symbol("onScroll");
class StyleEffector {
constructor(callback) {
this[_b] = {};
this[_c] = new ASTWalker(["function"]);
this[_d] = () => {
this[$computeStyleCallback]({ relatedState: "window-scroll" });
};
this[$computeStyleCallback] = callback;
}
observeEffectsFor(ast) {
const newDependencies = {};
const oldDependencies = this[$dependencies];
this[$astWalker].walk(ast, (functionNode) => {
const { name } = functionNode;
const firstArgument = functionNode.arguments[0];
const firstTerm = firstArgument.terms[0];
if (name.value !== "env" || firstTerm == null || firstTerm.type !== "ident") {
return;
}
switch (firstTerm.value) {
case "window-scroll-y":
if (newDependencies["window-scroll"] == null) {
const observer = "window-scroll" in oldDependencies ? oldDependencies["window-scroll"] : new ScrollObserver(this[$onScroll]);
observer.observe();
delete oldDependencies["window-scroll"];
newDependencies["window-scroll"] = observer;
}
break;
}
});
for (const environmentState in oldDependencies) {
const observer = oldDependencies[environmentState];
observer.disconnect();
}
this[$dependencies] = newDependencies;
}
dispose() {
for (const environmentState in this[$dependencies]) {
const observer = this[$dependencies][environmentState];
observer.disconnect();
}
}
}
_b = $dependencies, _c = $astWalker, _d = $onScroll;
export { StyleEffector };