impress/app/assets/javascripts/outfit-viewer.js

93 lines
3 KiB
JavaScript

class OutfitLayer extends HTMLElement {
#internals;
constructor() {
super();
this.#internals = this.attachInternals();
// An <outfit-layer> starts in the loading state, and then might very
// quickly decide it's not after `#connectToChildren`. This is to prevent a
// flash of *non*-loading state, when a new layer loads in. (e.g. In the
// time between our parent <turbo-frame> loading, which shows the loading
// spinner; and us being marked `:state(loading)`, which shows the loading
// spinner; we don't want the loading spinner to do its usual *immediate*
// total fade-out; then have to fade back in again, on the usual delay.)
this.#setStatus("loading");
}
connectedCallback() {
setTimeout(() => this.#connectToChildren(), 0);
}
disconnectedCallback() {
window.removeEventListener("message", this.#onMessage);
}
#connectToChildren() {
const image = this.querySelector("img");
const iframe = this.querySelector("iframe");
if (image) {
image.addEventListener("load", () => this.#setStatus("loaded"));
image.addEventListener("error", () => this.#setStatus("error"));
this.#setStatus(image.complete ? "loaded" : "loading");
} else if (iframe) {
this.iframe = iframe;
window.addEventListener("message", (m) => this.#onMessage(m));
this.#setStatus("loading");
} else {
throw new Error(`<outfit-layer> must contain an <img> or <iframe> tag`);
}
}
#onMessage({ source, data }) {
if (source !== this.iframe.contentWindow) {
return;
}
if (data.type === "status" && ["loaded", "error"].includes(data.status)) {
this.#setStatus(data.status);
} else {
throw new Error(
`<outfit-layer> got unexpected message: ${JSON.stringify(data)}`,
);
}
}
#setStatus(newStatus) {
this.#internals.states.clear();
this.#internals.states.add(newStatus);
}
}
customElements.define("outfit-layer", OutfitLayer);
// Morph turbo-frames on this page, to reuse asset nodes when we want to—very
// important for movies!—but ensure that it *doesn't* do its usual behavior of
// aggressively reusing existing <outfit-layer> nodes for entirely different
// assets. (It's a lot clearer for managing the loading state, and not showing
// old incorrect layers!) (We also tried using `id` to enforce this… no luck.)
addEventListener("turbo:before-frame-render", (event) => {
if (typeof Idiomorph !== "undefined") {
event.detail.render = (currentElement, newElement) => {
Idiomorph.morph(currentElement, newElement.innerHTML, {
morphStyle: "innerHTML",
callbacks: {
beforeNodeMorphed: (currentNode, newNode) => {
// If Idiomorph wants to transform an <outfit-layer> to
// have a different data-asset-id attribute, we replace
// the node ourselves and abort the morph.
if (
newNode.tagName === "OUTFIT-LAYER" &&
newNode.getAttribute("data-asset-id") !==
currentNode.getAttribute("data-asset-id")
) {
currentNode.replaceWith(newNode);
return false;
}
},
},
});
};
}
});