mirror of
https://github.com/Pomax/BezierInfo-2.git
synced 2025-09-26 08:09:11 +02:00
356 lines
10 KiB
JavaScript
356 lines
10 KiB
JavaScript
import { CustomElement } from "./custom-element.js";
|
|
|
|
import splitCodeSections from "./lib/split-code-sections.js";
|
|
import performCodeSurgery from "./lib/perform-code-surgery.js";
|
|
|
|
const MODULE_URL = import.meta.url;
|
|
const MODULE_PATH = MODULE_URL.slice(0, MODULE_URL.lastIndexOf(`/`));
|
|
|
|
// Until global `await` gets added to JS, we need to declare this "constant"
|
|
// using the `let` keyword instead, and then boostrap its value during the
|
|
// `loadSource` call (using the standard if(undefined){assignvalue} pattern).
|
|
let IMPORT_GLOBALS_FROM_GRAPHICS_API = undefined;
|
|
|
|
// Really wish this was baked into the DOM API. Having to use an
|
|
// IntersectionObserver with bounding box fallback is super dumb
|
|
// from an authoring perspective.
|
|
function isInViewport(e) {
|
|
if (typeof window === `undefined`) return true;
|
|
if (typeof document === `undefined`) return true;
|
|
|
|
var b = e.getBoundingClientRect();
|
|
return (
|
|
b.top >= 0 &&
|
|
b.left >= 0 &&
|
|
b.bottom <= (window.innerHeight || document.documentElement.clientHeight) &&
|
|
b.right <= (window.innerWidth || document.documentElement.clientWidth)
|
|
);
|
|
}
|
|
|
|
/**
|
|
* A simple "for programming code" element, for holding entire
|
|
* programs, rather than code snippets.
|
|
*/
|
|
CustomElement.register(class ProgramCode extends HTMLElement {});
|
|
|
|
/**
|
|
* Our custom element
|
|
*/
|
|
class GraphicsElement extends CustomElement {
|
|
static DEBUG = false;
|
|
|
|
/**
|
|
* Create an instance of this element
|
|
*/
|
|
constructor() {
|
|
super({ header: false, footer: false });
|
|
|
|
this.originalHTML = this.outerHTML;
|
|
|
|
// Do we load immediately?
|
|
if (isInViewport(this)) {
|
|
this.loadSource();
|
|
}
|
|
|
|
// Or do we load later, once we've been scrolled into view?
|
|
else {
|
|
let fallback = this.querySelector(`img`);
|
|
new IntersectionObserver(
|
|
(entries, observer) =>
|
|
entries.forEach((entry) => {
|
|
if (entry.isIntersecting) {
|
|
this.loadSource();
|
|
observer.disconnect();
|
|
}
|
|
}),
|
|
{ threshold: 0.1, rootMargin: `${window.innerHeight}px` }
|
|
).observe(fallback);
|
|
}
|
|
|
|
this.label = document.createElement(`label`);
|
|
if (!this.title) this.title = ``;
|
|
this.label.textContent = this.title;
|
|
}
|
|
|
|
/**
|
|
* part of the CustomElement API
|
|
*/
|
|
getStyle() {
|
|
return `
|
|
:host([hidden]) { display: none; }
|
|
:host { max-width: calc(2em + ${this.getAttribute(`width`)}px); }
|
|
:host style { display: none; }
|
|
:host .top-title { display: flex; flex-direction: row; justify-content: space-between; }
|
|
:host canvas { position: relative; z-index: 1; display: block; margin: auto; border-radius: 0; box-sizing: content-box!important; border: 1px solid lightgrey; }
|
|
:host canvas:focus { border: 1px solid red; }
|
|
:host a.view-source { font-size: 60%; text-decoration: none; }
|
|
:host button.reset { font-size: 0.5em; }
|
|
:host label { display: block; font-style:italic; font-size: 0.9em; text-align: right; }
|
|
`;
|
|
}
|
|
|
|
/**
|
|
* part of the CustomElement API
|
|
*/
|
|
handleChildChanges(added, removed) {
|
|
// debugLog(`child change:`, added, removed);
|
|
}
|
|
|
|
/**
|
|
* part of the CustomElement API
|
|
*/
|
|
handleAttributeChange(name, oldValue, newValue) {
|
|
if (name === `title`) {
|
|
this.label.textContent = this.getAttribute(`title`);
|
|
}
|
|
if (this.apiInstance) {
|
|
let instance = this.apiInstance;
|
|
if (name === `width`) {
|
|
instance.setSize(parseInt(newValue), false);
|
|
instance.redraw();
|
|
}
|
|
if (name === `height`) {
|
|
instance.setSize(false, parseInt(newValue));
|
|
instance.redraw();
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Load the graphics code, either from a src URL, a <program-code> element, or .textContent
|
|
*/
|
|
async loadSource() {
|
|
debugLog(`loading ${this.getAttribute(`src`)}`);
|
|
|
|
if (!IMPORT_GLOBALS_FROM_GRAPHICS_API) {
|
|
const importStatement = (
|
|
await fetch(`${MODULE_PATH}/api/graphics-api.js`).then((r) => r.text())
|
|
)
|
|
.match(/(export { [^}]+ })/)[0]
|
|
.replace(`export`, `import`);
|
|
IMPORT_GLOBALS_FROM_GRAPHICS_API = `${importStatement} from "${MODULE_PATH}/api/graphics-api.js"`;
|
|
}
|
|
|
|
let src = false;
|
|
let codeElement = this.querySelector(`program-code`);
|
|
|
|
let code = ``;
|
|
|
|
if (codeElement) {
|
|
src = codeElement.getAttribute("src");
|
|
if (src) {
|
|
this.src = src;
|
|
code = await fetch(src).then((response) => response.text());
|
|
} else {
|
|
code = codeElement.textContent;
|
|
}
|
|
} else {
|
|
src = this.getAttribute("src");
|
|
if (src) {
|
|
this.src = src;
|
|
code = await fetch(src).then((response) => response.text());
|
|
} else {
|
|
code = this.textContent;
|
|
}
|
|
}
|
|
|
|
if (!codeElement) {
|
|
codeElement = document.createElement(`program-code`);
|
|
codeElement.textContent = code;
|
|
this.prepend(codeElement);
|
|
}
|
|
|
|
codeElement.setAttribute(`hidden`, `hidden`);
|
|
|
|
new MutationObserver((_records) => {
|
|
// nornmally we don't want to completely recreate the shadow DOM
|
|
this.processSource(src, codeElement.textContent);
|
|
}).observe(codeElement, {
|
|
characterData: true,
|
|
attributes: false,
|
|
childList: true,
|
|
subtree: true,
|
|
});
|
|
|
|
// But on the first pass, we do.
|
|
this.processSource(src, code, true);
|
|
}
|
|
|
|
/**
|
|
* Transform the graphics source code into global and class code.
|
|
*/
|
|
processSource(src, code, rerender = false) {
|
|
if (this.script) {
|
|
if (this.script.parentNode) {
|
|
this.script.parentNode.removeChild(this.script);
|
|
}
|
|
this.canvas.parentNode.removeChild(this.canvas);
|
|
rerender = true;
|
|
}
|
|
|
|
const uid = (this.uid = `bg-uid-${Date.now()}-${`${Math.random()}`.replace(
|
|
`0.`,
|
|
``
|
|
)}`);
|
|
window[uid] = this;
|
|
|
|
// Step 1: fix the imports. This is ... a bit of work.
|
|
let path;
|
|
let base = document.querySelector(`base`);
|
|
if (base) {
|
|
path = base.href;
|
|
} else {
|
|
let loc = window.location.toString();
|
|
path = loc.substring(0, loc.lastIndexOf(`/`) + 1);
|
|
}
|
|
let modulepath = `${path}${src}`;
|
|
let modulebase = modulepath.substring(0, modulepath.lastIndexOf(`/`) + 1);
|
|
|
|
// okay, I lied, it's actually quite a lot of work.
|
|
code = code.replace(/(import .+? from) "([^"]+)"/g, (_, main, group) => {
|
|
return `${main} "${modulebase}${group}"`;
|
|
});
|
|
|
|
// Then, step 2: split up the code into "global" vs. "class" code.
|
|
const split = splitCodeSections(code);
|
|
const globalCode = split.quasiGlobal;
|
|
const classCode = performCodeSurgery(split.classCode);
|
|
|
|
this.setupCodeInjection(src, uid, globalCode, classCode, rerender);
|
|
}
|
|
|
|
/**
|
|
* Form the final, perfectly valid JS module code, and create the <script>
|
|
* element for it, to be inserted into the shadow DOM during render().
|
|
*/
|
|
setupCodeInjection(src, uid, globalCode, classCode, rerender) {
|
|
const width = this.getAttribute(`width`, 200);
|
|
const height = this.getAttribute(`height`, 200);
|
|
|
|
this.code = `
|
|
/**
|
|
* Program source: ${src}
|
|
* Data attributes: ${JSON.stringify(this.dataset)}
|
|
*/
|
|
${IMPORT_GLOBALS_FROM_GRAPHICS_API};
|
|
|
|
${globalCode}
|
|
|
|
class Example extends GraphicsAPI {
|
|
${classCode}
|
|
}
|
|
|
|
new Example('${uid}', ${width}, ${height});
|
|
`;
|
|
|
|
const script = (this.script = document.createElement(`script`));
|
|
script.type = "module";
|
|
script.src = `data:application/javascript;charset=utf-8,${encodeURIComponent(
|
|
this.code
|
|
)}`;
|
|
|
|
if (rerender) this.render();
|
|
}
|
|
|
|
/**
|
|
* Reload this graphics element the brute force way.
|
|
*/
|
|
async reset() {
|
|
this.outerHTML = this.originalHTML;
|
|
}
|
|
|
|
/**
|
|
* Hand the <graphics-element> a reference to the "Example" instance that it built.
|
|
*/
|
|
setGraphic(apiInstance) {
|
|
this.apiInstance = apiInstance;
|
|
this.setCanvas(apiInstance.canvas);
|
|
// at this point we can remove our placeholder image for this element, too.
|
|
let fallback = this.querySelector(`fallback-image`);
|
|
if (fallback) this.removeChild(fallback);
|
|
}
|
|
|
|
/**
|
|
* Locally bind the Example's canvas, since it needs to get added to the shadow DOM.
|
|
*/
|
|
setCanvas(canvas) {
|
|
this.canvas = canvas;
|
|
// Make sure focus works, Which is a CLUSTERFUCK OF BULLSHIT in the August, 2020,
|
|
// browser landscape, so this is the best I can give you right now. I am more
|
|
// disappointed about this than you will ever be.
|
|
this.canvas.setAttribute(`tabindex`, `0`);
|
|
this.canvas.addEventListener(`touchstart`, (evt) => this.canvas.focus());
|
|
this.canvas.addEventListener(`mousedown`, (evt) => this.canvas.focus());
|
|
// If we get here, there were no source code errors: undo the scheduled error print.
|
|
clearTimeout(this.errorPrintTimeout);
|
|
this.render();
|
|
}
|
|
|
|
/**
|
|
* This is a helper to aid debugging, mostly because dev tools are not super
|
|
* great at pointing you to the right line for an injected script that it
|
|
* can't actually find anywhere in the document or shadow DOM...
|
|
*/
|
|
printCodeDueToError() {
|
|
debugLog(
|
|
this.code
|
|
.split(`\n`)
|
|
.map((l, pos) => `${pos + 1}: ${l}`)
|
|
.join(`\n`)
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Regenerate the shadow DOM content.
|
|
*/
|
|
render() {
|
|
super.render();
|
|
|
|
if (this.script) {
|
|
if (!this.script.__inserted) {
|
|
// Schedule an error print, which will get cleared if there
|
|
// were no source code errors.
|
|
this.errorPrintTimeout = setTimeout(
|
|
() => this.printCodeDueToError(),
|
|
1000
|
|
);
|
|
this.script.__inserted = true;
|
|
this._shadow.appendChild(this.script);
|
|
}
|
|
}
|
|
|
|
const slotParent = this._slot.parentNode;
|
|
if (this.canvas) slotParent.insertBefore(this.canvas, this._slot);
|
|
if (this.label) slotParent.insertBefore(this.label, this._slot);
|
|
|
|
const toptitle = document.createElement(`div`);
|
|
toptitle.classList.add(`top-title`);
|
|
|
|
const a = document.createElement(`a`);
|
|
a.classList.add(`view-source`);
|
|
a.textContent = `view source`;
|
|
a.href = this.src;
|
|
a.target = `_blank`;
|
|
toptitle.append(a);
|
|
|
|
const r = document.createElement(`button`);
|
|
r.classList.add(`reset`);
|
|
r.textContent = `reset`;
|
|
r.addEventListener(`click`, () => this.reset());
|
|
toptitle.append(r);
|
|
|
|
if (this.label) slotParent.insertBefore(toptitle, this.canvas);
|
|
}
|
|
}
|
|
|
|
CustomElement.register(GraphicsElement);
|
|
|
|
// debugging should be behind a flag
|
|
function debugLog(...data) {
|
|
if (GraphicsElement.DEBUG) {
|
|
console.log(...data);
|
|
}
|
|
}
|
|
|
|
export { GraphicsElement };
|