folk-canvas/src/folk-base-connection.ts

88 lines
2.4 KiB
TypeScript

import { parseVertex } from './common/utils.ts';
import { ClientRectObserverEntry } from './common/client-rect-observer.ts';
import { FolkObserver } from './common/folk-observer.ts';
import { FolkElement } from './common/folk-element.ts';
import { property, state } from '@lit/reactive-element/decorators.js';
import { PropertyValues } from '@lit/reactive-element';
const folkObserver = new FolkObserver();
export class FolkBaseConnection extends FolkElement {
@property({ type: String, reflect: true }) source = '';
@state() sourceElement: Element | null = null;
@state() sourceRect: DOMRectReadOnly | null = null;
@property({ type: String, reflect: true }) target = '';
@state() targetRect: DOMRectReadOnly | null = null;
@state() targetElement: Element | null = null;
override disconnectedCallback() {
super.disconnectedCallback();
this.#unobserveSource();
this.#unobserveTarget();
}
override willUpdate(changedProperties: PropertyValues<this>) {
super.willUpdate(changedProperties);
if (changedProperties.has('source')) {
this.#unobserveSource();
const vertex = parseVertex(this.source);
if (vertex) {
this.sourceRect = DOMRectReadOnly.fromRect(vertex);
} else {
this.sourceElement = document.querySelector(this.source);
if (this.sourceElement === null) {
this.sourceRect = null;
} else {
folkObserver.observe(this.sourceElement, this.#sourceCallback);
}
}
}
if (changedProperties.has('target')) {
this.#unobserveTarget();
const vertex = parseVertex(this.target);
if (vertex) {
this.targetRect = DOMRectReadOnly.fromRect(vertex);
} else {
this.targetElement = document.querySelector(this.target);
if (this.targetElement === null) {
this.targetRect = null;
} else {
folkObserver.observe(this.targetElement, this.#targetCallback);
}
}
}
}
#sourceCallback = (entry: ClientRectObserverEntry) => {
this.sourceRect = entry.contentRect;
};
#unobserveSource() {
if (this.sourceElement === null) return;
folkObserver.unobserve(this.sourceElement, this.#sourceCallback);
}
#targetCallback = (entry: ClientRectObserverEntry) => {
this.targetRect = entry.contentRect;
};
#unobserveTarget() {
if (this.targetElement === null) return;
folkObserver.unobserve(this.targetElement, this.#targetCallback);
}
}