tp-splitter/tp-hsplitter.js
2023-02-06 14:16:10 +01:00

113 lines
2.7 KiB
JavaScript

/**
@license
Copyright (c) 2023 trading_peter
*/
import { LitElement, html, css } from 'lit';
class TpHSplitter extends LitElement {
static get styles() {
return [
css`
:host {
display: grid;
grid-template-rows: 1fr 5px 1fr;
}
:host([tophidden]),
:host([bottomhidden]) {
grid-template-rows: 1fr;
}
[hidden] {
display: none !important;
}
#top,
#bottom {
position: relative;
overflow: hidden;
}
.splitter {
background: var(--lighter-black);
cursor: row-resize;
opacity: 1;
}
.splitter:hover {
background: var(--hl-color);
opacity: 0.5;
}
`
];
}
render() {
const { topHidden, bottomHidden } = this;
return html`
<div id="top" ?hidden=${topHidden}><slot name="top"></slot></div>
<div class="splitter" @mousedown=${this._enableDrag} ?hidden=${topHidden || bottomHidden}></div>
<div id="bottom" ?hidden=${bottomHidden}><slot name="bottom"></slot></div>
`;
}
static get properties() {
return {
topHidden: { type: Boolean, reflect: true },
bottomHidden: { type: Boolean, reflect: true },
rows: { type: String },
_dragging: { type: Boolean },
};
}
constructor() {
super();
this._disableDrag = this._disableDrag.bind(this);
this._resize = this._resize.bind(this);
}
shouldUpdate(changes) {
if (changes.has('rows')) {
this.style.gridTemplateRows = this.rows;
}
return true;
}
get top() {
return this.shadowRoot.querySelector('#top');
}
get bottom() {
return this.shadowRoot.querySelector('#bottom');
}
_enableDrag(e) {
document.addEventListener('mouseup', this._disableDrag)
document.addEventListener('mousemove', this._resize);
document.body.style['userSelect'] = 'none';
this._startY = e.clientY;
this._topHeight = this.top.offsetHeight;
this._dragging = true;
}
_disableDrag() {
document.removeEventListener('mouseup', this._disableDrag)
document.removeEventListener('mousemove', this._resize);
document.body.style['userSelect'] = '';
this._dragging = false;
this.dispatchEvent(new CustomEvent('resize-done', { detail: this.style.gridTemplateRows, bubbles: true, composed: true }));
}
_resize(e) {
const delta = e.clientY - this._startY;
this.style.gridTemplateRows = `${this._topHeight + delta}px 5px 1fr`;
this.dispatchEvent(new CustomEvent('resized', { detail: null, bubbles: true, composed: true }));
}
}
window.customElements.define('tp-hsplitter', TpHSplitter);