Box

基本上不是作為排版的元件，但具有背景、邊框等。

Layout ⟩

設計原則：

具有「有形的邊界」：設計時需搭配 border, background-color, color
與內文「有一致的間距」：padding

box.mjs 更改樣式的策略與不同。

box.mjs 利用 setters 將樣式直接寫到個別的 <box> 樣式 (this.style) 中，因此無法共用。
vstack.mjs 則是間接將客製化的 <style> 樣式寫到 <head> 中，並同時將此 <style> 的專有 ID 寫到 <vstack> 的 "data-style" 屬性中，希望能共用這個 <style>。

source code

// 0.0.9 - Box: remove render(), use setters instead.

import {attr} from './helpers.mjs';

/**
 * Box
 * ---
 * <box- padding="" border="" background="" color="" dark>
 */
export default class Box extends HTMLElement {

    // ⭐ observed attributes
    static get observedAttributes() {
        return [
            'padding', 'border', 'color', 'background', 'dark'
        ];
    }

    // re-renders whenever one of attributes changes.
    attributeChangedCallback(attr, oldValue, newValue) {
        // ⭐️ 更新：全部透過 setter 處理就好。
        this[attr] = this[attr];
    }

    // -------------- ⭐️ getters/setters ------------------

    // this.padding
    get padding() { return attr(this, 'padding') }
    set padding(val) { 
        this.style.padding = val;
        return attr(this, 'padding', val) 
    }

    // this.border
    get border() { return attr(this, 'border') }
    set border(val) { 
        this.style.border = val;
        return attr(this, 'border', val) 
    }

    // this.color
    get color() { return attr(this, 'color') }
    set color(val) { 
        this.style.color = val;
        return attr(this, 'color', val) 
    }

    // this.background
    get background() { return attr(this, 'background') }
    set background(val) { 
        this.style.background = val;
        return attr(this, 'background', val) 
    }

    // this.dark
    get dark() { return this.hasAttribute('dark') }
    set dark(val) { 
        this.classList.toggle('dark', val);
        return attr(this, 'dark', val);
    }
    
}

// ⭐️ register <box->
customElements.get('box-') || 
customElements.define('box-', Box);

/* ⭐️ Box 0.0.6 + border */

/* box */
box- {

    /* default settings */
    --box-light-color: #eee;
    --box-dark-color: #222;

    display: block;
    
    /* 🔸 axiom: box's content should be away with its edges */
    padding: var(--spacing);

    /* 🔸 axiom: box should be visible */
    border: var(--border-thin);
    background-color: var(--box-light-color);
    color: var(--box-dark-color);

    /* 
        High contrast themes tend to eliminate backgrounds. By employing a transparent outline the box shape can be restored.

        When a high contrast theme is not running, the outline is invisible.
     */
    outline: 0.125rem solid transparent; 
    outline-offset: -0.125rem;
}

/* 
    box (dark theme) 
    ----------------
    In a greyscale design, it is possible to switch between 
    dark/light theme with `filter`.

    box.invert { filter: invert(100%); }
*/
box-.dark {
    color: var(--box-light-color);
    background-color: var(--box-dark-color);
    border: var(--border-thin);
}

/* elements in box */
box- * {
    /* 
        Changing `background-color` requires you to change `color` to ensure the content is still legible. This can be made easier by 
        applying `color: inherit` to any elements inside box.
     */
    color: inherit;
}

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Last updated 3 years ago

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