Class SpaceNode

src/mathMLTree.ts:186–255

 * depending on the width.
 */
export class SpaceNode implements MathDomNode {
    width: number;
    character: string | null | undefined;

    /**
     * Create a Space node with width given in CSS ems.
     */
    constructor(width: number) {
        this.width = width;
        // See https://www.w3.org/TR/2000/WD-MathML2-20000328/chapter6.html
        // for a table of space-like characters.  We use Unicode
        // representations instead of &LongNames; as it's not clear how to
        // make the latter via document.createTextNode.
        if (width >= 0.05555 && width <= 0.05556) {
            this.character = "\u200a";           // &VeryThinSpace;
        } else if (width >= 0.1666 && width <= 0.1667) {
            this.character = "\u2009";           // &ThinSpace;
        } else if (width >= 0.2222 && width <= 0.2223) {
            this.character = "\u2005";           // &MediumSpace;
        } else if (width >= 0.2777 && width <= 0.2778) {
            this.character = "\u2005\u200a";     // &ThickSpace;
        } else if (width >= -0.05556 && width <= -0.05555) {
            this.character = "\u200a\u2063";     // &NegativeVeryThinSpace;
        } else if (width >= -0.1667 && width <= -0.1666) {
            this.character = "\u2009\u2063";     // &NegativeThinSpace;
        } else if (width >= -0.2223 && width <= -0.2222) {
            this.character = "\u205f\u2063";     // &NegativeMediumSpace;
        } else if (width >= -0.2778 && width <= -0.2777) {
            this.character = "\u2005\u2063";     // &NegativeThickSpace;
        } else {
            this.character = null;
        }
    }

    /**
     * Converts the math node into a MathML-namespaced DOM element.
     */
    toNode(): Node {
        if (this.character) {
            return document.createTextNode(this.character);
        } else {
            const node = document.createElementNS(
                "http://www.w3.org/1998/Math/MathML", "mspace");
            node.setAttribute("width", makeEm(this.width));
            return node;
        }
    }

    /**
     * Converts the math node into an HTML markup string.
     */
    toMarkup(): string {
        if (this.character) {
            return `<mtext>${this.character}</mtext>`;
        } else {
            return `<mspace width="${makeEm(this.width)}"/>`;
        }
    }