site/node_modules/mathjax-full/ts/output/common/Wrappers/mfrac.ts

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/*************************************************************
*
* Copyright (c) 2017-2022 The MathJax Consortium
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @fileoverview Implements the CommonMfrac wrapper mixin for the MmlMfrac object
*
* @author dpvc@mathjax.org (Davide Cervone)
*/
import {AnyWrapper, WrapperConstructor, Constructor} from '../Wrapper.js';
import {CommonMo} from './mo.js';
import {BBox} from '../../../util/BBox.js';
import {DIRECTION} from '../FontData.js';
/*****************************************************************/
/**
* The CommonMfrac interface
*/
export interface CommonMfrac extends AnyWrapper {
/**
* @param {BBox} bbox The buonding box to modify
* @param {boolean} display True for display-mode fractions
* @param {number} t The thickness of the line
*/
getFractionBBox(bbox: BBox, display: boolean, t: number): void;
/**
* @param {boolean} display True for display-mode fractions
* @param {number} t The thickness of the line
* @return {Object} The expanded rule thickness (T), and baseline offsets
* for numerator and denomunator (u and v)
*/
getTUV(display: boolean, t: number): {T: number, u: number, v: number};
/**
* @param {BBox} bbox The bounding box to modify
* @param {boolean} display True for display-mode fractions
*/
getAtopBBox(bbox: BBox, display: boolean): void;
/**
* @param {boolean} display True for diplay-mode fractions
* @return {Object}
* The vertical offsets of the numerator (u), the denominator (v),
* the separation between the two, and the bboxes themselves.
*/
getUVQ(display: boolean): {u: number, v: number, q: number, nbox: BBox, dbox: BBox};
/**
* @param {BBox} bbox The boundng box to modify
* @param {boolean} display True for display-mode fractions
*/
getBevelledBBox(bbox: BBox, display: boolean): void;
/**
* @param {boolean} display True for display-style fractions
* @return {Object} The height (H) of the bevel, horizontal offest (delta)
* vertical offsets (u and v) of the parts, and
* bounding boxes of the parts.
*/
getBevelData(display: boolean): {H: number, delta: number, u: number, v: number, nbox: BBox, dbox: BBox};
/**
* @return {boolean} True if in display mode, false otherwise
*/
isDisplay(): boolean;
}
/**
* Shorthand for the CommonMfrac constructor
*/
export type MfracConstructor = Constructor<CommonMfrac>;
/*****************************************************************/
/**
* The CommonMfrac wrapper mixin for the MmlMfrac object
*
* @template T The Wrapper class constructor type
*/
export function CommonMfracMixin<T extends WrapperConstructor>(Base: T): MfracConstructor & T {
return class extends Base {
/**
* Wrapper for <mo> to use for bevelled fraction
*/
public bevel: CommonMo = null;
/**
* Padding around fractions
*/
public pad: number;
/************************************************/
/**
* @override
* @constructor
*/
constructor(...args: any[]) {
super(...args);
this.pad = (this.node.getProperty('withDelims') as boolean ? 0 : this.font.params.nulldelimiterspace);
//
// create internal bevel mo element
//
if (this.node.attributes.get('bevelled')) {
const {H} = this.getBevelData(this.isDisplay());
const bevel = this.bevel = this.createMo('/') as CommonMo;
bevel.node.attributes.set('symmetric', true);
bevel.canStretch(DIRECTION.Vertical);
bevel.getStretchedVariant([H], true);
}
}
/**
* @override
*/
public computeBBox(bbox: BBox, recompute: boolean = false) {
bbox.empty();
const {linethickness, bevelled} = this.node.attributes.getList('linethickness', 'bevelled');
const display = this.isDisplay();
let w = null as (number | null);
if (bevelled) {
this.getBevelledBBox(bbox, display);
} else {
const thickness = this.length2em(String(linethickness), .06);
w = -2 * this.pad;
if (thickness === 0) {
this.getAtopBBox(bbox, display);
} else {
this.getFractionBBox(bbox, display, thickness);
w -= .2;
}
w += bbox.w;
}
bbox.clean();
this.setChildPWidths(recompute, w);
}
/************************************************/
/**
* @param {BBox} bbox The buonding box to modify
* @param {boolean} display True for display-mode fractions
* @param {number} t The thickness of the line
*/
public getFractionBBox(bbox: BBox, display: boolean, t: number) {
const nbox = this.childNodes[0].getOuterBBox();
const dbox = this.childNodes[1].getOuterBBox();
const tex = this.font.params;
const a = tex.axis_height;
const {T, u, v} = this.getTUV(display, t);
bbox.combine(nbox, 0, a + T + Math.max(nbox.d * nbox.rscale, u));
bbox.combine(dbox, 0, a - T - Math.max(dbox.h * dbox.rscale, v));
bbox.w += 2 * this.pad + .2;
}
/**
* @param {boolean} display True for display-mode fractions
* @param {number} t The thickness of the line
* @return {Object} The expanded rule thickness (T), and baseline offsets
* for numerator and denomunator (u and v)
*/
public getTUV(display: boolean, t: number): {T: number, u: number, v: number} {
const tex = this.font.params;
const a = tex.axis_height;
const T = (display ? 3.5 : 1.5) * t;
return {T: (display ? 3.5 : 1.5) * t,
u: (display ? tex.num1 : tex.num2) - a - T,
v: (display ? tex.denom1 : tex.denom2) + a - T};
}
/************************************************/
/**
* @param {BBox} bbox The bounding box to modify
* @param {boolean} display True for display-mode fractions
*/
public getAtopBBox(bbox: BBox, display: boolean) {
const {u, v, nbox, dbox} = this.getUVQ(display);
bbox.combine(nbox, 0, u);
bbox.combine(dbox, 0, -v);
bbox.w += 2 * this.pad;
}
/**
* @param {boolean} display True for diplay-mode fractions
* @return {Object}
* The vertical offsets of the numerator (u), the denominator (v),
* the separation between the two, and the bboxes themselves.
*/
public getUVQ(display: boolean): {u: number, v: number, q: number, nbox: BBox, dbox: BBox} {
const nbox = this.childNodes[0].getOuterBBox();
const dbox = this.childNodes[1].getOuterBBox();
const tex = this.font.params;
//
// Initial offsets (u, v)
// Minimum separation (p)
// Actual separation with initial positions (q)
//
let [u, v] = (display ? [tex.num1, tex.denom1] : [tex.num3, tex.denom2]);
let p = (display ? 7 : 3) * tex.rule_thickness;
let q = (u - nbox.d * nbox.scale) - (dbox.h * dbox.scale - v);
//
// If actual separation is less than minimum, move them farther apart
//
if (q < p) {
u += (p - q) / 2;
v += (p - q) / 2;
q = p;
}
return {u, v, q, nbox, dbox};
}
/************************************************/
/**
* @param {BBox} bbox The boundng box to modify
* @param {boolean} display True for display-mode fractions
*/
public getBevelledBBox(bbox: BBox, display: boolean) {
const {u, v, delta, nbox, dbox} = this.getBevelData(display);
const lbox = this.bevel.getOuterBBox();
bbox.combine(nbox, 0, u);
bbox.combine(lbox, bbox.w - delta / 2, 0);
bbox.combine(dbox, bbox.w - delta / 2, v);
}
/**
* @param {boolean} display True for display-style fractions
* @return {Object} The height (H) of the bevel, horizontal offest (delta)
* vertical offsets (u and v) of the parts, and
* bounding boxes of the parts.
*/
public getBevelData(display: boolean): {
H: number, delta: number, u: number, v: number, nbox: BBox, dbox: BBox
} {
const nbox = this.childNodes[0].getOuterBBox();
const dbox = this.childNodes[1].getOuterBBox();
const delta = (display ? .4 : .15);
const H = Math.max(nbox.scale * (nbox.h + nbox.d), dbox.scale * (dbox.h + dbox.d)) + 2 * delta;
const a = this.font.params.axis_height;
const u = nbox.scale * (nbox.d - nbox.h) / 2 + a + delta;
const v = dbox.scale * (dbox.d - dbox.h) / 2 + a - delta;
return {H, delta, u, v, nbox, dbox};
}
/************************************************/
/**
* @override
*/
public canStretch(_direction: DIRECTION) {
return false;
}
/**
* @return {boolean} True if in display mode, false otherwise
*/
public isDisplay(): boolean {
const {displaystyle, scriptlevel} = this.node.attributes.getList('displaystyle', 'scriptlevel');
return displaystyle && scriptlevel === 0;
}
/**
* @override
*/
public getWrapWidth(i: number) {
const attributes = this.node.attributes;
if (attributes.get('bevelled')) {
return this.childNodes[i].getOuterBBox().w;
}
const w = this.getBBox().w;
const thickness = this.length2em(attributes.get('linethickness'));
return w - (thickness ? .2 : 0) - 2 * this.pad;
}
/**
* @override
*/
public getChildAlign(i: number) {
const attributes = this.node.attributes;
return (attributes.get('bevelled') ? 'left' : attributes.get(['numalign', 'denomalign'][i]) as string);
}
};
}