/*************************************************************
*
* 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 CommonMsubsup wrapper mixin for the MmlMsubsup object
* and the special cases CommonMsub and CommonMsup
*
* @author dpvc@mathjax.org (Davide Cervone)
*/
import {AnyWrapper, Constructor} from '../Wrapper.js';
import {CommonScriptbase, ScriptbaseConstructor} from './scriptbase.js';
import {BBox} from '../../../util/BBox.js';
import {MmlMsubsup, MmlMsub, MmlMsup} from '../../../core/MmlTree/MmlNodes/msubsup.js';
/*****************************************************************/
/**
* The CommonMsub interface
*
* @template W The child-node Wrapper class
*/
export interface CommonMsub<W extends AnyWrapper> extends CommonScriptbase<W> {
}
/**
* Shorthand for the CommonMsub constructor
*
* @template W The child-node Wrapper class
*/
export type MsubConstructor<W extends AnyWrapper> = Constructor<CommonMsub<W>>;
/*****************************************************************/
/**
* The CommonMsub wrapper mixin for the MmlMsub object
*
* @template W The child-node Wrapper class
* @template T The Wrapper class constructor type
*/
export function CommonMsubMixin<
W extends AnyWrapper,
T extends ScriptbaseConstructor<W>
>(Base: T): MsubConstructor<W> & T {
return class extends Base {
/**
* Do not include italic correction
*/
public static useIC: boolean = false;
/**
* @override
*/
public get scriptChild() {
return this.childNodes[(this.node as MmlMsub).sub];
}
/**
* Get the shift for the subscript
*
* @override
*/
public getOffset() {
return [0, -this.getV()];
}
};
}
/*****************************************************************/
/**
* The CommonMsup interface
*
* @template W The child-node Wrapper class
*/
export interface CommonMsup<W extends AnyWrapper> extends CommonScriptbase<W> {
}
/**
* Shorthand for the CommonMsup constructor
*
* @template W The child-node Wrapper class
*/
export type MsupConstructor<W extends AnyWrapper> = Constructor<CommonMsup<W>>;
/*****************************************************************/
/**
* The CommonMsup wrapper mixin for the MmlMsup object
*
* @template W The child-node Wrapper class
* @template T The Wrapper class constructor type
*/
export function CommonMsupMixin<
W extends AnyWrapper,
T extends ScriptbaseConstructor<W>
>(Base: T): MsupConstructor<W> & T {
return class extends Base {
/**
* @override
*/
public get scriptChild() {
return this.childNodes[(this.node as MmlMsup).sup];
}
/**
* Get the shift for the superscript
*
* @override
*/
public getOffset() {
const x = this.getAdjustedIc() - (this.baseRemoveIc ? 0 : this.baseIc);
return [x, this.getU()];
}
};
}
/*****************************************************************/
/**
* The CommonMsubsup interface
*
* @template W The child-node Wrapper class
*/
export interface CommonMsubsup<W extends AnyWrapper> extends CommonScriptbase<W> {
/**
* Cached values for the script offsets and separation (so if they are
* computed in computeBBox(), they don't have to be recomputed during output)
*/
UVQ: number[];
/**
* The wrapper for the subscript
*/
readonly subChild: W;
/**
* The wrapper for the superscript
*/
readonly supChild: W;
/**
* Get the shift for the scripts and their separation (TeXBook Appendix G 18adef)
*
* @param {BBox} subbox The bounding box of the superscript
* @param {BBox} supbox The bounding box of the subscript
* @return {number[]} The vertical offsets for super and subscripts, and the space between them
*/
getUVQ(subbox?: BBox, supbox?: BBox): number[];
}
/**
* Shorthand for the CommonMsubsup constructor
*
* @template W The child-node Wrapper class
*/
export type MsubsupConstructor<W extends AnyWrapper> = Constructor<CommonMsubsup<W>>;
/*****************************************************************/
/**
* The CommomMsubsup wrapper for the MmlMsubsup object
*
* @template W The child-node Wrapper class
* @template T The Wrapper class constructor type
*/
export function CommonMsubsupMixin<
W extends AnyWrapper,
T extends ScriptbaseConstructor<W>
>(Base: T): MsubsupConstructor<W> & T {
return class extends Base {
/**
* Do not include italic correction
*/
public static useIC: boolean = false;
/**
* Cached values for the script offsets and separation (so if they are
* computed in computeBBox(), they don't have to be recomputed during output)
*/
public UVQ: number[] = null;
/**
* @return {W} The wrapper for the subscript
*/
public get subChild(): W {
return this.childNodes[(this.node as MmlMsubsup).sub];
}
/**
* @return {W} The wrapper for the superscript
*/
public get supChild(): W {
return this.childNodes[(this.node as MmlMsubsup).sup];
}
/**
* @override
*/
public computeBBox(bbox: BBox, recompute: boolean = false) {
const basebox = this.baseChild.getOuterBBox();
const [subbox, supbox] = [this.subChild.getOuterBBox(), this.supChild.getOuterBBox()];
bbox.empty();
bbox.append(basebox);
const w = this.getBaseWidth();
const x = this.getAdjustedIc();
const [u, v] = this.getUVQ();
bbox.combine(subbox, w, v);
bbox.combine(supbox, w + x, u);
bbox.w += this.font.params.scriptspace;
bbox.clean();
this.setChildPWidths(recompute);
}
/**
* Get the shift for the scripts and their separation (TeXBook Appendix G 18adef)
*
* @param {BBox} subbox The bounding box of the superscript
* @param {BBox} supbox The bounding box of the subscript
* @return {number[]} The vertical offsets for super and subscripts, and the space between them
*/
public getUVQ(
subbox: BBox = this.subChild.getOuterBBox(),
supbox: BBox = this.supChild.getOuterBBox()
): number[] {
const basebox = this.baseCore.getOuterBBox();
if (this.UVQ) return this.UVQ;
const tex = this.font.params;
const t = 3 * tex.rule_thickness;
const subscriptshift = this.length2em(this.node.attributes.get('subscriptshift'), tex.sub2);
const drop = this.baseCharZero(basebox.d * this.baseScale + tex.sub_drop * subbox.rscale);
//
// u and v are the veritcal shifts of the scripts, initially set to minimum values and then adjusted
//
let [u, v] = [this.getU(), Math.max(drop, subscriptshift)];
//
// q is the space currently between the super- and subscripts.
// If it is less than 3 rule thicknesses,
// increase the subscript offset to make the space 3 rule thicknesses
// If the bottom of the superscript is below 4/5 of the x-height
// raise both the super- and subscripts by the difference
// (make the bottom of the superscript be at 4/5 the x-height, and the
// subscript 3 rule thickness below that).
//
let q = (u - supbox.d * supbox.rscale) - (subbox.h * subbox.rscale - v);
if (q < t) {
v += t - q;
const p = (4 / 5) * tex.x_height - (u - supbox.d * supbox.rscale);
if (p > 0) {
u += p;
v -= p;
}
}
//
// Make sure the shifts are at least the minimum amounts and
// return the shifts and the space between the scripts
//
u = Math.max(this.length2em(this.node.attributes.get('superscriptshift'), u), u);
v = Math.max(this.length2em(this.node.attributes.get('subscriptshift'), v), v);
q = (u - supbox.d * supbox.rscale) - (subbox.h * subbox.rscale - v);
this.UVQ = [u, -v, q];
return this.UVQ;
}
};
}