f63af87f17
Summary: Add comments everywhere! Also fix some small bugs like using Style.id instead of Style.size, and rename some variables to be more descriptive. Fixes #22 Test Plan: - Make sure the huxley screenshots didn't change - Make sure the tests still pass Reviewers: alpert Reviewed By: alpert Differential Revision: http://phabricator.khanacademy.org/D13158
127 lines
3.1 KiB
JavaScript
127 lines
3.1 KiB
JavaScript
/**
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* This file contains information and classes for the various kinds of styles
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* used in TeX. It provides a generic `Style` class, which holds information
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* about a specific style. It then provides instances of all the different kinds
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* of styles possible, and provides functions to move between them and get
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* information about them.
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*/
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/**
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* The main style class. Contains a unique id for the style, a size (which is
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* the same for cramped and uncramped version of a style), a cramped flag, and a
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* size multiplier, which gives the size difference between a style and
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* textstyle.
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*/
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function Style(id, size, multiplier, cramped) {
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this.id = id;
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this.size = size;
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this.cramped = cramped;
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this.sizeMultiplier = multiplier;
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}
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/**
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* Get the style of a superscript given a base in the current style.
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*/
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Style.prototype.sup = function() {
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return styles[sup[this.id]];
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};
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/**
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* Get the style of a subscript given a base in the current style.
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*/
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Style.prototype.sub = function() {
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return styles[sub[this.id]];
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};
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/**
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* Get the style of a fraction numerator given the fraction in the current
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* style.
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*/
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Style.prototype.fracNum = function() {
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return styles[fracNum[this.id]];
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};
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/**
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* Get the style of a fraction denominator given the fraction in the current
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* style.
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*/
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Style.prototype.fracDen = function() {
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return styles[fracDen[this.id]];
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};
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/**
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* Get the cramped version of a style (in particular, cramping a cramped style
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* doesn't change the style).
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*/
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Style.prototype.cramp = function() {
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return styles[cramp[this.id]];
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};
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/**
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* HTML class name, like "displaystyle cramped"
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*/
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Style.prototype.cls = function() {
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return sizeNames[this.size] + (this.cramped ? " cramped" : " uncramped");
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};
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/**
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* HTML Reset class name, like "reset-textstyle"
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*/
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Style.prototype.reset = function() {
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return resetNames[this.size];
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};
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// IDs of the different styles
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var D = 0;
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var Dc = 1;
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var T = 2;
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var Tc = 3;
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var S = 4;
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var Sc = 5;
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var SS = 6;
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var SSc = 7;
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// String names for the different sizes
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var sizeNames = [
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"displaystyle textstyle",
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"textstyle",
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"scriptstyle",
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"scriptscriptstyle"
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];
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// Reset names for the different sizes
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var resetNames = [
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"reset-textstyle",
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"reset-textstyle",
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"reset-scriptstyle",
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"reset-scriptscriptstyle",
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];
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// Instances of the different styles
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var styles = [
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new Style(D, 0, 1.0, false),
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new Style(Dc, 0, 1.0, true),
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new Style(T, 1, 1.0, false),
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new Style(Tc, 1, 1.0, true),
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new Style(S, 2, 0.7, false),
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new Style(Sc, 2, 0.7, true),
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new Style(SS, 3, 0.5, false),
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new Style(SSc, 3, 0.5, true)
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];
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// Lookup tables for switching from one style to another
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var sup = [S, Sc, S, Sc, SS, SSc, SS, SSc];
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var sub = [Sc, Sc, Sc, Sc, SSc, SSc, SSc, SSc];
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var fracNum = [T, Tc, S, Sc, SS, SSc, SS, SSc];
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var fracDen = [Tc, Tc, Sc, Sc, SSc, SSc, SSc, SSc];
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var cramp = [Dc, Dc, Tc, Tc, Sc, Sc, SSc, SSc];
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// We only export some of the styles. Also, we don't export the `Style` class so
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// no more styles can be generated.
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module.exports = {
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DISPLAY: styles[D],
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TEXT: styles[T],
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SCRIPT: styles[S],
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SCRIPTSCRIPT: styles[SS]
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};
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