/*************************************************************
*
* Copyright (c) 2018-2022 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 a lite CssStyleDeclaration replacement
* (very limited in scope)
*
* @author dpvc@mathjax.org (Davide Cervone)
*/
/**
* An object contining name: value pairs
*/
export type StyleList = {[name: string]: string};
/**
* Data for how to map a combined style (like border) to its children
*/
export type connection = {
children: string[], // suffix names to add to the base name
split: (name: string) => void, // function to split the value for the children
combine: (name: string) => void // function to combine the child values when one changes
};
/**
* A collection of connections
*/
export type connections = {[name: string]: connection};
/*********************************************************/
/**
* Some common children arrays
*/
const TRBL = ['top', 'right', 'bottom', 'left'];
const WSC = ['width', 'style', 'color'];
/**
* Split a style at spaces (taking quotation marks and commas into account)
*
* @param {string} text The combined styles to be split at spaces
* @return {string[]} Array of parts of the style (separated by spaces)
*/
function splitSpaces(text: string): string[] {
const parts = text.split(/((?:'[^']*'|"[^"]*"|,[\s\n]|[^\s\n])*)/g);
const split = [] as string[];
while (parts.length > 1) {
parts.shift();
split.push(parts.shift());
}
return split;
}
/*********************************************************/
/**
* Split a top-right-bottom-left group into its parts
* Format:
* x all are the same value
* x y same as x y x y
* x y z same as x y z y
* x y z w each specified
*
* @param {string} name The style to be processed
*/
function splitTRBL(name: string) {
const parts = splitSpaces(this.styles[name]);
if (parts.length === 0) {
parts.push('');
}
if (parts.length === 1) {
parts.push(parts[0]);
}
if (parts.length === 2) {
parts.push(parts[0]);
}
if (parts.length === 3) {
parts.push(parts[1]);
}
for (const child of Styles.connect[name].children) {
this.setStyle(this.childName(name, child), parts.shift());
}
}
/**
* Combine top-right-bottom-left into one entry
* (removing unneeded values)
*
* @param {string} name The style to be processed
*/
function combineTRBL(name: string) {
const children = Styles.connect[name].children;
const parts = [] as string[];
for (const child of children) {
const part = this.styles[name + '-' + child];
if (!part) {
delete this.styles[name];
return;
}
parts.push(part);
}
if (parts[3] === parts[1]) {
parts.pop();
if (parts[2] === parts[0]) {
parts.pop();
if (parts[1] === parts[0]) {
parts.pop();
}
}
}
this.styles[name] = parts.join(' ');
}
/*********************************************************/
/**
* Use the same value for all children
*
* @param {string} name The style to be processed
*/
function splitSame(name: string) {
for (const child of Styles.connect[name].children) {
this.setStyle(this.childName(name, child), this.styles[name]);
}
}
/**
* Check that all children have the same values and
* if so, set the parent to that value
*
* @param {string} name The style to be processed
*/
function combineSame(name: string) {
const children = [...Styles.connect[name].children];
const value = this.styles[this.childName(name, children.shift())];
for (const child of children) {
if (this.styles[this.childName(name, child)] !== value) {
delete this.styles[name];
return;
}
}
this.styles[name] = value;
}
/*********************************************************/
/**
* Patterns for the parts of a boarder
*/
const BORDER: {[name: string]: RegExp} = {
width: /^(?:[\d.]+(?:[a-z]+)|thin|medium|thick|inherit|initial|unset)$/,
style: /^(?:none|hidden|dotted|dashed|solid|double|groove|ridge|inset|outset|inherit|initial|unset)$/
};
/**
* Split a width-style-color border definition
*
* @param {string} name The style to be processed
*/
function splitWSC(name: string) {
let parts = {width: '', style: '', color: ''} as StyleList;
for (const part of splitSpaces(this.styles[name])) {
if (part.match(BORDER.width) && parts.width === '') {
parts.width = part;
} else if (part.match(BORDER.style) && parts.style === '') {
parts.style = part;
} else {
parts.color = part;
}
}
for (const child of Styles.connect[name].children) {
this.setStyle(this.childName(name, child), parts[child]);
}
}
/**
* Combine with-style-color border definition from children
*
* @param {string} name The style to be processed
*/
function combineWSC(name: string) {
const parts = [] as string[];
for (const child of Styles.connect[name].children) {
const value = this.styles[this.childName(name, child)];
if (value) {
parts.push(value);
}
}
if (parts.length) {
this.styles[name] = parts.join(' ');
} else {
delete this.styles[name];
}
}
/*********************************************************/
/**
* Patterns for the parts of a font declaration
*/
const FONT: {[name: string]: RegExp} = {
style: /^(?:normal|italic|oblique|inherit|initial|unset)$/,
variant: new RegExp('^(?:' +
['normal|none',
'inherit|initial|unset',
'common-ligatures|no-common-ligatures',
'discretionary-ligatures|no-discretionary-ligatures',
'historical-ligatures|no-historical-ligatures',
'contextual|no-contextual',
'(?:stylistic|character-variant|swash|ornaments|annotation)\\([^)]*\\)',
'small-caps|all-small-caps|petite-caps|all-petite-caps|unicase|titling-caps',
'lining-nums|oldstyle-nums|proportional-nums|tabular-nums',
'diagonal-fractions|stacked-fractions',
'ordinal|slashed-zero',
'jis78|jis83|jis90|jis04|simplified|traditional',
'full-width|proportional-width',
'ruby'].join('|') + ')$'),
weight: /^(?:normal|bold|bolder|lighter|[1-9]00|inherit|initial|unset)$/,
stretch: new RegExp('^(?:' +
['normal',
'(?:(?:ultra|extra|semi)-)?condensed',
'(?:(?:semi|extra|ulta)-)?expanded',
'inherit|initial|unset']. join('|') + ')$'),
size: new RegExp('^(?:' +
['xx-small|x-small|small|medium|large|x-large|xx-large|larger|smaller',
'[\d.]+%|[\d.]+[a-z]+',
'inherit|initial|unset'].join('|') + ')' +
'(?:\/(?:normal|[\d.\+](?:%|[a-z]+)?))?$')
};
/**
* Split a font declaration into is parts (not perfect but good enough for now)
*
* @param {string} name The style to be processed
*/
function splitFont(name: string) {
const parts = splitSpaces(this.styles[name]);
//
// The parts found (array means can be more than one word)
//
const value = {
style: '', variant: [], weight: '', stretch: '',
size: '', family: '', 'line-height': ''
} as {[name: string]: string | string[]};
for (const part of parts) {
value.family = part; // assume it is family unless otherwise (family must be present)
for (const name of Object.keys(FONT)) {
if ((Array.isArray(value[name]) || value[name] === '') && part.match(FONT[name])) {
if (name === 'size') {
//
// Handle size/line-height
//
const [size, height] = part.split(/\//);
value[name] = size;
if (height) {
value['line-height'] = height;
}
} else if (value.size === '') {
//
// style, weight, variant, stretch must appear before size
//
if (Array.isArray(value[name])) {
(value[name] as string[]).push(part);
} else {
value[name] = part;
}
}
}
}
}
saveFontParts(name, value);
delete this.styles[name]; // only use the parts, not the font declaration itself
}
/**
* @param {string} name The style to be processed
* @param {{[name: string]: string | string[]}} value The list of parts detected above
*/
function saveFontParts(name: string, value: {[name: string]: string | string[]}) {
for (const child of Styles.connect[name].children) {
const cname = this.childName(name, child);
if (Array.isArray(value[child])) {
const values = value[child] as string[];
if (values.length) {
this.styles[cname] = values.join(' ');
}
} else if (value[child] !== '') {
this.styles[cname] = value[child];
}
}
}
/**
* Combine font parts into one (we don't actually do that)
*/
function combineFont(_name: string) {}
/*********************************************************/
/**
* Implements the Styles object (lite version of CssStyleDeclaration)
*/
export class Styles {
/**
* Patterns for style values and comments
*/
public static pattern: {[name: string]: RegExp} = {
style: /([-a-z]+)[\s\n]*:[\s\n]*((?:'[^']*'|"[^"]*"|\n|.)*?)[\s\n]*(?:;|$)/g,
comment: /\/\*[^]*?\*\//g
};
/**
* The mapping of parents to children, and how to split and combine them
*/
public static connect: connections = {
padding: {
children: TRBL,
split: splitTRBL,
combine: combineTRBL
},
border: {
children: TRBL,
split: splitSame,
combine: combineSame
},
'border-top': {
children: WSC,
split: splitWSC,
combine: combineWSC
},
'border-right': {
children: WSC,
split: splitWSC,
combine: combineWSC
},
'border-bottom': {
children: WSC,
split: splitWSC,
combine: combineWSC
},
'border-left': {
children: WSC,
split: splitWSC,
combine: combineWSC
},
'border-width': {
children: TRBL,
split: splitTRBL,
combine: null // means its children combine to a different parent
},
'border-style': {
children: TRBL,
split: splitTRBL,
combine: null // means its children combine to a different parent
},
'border-color': {
children: TRBL,
split: splitTRBL,
combine: null // means its children combine to a different parent
},
font: {
children: ['style', 'variant', 'weight', 'stretch', 'line-height', 'size', 'family'],
split: splitFont,
combine: combineFont
}
};
/**
* The list of styles defined for this declaration
*/
protected styles: StyleList;
/**
* @param {string} cssText The initial definition for the style
* @constructor
*/
constructor(cssText: string = '') {
this.parse(cssText);
}
/**
* @return {string} The CSS string for the styles currently defined
*/
public get cssText(): string {
const styles = [] as string[];
for (const name of Object.keys(this.styles)) {
const parent = this.parentName(name);
if (!this.styles[parent]) {
styles.push(name + ': ' + this.styles[name] + ';');
}
}
return styles.join(' ');
}
/**
* @param {string} name The name of the style to set
* @param {string|number|boolean} value The value to set it to
*/
public set(name: string, value: string | number | boolean) {
name = this.normalizeName(name);
this.setStyle(name, value as string);
//
// If there is no combine function ,the children combine to
// a separate parent (e.g., border-width sets border-top-width, etc.
// and combines to border-top)
//
if (Styles.connect[name] && !Styles.connect[name].combine) {
this.combineChildren(name);
delete this.styles[name];
}
//
// If we just changed a child, we need to try to combine
// it with its parent's other children
//
while (name.match(/-/)) {
name = this.parentName(name);
if (!Styles.connect[name]) break;
Styles.connect[name].combine.call(this, name);
}
}
/**
* @param {string} name The name of the style to get
* @return {string} The value of the style (or empty string if not defined)
*/
public get(name: string): string {
name = this.normalizeName(name);
return (this.styles.hasOwnProperty(name) ? this.styles[name] : '');
}
/**
* @param {string} name The name of the style to set (without causing parent updates)
* @param {string} value The value to set it to
*/
protected setStyle(name: string, value: string) {
this.styles[name] = value;
if (Styles.connect[name] && Styles.connect[name].children) {
Styles.connect[name].split.call(this, name);
}
if (value === '') {
delete this.styles[name];
}
}
/**
* @param {string} name The name of the style whose parent is to be combined
*/
protected combineChildren(name: string) {
const parent = this.parentName(name);
for (const child of Styles.connect[name].children) {
const cname = this.childName(parent, child);
Styles.connect[cname].combine.call(this, cname);
}
}
/**
* @param {string} name The name of the style whose parent style is to be found
* @return {string} The name of the parent, or '' if none
*/
protected parentName(name: string): string {
const parent = name.replace(/-[^-]*$/, '');
return (name === parent ? '' : parent);
}
/**
* @param {string} name The name of the parent style
* @param {string} child The suffix to be added to the parent
* @preturn {string} The combined name
*/
protected childName(name: string, child: string) {
//
// If the child contains a dash, it is already the fill name
//
if (child.match(/-/)) {
return child;
}
//
// For non-combining styles, like border-width, insert
// the child name before the find word, e.g., border-top-width
//
if (Styles.connect[name] && !Styles.connect[name].combine) {
child += name.replace(/.*-/, '-');
name = this.parentName(name);
}
return name + '-' + child;
}
/**
* @param {string} name The name of a style to normalize
* @return {string} The name converted from CamelCase to lowercase with dashes
*/
protected normalizeName(name: string): string {
return name.replace(/[A-Z]/g, c => '-' + c.toLowerCase());
}
/**
* @param {string} cssText A style text string to be parsed into separate styles
* (by using this.set(), we get all the sub-styles created
* as well as the merged style shorthands)
*/
protected parse(cssText: string = '') {
let PATTERN = (this.constructor as typeof Styles).pattern;
this.styles = {};
const parts = cssText.replace(PATTERN.comment, '').split(PATTERN.style);
while (parts.length > 1) {
let [space, name, value] = parts.splice(0, 3);
if (space.match(/[^\s\n]/)) return;
this.set(name, value);
}
}
}