epiphany/node_modules/svgo/plugins/removeHiddenElems.js
2023-12-09 22:48:07 -08:00

396 lines
11 KiB
JavaScript

'use strict';
/**
* @typedef {import('../lib/types').XastChild} XastChild
* @typedef {import('../lib/types').XastElement} XastElement
* @typedef {import('../lib/types').XastParent} XastParent
*/
const { elemsGroups, referencesProps } = require('./_collections.js');
const {
visit,
visitSkip,
querySelector,
detachNodeFromParent,
} = require('../lib/xast.js');
const { collectStylesheet, computeStyle } = require('../lib/style.js');
const { parsePathData } = require('../lib/path.js');
const nonRendering = elemsGroups.nonRendering;
exports.name = 'removeHiddenElems';
exports.description =
'removes hidden elements (zero sized, with absent attributes)';
/**
* Remove hidden elements with disabled rendering:
* - display="none"
* - opacity="0"
* - circle with zero radius
* - ellipse with zero x-axis or y-axis radius
* - rectangle with zero width or height
* - pattern with zero width or height
* - image with zero width or height
* - path with empty data
* - polyline with empty points
* - polygon with empty points
*
* @author Kir Belevich
*
* @type {import('./plugins-types').Plugin<'removeHiddenElems'>}
*/
exports.fn = (root, params) => {
const {
isHidden = true,
displayNone = true,
opacity0 = true,
circleR0 = true,
ellipseRX0 = true,
ellipseRY0 = true,
rectWidth0 = true,
rectHeight0 = true,
patternWidth0 = true,
patternHeight0 = true,
imageWidth0 = true,
imageHeight0 = true,
pathEmptyD = true,
polylineEmptyPoints = true,
polygonEmptyPoints = true,
} = params;
const stylesheet = collectStylesheet(root);
/**
* Skip non-rendered nodes initially, and only detach if they have no ID, or
* their ID is not referenced by another node.
*
* @type {Map<XastElement, XastParent>}
*/
const nonRenderedNodes = new Map();
/**
* IDs for removed hidden definitions.
*
* @type {Set<string>}
*/
const removedDefIds = new Set();
/**
* @param {XastChild} node
* @param {XastParent} parentNode
*/
function removeElement(node, parentNode) {
if (
node.type === 'element' &&
node.attributes.id != null &&
parentNode.type === 'element' &&
parentNode.name === 'defs'
) {
removedDefIds.add(node.attributes.id);
}
detachNodeFromParent(node, parentNode);
}
visit(root, {
element: {
enter: (node, parentNode) => {
// transparent non-rendering elements still apply where referenced
if (nonRendering.includes(node.name)) {
if (node.attributes.id == null) {
detachNodeFromParent(node, parentNode);
return visitSkip;
}
nonRenderedNodes.set(node, parentNode);
return visitSkip;
}
const computedStyle = computeStyle(stylesheet, node);
// opacity="0"
//
// https://www.w3.org/TR/SVG11/masking.html#ObjectAndGroupOpacityProperties
if (
opacity0 &&
computedStyle.opacity &&
computedStyle.opacity.type === 'static' &&
computedStyle.opacity.value === '0'
) {
removeElement(node, parentNode);
}
},
},
});
return {
element: {
enter: (node, parentNode) => {
// Removes hidden elements
// https://www.w3schools.com/cssref/pr_class_visibility.asp
const computedStyle = computeStyle(stylesheet, node);
if (
isHidden &&
computedStyle.visibility &&
computedStyle.visibility.type === 'static' &&
computedStyle.visibility.value === 'hidden' &&
// keep if any descendant enables visibility
querySelector(node, '[visibility=visible]') == null
) {
removeElement(node, parentNode);
return;
}
// display="none"
//
// https://www.w3.org/TR/SVG11/painting.html#DisplayProperty
// "A value of display: none indicates that the given element
// and its children shall not be rendered directly"
if (
displayNone &&
computedStyle.display &&
computedStyle.display.type === 'static' &&
computedStyle.display.value === 'none' &&
// markers with display: none still rendered
node.name !== 'marker'
) {
removeElement(node, parentNode);
return;
}
// Circles with zero radius
//
// https://www.w3.org/TR/SVG11/shapes.html#CircleElementRAttribute
// "A value of zero disables rendering of the element"
//
// <circle r="0">
if (
circleR0 &&
node.name === 'circle' &&
node.children.length === 0 &&
node.attributes.r === '0'
) {
removeElement(node, parentNode);
return;
}
// Ellipse with zero x-axis radius
//
// https://www.w3.org/TR/SVG11/shapes.html#EllipseElementRXAttribute
// "A value of zero disables rendering of the element"
//
// <ellipse rx="0">
if (
ellipseRX0 &&
node.name === 'ellipse' &&
node.children.length === 0 &&
node.attributes.rx === '0'
) {
removeElement(node, parentNode);
return;
}
// Ellipse with zero y-axis radius
//
// https://www.w3.org/TR/SVG11/shapes.html#EllipseElementRYAttribute
// "A value of zero disables rendering of the element"
//
// <ellipse ry="0">
if (
ellipseRY0 &&
node.name === 'ellipse' &&
node.children.length === 0 &&
node.attributes.ry === '0'
) {
removeElement(node, parentNode);
return;
}
// Rectangle with zero width
//
// https://www.w3.org/TR/SVG11/shapes.html#RectElementWidthAttribute
// "A value of zero disables rendering of the element"
//
// <rect width="0">
if (
rectWidth0 &&
node.name === 'rect' &&
node.children.length === 0 &&
node.attributes.width === '0'
) {
removeElement(node, parentNode);
return;
}
// Rectangle with zero height
//
// https://www.w3.org/TR/SVG11/shapes.html#RectElementHeightAttribute
// "A value of zero disables rendering of the element"
//
// <rect height="0">
if (
rectHeight0 &&
rectWidth0 &&
node.name === 'rect' &&
node.children.length === 0 &&
node.attributes.height === '0'
) {
removeElement(node, parentNode);
return;
}
// Pattern with zero width
//
// https://www.w3.org/TR/SVG11/pservers.html#PatternElementWidthAttribute
// "A value of zero disables rendering of the element (i.e., no paint is applied)"
//
// <pattern width="0">
if (
patternWidth0 &&
node.name === 'pattern' &&
node.attributes.width === '0'
) {
removeElement(node, parentNode);
return;
}
// Pattern with zero height
//
// https://www.w3.org/TR/SVG11/pservers.html#PatternElementHeightAttribute
// "A value of zero disables rendering of the element (i.e., no paint is applied)"
//
// <pattern height="0">
if (
patternHeight0 &&
node.name === 'pattern' &&
node.attributes.height === '0'
) {
removeElement(node, parentNode);
return;
}
// Image with zero width
//
// https://www.w3.org/TR/SVG11/struct.html#ImageElementWidthAttribute
// "A value of zero disables rendering of the element"
//
// <image width="0">
if (
imageWidth0 &&
node.name === 'image' &&
node.attributes.width === '0'
) {
removeElement(node, parentNode);
return;
}
// Image with zero height
//
// https://www.w3.org/TR/SVG11/struct.html#ImageElementHeightAttribute
// "A value of zero disables rendering of the element"
//
// <image height="0">
if (
imageHeight0 &&
node.name === 'image' &&
node.attributes.height === '0'
) {
removeElement(node, parentNode);
return;
}
// Path with empty data
//
// https://www.w3.org/TR/SVG11/paths.html#DAttribute
//
// <path d=""/>
if (pathEmptyD && node.name === 'path') {
if (node.attributes.d == null) {
removeElement(node, parentNode);
return;
}
const pathData = parsePathData(node.attributes.d);
if (pathData.length === 0) {
removeElement(node, parentNode);
return;
}
// keep single point paths for markers
if (
pathData.length === 1 &&
computedStyle['marker-start'] == null &&
computedStyle['marker-end'] == null
) {
removeElement(node, parentNode);
return;
}
return;
}
// Polyline with empty points
//
// https://www.w3.org/TR/SVG11/shapes.html#PolylineElementPointsAttribute
//
// <polyline points="">
if (
polylineEmptyPoints &&
node.name === 'polyline' &&
node.attributes.points == null
) {
removeElement(node, parentNode);
return;
}
// Polygon with empty points
//
// https://www.w3.org/TR/SVG11/shapes.html#PolygonElementPointsAttribute
//
// <polygon points="">
if (
polygonEmptyPoints &&
node.name === 'polygon' &&
node.attributes.points == null
) {
removeElement(node, parentNode);
}
},
exit: (node, parentNode) => {
if (node.name === 'defs' && node.children.length === 0) {
removeElement(node, parentNode);
return;
}
if (node.name === 'use') {
const referencesRemovedDef = Object.entries(node.attributes).some(
([attrKey, attrValue]) =>
(attrKey === 'href' || attrKey.endsWith(':href')) &&
removedDefIds.has(
attrValue.slice(attrValue.indexOf('#') + 1).trim()
)
);
if (referencesRemovedDef) {
detachNodeFromParent(node, parentNode);
}
return;
}
if (node.name === 'svg' && parentNode.type === 'root') {
for (const [
nonRenderedNode,
nonRenderedParent,
] of nonRenderedNodes.entries()) {
const selector = referencesProps
.map(
(attr) => `[${attr}="url(#${nonRenderedNode.attributes.id})"]`
)
.join(',');
const element = querySelector(root, selector);
if (element == null) {
detachNodeFromParent(node, nonRenderedParent);
}
}
}
},
},
};
};