svgedit/editor/svgtransformlist.js

383 lines
10 KiB
JavaScript

/**
* Partial polyfill of `SVGTransformList`
* @module SVGTransformList
*
* @license MIT
*
* @copyright 2010 Alexis Deveria, 2010 Jeff Schiller
*/
import {NS} from './namespaces.js';
import {supportsNativeTransformLists} from './browser.js';
const svgroot = document.createElementNS(NS.SVG, 'svg');
// Helper function.
function transformToString (xform) {
const m = xform.matrix;
let text = '';
switch (xform.type) {
case 1: // MATRIX
text = 'matrix(' + [m.a, m.b, m.c, m.d, m.e, m.f].join(',') + ')';
break;
case 2: // TRANSLATE
text = 'translate(' + m.e + ',' + m.f + ')';
break;
case 3: // SCALE
if (m.a === m.d) {
text = 'scale(' + m.a + ')';
} else {
text = 'scale(' + m.a + ',' + m.d + ')';
}
break;
case 4: { // ROTATE
let cx = 0;
let cy = 0;
// this prevents divide by zero
if (xform.angle !== 0) {
const K = 1 - m.a;
cy = (K * m.f + m.b * m.e) / (K * K + m.b * m.b);
cx = (m.e - m.b * cy) / K;
}
text = 'rotate(' + xform.angle + ' ' + cx + ',' + cy + ')';
break;
}
}
return text;
}
/**
* Map of SVGTransformList objects.
*/
let listMap_ = {};
/**
* @interface module:SVGTransformList.SVGEditTransformList
* @property {Integer} numberOfItems unsigned long
*/
/**
* @function module:SVGTransformList.SVGEditTransformList#clear
* @returns {undefined}
*/
/**
* @function module:SVGTransformList.SVGEditTransformList#initialize
* @param {SVGTransform} newItem
* @returns {SVGTransform}
*/
/**
* (DOES NOT THROW DOMException, INDEX_SIZE_ERR)
* @function module:SVGTransformList.SVGEditTransformList#getItem
* @param {Integer} index unsigned long
* @returns {SVGTransform}
*/
/**
* (DOES NOT THROW DOMException, INDEX_SIZE_ERR)
* @function module:SVGTransformList.SVGEditTransformList#insertItemBefore
* @param {SVGTransform} newItem
* @param {Integer} index unsigned long
* @returns {SVGTransform}
*/
/**
* (DOES NOT THROW DOMException, INDEX_SIZE_ERR)
* @function module:SVGTransformList.SVGEditTransformList#replaceItem
* @param {SVGTransform} newItem
* @param {Integer} index unsigned long
* @returns {SVGTransform}
*/
/**
* (DOES NOT THROW DOMException, INDEX_SIZE_ERR)
* @function module:SVGTransformList.SVGEditTransformList#removeItem
* @param {Integer} index unsigned long
* @returns {SVGTransform}
*/
/**
* @function module:SVGTransformList.SVGEditTransformList#appendItem
* @param {SVGTransform} newItem
* @returns {SVGTransform}
*/
/**
* NOT IMPLEMENTED
* @ignore
* @function module:SVGTransformList.SVGEditTransformList#createSVGTransformFromMatrix
* @param {SVGMatrix} matrix
* @returns {SVGTransform}
*/
/**
* NOT IMPLEMENTED
* @ignore
* @function module:SVGTransformList.SVGEditTransformList#consolidate
* @returns {SVGTransform}
*/
/**
* SVGTransformList implementation for Webkit.
* These methods do not currently raise any exceptions.
* These methods also do not check that transforms are being inserted. This is basically
* implementing as much of SVGTransformList that we need to get the job done.
*/
export class SVGTransformList {
/**
* @param {Element} elem
*/
constructor (elem) {
this._elem = elem || null;
this._xforms = [];
// TODO: how do we capture the undo-ability in the changed transform list?
this._update = function () {
let tstr = '';
// /* const concatMatrix = */ svgroot.createSVGMatrix();
for (let i = 0; i < this.numberOfItems; ++i) {
const xform = this._list.getItem(i);
tstr += transformToString(xform) + ' ';
}
this._elem.setAttribute('transform', tstr);
};
this._list = this;
this._init = function () {
// Transform attribute parser
let str = this._elem.getAttribute('transform');
if (!str) { return; }
// TODO: Add skew support in future
const re = /\s*((scale|matrix|rotate|translate)\s*\(.*?\))\s*,?\s*/;
let m = true;
while (m) {
m = str.match(re);
str = str.replace(re, '');
if (m && m[1]) {
const x = m[1];
const bits = x.split(/\s*\(/);
const name = bits[0];
const valBits = bits[1].match(/\s*(.*?)\s*\)/);
valBits[1] = valBits[1].replace(/(\d)-/g, '$1 -');
const valArr = valBits[1].split(/[, ]+/);
const letters = 'abcdef'.split('');
const mtx = svgroot.createSVGMatrix();
Object.values(valArr).forEach(function (item, i) {
valArr[i] = parseFloat(item);
if (name === 'matrix') {
mtx[letters[i]] = valArr[i];
}
});
const xform = svgroot.createSVGTransform();
const fname = 'set' + name.charAt(0).toUpperCase() + name.slice(1);
const values = name === 'matrix' ? [mtx] : valArr;
if (name === 'scale' && values.length === 1) {
values.push(values[0]);
} else if (name === 'translate' && values.length === 1) {
values.push(0);
} else if (name === 'rotate' && values.length === 1) {
values.push(0, 0);
}
xform[fname].apply(xform, values);
this._list.appendItem(xform);
}
}
};
this._removeFromOtherLists = function (item) {
if (item) {
// Check if this transform is already in a transformlist, and
// remove it if so.
let found = false;
for (const id in listMap_) {
const tl = listMap_[id];
for (let i = 0, len = tl._xforms.length; i < len; ++i) {
if (tl._xforms[i] === item) {
found = true;
tl.removeItem(i);
break;
}
}
if (found) {
break;
}
}
}
};
this.numberOfItems = 0;
}
/**
* @returns {undefined}
*/
clear () {
this.numberOfItems = 0;
this._xforms = [];
}
/**
* @param {SVGTransform} newItem
* @returns {SVGTransform}
*/
initialize (newItem) {
this.numberOfItems = 1;
this._removeFromOtherLists(newItem);
this._xforms = [newItem];
}
/**
* @param {Integer} index unsigned long
* @throws {Error}
* @returns {SVGTransform}
*/
getItem (index) {
if (index < this.numberOfItems && index >= 0) {
return this._xforms[index];
}
const err = new Error('DOMException with code=INDEX_SIZE_ERR');
err.code = 1;
throw err;
}
/**
* @param {SVGTransform} newItem
* @param {Integer} index unsigned long
* @returns {SVGTransform}
*/
insertItemBefore (newItem, index) {
let retValue = null;
if (index >= 0) {
if (index < this.numberOfItems) {
this._removeFromOtherLists(newItem);
const newxforms = new Array(this.numberOfItems + 1);
// TODO: use array copying and slicing
let i;
for (i = 0; i < index; ++i) {
newxforms[i] = this._xforms[i];
}
newxforms[i] = newItem;
for (let j = i + 1; i < this.numberOfItems; ++j, ++i) {
newxforms[j] = this._xforms[i];
}
this.numberOfItems++;
this._xforms = newxforms;
retValue = newItem;
this._list._update();
} else {
retValue = this._list.appendItem(newItem);
}
}
return retValue;
}
/**
* @param {SVGTransform} newItem
* @param {Integer} index unsigned long
* @returns {SVGTransform}
*/
replaceItem (newItem, index) {
let retValue = null;
if (index < this.numberOfItems && index >= 0) {
this._removeFromOtherLists(newItem);
this._xforms[index] = newItem;
retValue = newItem;
this._list._update();
}
return retValue;
}
/**
* @param {Integer} index unsigned long
* @throws {Error}
* @returns {SVGTransform}
*/
removeItem (index) {
if (index < this.numberOfItems && index >= 0) {
const retValue = this._xforms[index];
const newxforms = new Array(this.numberOfItems - 1);
let i;
for (i = 0; i < index; ++i) {
newxforms[i] = this._xforms[i];
}
for (let j = i; j < this.numberOfItems - 1; ++j, ++i) {
newxforms[j] = this._xforms[i + 1];
}
this.numberOfItems--;
this._xforms = newxforms;
this._list._update();
return retValue;
}
const err = new Error('DOMException with code=INDEX_SIZE_ERR');
err.code = 1;
throw err;
}
/**
* @param {SVGTransform} newItem
* @returns {SVGTransform}
*/
appendItem (newItem) {
this._removeFromOtherLists(newItem);
this._xforms.push(newItem);
this.numberOfItems++;
this._list._update();
return newItem;
}
}
/**
* @function module:SVGTransformList.resetListMap
* @returns {undefined}
*/
export const resetListMap = function () {
listMap_ = {};
};
/**
* Removes transforms of the given element from the map.
* @function module:SVGTransformList.removeElementFromListMap
* @param {Element} elem - a DOM Element
* @returns {undefined}
*/
export let removeElementFromListMap = function (elem) {
if (elem.id && listMap_[elem.id]) {
delete listMap_[elem.id];
}
};
/**
* Returns an object that behaves like a `SVGTransformList` for the given DOM element.
* @function module:SVGTransformList.getTransformList
* @param {Element} elem - DOM element to get a transformlist from
* @todo The polyfill should have `SVGAnimatedTransformList` and this should use it
* @returns {SVGAnimatedTransformList|SVGTransformList}
*/
export const getTransformList = function (elem) {
if (!supportsNativeTransformLists()) {
const id = elem.id || 'temp';
let t = listMap_[id];
if (!t || id === 'temp') {
listMap_[id] = new SVGTransformList(elem);
listMap_[id]._init();
t = listMap_[id];
}
return t;
}
if (elem.transform) {
return elem.transform.baseVal;
}
if (elem.gradientTransform) {
return elem.gradientTransform.baseVal;
}
if (elem.patternTransform) {
return elem.patternTransform.baseVal;
}
return null;
};
/**
* @callback module:SVGTransformList.removeElementFromListMap
* @param {Element} elem
*/
/**
* Replace `removeElementFromListMap` for unit-testing.
* @function module:SVGTransformList.changeRemoveElementFromListMap
* @param {module:SVGTransformList.removeElementFromListMap} cb Passed a single argument `elem`
* @returns {undefined}
*/
export const changeRemoveElementFromListMap = function (cb) {
removeElementFromListMap = cb;
};