svgedit/editor/recalculate.js

/* eslint-disable no-var, no-redeclare */
/* globals $, getRefElem */
/**
 * Recalculate.
 *
 * Licensed under the MIT License
 *
 */

// Dependencies:
// 1) jquery
// 2) jquery-svg.js
// 3) svgedit.js
// 4) pathseg.js
// 5) browser.js
// 6) math.js
// 7) history.js
// 8) units.js
// 9) svgtransformlist.js
// 10) svgutils.js
// 11) coords.js

var svgedit = svgedit || {}; // eslint-disable-line no-use-before-define

(function () {
if (!svgedit.recalculate) {
	svgedit.recalculate = {};
}

var NS = svgedit.NS;
var context_;

// Function: svgedit.recalculate.init
svgedit.recalculate.init = function (editorContext) {
	context_ = editorContext;
};

// Function: svgedit.recalculate.updateClipPath
// Updates a <clipPath>s values based on the given translation of an element
//
// Parameters:
// attr - The clip-path attribute value with the clipPath's ID
// tx - The translation's x value
// ty - The translation's y value
svgedit.recalculate.updateClipPath = function (attr, tx, ty) {
	var path = getRefElem(attr).firstChild;
	var cpXform = svgedit.transformlist.getTransformList(path);
	var newxlate = context_.getSVGRoot().createSVGTransform();
	newxlate.setTranslate(tx, ty);

	cpXform.appendItem(newxlate);

	// Update clipPath's dimensions
	svgedit.recalculate.recalculateDimensions(path);
};

// Function: svgedit.recalculate.recalculateDimensions
// Decides the course of action based on the element's transform list
//
// Parameters:
// selected - The DOM element to recalculate
//
// Returns:
// Undo command object with the resulting change
svgedit.recalculate.recalculateDimensions = function (selected) {
	if (selected == null) { return null; }

	// Firefox Issue - 1081
	if (selected.nodeName === 'svg' && navigator.userAgent.indexOf('Firefox/20') >= 0) {
		return null;
	}

	var svgroot = context_.getSVGRoot();
	var tlist = svgedit.transformlist.getTransformList(selected);
	var k;
	// remove any unnecessary transforms
	if (tlist && tlist.numberOfItems > 0) {
		k = tlist.numberOfItems;
		var noi = k;
		while (k--) {
			var xform = tlist.getItem(k);
			if (xform.type === 0) {
				tlist.removeItem(k);
			// remove identity matrices
			} else if (xform.type === 1) {
				if (svgedit.math.isIdentity(xform.matrix)) {
					if (noi === 1) {
						// Overcome Chrome bug (though only when noi is 1) with
						//    `removeItem` preventing `removeAttribute` from
						//    subsequently working
						// See https://bugs.chromium.org/p/chromium/issues/detail?id=843901
						selected.removeAttribute('transform');
						return null;
					}
					tlist.removeItem(k);
				}
			// remove zero-degree rotations
			} else if (xform.type === 4) {
				if (xform.angle === 0) {
					tlist.removeItem(k);
				}
			}
		}
		// End here if all it has is a rotation
		if (tlist.numberOfItems === 1 &&
				svgedit.utilities.getRotationAngle(selected)) { return null; }
	}

	// if this element had no transforms, we are done
	if (!tlist || tlist.numberOfItems === 0) {
		// Chrome apparently had a bug that requires clearing the attribute first.
		selected.setAttribute('transform', '');
		// However, this still next line currently doesn't work at all in Chrome
		selected.removeAttribute('transform');
		// selected.transform.baseVal.clear(); // Didn't help for Chrome bug
		return null;
	}

	// TODO: Make this work for more than 2
	if (tlist) {
		k = tlist.numberOfItems;
		var mxs = [];
		while (k--) {
			var xform = tlist.getItem(k);
			if (xform.type === 1) {
				mxs.push([xform.matrix, k]);
			} else if (mxs.length) {
				mxs = [];
			}
		}
		if (mxs.length === 2) {
			var mNew = svgroot.createSVGTransformFromMatrix(svgedit.math.matrixMultiply(mxs[1][0], mxs[0][0]));
			tlist.removeItem(mxs[0][1]);
			tlist.removeItem(mxs[1][1]);
			tlist.insertItemBefore(mNew, mxs[1][1]);
		}

		// combine matrix + translate
		k = tlist.numberOfItems;
		if (k >= 2 && tlist.getItem(k - 2).type === 1 && tlist.getItem(k - 1).type === 2) {
			var mt = svgroot.createSVGTransform();

			var m = svgedit.math.matrixMultiply(
				tlist.getItem(k - 2).matrix,
				tlist.getItem(k - 1).matrix);
			mt.setMatrix(m);
			tlist.removeItem(k - 2);
			tlist.removeItem(k - 2);
			tlist.appendItem(mt);
		}
	}

	// If it still has a single [M] or [R][M], return null too (prevents BatchCommand from being returned).
	switch (selected.tagName) {
	// Ignore these elements, as they can absorb the [M]
	case 'line':
	case 'polyline':
	case 'polygon':
	case 'path':
		break;
	default:
		if ((tlist.numberOfItems === 1 && tlist.getItem(0).type === 1) ||
				(tlist.numberOfItems === 2 && tlist.getItem(0).type === 1 && tlist.getItem(0).type === 4)) {
			return null;
		}
	}

	// Grouped SVG element
	var gsvg = $(selected).data('gsvg');

	// we know we have some transforms, so set up return variable
	var batchCmd = new svgedit.history.BatchCommand('Transform');

	// store initial values that will be affected by reducing the transform list
	var changes = {}, initial = null, attrs = [];
	switch (selected.tagName) {
	case 'line':
		attrs = ['x1', 'y1', 'x2', 'y2'];
		break;
	case 'circle':
		attrs = ['cx', 'cy', 'r'];
		break;
	case 'ellipse':
		attrs = ['cx', 'cy', 'rx', 'ry'];
		break;
	case 'foreignObject':
	case 'rect':
	case 'image':
		attrs = ['width', 'height', 'x', 'y'];
		break;
	case 'use':
	case 'text':
	case 'tspan':
		attrs = ['x', 'y'];
		break;
	case 'polygon':
	case 'polyline':
		initial = {};
		initial.points = selected.getAttribute('points');
		var list = selected.points;
		var len = list.numberOfItems;
		changes.points = new Array(len);
		var i;
		for (i = 0; i < len; ++i) {
			var pt = list.getItem(i);
			changes.points[i] = {x: pt.x, y: pt.y};
		}
		break;
	case 'path':
		initial = {};
		initial.d = selected.getAttribute('d');
		changes.d = selected.getAttribute('d');
		break;
	} // switch on element type to get initial values

	if (attrs.length) {
		changes = $(selected).attr(attrs);
		$.each(changes, function (attr, val) {
			changes[attr] = svgedit.units.convertToNum(attr, val);
		});
	} else if (gsvg) {
		// GSVG exception
		changes = {
			x: $(gsvg).attr('x') || 0,
			y: $(gsvg).attr('y') || 0
		};
	}

	// if we haven't created an initial array in polygon/polyline/path, then
	// make a copy of initial values and include the transform
	if (initial == null) {
		initial = $.extend(true, {}, changes);
		$.each(initial, function (attr, val) {
			initial[attr] = svgedit.units.convertToNum(attr, val);
		});
	}
	// save the start transform value too
	initial.transform = context_.getStartTransform() || '';

	// if it's a regular group, we have special processing to flatten transforms
	if ((selected.tagName === 'g' && !gsvg) || selected.tagName === 'a') {
		var box = svgedit.utilities.getBBox(selected),
			oldcenter = {x: box.x + box.width / 2, y: box.y + box.height / 2},
			newcenter = svgedit.math.transformPoint(box.x + box.width / 2,
				box.y + box.height / 2,
				svgedit.math.transformListToTransform(tlist).matrix),
			m = svgroot.createSVGMatrix();

		// temporarily strip off the rotate and save the old center
		var gangle = svgedit.utilities.getRotationAngle(selected);
		if (gangle) {
			var a = gangle * Math.PI / 180;
			if (Math.abs(a) > (1.0e-10)) {
				var s = Math.sin(a) / (1 - Math.cos(a));
			} else {
				// FIXME: This blows up if the angle is exactly 0!
				var s = 2 / a;
			}
			var i;
			for (i = 0; i < tlist.numberOfItems; ++i) {
				var xform = tlist.getItem(i);
				if (xform.type === 4) {
					// extract old center through mystical arts
					var rm = xform.matrix;
					oldcenter.y = (s * rm.e + rm.f) / 2;
					oldcenter.x = (rm.e - s * rm.f) / 2;
					tlist.removeItem(i);
					break;
				}
			}
		}
		var tx = 0, ty = 0,
			operation = 0,
			N = tlist.numberOfItems;

		if (N) {
			var firstM = tlist.getItem(0).matrix;
		}

		// first, if it was a scale then the second-last transform will be it
		if (N >= 3 && tlist.getItem(N - 2).type === 3 &&
			tlist.getItem(N - 3).type === 2 && tlist.getItem(N - 1).type === 2) {
			operation = 3; // scale

			// if the children are unrotated, pass the scale down directly
			// otherwise pass the equivalent matrix() down directly
			var tm = tlist.getItem(N - 3).matrix,
				sm = tlist.getItem(N - 2).matrix,
				tmn = tlist.getItem(N - 1).matrix;

			var children = selected.childNodes;
			var c = children.length;
			while (c--) {
				var child = children.item(c);
				tx = 0;
				ty = 0;
				if (child.nodeType === 1) {
					var childTlist = svgedit.transformlist.getTransformList(child);

					// some children might not have a transform (<metadata>, <defs>, etc)
					if (!childTlist) { continue; }

					var m = svgedit.math.transformListToTransform(childTlist).matrix;

					// Convert a matrix to a scale if applicable
					// if (svgedit.math.hasMatrixTransform(childTlist) && childTlist.numberOfItems == 1) {
					// 	if (m.b==0 && m.c==0 && m.e==0 && m.f==0) {
					// 		childTlist.removeItem(0);
					// 		var translateOrigin = svgroot.createSVGTransform(),
					// 			scale = svgroot.createSVGTransform(),
					// 			translateBack = svgroot.createSVGTransform();
					// 		translateOrigin.setTranslate(0, 0);
					// 		scale.setScale(m.a, m.d);
					// 		translateBack.setTranslate(0, 0);
					// 		childTlist.appendItem(translateBack);
					// 		childTlist.appendItem(scale);
					// 		childTlist.appendItem(translateOrigin);
					// 	}
					// }

					var angle = svgedit.utilities.getRotationAngle(child);
					var oldStartTransform = context_.getStartTransform();
					var childxforms = [];
					context_.setStartTransform(child.getAttribute('transform'));
					if (angle || svgedit.math.hasMatrixTransform(childTlist)) {
						var e2t = svgroot.createSVGTransform();
						e2t.setMatrix(svgedit.math.matrixMultiply(tm, sm, tmn, m));
						childTlist.clear();
						childTlist.appendItem(e2t);
						childxforms.push(e2t);
					// if not rotated or skewed, push the [T][S][-T] down to the child
					} else {
						// update the transform list with translate,scale,translate

						// slide the [T][S][-T] from the front to the back
						// [T][S][-T][M] = [M][T2][S2][-T2]

						// (only bringing [-T] to the right of [M])
						// [T][S][-T][M] = [T][S][M][-T2]
						// [-T2] = [M_inv][-T][M]
						var t2n = svgedit.math.matrixMultiply(m.inverse(), tmn, m);
						// [T2] is always negative translation of [-T2]
						var t2 = svgroot.createSVGMatrix();
						t2.e = -t2n.e;
						t2.f = -t2n.f;

						// [T][S][-T][M] = [M][T2][S2][-T2]
						// [S2] = [T2_inv][M_inv][T][S][-T][M][-T2_inv]
						var s2 = svgedit.math.matrixMultiply(t2.inverse(), m.inverse(), tm, sm, tmn, m, t2n.inverse());

						var translateOrigin = svgroot.createSVGTransform(),
							scale = svgroot.createSVGTransform(),
							translateBack = svgroot.createSVGTransform();
						translateOrigin.setTranslate(t2n.e, t2n.f);
						scale.setScale(s2.a, s2.d);
						translateBack.setTranslate(t2.e, t2.f);
						childTlist.appendItem(translateBack);
						childTlist.appendItem(scale);
						childTlist.appendItem(translateOrigin);
						childxforms.push(translateBack);
						childxforms.push(scale);
						childxforms.push(translateOrigin);
						// logMatrix(translateBack.matrix);
						// logMatrix(scale.matrix);
					} // not rotated
					batchCmd.addSubCommand(svgedit.recalculate.recalculateDimensions(child));
					// TODO: If any <use> have this group as a parent and are
					// referencing this child, then we need to impose a reverse
					// scale on it so that when it won't get double-translated
					// var uses = selected.getElementsByTagNameNS(NS.SVG, 'use');
					// var href = '#' + child.id;
					// var u = uses.length;
					// while (u--) {
					// 	var useElem = uses.item(u);
					// 	if (href == svgedit.utilities.getHref(useElem)) {
					// 		var usexlate = svgroot.createSVGTransform();
					// 		usexlate.setTranslate(-tx,-ty);
					// 		svgedit.transformlist.getTransformList(useElem).insertItemBefore(usexlate,0);
					// 		batchCmd.addSubCommand( svgedit.recalculate.recalculateDimensions(useElem) );
					// 	}
					// }
					context_.setStartTransform(oldStartTransform);
				} // element
			} // for each child
			// Remove these transforms from group
			tlist.removeItem(N - 1);
			tlist.removeItem(N - 2);
			tlist.removeItem(N - 3);
		} else if (N >= 3 && tlist.getItem(N - 1).type === 1) {
			operation = 3; // scale
			m = svgedit.math.transformListToTransform(tlist).matrix;
			var e2t = svgroot.createSVGTransform();
			e2t.setMatrix(m);
			tlist.clear();
			tlist.appendItem(e2t);
		// next, check if the first transform was a translate
		// if we had [ T1 ] [ M ] we want to transform this into [ M ] [ T2 ]
		// therefore [ T2 ] = [ M_inv ] [ T1 ] [ M ]
		} else if ((N === 1 || (N > 1 && tlist.getItem(1).type !== 3)) &&
			tlist.getItem(0).type === 2) {
			operation = 2; // translate
			var T_M = svgedit.math.transformListToTransform(tlist).matrix;
			tlist.removeItem(0);
			var mInv = svgedit.math.transformListToTransform(tlist).matrix.inverse();
			var M2 = svgedit.math.matrixMultiply(mInv, T_M);

			tx = M2.e;
			ty = M2.f;

			if (tx !== 0 || ty !== 0) {
				// we pass the translates down to the individual children
				var children = selected.childNodes;
				var c = children.length;

				var clipPathsDone = [];

				while (c--) {
					var child = children.item(c);
					if (child.nodeType === 1) {
						// Check if child has clip-path
						if (child.getAttribute('clip-path')) {
							// tx, ty
							var attr = child.getAttribute('clip-path');
							if (clipPathsDone.indexOf(attr) === -1) {
								svgedit.recalculate.updateClipPath(attr, tx, ty);
								clipPathsDone.push(attr);
							}
						}

						var oldStartTransform = context_.getStartTransform();
						context_.setStartTransform(child.getAttribute('transform'));

						var childTlist = svgedit.transformlist.getTransformList(child);
						// some children might not have a transform (<metadata>, <defs>, etc)
						if (childTlist) {
							var newxlate = svgroot.createSVGTransform();
							newxlate.setTranslate(tx, ty);
							if (childTlist.numberOfItems) {
								childTlist.insertItemBefore(newxlate, 0);
							} else {
								childTlist.appendItem(newxlate);
							}
							batchCmd.addSubCommand(svgedit.recalculate.recalculateDimensions(child));
							// If any <use> have this group as a parent and are
							// referencing this child, then impose a reverse translate on it
							// so that when it won't get double-translated
							var uses = selected.getElementsByTagNameNS(NS.SVG, 'use');
							var href = '#' + child.id;
							var u = uses.length;
							while (u--) {
								var useElem = uses.item(u);
								if (href === svgedit.utilities.getHref(useElem)) {
									var usexlate = svgroot.createSVGTransform();
									usexlate.setTranslate(-tx, -ty);
									svgedit.transformlist.getTransformList(useElem).insertItemBefore(usexlate, 0);
									batchCmd.addSubCommand(svgedit.recalculate.recalculateDimensions(useElem));
								}
							}
							context_.setStartTransform(oldStartTransform);
						}
					}
				}

				clipPathsDone = [];
				context_.setStartTransform(oldStartTransform);
			}
		// else, a matrix imposition from a parent group
		// keep pushing it down to the children
		} else if (N === 1 && tlist.getItem(0).type === 1 && !gangle) {
			operation = 1;
			var m = tlist.getItem(0).matrix,
				children = selected.childNodes,
				c = children.length;
			while (c--) {
				var child = children.item(c);
				if (child.nodeType === 1) {
					var oldStartTransform = context_.getStartTransform();
					context_.setStartTransform(child.getAttribute('transform'));
					var childTlist = svgedit.transformlist.getTransformList(child);

					if (!childTlist) { continue; }

					var em = svgedit.math.matrixMultiply(m, svgedit.math.transformListToTransform(childTlist).matrix);
					var e2m = svgroot.createSVGTransform();
					e2m.setMatrix(em);
					childTlist.clear();
					childTlist.appendItem(e2m, 0);

					batchCmd.addSubCommand(svgedit.recalculate.recalculateDimensions(child));
					context_.setStartTransform(oldStartTransform);

					// Convert stroke
					// TODO: Find out if this should actually happen somewhere else
					var sw = child.getAttribute('stroke-width');
					if (child.getAttribute('stroke') !== 'none' && !isNaN(sw)) {
						var avg = (Math.abs(em.a) + Math.abs(em.d)) / 2;
						child.setAttribute('stroke-width', sw * avg);
					}
				}
			}
			tlist.clear();
		// else it was just a rotate
		} else {
			if (gangle) {
				var newRot = svgroot.createSVGTransform();
				newRot.setRotate(gangle, newcenter.x, newcenter.y);
				if (tlist.numberOfItems) {
					tlist.insertItemBefore(newRot, 0);
				} else {
					tlist.appendItem(newRot);
				}
			}
			if (tlist.numberOfItems === 0) {
				selected.removeAttribute('transform');
			}
			return null;
		}

		// if it was a translate, put back the rotate at the new center
		if (operation === 2) {
			if (gangle) {
				newcenter = {
					x: oldcenter.x + firstM.e,
					y: oldcenter.y + firstM.f
				};

				var newRot = svgroot.createSVGTransform();
				newRot.setRotate(gangle, newcenter.x, newcenter.y);
				if (tlist.numberOfItems) {
					tlist.insertItemBefore(newRot, 0);
				} else {
					tlist.appendItem(newRot);
				}
			}
		// if it was a resize
		} else if (operation === 3) {
			var m = svgedit.math.transformListToTransform(tlist).matrix;
			var roldt = svgroot.createSVGTransform();
			roldt.setRotate(gangle, oldcenter.x, oldcenter.y);
			var rold = roldt.matrix;
			var rnew = svgroot.createSVGTransform();
			rnew.setRotate(gangle, newcenter.x, newcenter.y);
			var rnewInv = rnew.matrix.inverse(),
				mInv = m.inverse(),
				extrat = svgedit.math.matrixMultiply(mInv, rnewInv, rold, m);

			tx = extrat.e;
			ty = extrat.f;

			if (tx !== 0 || ty !== 0) {
				// now push this transform down to the children
				// we pass the translates down to the individual children
				var children = selected.childNodes;
				var c = children.length;
				while (c--) {
					var child = children.item(c);
					if (child.nodeType === 1) {
						var oldStartTransform = context_.getStartTransform();
						context_.setStartTransform(child.getAttribute('transform'));
						var childTlist = svgedit.transformlist.getTransformList(child);
						var newxlate = svgroot.createSVGTransform();
						newxlate.setTranslate(tx, ty);
						if (childTlist.numberOfItems) {
							childTlist.insertItemBefore(newxlate, 0);
						} else {
							childTlist.appendItem(newxlate);
						}

						batchCmd.addSubCommand(svgedit.recalculate.recalculateDimensions(child));
						context_.setStartTransform(oldStartTransform);
					}
				}
			}

			if (gangle) {
				if (tlist.numberOfItems) {
					tlist.insertItemBefore(rnew, 0);
				} else {
					tlist.appendItem(rnew);
				}
			}
		}
	// else, it's a non-group
	} else {
		// FIXME: box might be null for some elements (<metadata> etc), need to handle this
		var box = svgedit.utilities.getBBox(selected);

		// Paths (and possbly other shapes) will have no BBox while still in <defs>,
		// but we still may need to recalculate them (see issue 595).
		// TODO: Figure out how to get BBox from these elements in case they
		// have a rotation transform

		if (!box && selected.tagName !== 'path') return null;

		var m = svgroot.createSVGMatrix(),
			// temporarily strip off the rotate and save the old center
			angle = svgedit.utilities.getRotationAngle(selected);
		if (angle) {
			var oldcenter = {x: box.x + box.width / 2, y: box.y + box.height / 2},
				newcenter = svgedit.math.transformPoint(box.x + box.width / 2, box.y + box.height / 2,
					svgedit.math.transformListToTransform(tlist).matrix);

			var a = angle * Math.PI / 180;
			if (Math.abs(a) > (1.0e-10)) {
				var s = Math.sin(a) / (1 - Math.cos(a));
			} else {
				// FIXME: This blows up if the angle is exactly 0!
				var s = 2 / a;
			}
			for (var i = 0; i < tlist.numberOfItems; ++i) {
				var xform = tlist.getItem(i);
				if (xform.type === 4) {
					// extract old center through mystical arts
					var rm = xform.matrix;
					oldcenter.y = (s * rm.e + rm.f) / 2;
					oldcenter.x = (rm.e - s * rm.f) / 2;
					tlist.removeItem(i);
					break;
				}
			}
		}

		// 2 = translate, 3 = scale, 4 = rotate, 1 = matrix imposition
		var operation = 0;
		var N = tlist.numberOfItems;

		// Check if it has a gradient with userSpaceOnUse, in which case
		// adjust it by recalculating the matrix transform.
		// TODO: Make this work in Webkit using svgedit.transformlist.SVGTransformList
		if (!svgedit.browser.isWebkit()) {
			var fill = selected.getAttribute('fill');
			if (fill && fill.indexOf('url(') === 0) {
				var paint = getRefElem(fill);
				var type = 'pattern';
				if (paint.tagName !== type) type = 'gradient';
				var attrVal = paint.getAttribute(type + 'Units');
				if (attrVal === 'userSpaceOnUse') {
					// Update the userSpaceOnUse element
					m = svgedit.math.transformListToTransform(tlist).matrix;
					var gtlist = svgedit.transformlist.getTransformList(paint);
					var gmatrix = svgedit.math.transformListToTransform(gtlist).matrix;
					m = svgedit.math.matrixMultiply(m, gmatrix);
					var mStr = 'matrix(' + [m.a, m.b, m.c, m.d, m.e, m.f].join(',') + ')';
					paint.setAttribute(type + 'Transform', mStr);
				}
			}
		}

		// first, if it was a scale of a non-skewed element, then the second-last
		// transform will be the [S]
		// if we had [M][T][S][T] we want to extract the matrix equivalent of
		// [T][S][T] and push it down to the element
		if (N >= 3 && tlist.getItem(N - 2).type === 3 &&
			tlist.getItem(N - 3).type === 2 && tlist.getItem(N - 1).type === 2) {
			// Removed this so a <use> with a given [T][S][T] would convert to a matrix.
			// Is that bad?
			//	&& selected.nodeName != 'use'
			operation = 3; // scale
			m = svgedit.math.transformListToTransform(tlist, N - 3, N - 1).matrix;
			tlist.removeItem(N - 1);
			tlist.removeItem(N - 2);
			tlist.removeItem(N - 3);
		// if we had [T][S][-T][M], then this was a skewed element being resized
		// Thus, we simply combine it all into one matrix
		} else if (N === 4 && tlist.getItem(N - 1).type === 1) {
			operation = 3; // scale
			m = svgedit.math.transformListToTransform(tlist).matrix;
			var e2t = svgroot.createSVGTransform();
			e2t.setMatrix(m);
			tlist.clear();
			tlist.appendItem(e2t);
			// reset the matrix so that the element is not re-mapped
			m = svgroot.createSVGMatrix();
		// if we had [R][T][S][-T][M], then this was a rotated matrix-element
		// if we had [T1][M] we want to transform this into [M][T2]
		// therefore [ T2 ] = [ M_inv ] [ T1 ] [ M ] and we can push [T2]
		// down to the element
		} else if ((N === 1 || (N > 1 && tlist.getItem(1).type !== 3)) &&
			tlist.getItem(0).type === 2) {
			operation = 2; // translate
			var oldxlate = tlist.getItem(0).matrix,
				meq = svgedit.math.transformListToTransform(tlist, 1).matrix,
				meqInv = meq.inverse();
			m = svgedit.math.matrixMultiply(meqInv, oldxlate, meq);
			tlist.removeItem(0);
		// else if this child now has a matrix imposition (from a parent group)
		// we might be able to simplify
		} else if (N === 1 && tlist.getItem(0).type === 1 && !angle) {
			// Remap all point-based elements
			m = svgedit.math.transformListToTransform(tlist).matrix;
			switch (selected.tagName) {
			case 'line':
				changes = $(selected).attr(['x1', 'y1', 'x2', 'y2']);
				// Fallthrough
			case 'polyline':
			case 'polygon':
				changes.points = selected.getAttribute('points');
				if (changes.points) {
					var list = selected.points;
					var len = list.numberOfItems;
					changes.points = new Array(len);
					for (var i = 0; i < len; ++i) {
						var pt = list.getItem(i);
						changes.points[i] = {x: pt.x, y: pt.y};
					}
				}
				// Fallthrough
			case 'path':
				changes.d = selected.getAttribute('d');
				operation = 1;
				tlist.clear();
				break;
			default:
				break;
			}
		// if it was a rotation, put the rotate back and return without a command
		// (this function has zero work to do for a rotate())
		} else {
			operation = 4; // rotation
			if (angle) {
				var newRot = svgroot.createSVGTransform();
				newRot.setRotate(angle, newcenter.x, newcenter.y);

				if (tlist.numberOfItems) {
					tlist.insertItemBefore(newRot, 0);
				} else {
					tlist.appendItem(newRot);
				}
			}
			if (tlist.numberOfItems === 0) {
				selected.removeAttribute('transform');
			}
			return null;
		}

		// if it was a translate or resize, we need to remap the element and absorb the xform
		if (operation === 1 || operation === 2 || operation === 3) {
			svgedit.coords.remapElement(selected, changes, m);
		} // if we are remapping

		// if it was a translate, put back the rotate at the new center
		if (operation === 2) {
			if (angle) {
				if (!svgedit.math.hasMatrixTransform(tlist)) {
					newcenter = {
						x: oldcenter.x + m.e,
						y: oldcenter.y + m.f
					};
				}
				var newRot = svgroot.createSVGTransform();
				newRot.setRotate(angle, newcenter.x, newcenter.y);
				if (tlist.numberOfItems) {
					tlist.insertItemBefore(newRot, 0);
				} else {
					tlist.appendItem(newRot);
				}
			}
			// We have special processing for tspans:	Tspans are not transformable
			// but they can have x,y coordinates (sigh).	Thus, if this was a translate,
			// on a text element, also translate any tspan children.
			if (selected.tagName === 'text') {
				var children = selected.childNodes;
				var c = children.length;
				while (c--) {
					var child = children.item(c);
					if (child.tagName === 'tspan') {
						var tspanChanges = {
							x: $(child).attr('x') || 0,
							y: $(child).attr('y') || 0
						};
						svgedit.coords.remapElement(child, tspanChanges, m);
					}
				}
			}
		// [Rold][M][T][S][-T] became [Rold][M]
		// we want it to be [Rnew][M][Tr] where Tr is the
		// translation required to re-center it
		// Therefore, [Tr] = [M_inv][Rnew_inv][Rold][M]
		} else if (operation === 3 && angle) {
			var m = svgedit.math.transformListToTransform(tlist).matrix;
			var roldt = svgroot.createSVGTransform();
			roldt.setRotate(angle, oldcenter.x, oldcenter.y);
			var rold = roldt.matrix;
			var rnew = svgroot.createSVGTransform();
			rnew.setRotate(angle, newcenter.x, newcenter.y);
			var rnewInv = rnew.matrix.inverse();
			var mInv = m.inverse();
			var extrat = svgedit.math.matrixMultiply(mInv, rnewInv, rold, m);

			svgedit.coords.remapElement(selected, changes, extrat);
			if (angle) {
				if (tlist.numberOfItems) {
					tlist.insertItemBefore(rnew, 0);
				} else {
					tlist.appendItem(rnew);
				}
			}
		}
	} // a non-group

	// if the transform list has been emptied, remove it
	if (tlist.numberOfItems === 0) {
		selected.removeAttribute('transform');
	}

	batchCmd.addSubCommand(new svgedit.history.ChangeElementCommand(selected, initial));

	return batchCmd;
};
})();