cz.vutbr.web.csskit.fn.GenericRadialGradient Maven / Gradle / Ivy
/**
* GenericRadialGradient.java
*
* Created on 17. 5. 2018, 13:14:05 by burgetr
*/
package cz.vutbr.web.csskit.fn;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import cz.vutbr.web.css.CSSFactory;
import cz.vutbr.web.css.Term;
import cz.vutbr.web.css.TermFactory;
import cz.vutbr.web.css.TermIdent;
import cz.vutbr.web.css.TermLength;
import cz.vutbr.web.css.TermLengthOrPercent;
import cz.vutbr.web.css.TermList;
import cz.vutbr.web.css.TermPercent;
/**
* Base class for both the radial and repating-radial gradient implementations.
*
* @author burgetr
*/
public class GenericRadialGradient extends GenericGradient {
//default property values
private static final TermPercent DEFAULT_POSITION = CSSFactory.getTermFactory().createPercent(50.0f);
private static final TermIdent DEFAULT_SHAPE = CSSFactory.getTermFactory().createIdent("ellipse");
private static final TermIdent CIRCLE_SHAPE = CSSFactory.getTermFactory().createIdent("circle");
private static final TermIdent DEFAULT_SIZE = CSSFactory.getTermFactory().createIdent("farthest-corner");
private TermIdent shape;
private TermLengthOrPercent[] size;
private TermIdent sizeIdent;
private TermLengthOrPercent[] position;
public TermIdent getShape() {
return shape;
}
public TermLengthOrPercent[] getSize() {
return size;
}
public TermIdent getSizeIdent() {
return sizeIdent;
}
public TermLengthOrPercent[] getPosition() {
return position;
}
public TermList setValue(List> value) {
super.setValue(value);
List>> args = getSeparatedArgs(DEFAULT_ARG_SEP);
if (args.size() > 1) {
int firstStop = 0;
//check for shape and size
if (decodeShape(args.get(0))) {
firstStop = 1;
} else { //no shape info provided, use defaults
sizeIdent = DEFAULT_SIZE;
shape = DEFAULT_SHAPE;
position = new TermLengthOrPercent[2];
position[0] = position[1] = DEFAULT_POSITION;
}
//check for stops
loadColorStops(args, firstStop);
if (getColorStops() != null)
setValid(true);
}
return this;
}
private boolean decodeShape(List> arglist) {
List> args = new ArrayList<>(arglist);
//determine the 'at' position
int atpos = -1;
for (int i = 0; i < args.size(); i++) {
Term arg = args.get(i);
if (arg instanceof TermIdent && ((TermIdent) arg).getValue().equalsIgnoreCase("at")) {
atpos = i;
break;
}
}
if (atpos != -1) {
List> posList = args.subList(atpos + 1, args.size());
if (!decodePosition(posList))
return false;
args = args.subList(0, atpos);
} else { //no position, use the default (center)
position = new TermLengthOrPercent[2];
position[0] = position[1] = DEFAULT_POSITION;
}
//determine the shape
boolean isCircle = false;
for (Iterator> it = args.iterator(); it.hasNext();)
{
Term arg = it.next();
String idval = (arg instanceof TermIdent) ? ((TermIdent) arg).getValue() : null;
if (idval != null && (idval.equalsIgnoreCase("circle") || idval.equalsIgnoreCase("ellipse"))) {
shape = (TermIdent) arg;
isCircle = idval.equalsIgnoreCase("circle");
it.remove();
break;
}
}
//determine the size
if (shape == null) { //shape not given
if (args.size() == 0) {
sizeIdent = DEFAULT_SIZE;
shape = DEFAULT_SHAPE;
} else if (args.size() == 1) {
Term arg = args.get(0);
if (isExtentKeyword(arg)) {
sizeIdent = (TermIdent) arg;
shape = DEFAULT_SHAPE; //see https://drafts.csswg.org/css-images-3/#radial-gradients
} else if (arg instanceof TermLength) {
size = new TermLengthOrPercent[1];
size[0] = (TermLength) arg;
shape = CIRCLE_SHAPE;
} else {
return false;
}
} else if (args.size() == 2) {
size = new TermLengthOrPercent[2];
int i = 0;
for (Term arg : args) {
if (arg instanceof TermLengthOrPercent) {
size[i++] = (TermLengthOrPercent) arg;
} else {
size = null;
return false;
}
}
shape = DEFAULT_SHAPE;
} else {
return false;
}
} else if (!isCircle) { //ellipse
if (args.size() == 0) {
sizeIdent = DEFAULT_SIZE;
} else if (args.size() == 1) {
Term arg = args.get(0);
if (isExtentKeyword(arg)) {
sizeIdent = (TermIdent) arg;
} else {
return false;
}
} else if (args.size() == 2) {
size = new TermLengthOrPercent[2];
int i = 0;
for (Term arg : args) {
if (arg instanceof TermLengthOrPercent) {
size[i++] = (TermLengthOrPercent) arg;
} else {
size = null;
return false;
}
}
} else {
return false;
}
} else { //circle
if (args.size() == 0) {
sizeIdent = DEFAULT_SIZE;
} else if (args.size() == 1) {
Term arg = args.get(0);
if (isExtentKeyword(arg)) {
sizeIdent = (TermIdent) arg;
} else if (arg instanceof TermLength) {
size = new TermLengthOrPercent[1];
size[0] = (TermLength) arg;
} else {
return false;
}
} else {
return false;
}
}
//parsed ok
return true;
}
private boolean decodePosition(List> arglist) {
if (arglist.size() == 1 || arglist.size() == 2) {
position = new TermLengthOrPercent[2];
//distribute terms to position
for (Term term : arglist) {
if (term instanceof TermIdent || term instanceof TermLengthOrPercent) {
storeBackgroundPosition(position, term);
} else {
return false;
}
}
//check validity
int assigned = 0;
int valid = 0;
for (int i = 0; i < 2; i++) {
if (position[i] == null) {
position[i] = DEFAULT_POSITION;
valid++;
} else if (position[i] instanceof TermLengthOrPercent) {
assigned++;
valid++;
}
}
return (assigned > 0 && valid == 2);
} else {
return false;
}
}
private void storeBackgroundPosition(Term[] storage, Term term) {
if (term instanceof TermIdent) {
String idval = ((TermIdent) term).getValue();
TermFactory tf = CSSFactory.getTermFactory();
if (idval.equalsIgnoreCase("left"))
setPositionValue(storage, 0, tf.createPercent(0.0f));
else if (idval.equalsIgnoreCase("right"))
setPositionValue(storage, 0, tf.createPercent(100.0f));
else if (idval.equalsIgnoreCase("top"))
setPositionValue(storage, 1, tf.createPercent(0.0f));
else if (idval.equalsIgnoreCase("bottom"))
setPositionValue(storage, 1, tf.createPercent(100.0f));
else if (idval.equalsIgnoreCase("center"))
setPositionValue(storage, -1, tf.createPercent(50.0f));
}
else
setPositionValue(storage, -1, term);
}
private void setPositionValue(Term[] s, int index, Term term) {
switch (index) {
case -1: if (s[0] == null) //any position - use the free position
s[0] = term;
else
s[1] = term;
break;
case 0: if (s[0] != null) //if the position is occupied, move the old value
s[1] = s[0];
s[0] = term;
break;
case 1: if (s[1] != null)
s[0] = s[1];
s[1] = term;
break;
}
}
private boolean isExtentKeyword(Term term) {
if (term instanceof TermIdent) {
switch (((TermIdent) term).getValue()) {
case "closest-corner":
case "closest-side":
case "farthest-corner":
case "farthest-side":
return true;
default:
return false;
}
} else {
return false;
}
}
}