org.w3c.css.properties.css2.CssBackgroundPositionCSS2 Maven / Gradle / Ivy
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//
// $Id: CssBackgroundPositionCSS2.java,v 1.2 2010-01-05 19:49:51 ylafon Exp $
// From Philippe Le Hegaret ([email protected])
//
// (c) COPYRIGHT MIT and INRIA, 1997.
// Please first read the full copyright statement in file COPYRIGHT.html
package org.w3c.css.properties.css2;
import org.w3c.css.parser.CssStyle;
import org.w3c.css.properties.css.CssBackgroundPosition;
import org.w3c.css.properties.css.CssProperty;
import org.w3c.css.properties.css1.Css1Style;
import org.w3c.css.util.ApplContext;
import org.w3c.css.util.InvalidParamException;
import org.w3c.css.values.CssExpression;
import org.w3c.css.values.CssIdent;
import org.w3c.css.values.CssNumber;
import org.w3c.css.values.CssPercentage;
import org.w3c.css.values.CssTypes;
import org.w3c.css.values.CssValue;
import java.util.HashMap;
import static org.w3c.css.values.CssOperator.SPACE;
/**
*
* 'background-position'
*
*
* Value: [<percentage> | <length>]{1,2} | [top | center
* | bottom] || [left | center | right]
* Initial: 0% 0%
* Applies to: block-level and replaced elements
* Inherited: no
* Percentage values: refer to the size of the element itself
* If a background image has been specified, the value of
* 'background-position' specifies its initial position.
*
With a value pair of '0% 0%', the upper left corner of the image is
* placed in the upper left corner of the box that surrounds the content of
* the element (i.e., not the box that surrounds the padding, border or
* margin). A value pair of '100% 100%' places the lower right corner of the
* image in the lower right corner of the element. With a value pair of '14%
* 84%', the point 14% across and 84% down the image is to be placed at the
* point 14% across and 84% down the element.
*
With a value pair of '2cm 2cm', the upper left corner of the image is
* placed 2cm to the right and 2cm below the upper left corner of the element.
*
If only one percentage or length value is given, it sets the horizontal
* position only, the vertical position will be 50%. If two values are given,
* the horizontal position comes first. Combinations of length and percentage
* values are allowed, e.g. '50% 2cm'. Negative positions are allowed.
*
One can also use keyword values to indicate the position of the
* background image. Keywords cannot be combined with percentage values, or
* length values. The possible combinations of keywords and their
* interpretations are as follows:
*
*
* -
* 'top left' and 'left top' both mean the same as '0% 0%'.
*
-
* 'top', 'top center' and 'center top' mean the same as '50% 0%'.
*
-
* 'right top' and 'top right' mean the same as '100% 0%'.
*
-
* 'left', 'left center' and 'center left' mean the same as '0% 50%'.
*
-
* 'center' and 'center center' mean the same as '50% 50%'.
*
-
* 'right', 'right center' and 'center right' mean the same as '100% 50%'.
*
-
* 'bottom left' and 'left bottom' mean the same as '0% 100%'.
*
-
* 'bottom', 'bottom center' and 'center bottom' mean the same as
* '50% 100%'.
*
-
* 'bottom right' and 'right bottom' mean the same as '100% 100%'.
*
*
* examples:
*
* BODY { background: url(banner.jpeg) right top } / * 100% 0% * /
* BODY { background: url(banner.jpeg) top center } / * 50% 0% * /
* BODY { background: url(banner.jpeg) center } / * 50% 50% * /
* BODY { background: url(banner.jpeg) bottom } / * 50% 100% * /
*
*
* If the background image is fixed with regard to the canvas (see the
* 'background-attachment' property above), the image is placed relative to
* the canvas instead of the element. E.g.:
*
* BODY {
* background-image: url(logo.png);
* background-attachment: fixed;
* background-position: 100% 100%;
* }
*
*
* In the example above, the image is placed in the lower right corner of the
* canvas.
*
* @version $Revision: 1.2 $
* @see org.w3c.css.properties.css.CssBackgroundAttachment
*/
public class CssBackgroundPositionCSS2 extends CssBackgroundPosition {
public static boolean checkMatchingIdent(CssIdent ident) {
return allowed_values.containsValue(ident);
}
private static final String propertyName = "background-position";
public static HashMap allowed_values;
public static CssIdent center, top, bottom, left, right;
private static CssPercentage defaultPercent0, defaultPercent50;
private static CssPercentage defaultPercent100;
static {
top = CssIdent.getIdent("top");
bottom = CssIdent.getIdent("bottom");
left = CssIdent.getIdent("left");
right = CssIdent.getIdent("right");
center = CssIdent.getIdent("center");
allowed_values = new HashMap();
allowed_values.put("top", top);
allowed_values.put("bottom", bottom);
allowed_values.put("left", left);
allowed_values.put("right", right);
allowed_values.put("center", center);
defaultPercent0 = new CssPercentage(0);
defaultPercent50 = new CssPercentage(50);
defaultPercent100 = new CssPercentage(100);
}
public CssValue value;
/**
* Create a new CssBackgroundPositionCSS2
*/
public CssBackgroundPositionCSS2() {
super();
}
/**
* Creates a new CssBackgroundPositionCSS2
*
* @param expression The expression for this property
* @throws InvalidParamException Values are incorrect
*/
public CssBackgroundPositionCSS2(ApplContext ac, CssExpression expression,
boolean check) throws InvalidParamException {
int nb_val = expression.getCount();
if (check && nb_val > 2) {
throw new InvalidParamException("unrecognize", ac);
}
setByUser();
setByUser();
CssValue val;
CssBackgroundPositionValue b_val = null;
char op;
// we just accumulate values and check at validation
while (!expression.end()) {
val = expression.getValue();
op = expression.getOperator();
if (inherit.equals(val)) {
if (expression.getCount() > 1) {
throw new InvalidParamException("value", val,
getPropertyName(), ac);
}
value = inherit;
expression.next();
return;
}
if (b_val == null) {
b_val = new CssBackgroundPositionValue();
}
// we will check later
b_val.add(val);
expression.next();
if (op != SPACE) {
throw new InvalidParamException("operator",
((new Character(op)).toString()), ac);
}
}
// if we reach the end in a value that can come in pair
if (b_val != null) {
check(b_val, ac);
value = b_val;
}
}
// check the value
public void check(CssBackgroundPositionValue v, ApplContext ac)
throws InvalidParamException {
int nb_keyword = 0;
int nb_percentage = 0;
int nb_length = 0;
int nb_values = v.value.size();
if (nb_values > 2) {
throw new InvalidParamException("unrecognize", ac);
}
// basic check
for (CssValue aValue : v.value) {
switch (aValue.getType()) {
case CssTypes.CSS_NUMBER:
aValue = ((CssNumber) aValue).getLength();
case CssTypes.CSS_LENGTH:
nb_length++;
break;
case CssTypes.CSS_PERCENTAGE:
nb_percentage++;
break;
case CssTypes.CSS_IDENT:
nb_keyword++;
break;
default:
throw new InvalidParamException("unrecognize", aValue,
ac);
}
}
// this is unnecessary complex, blame it on the CSS3 spec.
switch (nb_keyword) {
case 0:
// no keyword, so it's easy, it depends on the number
// of values :)
switch (nb_values) {
case 1:
// If only one value is specified, the second value
// is assumed to be 'center'.
v.horizontal = v.value.get(0);
if (v.horizontal.getType() == CssTypes.CSS_NUMBER) {
v.horizontal = defaultPercent0;
}
v.val_horizontal = v.horizontal;
v.val_vertical = defaultPercent50;
break;
case 2:
v.horizontal = v.value.get(0);
if (v.horizontal.getType() == CssTypes.CSS_NUMBER) {
v.horizontal = defaultPercent0;
}
v.val_horizontal = v.horizontal;
v.vertical = v.value.get(1);
if (v.vertical.getType() == CssTypes.CSS_NUMBER) {
v.vertical = defaultPercent0;
}
v.val_vertical = v.vertical;
break;
default:
// should never happen
throw new InvalidParamException("unrecognize",
ac);
}
break;
// we got one keyword... let's have fun...
case 1:
switch (nb_values) {
case 1:
CssIdent ident = (CssIdent) v.value.get(0);
// ugly as we need to set values for equality tests
v.val_vertical = defaultPercent50;
v.val_horizontal = defaultPercent50;
ident = allowed_values.get(ident.toString());
if (ident != null) {
if (isVertical(ident)) {
v.vertical = ident;
v.val_vertical = identToPercent(ident);
} else {
// horizontal || center
v.horizontal = ident;
v.val_horizontal = identToPercent(ident);
}
break;
}
throw new InvalidParamException("unrecognize",
ident, propertyName, ac);
case 2:
// one ident, two values... first MUST be horizontal
// and second vertical
CssValue val0 = v.value.get(0);
if (val0.getType() == CssTypes.CSS_IDENT) {
ident = allowed_values.get(val0.toString());
if (ident == null) {
throw new InvalidParamException("unrecognize",
ident, propertyName, ac);
}
if (isVertical(ident)) {
throw new InvalidParamException("incompatible",
ident, v.value.get(1), ac);
}
v.horizontal = ident;
v.val_horizontal = identToPercent(ident);
// and the vertical value...
v.vertical = v.value.get(1);
if (v.vertical.getType() == CssTypes.CSS_NUMBER) {
v.vertical = defaultPercent0;
}
v.val_vertical = v.vertical;
} else {
ident = allowed_values.get(v.value.get(1).toString());
if (ident == null) {
throw new InvalidParamException("unrecognize",
ident, propertyName, ac);
}
if (isHorizontal(ident)) {
throw new InvalidParamException("incompatible",
val0, v.value.get(1), ac);
}
v.vertical = ident;
v.val_vertical = identToPercent(ident);
// and the first value
v.horizontal = val0;
if (v.horizontal.getType() == CssTypes.CSS_NUMBER) {
v.horizontal = defaultPercent0;
}
v.val_horizontal = v.horizontal;
}
break;
default:
// one ident, 3 or 4 values is not allowed
throw new InvalidParamException("unrecognize",
ac);
}
break;
default:
// we got two keywords for two values, yeah!
CssIdent id1 = (CssIdent) v.value.get(0);
CssIdent id2 = (CssIdent) v.value.get(1);
if (((isVertical(id1) && isVertical(id2))) ||
(isHorizontal(id1) && isHorizontal(id2))) {
throw new InvalidParamException("incompatible",
id1, id2, ac);
}
if (isVertical(id1) || isHorizontal(id2)) {
v.horizontal = id2;
v.val_horizontal = identToPercent(id2);
v.vertical = id1;
v.val_vertical = identToPercent(id1);
} else {
v.horizontal = id1;
v.val_horizontal = identToPercent(id1);
v.vertical = id2;
v.val_vertical = identToPercent(id2);
}
}
}
public CssBackgroundPositionCSS2(ApplContext ac, CssExpression expression)
throws InvalidParamException {
this(ac, expression, false);
}
public String toString() {
return value.toString();
}
/**
* Add this property to the CssStyle.
*
* @param style The CssStyle
*/
public void addToStyle(ApplContext ac, CssStyle style) {
CssBackgroundCSS2 cssBackground = ((Css1Style) style).cssBackgroundCSS2;
if (cssBackground.position != null)
style.addRedefinitionWarning(ac, this);
cssBackground.position = this;
}
/**
* Get this property in the style.
*
* @param style The style where the property is
* @param resolve if true, resolve the style to find this property
*/
public CssProperty getPropertyInStyle(CssStyle style, boolean resolve) {
if (resolve) {
return ((Css1Style) style).getBackgroundPositionCSS2();
} else {
return ((Css1Style) style).cssBackgroundCSS2.position;
}
}
}