* 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: * *
* 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: 1.6 $
* @see CssBackgroundAttachment
*/
public class CssBackgroundPositionCSS1 extends CssProperty
implements CssBackgroundConstants, CssOperator {
CssValue first;
CssValue second;
/**
* Create a new CssBackgroundPositionCSS1
*/
public CssBackgroundPositionCSS1() {
first = DefaultValue0;
second = DefaultValue0;
}
/**
* Creates a new CssBackgroundPositionCSS1
*
* @param expression The expression for this property
* @exception InvalidParamException Values are incorrect
*/
public CssBackgroundPositionCSS1(ApplContext ac, CssExpression expression,
boolean check) throws InvalidParamException {
if(check && expression.getCount() > 2) {
throw new InvalidParamException("unrecognize", ac);
}
setByUser();
CssValue val = expression.getValue();
char op = expression.getOperator();
if (op != SPACE)
throw new InvalidParamException("operator",
((new Character(op)).toString()),
ac);
CssValue next = expression.getNextValue();
if(val instanceof CssIdent) {
int index1 = IndexOfIdent((String) val.get());
if(index1 == -1) {
throw new InvalidParamException("value", val, "background-position", ac);
}
// two keywords
if(next instanceof CssIdent) {
int index2 = IndexOfIdent((String) next.get());
if(index2 == -1 && check) {
throw new InvalidParamException("value", next, "background-position", ac);
}
// one is vertical, the other is vertical
// or the two are 'center'
if((isHorizontal(index1) && isVertical(index2)) ||
(isHorizontal(index2) && isVertical(index1))) {
first = val;
second = next;
}
// both are horizontal or vertical but not 'center'
else if(check){
throw new InvalidParamException("incompatible",
val, next, ac);
}
else {
first = val;
}
}
// only one value
else if(!check || next == null) {
first = val;
}
// the second value is invalid
else {
throw new InvalidParamException("value", next,
getPropertyName(), ac);
}
}
else if(val instanceof CssLength || val instanceof CssPercentage
|| val instanceof CssNumber) {
if(val instanceof CssNumber) {
val = ((CssNumber) val).getLength();
}
if(next instanceof CssLength || next instanceof CssPercentage ||
next instanceof CssNumber) {
if(next instanceof CssNumber) {
next = ((CssNumber) next).getLength();
}
first = val;
second = next;
}
else if(next == null || !check) {
first = val;
}
else {
throw new InvalidParamException("incompatible", val, next, ac);
}
}
else if(check){
throw new InvalidParamException("value", expression.getValue(),
getPropertyName(), ac);
}
// we only move the cursor if we found valid values
if(first != null) {
expression.next();
}
if(second != null) {
expression.next();
}
}
public CssBackgroundPositionCSS1(ApplContext ac, CssExpression expression)
throws InvalidParamException {
this(ac, expression, false);
}
/**
* Returns the value of this property
*/
public Object get() {
return first;
}
/**
* Returns the name of this property
*/
public String getPropertyName() {
return "background-position";
}
/**
* Returns the first value of the position
*/
public CssValue getHorizontalPosition() {
return first;
}
/**
* Returns the second value of the position
*/
public CssValue getVerticalPosition() {
return second;
}
/**
* Returns true if this property is "softly" inherited
* e.g. his value equals inherit
*/
public boolean isSoftlyInherited() {
return first == inherit;
}
/**
* Returns a string representation of the object.
*/
public String toString() {
if (first == inherit) {
return inherit.toString();
}
else {
String ret = "";
if (first != null) {
ret += first;
}
if (second != null) {
if (!ret.equals("")) {
ret += " ";
}
ret += second;
}
return ret;
}
}
private boolean isHorizontal(int index) {
return index == POSITION_LEFT || index == POSITION_RIGHT ||
index == POSITION_CENTER;
}
private boolean isVertical(int index) {
return index == POSITION_TOP || index == POSITION_BOTTOM ||
index == POSITION_CENTER;
}
/*
private void getPercentageFromIdent(int first, int second) {
this.first = DefaultValue50;
this.second = DefaultValue50;
if (first == POSITION_LEFT || second == POSITION_LEFT)
this.first = DefaultValue0;
if (first == POSITION_RIGHT || second == POSITION_RIGHT)
this.first = DefaultValue100;
if (first == POSITION_TOP || second == POSITION_TOP)
this.second = DefaultValue0;
if (first == POSITION_BOTTOM || second == POSITION_BOTTOM)
this.second = DefaultValue100;
}
*/
/**
* Add this property to the CssStyle.
*
* @param style The CssStyle
*/
public void addToStyle(ApplContext ac, CssStyle style) {
CssBackgroundCSS1 cssBackground = ((Css1Style) style).cssBackgroundCSS1;
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).getBackgroundPositionCSS1();
} else {
return ((Css1Style) style).cssBackgroundCSS1.position;
}
}
/**
* Compares two properties for equality.
*
* @param value The other property.
*/
public boolean equals(CssProperty property) {
return (property instanceof CssBackgroundPositionCSS1 &&
first.equals(((CssBackgroundPositionCSS1) property).first)
&& second.equals(((CssBackgroundPositionCSS1) property).second));
}
/**
* Is the value of this property is a default value.
* It is used by all macro for the function print
*/
public boolean isDefault() {
return first.equals(DefaultValue0) && second.equals(DefaultValue0);
}
private int IndexOfIdent(String ident) throws InvalidParamException {
int hash = ident.hashCode();
for (int i = 0; i < POSITION.length; i++)
if (hash_values[i] == hash)
return i;
return -1;
}
private static int[] hash_values;
//private static int INVALID = -1;
private static CssPercentage DefaultValue0 = new CssPercentage(0);
//private static CssPercentage DefaultValue50 = new CssPercentage(50);
//private static CssPercentage DefaultValue100 = new CssPercentage(100);
static {
hash_values = new int[POSITION.length];
for (int i = 0; i < POSITION.length; i++)
hash_values[i] = POSITION[i].hashCode();
}
}