w3c.css.properties.css3.CssBackgroundAttachment Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of cssvalidator Show documentation
Backend for the W3C CSS Validation Service
There is a newer version: 1.0.8
// $Id$
// @author Yves Lafon 

// (c) COPYRIGHT MIT, ERCIM and Keio, 2010.
// Please first read the full copyright statement in file COPYRIGHT.html

package org.w3c.css.properties.css3;

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.CssLayerList;
import org.w3c.css.values.CssTypes;
import org.w3c.css.values.CssValue;

import java.util.ArrayList;

import static org.w3c.css.values.CssOperator.COMMA;

/**
 * @spec http://www.w3.org/TR/2009/CR-css3-background-20091217/#the-background-attachment
 */
public class CssBackgroundAttachment extends org.w3c.css.properties.css.CssBackgroundAttachment {

    private static CssIdent[] allowed_values;

    static {
        allowed_values = new CssIdent[3];
        allowed_values[0] = CssIdent.getIdent("scroll");
        allowed_values[1] = CssIdent.getIdent("fixed");
        allowed_values[2] = CssIdent.getIdent("local");
    }

    public static boolean isMatchingIdent(CssIdent ident) {
        for (CssIdent id : allowed_values) {
            if (id.equals(ident)) {
                return true;
            }
        }
        return false;
    }

    public static CssIdent getMatchingIdent(CssIdent ident) {
        for (CssIdent id : allowed_values) {
            if (id.equals(ident)) {
                return id;
            }
        }
        return null;
    }

    /**
     * Create a new CssBackgroundAttachment
     */
    public CssBackgroundAttachment() {
        value = initial;
    }

    /**
     * Creates a new CssBackgroundAttachment
     *
     * @param ac         the context
     * @param expression The expression for this property
     * @param check      if some length checking is required
     * @throws org.w3c.css.util.InvalidParamException
     *          Values are incorrect
     */
    public CssBackgroundAttachment(ApplContext ac, CssExpression expression,
                                   boolean check) throws InvalidParamException {

        ArrayList values = new ArrayList();
        char op;
        CssValue val;

        setByUser();

        while (!expression.end()) {
            val = expression.getValue();
            op = expression.getOperator();
            if (val.getType() != CssTypes.CSS_IDENT) {
                throw new InvalidParamException("value", val,
                        getPropertyName(), ac);
            }
            if (inherit.equals(val)) {
                // if we got inherit after other values, fail
                // if we got more than one value... fail
                if ((values.size() > 0) || (expression.getCount() > 1)) {
                    throw new InvalidParamException("value", val,
                            getPropertyName(), ac);
                }
                values.add(inherit);
            } else {
                // check that it's in the allowed values
                CssValue new_val = getMatchingIdent((CssIdent) val);
                if (new_val == null) {
                    throw new InvalidParamException("value", val,
                            getPropertyName(), ac);
                }
                values.add(new_val);
            }
            expression.next();
            // and check that values are separated by commas
            if (!expression.end() && (op != COMMA)) {
                throw new InvalidParamException("operator",
                        ((new Character(op)).toString()), ac);
            }
        }

        if (values.size() == 1) {
            value = values.get(0);
        } else {
            value = new CssLayerList(values);
        }
    }

    public CssBackgroundAttachment(ApplContext ac, CssExpression expression)
            throws InvalidParamException {
        this(ac, expression, false);
    }

    /**
     * Is the value of this property is a default value.
     * It is used by all macro for the function print
     */
    public boolean isDefault() {
        return (initial == value);
    }
}