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

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// $Id$
// From Sijtsche de Jong ([email protected])
//
// (c) COPYRIGHT 1995-2000  World Wide Web Consortium (MIT, INRIA, Keio University)
// Please first read the full copyright statement at
// http://www.w3.org/Consortium/Legal/copyright-software-19980720

package org.w3c.css.properties.css3;

import org.w3c.css.util.ApplContext;
import org.w3c.css.util.InvalidParamException;
import org.w3c.css.util.Util;
import org.w3c.css.values.CssExpression;
import org.w3c.css.values.CssNumber;
import org.w3c.css.values.CssTypes;
import org.w3c.css.values.CssValue;

/**
 * @spec http://www.w3.org/TR/2011/REC-css3-color-20110607/#opacity
 */

public class CssOpacity extends org.w3c.css.properties.css.CssOpacity {

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

    /**
     * Create a new CssOpacity
     *
     * @param expression The expression for this property
     * @throws InvalidParamException Values are incorrect
     */
    public CssOpacity(ApplContext ac, CssExpression expression, boolean check)
            throws InvalidParamException {
        setByUser(); // tell this property is set by the user
        CssValue val = expression.getValue();

        switch (val.getType()) {
            case CssTypes.CSS_NUMBER:
                if (val.getRawType() == CssTypes.CSS_NUMBER) {
                    // this will generate a warning if necessary
                    CssNumber number = val.getNumber();
                    number.setFloatValue(clampedValue(ac, number.getValue()));
                } else {
                    // we can only check if >= 0 for now
                    val.getCheckableValue().warnPositiveness(ac, this);
                }
                value = val;
                break;
            case CssTypes.CSS_IDENT:
                if (inherit.equals(val)) {
                    value = inherit;
                    break;
                }
                // let it flow through the exception
            default:
                throw new InvalidParamException("value", val.toString(),
                        getPropertyName(), ac);
        }
        expression.next();
    }

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

    /**
     * Brings all values back between 0 and 1
     *
     * @param opacity The value to be modified if necessary
     */
    private float clampedValue(ApplContext ac, float opacity) {
        if (opacity < 0.f || opacity > 1.f) {
            ac.getFrame().addWarning("out-of-range", Util.displayFloat(opacity));
            return ((opacity < 0.f) ? 0.f : 1.f);
        }
        return opacity;
    }

    /**
     * Is the value of this property a default value It is used by all macro for
     * the function print
     */
    public boolean isDefault() {
        if (value.getRawType() == CssTypes.CSS_NUMBER) {
            try {
                return (value.getNumber().getValue() == 1.f);
            } catch (Exception ex) {
                return false;
            }
        }
        return (value == initial);
    }

}