/*

   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */
package org.apache.batik.dom.svg;

import org.apache.batik.parser.AngleParser;
import org.apache.batik.parser.DefaultAngleHandler;
import org.apache.batik.parser.ParseException;

import org.w3c.dom.DOMException;
import org.w3c.dom.svg.SVGAngle;

Implementation of an SVGAngle not associated with any attribute. 
Author:
Cameron McCormack
Version:
$Id: SVGOMAngle.java 1733416 2016-03-03 07:07:13Z gadams $/**
 * Implementation of an {@link SVGAngle} not associated with any attribute.
 *
 * @author <a href="mailto:cam%40mcc%2eid%2eau">Cameron McCormack</a>
 * @version $Id: SVGOMAngle.java 1733416 2016-03-03 07:07:13Z gadams $
 */
public class SVGOMAngle implements SVGAngle {

    
The type of this angle.
/**
     * The type of this angle.
     */
    private short unitType;

    
The value of this angle.
/**
     * The value of this angle.
     */
    protected float value;

    
The unit string representations.
/**
     * The unit string representations.
     */
    protected static final String[] UNITS = {
        "", "", "deg", "rad", "grad"
    };

    
DOM: Implements SVGAngle.getUnitType(). /**
     * <b>DOM</b>: Implements {@link SVGAngle#getUnitType()}.
     */
    public short getUnitType() {
        revalidate();
        return unitType;
    }

    
DOM: Implements SVGAngle.getValue(). /**
     * <b>DOM</b>: Implements {@link SVGAngle#getValue()}.
     */
    public float getValue() {
        revalidate();
        return toUnit(getUnitType(), value, SVG_ANGLETYPE_DEG);
    }

    
DOM: Implements SVGAngle.setValue(float). /**
     * <b>DOM</b>: Implements {@link SVGAngle#setValue(float)}.
     */
    public void setValue(float value) throws DOMException {
        revalidate();
        this.setUnitType(SVG_ANGLETYPE_DEG);
        this.value = value;
        reset();
    }

    
DOM: Implements SVGAngle.getValueInSpecifiedUnits(). /**
     * <b>DOM</b>: Implements {@link SVGAngle#getValueInSpecifiedUnits()}.
     */
    public float getValueInSpecifiedUnits() {
        revalidate();
        return value;
    }

    
DOM: Implements SVGAngle.setValueInSpecifiedUnits(float). /**
     * <b>DOM</b>: Implements {@link
     * SVGAngle#setValueInSpecifiedUnits(float)}.
     */
    public void setValueInSpecifiedUnits(float value) throws DOMException {
        revalidate();
        this.value = value;
        reset();
    }

    
DOM: Implements SVGAngle.getValueAsString(). /**
     * <b>DOM</b>: Implements {@link SVGAngle#getValueAsString()}.
     */
    public String getValueAsString() {
        revalidate();
        return Float.toString(value) + UNITS[getUnitType()];
    }

    
DOM: Implements SVGAngle.setValueAsString(String). /**
     * <b>DOM</b>: Implements {@link SVGAngle#setValueAsString(String)}.
     */
    public void setValueAsString(String value) throws DOMException {
        parse(value);
        reset();
    }

    
DOM: Implements SVGAngle.newValueSpecifiedUnits(short, float). /**
     * <b>DOM</b>: Implements {@link
     * SVGAngle#newValueSpecifiedUnits(short,float)}.
     */
    public void newValueSpecifiedUnits(short unit, float value) {
        setUnitType(unit);
        this.value = value;
        reset();
    }

    
DOM: Implements SVGAngle.convertToSpecifiedUnits(short). /**
     * <b>DOM</b>: Implements {@link
     * SVGAngle#convertToSpecifiedUnits(short)}.
     */
    public void convertToSpecifiedUnits(short unit) {
        value = toUnit(getUnitType(), value, unit);
        setUnitType(unit);
    }

    
Resets the associated attribute value according to the current value.
This should be overridden in descendant classes that associate the
angle object with an attribute.
/**
     * Resets the associated attribute value according to the current value.
     * This should be overridden in descendant classes that associate the
     * angle object with an attribute.
     */
    protected void reset() {
    }

    
Updates the values in this object according to the associated attribute
value.  This should be overridden in descendant classes that associate
the angle object with an attribute.
/**
     * Updates the values in this object according to the associated attribute
     * value.  This should be overridden in descendant classes that associate
     * the angle object with an attribute.
     */
    protected void revalidate() {
    }

    
Parse a String value as an SVGAngle.
/**
     * Parse a String value as an SVGAngle.
     */
    protected void parse(String s) {
        try {
            AngleParser angleParser = new AngleParser();
            angleParser.setAngleHandler(new DefaultAngleHandler() {
                public void angleValue(float v) throws ParseException {
                    value = v;
                }
                public void deg() throws ParseException {
                    setUnitType(SVG_ANGLETYPE_DEG);
                }
                public void rad() throws ParseException {
                    setUnitType(SVG_ANGLETYPE_RAD);
                }
                public void grad() throws ParseException {
                    setUnitType(SVG_ANGLETYPE_GRAD);
                }
            });
            setUnitType(SVG_ANGLETYPE_UNSPECIFIED);
            angleParser.parse(s);
        } catch (ParseException e) {
            setUnitType(SVG_ANGLETYPE_UNKNOWN);
            value = 0;
        }
    }

    
Table of multipliers for angle unit conversion.
/**
     * Table of multipliers for angle unit conversion.
     */
    protected static double[][] K = {
        {             1,      Math.PI / 180,        Math.PI / 200 },
        { 180 / Math.PI,                  1, 1800 / (9 * Math.PI) },
        {           0.9, 9 * Math.PI / 1800,                    1 }
    };

    
Converts an angle from one unit to another.
/**
     * Converts an angle from one unit to another.
     */
    public static float toUnit(short fromUnit, float value, short toUnit) {
        if (fromUnit == 1) {
            fromUnit = 2;
        }
        if (toUnit == 1) {
            toUnit = 2;
        }
        return (float) (K[fromUnit - 2][toUnit - 2] * value);
    }

    public void setUnitType(short unitType) {
        this.unitType = unitType;
    }
}