AbstractSVGPrimitiveTranslator.java

/*
 * Copyright 2017 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed 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.kie.workbench.common.stunner.svg.gen.translator.impl;

import org.apache.commons.lang3.StringUtils;
import org.kie.workbench.common.stunner.svg.gen.exception.TranslatorException;
import org.kie.workbench.common.stunner.svg.gen.model.LayoutDefinition;
import org.kie.workbench.common.stunner.svg.gen.model.StyleDefinition;
import org.kie.workbench.common.stunner.svg.gen.model.TransformDefinition;
import org.kie.workbench.common.stunner.svg.gen.model.impl.AbstractPrimitiveDefinition;
import org.kie.workbench.common.stunner.svg.gen.translator.SVGDocumentTranslator;
import org.kie.workbench.common.stunner.svg.gen.translator.SVGElementTranslator;
import org.kie.workbench.common.stunner.svg.gen.translator.SVGTranslatorContext;
import org.kie.workbench.common.stunner.svg.gen.translator.css.SVGAttributeParserUtils;
import org.kie.workbench.common.stunner.svg.gen.translator.css.SVGStyleTranslatorHelper;
import org.w3c.dom.Element;

public abstract class AbstractSVGPrimitiveTranslator<E extends Element, O extends AbstractPrimitiveDefinition<?>>
        implements SVGElementTranslator<E, O> {

    private static final String ID = "id";
    private static final String X = "x";
    private static final String Y = "y";

    protected abstract O doTranslate(final E pathElement,
                                     final SVGTranslatorContext context) throws TranslatorException;

    @Override
    public O translate(final E element,
                       final SVGTranslatorContext context) throws TranslatorException {
        // Delegate to subtypes the instantiation and initial population of the definition.
        final O def = doTranslate(element,
                                  context);
        if (null != def) {
            // Parse the stunner's specific primitives attributes.
            translatePrimitiveSpecific(element,
                                       def,
                                       context);
            // Parse the stunner's child layout, if any.
            translateLayout(element,
                            def,
                            context);
            // Parse and populate the definition with styles.
            translateStyles(element,
                            def,
                            context);
            // Same for transforms.
            translateTransforms(element,
                                def,
                                context);
        }
        return def;
    }

    protected void translatePrimitiveSpecific(final E element,
                                              final O def,
                                              final SVGTranslatorContext context) throws TranslatorException {
        // Position.
        translatePosition(element,
                          def,
                          context);
        // Other tags for custom stunner's namespace.
        final String shapeRaw = element.getAttributeNS(SVGDocumentTranslator.STUNNER_URI,
                                                       SVGDocumentTranslator.STUNNER_ATTR_SHAPE);
        final boolean nonScalable = isEmpty(shapeRaw)
                || !SVGDocumentTranslator.STUNNER_ATTR_SHAPE_SCALABLE_GROUP.equalsIgnoreCase(shapeRaw);
        final boolean isMainShape = !isEmpty(shapeRaw)
                && SVGDocumentTranslator.STUNNER_ATTR_SHAPE_MAIN.equalsIgnoreCase(shapeRaw);
        def.setScalable(!nonScalable);
        def.setMainShape(isMainShape);
    }

    protected void translatePosition(final E element,
                                     final O def,
                                     final SVGTranslatorContext context) throws TranslatorException {
        final String xr = element.getAttribute(getXAttributeName());
        final String yr = element.getAttribute(getYAttributeName());
        final double x = SVGAttributeParserUtils.toPixelValue(xr,
                                                              0d);
        final double y = SVGAttributeParserUtils.toPixelValue(yr,
                                                              0d);
        def.setX(x);
        def.setY(y);
    }

    protected String getXAttributeName() {
        return X;
    }

    protected String getYAttributeName() {
        return Y;
    }

    protected LayoutDefinition translateLayout(final E element,
                                               final O def,
                                               final SVGTranslatorContext context) throws TranslatorException {
        final String layoutRaw = element.getAttributeNS(SVGDocumentTranslator.STUNNER_URI,
                                                        SVGDocumentTranslator.STUNNER_ATTR_LAYOUT);
        final LayoutDefinition l = isEmpty(layoutRaw) ? LayoutDefinition.NONE : LayoutDefinition.valueOf(layoutRaw);
        def.setLayoutDefinition(l);
        return l;
    }

    protected TransformDefinition translateTransforms(final E element,
                                                      final O def,
                                                      final SVGTranslatorContext context) throws TranslatorException {
        final TransformDefinition transformDefinition = SVGStyleTranslatorHelper.parseTransformDefinition(element);
        def.setTransformDefinition(transformDefinition);
        return transformDefinition;
    }

    protected StyleDefinition translateStyles(final E element,
                                              final O def,
                                              final SVGTranslatorContext context) throws TranslatorException {
        final StyleDefinition styleDefinition = SVGStyleTranslatorHelper.parseStyleDefinition(element);
        def.setAlpha(styleDefinition.getAlpha());
        return styleDefinition;
    }

    protected String getId(final Element element) {
        return element.getAttribute(ID);
    }

    protected static void failIfEmpty(final String key,
                                      final String value) throws TranslatorException {
        if (isEmpty(value)) {
            throw new TranslatorException("Empty value for key [" + key + "]");
        }
    }

    protected static boolean isEmpty(final String s) {
        return StringUtils.isEmpty(s);
    }
}