org.daisy.dotify.api.translator.DefaultAttributeWithContext Maven / Gradle / Ivy

Go to download
package org.daisy.dotify.api.translator;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Optional;

/**
 * Provides a default implementation of attributes with context.
 *
 * @author Joel Håkansson
 */
public class DefaultAttributeWithContext implements AttributeWithContext {
    protected final int length;
    private final Optional name;
    private final List attributes;

    /**
     * Provides a builder for a default text attribute.
     */
    public static class Builder {
        private final String name;
        private final List attributes;

        /**
         * Creates a new builder.
         */
        public Builder() {
            this(null);
        }

        /**
         * Creates a new builder with the specified attribute name.
         *
         * @param attribute the attribute name
         */
        public Builder(String attribute) {
            this.attributes = new ArrayList<>();
            this.name = attribute;
        }

        /**
         * Adds a text attribute to the list of attributes.
         *
         * @param data the attribute
         * @return this builder
         */
        public Builder add(AttributeWithContext data) {
            attributes.add(data);
            return this;
        }

        /**
         * Adds a new attribute with the specified width.
         *
         * @param val the width of the attribute
         * @return this builder
         */
        public Builder add(int val) {
            attributes.add(new DefaultAttributeWithContext.Builder().build(val));
            return this;
        }

        /**
         * Creates a new default text attribute based on the current
         * state of the builder.
         *
         * @param length the total length of the contained attributes
         * @return a new default text attribute
         */
        public DefaultAttributeWithContext build(int length) {
            return new DefaultAttributeWithContext(length, this);
        }
    }

    protected DefaultAttributeWithContext(int length, Builder builder) {
        this.length = length;
        this.name = Optional.ofNullable(builder.name);
        this.attributes = builder.attributes;
        int s = 0;
        for (AttributeWithContext a : builder.attributes) {
            s += a.getWidth();
        }
        if (s > 0 && s != length) {
            throw new IllegalArgumentException(
                "Text attribute size (" + s + ") does not match specified length (" + length + ")."
            );
        }
    }

    @Override
    public int getWidth() {
        return length;
    }

    @Override
    public boolean hasChildren() {
        return !attributes.isEmpty();
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        for (AttributeWithContext t : attributes) {
            sb.append('\n').append(t.toString());
        }
        return this.getClass().getSimpleName() +
            " [length=" + length + (name != null ? ", name=" + name : "") + ", attributes=" + sb.toString() + "]";
    }

    @Override
    public Optional getName() {
        return name;
    }

    @Override
    public Iterator iterator() {
        return attributes.iterator();
    }

}