PulseaudioGenericBindingProvider.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.openhab.binding.pulseaudio.internal;

import org.apache.commons.lang.StringUtils;
import org.openhab.binding.pulseaudio.PulseaudioBindingProvider;
import org.openhab.core.binding.BindingConfig;
import org.openhab.core.items.Item;
import org.openhab.core.library.items.DimmerItem;
import org.openhab.core.library.items.NumberItem;
import org.openhab.core.library.items.StringItem;
import org.openhab.core.library.items.SwitchItem;
import org.openhab.model.item.binding.AbstractGenericBindingProvider;
import org.openhab.model.item.binding.BindingConfigParseException;

/**
 * <p>
 * This class can parse information from the generic binding format and
 * provides Pulseaudio binding information from it. It registers as a
 * {@link PulseaudioBindingProvider} service as well.
 * </p>
 *
 * <p>
 * The syntax of the binding configuration strings accepted is the following:
 * <p>
 * <p>
 * <code>
 * 	pulseaudio="<sink-name>"
 * </code>
 * </p>
 *
 * <p>
 * Here are some examples for valid binding configuration strings:
 * <ul>
 * <li><code>pulseaudio="alsa_output.pci-0000_00_1b.0.analog-stereo"</code></li>
 * </ul>
 *
 * @author Tobias Bräutigam
 * @since 1.2.0
 */
public class PulseaudioGenericBindingProvider extends AbstractGenericBindingProvider
        implements PulseaudioBindingProvider {

    /**
     * {@inheritDoc}
     */
    @Override
    public String getBindingType() {
        return "pulseaudio";
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void validateItemType(Item item, String bindingConfig) throws BindingConfigParseException {
        if ((item instanceof NumberItem) || (item instanceof StringItem) || (item instanceof SwitchItem)
                || (item instanceof DimmerItem)) {
            return;
        }
        throw new BindingConfigParseException("item '" + item.getName() + "' is of type '"
                + item.getClass().getSimpleName()
                + "', which is not supported by the pulseaudio binding - please check your *.items configuration");
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void processBindingConfiguration(String context, Item item, String bindingConfig)
            throws BindingConfigParseException {
        PulseaudioBindingConfig config = new PulseaudioBindingConfig();
        String[] configParts = bindingConfig.split(":");
        if (item instanceof StringItem) {
            if (configParts.length != 1 && configParts.length != 3) {
                throw new BindingConfigParseException(
                        "Pulseaudio binding configuration for StringItems must consist of one or three part [config="
                                + configParts + "]");
            }
            config.serverId = StringUtils.trim(configParts[0]);
            config.itemType = item.getClass();

            addBindingConfig(item, config);
            return;
        } else if (configParts.length < 2 || configParts.length > 3) {
            throw new BindingConfigParseException(
                    "Pulseaudio binding configuration must consist of two or three parts [config=" + configParts + "]");
        }

        config.serverId = StringUtils.trim(configParts[0]);
        config.itemName = StringUtils.trim(configParts[1]);
        if (configParts.length == 3) {
            config.command = StringUtils.trim(configParts[2]);
        }
        config.itemType = item.getClass();

        addBindingConfig(item, config);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getItemName(String itemName) {
        PulseaudioBindingConfig config = (PulseaudioBindingConfig) bindingConfigs.get(itemName);
        return config != null ? config.itemName : null;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getServerId(String itemName) {
        PulseaudioBindingConfig config = (PulseaudioBindingConfig) bindingConfigs.get(itemName);
        return config != null ? config.serverId : null;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Class<? extends Item> getItemType(String itemName) {
        PulseaudioBindingConfig config = (PulseaudioBindingConfig) bindingConfigs.get(itemName);
        return config != null ? config.itemType : null;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getCommand(String itemName) {
        PulseaudioBindingConfig config = (PulseaudioBindingConfig) bindingConfigs.get(itemName);
        return config != null ? config.command : null;
    }

    /**
     * This is an internal data structure to store information from the binding
     * config strings and use it to answer the requests to the Pulseaudio binding
     * provider.
     * 
     * @author Tobias Bräutigam
     */
    static private class PulseaudioBindingConfig implements BindingConfig {

        public String serverId;
        public String itemName;
        public String command;
        public Class<? extends Item> itemType;

    }

}