org.waveprotocol.wave.client.gadget.renderer.GadgetUserPrefs.java Source code

Introduction

Here is the source code for org.waveprotocol.wave.client.gadget.renderer.GadgetUserPrefs.java

Source

/**
 * 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.waveprotocol.wave.client.gadget.renderer;

import static org.waveprotocol.wave.client.gadget.GadgetLog.log;

import com.google.gwt.json.client.JSONObject;
import com.google.gwt.json.client.JSONValue;
import org.waveprotocol.wave.client.gadget.StateMap;

/**
 * Gadget user preferences container and parser class.
 *
 */
public final class GadgetUserPrefs extends StateMap {
    /**
     * External construction is banned.
     */
    protected GadgetUserPrefs() {
    }

    /**
     * Creates gadget state object.
     */
    public static GadgetUserPrefs create() {
        return StateMap.create().cast();
    }

    /**
     * Extracts default preference values from the gadget metadata JSON object
     * returned from GGS.
     *
     * @param prefs the preference JSON object received from GGS.
     */
    public void parseDefaultValues(JSONObject prefs) {
        if (prefs != null) {
            for (String pref : prefs.keySet()) {
                if (!has(pref)) {
                    JSONObject prefJson = prefs.get(pref).isObject();
                    if (prefJson != null) {
                        JSONValue value = prefJson.get("default");
                        if ((value != null) && (value.isString() != null)) {
                            put(pref, value.isString().stringValue());
                            log("Gadget pref '" + pref + "' = '" + get(pref) + "'");
                        }
                    } else {
                        log("Invalid pref '" + pref + "' value in Gadget metadata.");
                    }
                }
            }
        }
    }

    /**
     * Merges data from a state object containing another set of preference values.
     *
     * @param state state object with preference values to merge.
     * @param overwrite true to overwrite values in this object with values from
     *        the merged object; false to ignore values from the merged object if
     *        they are present in this object.
     */
    public void parse(StateMap state, final boolean overwrite) {
        if (state != null) {
            state.each(new StateMap.Each() {
                @Override
                public void apply(String key, String value) {
                    setPref(key, value, overwrite);
                }
            });
        }
    }

    /**
     * Assigns an individual preference key.
     *
     * @param pref Preference name.
     * @param value JSON value assigned to this key.
     * @param overwrite If true, will overwrite any value already assigned to this
     *        key.
     */
    public void setPref(String pref, String value, boolean overwrite) {
        if (overwrite || has(pref)) {
            put(pref, value);
        }
    }
}