annis.gui.components.OnLoadCallbackExtension.java Source code

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Here is the source code for annis.gui.components.OnLoadCallbackExtension.java

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/*
 * Copyright 2013 Corpuslinguistic working group Humboldt University Berlin.
 *
 * 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 annis.gui.components;

import com.vaadin.annotations.JavaScript;
import com.vaadin.server.AbstractClientConnector;
import com.vaadin.server.AbstractJavaScriptExtension;
import com.vaadin.ui.JavaScriptFunction;
import elemental.json.JsonArray;
import org.json.JSONException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 *
 * @author Thomas Krause <krauseto@hu-berlin.de>
 */
@JavaScript({ "vaadin://jquery.js", "onloadcallback.js" })
public class OnLoadCallbackExtension extends AbstractJavaScriptExtension {

    private static final Logger log = LoggerFactory.getLogger(OnLoadCallbackExtension.class);
    private AbstractClientConnector target;

    public OnLoadCallbackExtension(Callback c) {
        this(c, 250);
    }

    public OnLoadCallbackExtension(final Callback c, final int recallDelay) {
        addFunction("loaded", new JavaScriptFunction() {
            @Override
            public void call(JsonArray arguments) throws JSONException {
                if (c != null) {
                    boolean handled = c.onCompononentLoaded(target);
                    if (!handled) {
                        callFunction("requestRecall", recallDelay);
                    }
                }
            }
        });
    }

    @Override
    public void extend(AbstractClientConnector target) {
        super.extend(target);
        this.target = target;
    }

    /**
     * A callback for {@link OnLoadCallbackExtension}.
     */
    public static interface Callback {

        /**
         * Called whenever the extended component was rendered. If you want to get a
         * repeated callback (e.g. because you are waiting for a longer process to
         * complete it's calculation) you can return "false".
         *
         * @param source
         * @return True if handled, if false the callback will be called again after
         * a certain time span.
         */
        public boolean onCompononentLoaded(AbstractClientConnector source);
    }
}