thothbot.parallax.loader.shared.XHRLoader.java Source code

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Here is the source code for thothbot.parallax.loader.shared.XHRLoader.java

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/*
 * Copyright 2012 Alex Usachev, thothbot@gmail.com
 * 
 * This file is part of Parallax project.
 * 
 * Parallax is free software: you can redistribute it and/or modify it 
 * under the terms of the Creative Commons Attribution 3.0 Unported License.
 * 
 * Parallax is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
 * or FITNESS FOR A PARTICULAR PURPOSE. See the Creative Commons Attribution 
 * 3.0 Unported License. for more details.
 * 
 * You should have received a copy of the the Creative Commons Attribution 
 * 3.0 Unported License along with Parallax. 
 * If not, see http://creativecommons.org/licenses/by/3.0/.
 */

package thothbot.parallax.loader.shared;

import java.util.ArrayList;
import java.util.List;

import thothbot.parallax.core.client.gl2.arrays.ArrayBuffer;
import thothbot.parallax.core.shared.Log;
import thothbot.parallax.core.shared.core.AbstractGeometry;

import com.google.gwt.xhr.client.ReadyStateChangeHandler;
import com.google.gwt.xhr.client.XMLHttpRequest;
import com.google.gwt.xhr.client.XMLHttpRequest.ResponseType;

public abstract class XHRLoader {
    private static List<ModelLoadHandler> loadHandlers = new ArrayList<ModelLoadHandler>();
    private static LoaderProgressHandler loaderProgressHandler;

    public static void addLoaderProgress(LoaderProgressHandler loaderProgressHandler) {
        XHRLoader.loaderProgressHandler = loaderProgressHandler;
    }

    public interface LoaderProgressHandler {
        public void onProgressUpdate(int left);
    }

    public interface ModelLoadHandler {
        public void onModelLoaded(XHRLoader loader, AbstractGeometry geometry);
    }

    private String url;
    private String texturePath;
    private ModelLoadHandler modelLoadHandler;
    private ResponseType responseType = ResponseType.Default;

    public XHRLoader(String url, ModelLoadHandler modelLoadHandler) {
        this.url = url;
        this.texturePath = extractUrlBase(url);

        this.modelLoadHandler = modelLoadHandler;
    }

    protected void load() {
        final XMLHttpRequest request = XMLHttpRequest.create();
        request.open("GET", url);
        request.setResponseType(this.responseType);
        request.send(null);

        loadHandlers.add(modelLoadHandler);

        if (XHRLoader.loaderProgressHandler != null)
            XHRLoader.loaderProgressHandler.onProgressUpdate(loadHandlers.size());

        request.setOnReadyStateChange(new ReadyStateChangeHandler() {

            @Override
            public void onReadyStateChange(XMLHttpRequest xhr) {
                if (xhr.getReadyState() == XMLHttpRequest.DONE) {
                    if (xhr.getStatus() >= 400) {
                        Log.error("Error while loading file: " + url + ", status: " + xhr.getStatus());
                    } else {
                        AbstractGeometry geometry = null;

                        if (xhr.getResponseType().equals("arraybuffer")) {
                            com.google.gwt.typedarrays.shared.ArrayBuffer origin = xhr.getResponseArrayBuffer();

                            geometry = parse(ArrayBuffer.copy(origin));
                        } else
                            geometry = parse(xhr.getResponseText());

                        modelLoadHandler.onModelLoaded(XHRLoader.this, geometry);
                    }

                    request.clearOnReadyStateChange();
                    request.abort();

                    loadHandlers.remove(modelLoadHandler);
                    if (XHRLoader.loaderProgressHandler != null)
                        XHRLoader.loaderProgressHandler.onProgressUpdate(loadHandlers.size());
                }
            }
        });
    }

    protected abstract AbstractGeometry parse(String string);

    protected AbstractGeometry parse(ArrayBuffer buffer) {
        return null;
    }

    public String getTexturePath() {
        return this.texturePath;
    }

    public void setResponseType(ResponseType responseType) {
        this.responseType = responseType;
    }

    private String extractUrlBase(String url) {
        int i = url.lastIndexOf('/');
        if (i >= 0) {
            return url.substring(0, i) + '/';
        } else {
            return "";
        }
    }
}