DtachoViewer.java

package dtachoviewer.client;

import static com.google.gwt.safehtml.shared.SafeHtmlUtils.htmlEscape;
import static elemental.events.Event.CHANGE;
import static elemental.events.Event.COPY;
import static elemental.events.Event.DRAGLEAVE;
import static elemental.events.Event.DRAGOVER;
import static elemental.events.Event.DROP;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.typedarrays.shared.ArrayBuffer;
import com.google.gwt.typedarrays.shared.Int8Array;
import com.google.gwt.typedarrays.shared.TypedArrays;
import com.intendia.dtacho.DDDQuery.DDDDataSource;
import com.intendia.dtacho.DDDQuery.dumper.Content;
import com.intendia.dtacho.DDDQuery.dumper.ContentVisitor;
import com.intendia.dtacho.DDDQuery.dumper.Element;
import com.intendia.dtacho.DDDQuery.dumper.Text;
import com.intendia.dtacho.DDDQuery.internalData.DTCODataClass;
import elemental.client.Browser;
import elemental.dom.Clipboard;
import elemental.dom.Document;
import elemental.events.EventListener;
import elemental.html.DivElement;
import elemental.html.File;
import elemental.html.FileList;
import elemental.html.FileReader;
import elemental.html.InputElement;
import elemental.html.OutputElement;
import elemental.html.Window;

// http://www.html5rocks.com/en/tutorials/file/dndfiles/
public class DtachoViewer implements EntryPoint {
    private Window wnd;
    private OutputElement list;
    private OutputElement ddd;

    @Override public void onModuleLoad() {
        wnd = Browser.getWindow();
        Document doc = Browser.getDocument();

        if (def(wnd, "File") && def(wnd, "FileReader") && def(wnd, "FileList") && def(wnd, "Blob")) {
            // Great success! All the File APIs are supported.
        } else {
            wnd.alert("The File APIs are not fully supported in this browser.");
        }

        DivElement dropHere = doc.createDivElement();
        dropHere.setClassName("drop-here");

        InputElement file = doc.createInputElement();
        file.setType("file"); file.setId("files"); file.setName("files[]"); file.setMultiple(true);
        dropHere.appendChild(doc.createTextNode("Drop files here or use "));
        dropHere.appendChild(file);
        dropHere.appendChild(list = doc.createOutputElement());

        doc.getBody().appendChild(dropHere);
        doc.getBody().appendChild(ddd = doc.createOutputElement());

        file.addEventListener(CHANGE, evt -> show(((InputElement) evt.getTarget()).getFiles()), false);

        dropHere.addEventListener(DRAGOVER, evt -> {
            evt.stopPropagation();
            evt.preventDefault();
            dropHere.getClassList().add("dragover");
            js(evt, "dataTransfer", Clipboard.class).setDropEffect(COPY);
        }, false);
        dropHere.addEventListener(DRAGLEAVE, evt -> dropHere.getClassList().remove("dragover"), false);
        dropHere.addEventListener(DROP, evt -> {
            evt.stopPropagation();
            evt.preventDefault();
            dropHere.getClassList().remove("dragover");
            list.setInnerHTML("");
            ddd.setInnerHTML("");
            FileList files = js(evt, "dataTransfer", Clipboard.class).getFiles();
            wnd.getConsole().log("setting files to file");
            file.setFiles(files);
            show(files);
        }, false);
    }

    private void show(FileList files) {
        String out = "";
        for (int i = 0; i < files.length(); i++) {
            File f = files.item(i);

            final String name = htmlEscape(f.getName());
            final String type = htmlEscape(f.getType());
            out += "<li><strong>" + name + "</strong> (" + type + ") - " + f.getSize() + " bytes, "
                    + "last modified: " + f.getLastModifiedDate() + "</li>";

            FileReader reader = wnd.newFileReader();
            final EventListener eventListener = loaded -> {
                wnd.getConsole().log(loaded);

                final Object result = reader.getResult();
                wnd.getConsole().log(result);

                ArrayBuffer buf = (ArrayBuffer) result;
                final Int8Array int8Array = TypedArrays.createInt8Array(buf);
                final int length = int8Array.length();

                byte[] byteArray = new byte[length];
                for (int j = 0; j < length; j++) {
                    byteArray[j] = int8Array.get(j);
                }

                final DDDDataSource ds = new DDDDataSource();
                final DTCODataClass dtco = ds.processFile(f.getName(), byteArray);
                Element element = dtco.generateXMLElement();
                ddd.setInnerHTML(element.accept(new ContentVisitor<String>() {
                    public String element(Element node) {
                        switch (node.name) {
                            case "activityChangeInfo":
                            case "vuDetailedSpeedBlock" : {
                                String s = node.name + " ";
                                for (Content c : node.content)
                                    s += c.accept(new ContentVisitor<String>() {
                                        public String element(Element node) {
                                            String s = "";
                                            for (Content c : node.content) s += c.accept(this) + " ";
                                            return s;
                                        }
                                        public String text(Text node) { return node.text; }
                                    });
                                return s;
                            }
                            default: {
                                String s = "<label>" + node.name + "</label><ul>";
                                for (Content c : node.content) s += "<li>" + c.accept(this);
                                return s + "</ul>";
                            }
                        }
                    }
                    public String text(Text node) {
                        return node.text;
                    }
                }));
            };
            reader.setOnload(eventListener);
            reader.readAsArrayBuffer(f);
        }
        list.setInnerHTML("<ul>" + out + "</ul>");
    }

    static <T> T js(Object jso, String property, Class<T> as) { return js(jso, property); }

    static boolean def(Object jso, String property) { return js(jso, property) != null; }

    static native <T> T js(Object jso, String property) /*-{
        return property.split(".").reduce(function (acc, x) {
            return acc && acc[x];
        }, jso);
    }-*/;
}