com.mecatran.otp.gwt.client.view.AddressAutoCompleteBox.java Source code

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Here is the source code for com.mecatran.otp.gwt.client.view.AddressAutoCompleteBox.java

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/* -------------------------------------------------------------------------
OpenTripPlanner GWT Client
Copyright (C) 2015 Mecatran - info@mecatran.com
    
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
    
This program 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
GNU General Public License for more details.
    
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
   ------------------------------------------------------------------------- */
package com.mecatran.otp.gwt.client.view;

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

import com.google.gwt.event.dom.client.FocusEvent;
import com.google.gwt.event.dom.client.FocusHandler;
import com.google.gwt.event.logical.shared.SelectionEvent;
import com.google.gwt.event.logical.shared.SelectionHandler;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.SuggestBox;
import com.google.gwt.user.client.ui.SuggestOracle;
import com.google.gwt.user.client.ui.SuggestOracle.Suggestion;
import com.google.gwt.user.client.ui.Widget;
import com.mecatran.otp.gwt.client.model.LocationBean;
import com.mecatran.otp.gwt.client.proxies.GeocoderProxy;
import com.mecatran.otp.gwt.client.proxies.GeocoderProxy.GeocoderListener;

/**
 * An implementation of an AddressBox with auto-completion on input.
 * 
 * Drawback: load heavily the geocoder as up to one request can be made per user
 * keystroke.
 * 
 */
public class AddressAutoCompleteBox extends Composite implements AddressBox {

    private GeocodingOracle oracle;
    private SuggestBox suggestBox;
    private LocationBean location;
    private AddressSuggestBoxListener listener;

    public AddressAutoCompleteBox() {
        oracle = new GeocodingOracle();
        suggestBox = new SuggestBox(oracle);
        suggestBox.setAutoSelectEnabled(false);
        suggestBox.setText("");
        suggestBox.addValueChangeHandler(new ValueChangeHandler<String>() {
            @Override
            public void onValueChange(ValueChangeEvent<String> event) {
                if (location != null)
                    location.setLocation(null);
                // TODO ???
            }
        });
        suggestBox.addSelectionHandler(new SelectionHandler<Suggestion>() {
            @Override
            public void onSelection(SelectionEvent<Suggestion> event) {
                GeocodedAddressSuggestion geocodedSuggestion = (GeocodedAddressSuggestion) event.getSelectedItem();
                location = geocodedSuggestion.getLocation();
                listener.onLocationSelected(location);
            }
        });
        suggestBox.getValueBox().addFocusHandler(new FocusHandler() {
            @Override
            public void onFocus(FocusEvent event) {
                listener.onFocus();
            }
        });
        HorizontalPanel rootPanel = new HorizontalPanel();
        rootPanel.add(suggestBox);
        initWidget(rootPanel);
    }

    @Override
    public void setAddressSuggestBoxListener(AddressSuggestBoxListener listener) {
        this.listener = listener;
    }

    @Override
    public LocationBean getLocation() {
        if (location == null)
            location = new LocationBean();
        location.setAddress(suggestBox.getText());
        return location;
    }

    @Override
    public void setLocation(LocationBean location) {
        this.location = location;
        suggestBox.setText(location.getAddress());
    }

    @Override
    public void setGeocoderProxy(GeocoderProxy geocoderProxy) {
        oracle.setGeocoderProxy(geocoderProxy);
    }

    @Override
    public Widget getAsWidget() {
        return this;
    }

    private static class GeocodingOracle extends SuggestOracle {

        private GeocoderProxy geocoderProxy;

        public GeocodingOracle() {
        }

        public void setGeocoderProxy(GeocoderProxy geocoderProxy) {
            this.geocoderProxy = geocoderProxy;
        }

        @Override
        public void requestSuggestions(final Request request, final Callback callback) {
            if (geocoderProxy == null)
                return;
            geocoderProxy.geocode(request.getQuery(), new GeocoderListener() {

                @Override
                public void onGeocodingDone(List<LocationBean> locations) {
                    Response response = new Response();
                    List<Suggestion> suggestions = new ArrayList<Suggestion>();
                    if (locations != null) {
                        int n = 0;
                        for (LocationBean location : locations) {
                            if (n >= request.getLimit())
                                break;
                            suggestions.add(new GeocodedAddressSuggestion(location));
                            n++;
                        }
                        if (locations.size() > n)
                            response.setMoreSuggestionsCount(locations.size() - n);
                    }
                    response.setSuggestions(suggestions);
                    callback.onSuggestionsReady(request, response);
                }
            });
        }
    }

    private static class GeocodedAddressSuggestion implements Suggestion {

        private LocationBean location;

        public GeocodedAddressSuggestion(LocationBean location) {
            this.location = location;
        }

        @Override
        public String getDisplayString() {
            return location.getAddress();
        }

        @Override
        public String getReplacementString() {
            return getDisplayString();
        }

        public LocationBean getLocation() {
            return location;
        }
    }

}