CountrySelector.java

/*
 * WBI Indicator Explorer
 *
 * Copyright 2015 Sebastian Nogara <snogaraleal@gmail.com>
 *
 * This file is part of WBI.
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

package client.ui.views.country;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.KeyUpEvent;
import com.google.gwt.event.dom.client.KeyUpHandler;
import com.google.gwt.uibinder.client.UiBinder;
import com.google.gwt.uibinder.client.UiField;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.Widget;

import models.Country;

import client.managers.models.CountryManager;
import client.ui.components.MaterialItem;
import client.ui.components.MaterialSearch;

/**
 * Country selector implementing {@link CountryManager.View}.
 */
public class CountrySelector extends Composite
    implements CountryManager.View, CountryManager.Listener {

    /**
     * {@link MaterialItem} displaying a {@link Country}.
     */
    public static class Item extends MaterialItem {
        /**
         * {@code CountrySelector} that created this item.
         */
        private CountrySelector selector;

        /**
         * {@code Country} displayed in this item.
         */
        private Country country;

        /**
         * Initialize {@code Item}.
         *
         * @param selector {@link CountrySelector} that created this item.
         * @param country {@link Country} to display.
         */
        public Item(CountrySelector selector, Country country) {
            super();

            this.selector = selector;

            setCountry(country);
            setAnimationEnabled(true);
        }

        /**
         * Set the {@link Country} displayed in this item.
         *
         * @param country {@code Country} to display.
         */
        public void setCountry(Country country) {
            this.country = country;

            setTitleText(country.getName());
            setSubtitleText(country.getRegion().getName());
        }

        @Override
        public void onClick(ClickEvent event) {
            super.onClick(event);
            CountryManager manager = selector.getCurrentManager();
            manager.toggle(country);
        }
    }

    public interface CountrySelectorUiBinder
        extends UiBinder<Widget, CountrySelector> {}
    private static CountrySelectorUiBinder uiBinder =
        GWT.create(CountrySelectorUiBinder.class);

    /**
     * {@code Item} widgets by {@code Country}.
     */
    private Map<Country, Item> map = new HashMap<Country, Item>();

    /**
     * {@code CountryManager} this view is currently attached to.
     */
    private CountryManager manager;

    /**
     * Time required after a keystroke to perform a search.
     */
    private static final int SEARCH_INPUT_DELAY = 300;

    /**
     * Text of {@link CountrySelector#search}.
     */
    private String searchInputText;

    /**
     * Timer for performing a search.
     */
    private Timer searchInputTimer;

    /**
     * Search box.
     */
    @UiField
    public MaterialSearch search;

    /**
     * Panel containing {@link Item} widgets.
     */
    @UiField
    public FlowPanel panel;

    /**
     * Initialize {@code CountrySelector}.
     */
    public CountrySelector() {
        initWidget(uiBinder.createAndBindUi(this));

        searchInputTimer = new Timer() {
            @Override
            public void run() {
                if (searchInputText != null && !searchInputText.isEmpty()) {
                    manager.search(searchInputText);
                }
            }
        };

        search.addKeyUpHandler(new KeyUpHandler() {
            @Override
            public void onKeyUp(KeyUpEvent event) {
                searchInputText = search.getText().trim();
                searchInputTimer.cancel();

                if (searchInputText.isEmpty()) {
                    manager.clearSearch();

                    panel.clear();
                    map.clear();

                    List<Country> selectedCountries =
                        manager.getSelectedCountries();

                    onSearch(selectedCountries, selectedCountries);

                } else {
                    searchInputTimer.schedule(SEARCH_INPUT_DELAY);
                }
            }
        });
    }

    @Override
    public void onSearch(
            List<Country> countries,
            List<Country> selectedCountries) {

        panel.clear();
        map.clear();

        for (Country country : countries) {
            Item item = new Item(this, country);

            panel.add(item);
            map.put(country, item);

            if (selectedCountries.contains(country)) {
                item.setActive(true);
            }
        }
    }

    @Override
    public void onAdd(Country country) {
        Item item = map.get(country);
        if (item == null) {
            if (searchInputText == null || searchInputText.isEmpty()) {
                item = new Item(this, country);
                item.setActive(true);

                panel.add(item);
                map.put(country, item);
            }
        } else {
            item.setActive(true);
        }
    }

    @Override
    public void onRemove(Country country) {
        Item item = map.get(country);
        if (item != null) {
            item.setActive(false);
        }
    }

    @Override
    public void onClear(List<Country> selectedCountries) {
        search.setText("");
        searchInputText = null;
        manager.clearSearch();

        panel.clear();
        map.clear();
    }

    @Override
    public void onAttach(CountryManager manager) {
        assert this.manager == null;

        this.manager = manager;
        this.manager.addListener(this);
    }

    @Override
    public void onDetach() {
        assert this.manager != null;

        this.manager.removeListener(this);
        this.manager = null;
    }

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

    @Override
    public CountryManager getCurrentManager() {
        return manager;
    }
}