DatePickerWithYearSelector.java

package es.upm.fi.dia.oeg.map4rdf.client.widget;

import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.user.client.ui.Grid;
import com.google.gwt.user.client.ui.HTMLTable.CellFormatter;
import com.google.gwt.user.client.ui.PushButton;
import com.google.gwt.user.datepicker.client.CalendarModel;
import com.google.gwt.user.datepicker.client.DatePicker;
import com.google.gwt.user.datepicker.client.DefaultCalendarView;
import com.google.gwt.user.datepicker.client.MonthSelector;

public class DatePickerWithYearSelector extends DatePicker {

	public DatePickerWithYearSelector() {
		super(new MonthAndYearSelector(), new DefaultCalendarView(),
				new CalendarModel());
		MonthAndYearSelector monthSelector = (MonthAndYearSelector) this
				.getMonthSelector();
		monthSelector.setPicker(this);
		monthSelector.setModel(this.getModel());
	}

	public void refreshComponents() {
		super.refreshAll();
	}

	private static class MonthAndYearSelector extends MonthSelector {

		private static String BASE_NAME = "datePicker";

		private PushButton backwards;
		private PushButton forwards;
		private PushButton backwardsYear;
		private PushButton forwardsYear;
		private Grid grid;
		private int previousYearColumn = 0;
		private int previousMonthColumn = 1;
		private int monthColumn = 2;
		private int nextMonthColumn = 3;
		private int nextYearColumn = 4;
		private CalendarModel model;
		private DatePickerWithYearSelector picker;

		public void setModel(CalendarModel model) {
			this.model = model;
		}

		public void setPicker(DatePickerWithYearSelector picker) {
			this.picker = picker;
		}

		@Override
		protected void refresh() {
			String formattedMonth = getModel().formatCurrentMonth();
			grid.setText(0, monthColumn, formattedMonth);
		}

		@Override
		protected void setup() {
			// Set up backwards.
			backwards = new PushButton();
			backwards.addClickHandler(new ClickHandler() {
				public void onClick(ClickEvent event) {
					addMonths(-1);
				}
			});

			backwards.getUpFace().setHTML("‹");
			backwards.setStyleName(BASE_NAME + "PreviousButton");

			forwards = new PushButton();
			forwards.getUpFace().setHTML("›");
			forwards.setStyleName(BASE_NAME + "NextButton");
			forwards.addClickHandler(new ClickHandler() {
				public void onClick(ClickEvent event) {
					addMonths(+1);
				}
			});

			// Set up backwards year
			backwardsYear = new PushButton();
			backwardsYear.addClickHandler(new ClickHandler() {
				public void onClick(ClickEvent event) {
					addMonths(-12);
				}
			});

			backwardsYear.getUpFace().setHTML("«");
			backwardsYear.setStyleName(BASE_NAME + "PreviousButton");

			forwardsYear = new PushButton();
			forwardsYear.getUpFace().setHTML("»");
			forwardsYear.setStyleName(BASE_NAME + "NextButton");
			forwardsYear.addClickHandler(new ClickHandler() {
				public void onClick(ClickEvent event) {
					addMonths(+12);
				}
			});

			// Set up grid.
			grid = new Grid(1, 5);
			grid.setWidget(0, previousYearColumn, backwardsYear);
			grid.setWidget(0, previousMonthColumn, backwards);
			grid.setWidget(0, nextMonthColumn, forwards);
			grid.setWidget(0, nextYearColumn, forwardsYear);

			CellFormatter formatter = grid.getCellFormatter();
			formatter.setStyleName(0, monthColumn, BASE_NAME + "Month");
			formatter.setWidth(0, previousYearColumn, "1");
			formatter.setWidth(0, previousMonthColumn, "1");
			formatter.setWidth(0, monthColumn, "100%");
			formatter.setWidth(0, nextMonthColumn, "1");
			formatter.setWidth(0, nextYearColumn, "1");
			grid.setStyleName(BASE_NAME + "MonthSelector");
			initWidget(grid);
		}

		public void addMonths(int numMonths) {
			model.shiftCurrentMonth(numMonths);
			picker.refreshComponents();
		}

	}
}