/*******************************************************************************
 * Copyright (c) 2000, 2018 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Red Hat         - GtkSpinButton rewrite. 2014.10.09
 *     Lablicate GmbH  - add locale support/improve editing support for date/time styles. 2017.02.08
 *******************************************************************************/
package org.eclipse.swt.widgets;

import java.text.*;
import java.text.AttributedCharacterIterator.*;
import java.text.DateFormat.*;
import java.util.*;

import org.eclipse.swt.*;
import org.eclipse.swt.accessibility.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.gtk.*;

/*
 * Developer note: Unit tests for this class can be found under:
 * org.eclipse.swt.tests.junit.Test_org_eclipse_swt_widgets_DateTime
 */

/**
 * Instances of this class are selectable user interface
 * objects that allow the user to enter and modify date
 * or time values.
 * <p>
 * Note that although this class is a subclass of <code>Composite</code>,
 * it does not make sense to add children to it, or set a layout on it.
 * </p>
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>DATE, TIME, CALENDAR, SHORT, MEDIUM, LONG, DROP_DOWN, CALENDAR_WEEKNUMBERS</dd>
 * <dt><b>Events:</b></dt>
 * <dd>DefaultSelection, Selection</dd>
 * </dl>
 * <p>
 * Note: Only one of the styles DATE, TIME, or CALENDAR may be specified,
 * and only one of the styles SHORT, MEDIUM, or LONG may be specified.
 * The DROP_DOWN style is only valid with the DATE style.
 * </p><p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 *
 * @see <a href="http://www.eclipse.org/swt/snippets/#datetime">DateTime snippets</a>
 * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ControlExample</a>
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 *
 * @since 3.3
 * @noextend This class is not intended to be subclassed by clients.
 */
public class DateTime extends Composite {
	int day, month, year, hours, minutes, seconds;

	/**
	 * Major handles of this class.
	 * Note, these can vary or all equal each other depending on Date/Time/Calendar/Drop_down
	 * configuration used. See createHandle () */
	long /*int*/ textEntryHandle,
	containerHandle,
	calendarHandle;

	/* Emulated DATE and TIME fields */
	Calendar calendar;
	Button down;
	FieldPosition currentField;
	StringBuilder typeBuffer = new StringBuilder();
	int typeBufferPos = -1;
	boolean firstTime = true;
	private DateFormat dateFormat;
	/* DROP_DOWN calendar fields for DATE */
	Color fg, bg;
	boolean hasFocus;
	int savedYear, savedMonth, savedDay;
	Shell popupShell;
	DateTime popupCalendar;
	Listener popupListener, popupFilter;

	Point prefferedSize;

	/** Used when SWT.DROP_DOWN is set */
	Listener mouseEventListener;

	static final String DEFAULT_SHORT_DATE_FORMAT = "MM/YYYY";
	static final String DEFAULT_MEDIUM_DATE_FORMAT = "MM/DD/YYYY";
	static final String DEFAULT_LONG_DATE_FORMAT = "MM/DD/YYYY";
	static final String DEFAULT_SHORT_TIME_FORMAT = "HH:MM AM";
	static final String DEFAULT_MEDIUM_TIME_FORMAT = "HH:MM:SS AM";
	static final String DEFAULT_LONG_TIME_FORMAT = "HH:MM:SS AM";
	static final int MIN_YEAR = 1752; // Gregorian switchover in North America: September 19, 1752
	static final int MAX_YEAR = 9999;
	static final int SPACE_FOR_CURSOR = 1;
	static final int GTK2_MANUAL_BORDER_PADDING = 2;

	private int mdYear;

	private int mdMonth;

/**
 * Constructs a new instance of this class given its parent
 * and a style value describing its behavior and appearance.
 * <p>
 * The style value is either one of the style constants defined in
 * class <code>SWT</code> which is applicable to instances of this
 * class, or must be built by <em>bitwise OR</em>'ing together
 * (that is, using the <code>int</code> "|" operator) two or more
 * of those <code>SWT</code> style constants. The class description
 * lists the style constants that are applicable to the class.
 * Style bits are also inherited from superclasses.
 * </p>
 *
 * @param parent a composite control which will be the parent of the new instance (cannot be null)
 * @param style the style of control to construct
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
 * </ul>
 *
 * @see SWT#DATE
 * @see SWT#TIME
 * @see SWT#CALENDAR
 * @see SWT#CALENDAR_WEEKNUMBERS
 * @see SWT#SHORT
 * @see SWT#MEDIUM
 * @see SWT#LONG
 * @see SWT#DROP_DOWN
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public DateTime (Composite parent, int style) {
	super (parent, checkStyle (style));
	if (isDate () || isTime ()) {
		createText ();
	}

	if (isCalendar ()) {
		GTK.gtk_calendar_mark_day (calendarHandle, Calendar.getInstance ().get (Calendar.DAY_OF_MONTH));
	}

	if (isDateWithDropDownButton ()) {
		createDropDownButton ();
		createPopupShell (-1, -1, -1);
		addListener (SWT.Resize, event -> setDropDownButtonSize ());
	}
	initAccessible ();

	if (isDateWithDropDownButton ()) {
		//Date w/ drop down button is in containers.
		//first time round we set the bounds manually for correct Right_to_left behaviour
		Point size = computeSizeInPixels (SWT.DEFAULT, SWT.DEFAULT);
		setBoundsInPixels (0, 0, size.x, size.y);
	}
}

void createText() {
	String property = System.getProperty("swt.datetime.locale");
	Locale locale;
	if (property == null || property.isEmpty()) {
		locale = Locale.getDefault();
	} else {
		locale = Locale.forLanguageTag(property);
	}

	dateFormat = getFormat(locale, style);
	dateFormat.setLenient(false);
	calendar = Calendar.getInstance(locale);
	updateControl();
	selectField(updateField(currentField));
}

DateFormat getFormat(Locale locale, int style) {
	int dfStyle;
	if ((style & SWT.LONG) != 0) {
		dfStyle = DateFormat.LONG;
	} else if ((style & SWT.SHORT) != 0) {
		dfStyle = DateFormat.SHORT;
	} else {
		dfStyle = DateFormat.MEDIUM;
	}
	if (isDate()) {
		return DateFormat.getDateInstance(dfStyle, locale);
	} else if (isTime()) {
		return DateFormat.getTimeInstance(dfStyle, locale);
	} else {
		throw new IllegalStateException("can only be called for date or time widgets!");
	}
}

static int checkStyle (int style) {
	/*
	* Even though it is legal to create this widget
	* with scroll bars, they serve no useful purpose
	* because they do not automatically scroll the
	* widget's client area.  The fix is to clear
	* the SWT style.
	*/
	style &= ~(SWT.H_SCROLL | SWT.V_SCROLL);

	//Workaround. Right_to_left is buggy on gtk2. Only allow on gtk3 onwards
	if (!GTK.GTK3 && isDateWithDropDownButton (style)) {
		style &= ~(SWT.RIGHT_TO_LEFT);
	}

	style = checkBits (style, SWT.DATE, SWT.TIME, SWT.CALENDAR, 0, 0, 0);
	if ((style & SWT.DATE) == 0) style &=~ SWT.DROP_DOWN;
	return checkBits (style, SWT.MEDIUM, SWT.SHORT, SWT.LONG, 0, 0, 0);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the control is selected by the user, by sending
 * it one of the messages defined in the <code>SelectionListener</code>
 * interface.
 * <p>
 * <code>widgetSelected</code> is called when the user changes the control's value.
 * <code>widgetDefaultSelected</code> is typically called when ENTER is pressed.
 * </p>
 *
 * @param listener the listener which should be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see SelectionListener
 * @see #removeSelectionListener
 * @see SelectionEvent
 */
public void addSelectionListener (SelectionListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Selection, typedListener);
	addListener (SWT.DefaultSelection, typedListener);
}

@Override
protected void checkSubclass () {
	if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);
}

@Override
Point computeSizeInPixels (int wHint, int hHint, boolean changed) {
	checkWidget ();

	int width = 0, height = 0;
	//For Date and Time, we cache the preffered size as there is no need to recompute it.
	if (!changed && (isDate () || isTime ()) && GTK.GTK3 && prefferedSize != null) {
		width = (wHint != SWT.DEFAULT) ? wHint : prefferedSize.x;
		height= (hHint != SWT.DEFAULT) ? hHint : prefferedSize.y;
		return new Point (width,height);
	}

	if (wHint == SWT.DEFAULT || hHint == SWT.DEFAULT) {
		if (isCalendar ()) {
			Point size = computeNativeSize (containerHandle, wHint, hHint, changed);
			width = size.x;
			height = size.y;
		} else {
			Point textSize = computeNativeSize (textEntryHandle, wHint, hHint, changed);
			Rectangle trim = computeTrimInPixels (0,0, textSize.x,textSize.y);
			if (isDateWithDropDownButton ()){
				Point buttonSize = down.computeSizeInPixels (SWT.DEFAULT, SWT.DEFAULT, changed);
				width = trim.width + buttonSize.x;
				height = Math.max (trim.height, buttonSize.y);
			} else if (isDate () || isTime ()) {
				if (GTK.GTK3) {
					width = trim.width;
					height = trim.height;
				} else
				{ //in GTK2, spin button looks broken if you incorperate the trim. Thus do not compute trim.
					width = textSize.x;
					height = textSize.y;
				}
			}
		}
	}
	if (width == 0) width = DEFAULT_WIDTH;
	if (height == 0) height = DEFAULT_HEIGHT;
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	int borderWidth = getBorderWidthInPixels ();

	if (prefferedSize == null && (isDateWithDropDownButton () && GTK.GTK3)) {
		prefferedSize = new Point (width + 2*borderWidth, height+ 2*borderWidth);
		return prefferedSize;
	} else {
		return new Point (width + 2*borderWidth, height+ 2*borderWidth);
	}
}

@Override
Rectangle computeTrimInPixels (int x, int y, int width, int height) {
	if (isCalendar ()) {
		return super.computeTrimInPixels (x, y, width, height);
	}

	checkWidget ();
	Rectangle trim = super.computeTrimInPixels (x, y, width, height);
	int xborder = 0, yborder = 0;
		if (GTK.GTK3) {
			GtkBorder tmp = new GtkBorder ();
			long /*int*/ context = GTK.gtk_widget_get_style_context (textEntryHandle);
			if (GTK.GTK_VERSION < OS.VERSION(3, 18, 0)) {
				GTK.gtk_style_context_get_padding (context, GTK.GTK_STATE_FLAG_NORMAL, tmp);
			} else {
				GTK.gtk_style_context_get_padding (context, GTK.gtk_widget_get_state_flags(textEntryHandle), tmp);
			}
			trim.x -= tmp.left;
			trim.y -= tmp.top;
			trim.width += tmp.left + tmp.right;
			trim.height += tmp.top + tmp.bottom;
			if ((style & SWT.BORDER) != 0) {
				if (GTK.GTK_VERSION < OS.VERSION(3, 18, 0)) {
					GTK.gtk_style_context_get_border (context, GTK.GTK_STATE_FLAG_NORMAL, tmp);
				} else {
					GTK.gtk_style_context_get_border (context, GTK.gtk_widget_get_state_flags(textEntryHandle), tmp);
				}
				trim.x -= tmp.left;
				trim.y -= tmp.top;
				trim.width += tmp.left + tmp.right;
				trim.height += tmp.top + tmp.bottom;
			}
		} else {
			if ((style & SWT.BORDER) != 0) {
				Point thickness = getThickness (textEntryHandle);
				xborder += thickness.x;
				yborder += thickness.y;
			}
			GtkBorder innerBorder = Display.getEntryInnerBorder (textEntryHandle);
			trim.x -= innerBorder.left;
			trim.y -= innerBorder.top;
			trim.width += innerBorder.left + innerBorder.right;
			trim.height += innerBorder.top + innerBorder.bottom;
		}
		trim.x -= xborder;
		trim.y -= yborder;
		trim.width += 2 * xborder;
		trim.height += 2 * yborder;
		trim.width += SPACE_FOR_CURSOR;
		return new Rectangle (trim.x, trim.y, trim.width, trim.height);
}


@Override
void createHandle (int index) {
	createHandle ();
}

/**
 * Here we carefully define the three internal handles:
 *  textEntryHandle
 *  containerHandle
 *  calendarHandle
 */
void createHandle () {
	if (isCalendar ()) {
		state |= HANDLE;
		createHandleForFixed ();
		createHandleForCalendar ();

	} else {
		createHandleForFixed ();
		if (isDateWithDropDownButton ()) {
			createHandleForDateWithDropDown ();
		} else {
			createHandleForDateTime ();
		}
		GTK.gtk_editable_set_editable (textEntryHandle, (style & SWT.READ_ONLY) == 0);
		if (GTK.GTK_VERSION <= OS.VERSION(3, 20, 0)) {
			GTK.gtk_entry_set_has_frame (textEntryHandle, (style & SWT.BORDER) != 0);
		}
	}
}

private void createHandleForFixed () {
	fixedHandle = OS.g_object_new (display.gtk_fixed_get_type (), 0);
	if (fixedHandle == 0) error (SWT.ERROR_NO_HANDLES);
	GTK.gtk_widget_set_has_window (fixedHandle, true);
}

private void createHandleForCalendar () {
	calendarHandle = GTK.gtk_calendar_new ();
	if (calendarHandle == 0) error (SWT.ERROR_NO_HANDLES);

	//Calenadar becomes container in this case.
	handle = calendarHandle;
	containerHandle = calendarHandle;

	GTK.gtk_container_add (fixedHandle, calendarHandle);

	int flags = GTK.GTK_CALENDAR_SHOW_HEADING | GTK.GTK_CALENDAR_SHOW_DAY_NAMES;
	if (showWeekNumbers()) {
		flags |= GTK.GTK_CALENDAR_SHOW_WEEK_NUMBERS;
	}
	GTK.gtk_calendar_set_display_options (calendarHandle, flags);
	GTK.gtk_widget_show (calendarHandle);
}

private void createHandleForDateWithDropDown () {
	//Create box to put entry and button into box.
	containerHandle = gtk_box_new (GTK.GTK_ORIENTATION_HORIZONTAL, false, 0);
	if (containerHandle == 0) error (SWT.ERROR_NO_HANDLES);
	GTK.gtk_container_add (fixedHandle, containerHandle);

	//Create entry
	textEntryHandle = GTK.gtk_entry_new ();
	if (textEntryHandle == 0) error (SWT.ERROR_NO_HANDLES);
	GTK.gtk_container_add (containerHandle, textEntryHandle);

	GTK.gtk_widget_show (containerHandle);
	GTK.gtk_widget_show (textEntryHandle);

	handle = containerHandle;
	if (handle == 0) error (SWT.ERROR_NO_HANDLES);

	// In GTK 3 font description is inherited from parent widget which is not how SWT has always worked,
	// reset to default font to get the usual behavior
	if (GTK.GTK3) {
		setFontDescription (defaultFont ().handle);
	}
}

private void createHandleForDateTime () {
	long /*int*/ adjusment = GTK.gtk_adjustment_new (0, -9999, 9999, 1, 0, 0);
	textEntryHandle = GTK.gtk_spin_button_new (adjusment, 1, 0);
	if (textEntryHandle == 0) error (SWT.ERROR_NO_HANDLES);

	//in this case,the Entry becomes the container.
	handle = textEntryHandle;
	containerHandle = textEntryHandle;

	GTK.gtk_spin_button_set_numeric (textEntryHandle, false);
	GTK.gtk_container_add (fixedHandle, textEntryHandle);
	GTK.gtk_spin_button_set_wrap (textEntryHandle, (style & SWT.WRAP) != 0);
}

void createDropDownButton () {
	down = new Button (this, SWT.ARROW  | SWT.DOWN);
	GTK.gtk_widget_set_can_focus (down.handle, false);
	down.addListener (SWT.Selection, event -> {
		setFocus ();
		dropDownCalendar (!isDropped ());
	});

	popupListener = event -> {
		if (event.widget == popupShell) {
			popupShellEvent (event);
			return;
		}
		if (event.widget == popupCalendar) {
			popupCalendarEvent (event);
			return;
		}
		if (event.widget == DateTime.this) {
			onDispose (event);
			return;
		}
		if (event.widget == getShell ()) {
			getDisplay ().asyncExec (() -> {
				if (isDisposed ()) return;
				handleFocus (SWT.FocusOut);
			});
		}
	};
	popupFilter = event -> {
		Shell shell = ((Control)event.widget).getShell ();
		if (shell == DateTime.this.getShell ()) {
			handleFocus (SWT.FocusOut);
		}
	};
}

void createPopupShell (int year, int month, int day) {
	popupShell = new Shell (getShell (), SWT.NO_TRIM | SWT.ON_TOP);
	int popupStyle = SWT.CALENDAR;
	if (showWeekNumbers()) {
		popupStyle |= SWT.CALENDAR_WEEKNUMBERS;
	}
	popupCalendar = new DateTime (popupShell, popupStyle);
	if (font != null) popupCalendar.setFont (font);
	if (fg != null) popupCalendar.setForeground (fg);
	if (bg != null) popupCalendar.setBackground (bg);

	mouseEventListener = event -> {
		if (event.widget instanceof Control) {
			Control c = (Control)event.widget;
			if (c != down && c.getShell () != popupShell)
				dropDownCalendar (false);
		}
	};

	int [] listeners = {SWT.Close, SWT.MouseUp};
	for (int i=0; i < listeners.length; i++) {
		popupShell.addListener (listeners [i], popupListener);
	}
	listeners = new int [] {SWT.MouseDown, SWT.MouseUp, SWT.Selection, SWT.Traverse, SWT.KeyDown, SWT.KeyUp, SWT.FocusIn, SWT.FocusOut, SWT.Dispose};
	for (int i=0; i < listeners.length; i++) {
		popupCalendar.addListener (listeners [i], popupListener);
	}
	addListener (SWT.Dispose, popupListener);
	if (year != -1) popupCalendar.setDate (year, month, day);
}

@Override
void setFontDescription (long /*int*/ font) {
	if (isDateWithDropDownButton ()) {
		prefferedSize = null; //flush cache for computeSize as font can cause size to change.
		setFontDescription (textEntryHandle, font);
	}
	super.setFontDescription (font);
}

@Override
boolean checkSubwindow () {
	return false;
}

@Override
void createWidget (int index) {
	super.createWidget (index);
	if (isCalendar ()) {
		getDate ();
	}
}

void onDispose (Event event) {
	if (popupShell != null && !popupShell.isDisposed ()) {
		popupCalendar.removeListener (SWT.Dispose, popupListener);
		popupShell.dispose ();
	}
	Shell shell = getShell ();
	shell.removeListener (SWT.Deactivate, popupListener);
	Display display = getDisplay ();
	display.removeFilter (SWT.FocusIn, popupFilter);
	popupShell = null;
	popupCalendar = null;
	down = null;
}

/**
 * Called when pressing the SWT.DROP_DOWN button on a Date Field
 * @param drop true if the calendar is suppose to drop down.
 */
void dropDownCalendar (boolean drop) {
	if (drop == isDropped ()) return;

	if (!drop) {
		hideDropDownCalendar ();
		return;
	}

	setCurrentDate ();

	if (getShell () != popupShell.getParent ()) {
		recreateCalendar ();
	}

	//This is the x/y/width/height of the container of DateTime
	Point containerBounds = getSizeInPixels ();
	Point calendarSize = popupCalendar.computeSizeInPixels (SWT.DEFAULT, SWT.DEFAULT, false);

	//Set the inner calendar pos/size. (not the popup shell pos/size)
	popupCalendar.setBoundsInPixels (1, 1, Math.max (containerBounds.x - 2, calendarSize.x), calendarSize.y);

	//Set Date & focus current day
	popupCalendar.setDate (savedYear, savedMonth, savedDay);
	focusDayOnPopupCalendar ();

	Display display = getDisplay ();

	//To display popup calendar, we need to know where the parent is relative to the whole screen.
	Rectangle coordsRelativeToScreen = display.mapInPixels (getParent (), null, getBoundsInPixels ());
	Rectangle displayRect = DPIUtil.autoScaleUp(getMonitor ().getClientArea ());

	showPopupShell (containerBounds, calendarSize, coordsRelativeToScreen, displayRect);

	display.addFilter (SWT.MouseDown, mouseEventListener);
}

private void showPopupShell (Point containerBounds, Point calendarSize, Rectangle coordsRelativeToScreen,
		Rectangle displayRect) {
	int width = Math.max (containerBounds.x, calendarSize.x + 2);
	int height = calendarSize.y + 2;
	int y = calculateCalendarYpos (containerBounds, coordsRelativeToScreen, height, displayRect);
	int x = calculateCalendarXpos (calendarSize, coordsRelativeToScreen, displayRect, width);

	popupShell.setBoundsInPixels (x, y, width, height);
	popupShell.setVisible (true);
	if (isFocusControl ()) {
		popupCalendar.setFocus ();
	}
}

private int calculateCalendarYpos (Point containerBounds, Rectangle coordsRelativeToScreen, int height,
		Rectangle displayRect) {
	int dateEntryHeight = computeNativeSize (containerHandle, SWT.DEFAULT, SWT.DEFAULT, false).y;
	int y = coordsRelativeToScreen.y + containerBounds.y/2 + dateEntryHeight/2;

	//Put Calendar above control if it would be cut off at the bottom.
	if (y + height > displayRect.y + displayRect.height) {
		y -= (height + dateEntryHeight);
	}
	return y;
}

private int calculateCalendarXpos (Point calendarSize, Rectangle coordsRelativeToScreen, Rectangle displayRect,
		int width) {
	Integer x;
	x = coordsRelativeToScreen.x;
	//Move calendar to the right if it would be cut off.
	if (x + width > displayRect.x + displayRect.width) {
		x = displayRect.x + displayRect.width - calendarSize.x;
	}
	return x;
}


private void focusDayOnPopupCalendar () {
	int currentYear = Calendar.getInstance ().get (Calendar.YEAR);
	int currentMonth = Calendar.getInstance ().get (Calendar.MONTH);

	if (savedYear == currentYear && savedMonth == currentMonth) {
		int currentDay = Calendar.getInstance ().get (Calendar.DAY_OF_MONTH);
		GTK.gtk_calendar_mark_day (popupCalendar.handle, currentDay);
	}
}

private void setCurrentDate () {
	savedYear = getYear ();
	savedMonth = getMonth ();
	savedDay = getDay ();
}

private void recreateCalendar () {
	int year = popupCalendar.getYear ();
	int month = popupCalendar.getMonth ();
	int day = popupCalendar.getDay ();
	popupCalendar.removeListener (SWT.Dispose, popupListener);
	popupShell.dispose ();
	popupShell = null;
	popupCalendar = null;
	createPopupShell (year, month, day);
}

private void hideDropDownCalendar () {
	popupShell.setVisible (false);
	GTK.gtk_calendar_clear_marks (popupCalendar.handle);
	display.removeFilter (SWT.MouseDown, mouseEventListener);
	return;
}

@Override
GdkColor getBackgroundGdkColor () {
	assert !GTK.GTK3 : "GTK2 code was run by GTK3";
	if (isCalendar ()) {
		return getBaseGdkColor ();
	} else {
		return super.getBackgroundGdkColor ();
	}
}

String getComputeSizeString (int style) {
	if ((style & SWT.DATE) != 0) {
		return (style & SWT.SHORT) != 0 ? DEFAULT_SHORT_DATE_FORMAT : (style & SWT.LONG) != 0 ? DEFAULT_LONG_DATE_FORMAT : DEFAULT_MEDIUM_DATE_FORMAT;
	}
	// SWT.TIME
	return (style & SWT.SHORT) != 0 ? DEFAULT_SHORT_TIME_FORMAT : (style & SWT.LONG) != 0 ? DEFAULT_LONG_TIME_FORMAT : DEFAULT_MEDIUM_TIME_FORMAT;
}

String getFormattedString() {
	return dateFormat.format(calendar.getTime());
}

void getDate () {
	int [] y = new int [1];
	int [] m = new int [1];
	int [] d = new int [1];
	GTK.gtk_calendar_get_date (calendarHandle, y, m, d);
	year = y[0];
	month = m[0];
	day = d[0];
}

/**
 * Returns the receiver's date, or day of the month.
 * <p>
 * The first day of the month is 1, and the last day depends on the month and year.
 * </p>
 *
 * @return a positive integer beginning with 1
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getDay () {
	checkWidget ();
	if (isCalendar ()) {
		getDate ();
		return day;
	} else {
		return calendar.get (Calendar.DAY_OF_MONTH);
	}
}

/**
 * Returns the receiver's hours.
 * <p>
 * Hours is an integer between 0 and 23.
 * </p>
 *
 * @return an integer between 0 and 23
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getHours () {
	checkWidget ();
	if (isCalendar ()) {
		return hours;
	} else {
		return calendar.get (Calendar.HOUR_OF_DAY);
	}
}

/**
 * Returns the receiver's minutes.
 * <p>
 * Minutes is an integer between 0 and 59.
 * </p>
 *
 * @return an integer between 0 and 59
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getMinutes () {
	checkWidget ();
	if (isCalendar ()) {
		return minutes;
	} else {
		return calendar.get (Calendar.MINUTE);
	}
}

/**
 * Returns the receiver's month.
 * <p>
 * The first month of the year is 0, and the last month is 11.
 * </p>
 *
 * @return an integer between 0 and 11
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getMonth () {
	checkWidget ();
	if (isCalendar ()) {
		getDate ();
		return month;
	} else {
		return calendar.get (Calendar.MONTH);
	}
}

@Override
String getNameText () {
	if(calendar == null) {
		return "";
	}
	if (isTime ()) {
		return getHours () + ":" + getMinutes () + ":" + getSeconds ();
	} else {
		return (getMonth () + 1) + "/" + getDay () + "/" + getYear ();
	}
}

/**
 * Returns the receiver's seconds.
 * <p>
 * Seconds is an integer between 0 and 59.
 * </p>
 *
 * @return an integer between 0 and 59
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getSeconds () {
	checkWidget ();
	if (isCalendar ()) {
		return seconds;
	} else {
		return calendar.get (Calendar.SECOND);
	}
}

/*
 * Returns a textual representation of the receiver,
 * intended for speaking the text aloud.
 */
String getSpokenText() {
	if (isTime()) {
		return DateFormat.getTimeInstance(DateFormat.FULL).format(calendar.getTime());
	} else if (isDate()) {
		return DateFormat.getDateInstance(DateFormat.FULL).format(calendar.getTime());
	} else {
		Calendar cal = Calendar.getInstance();
		getDate();
		cal.set(year, month, day);
		return DateFormat.getDateInstance(DateFormat.FULL).format(cal.getTime());
	}
}

/**
 * Returns the receiver's year.
 * <p>
 * The first year is 1752 and the last year is 9999.
 * </p>
 *
 * @return an integer between 1752 and 9999
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getYear () {
	checkWidget ();
	if (isCalendar ()) {
		getDate ();
		return year;
	} else {
		return calendar.get (Calendar.YEAR);
	}
}

@Override
long /*int*/ gtk_day_selected (long /*int*/ widget) {
	sendSelectionEvent ();
	return 0;
}

@Override
long /*int*/ gtk_day_selected_double_click (long /*int*/ widget) {
	sendSelectionEvent (SWT.DefaultSelection);
	return 0;
}

@Override
long /*int*/ gtk_month_changed (long /*int*/ widget) {
	sendSelectionEvent ();
	return 0;
}

@Override
long /*int*/ eventHandle () {
	return dateTimeHandle ();
}

@Override
long /*int*/ focusHandle () {
	return dateTimeHandle ();
}

@Override
long /*int*/ fontHandle () {
	return dateTimeHandle ();
}

private long /*int*/ dateTimeHandle () {
	if (isCalendar () && calendarHandle != 0) {
		 return calendarHandle;
	} else if ((isDate () || isTime ()) && textEntryHandle != 0) {
		 return textEntryHandle;
	} else {
		return super.focusHandle ();
	}
}

@Override
void hookEvents () {
	super.hookEvents ();
	if (isCalendar ()) {
		hookEventsForCalendar ();
	} else {
		int eventMask =	GDK.GDK_POINTER_MOTION_MASK | GDK.GDK_BUTTON_PRESS_MASK | GDK.GDK_BUTTON_RELEASE_MASK;
		GTK.gtk_widget_add_events (textEntryHandle, eventMask);


		if ((style & SWT.DROP_DOWN) == 0 ) {
			hookEventsForDateTimeSpinner ();
		}
		if (OS.G_OBJECT_TYPE (textEntryHandle) == GTK.GTK_TYPE_MENU ()) {
			hookEventsForMenu ();
		}
	}
}


final private void hookEventsForCalendar () {
	OS.g_signal_connect_closure (calendarHandle, OS.day_selected, display.getClosure (DAY_SELECTED), false);
	OS.g_signal_connect_closure (calendarHandle, OS.day_selected_double_click, display.getClosure (DAY_SELECTED_DOUBLE_CLICK), false);
	OS.g_signal_connect_closure (calendarHandle, OS.month_changed, display.getClosure (MONTH_CHANGED), false);
}

final private void hookEventsForDateTimeSpinner () {
	OS.g_signal_connect_closure (textEntryHandle, OS.output, display.getClosure (OUTPUT), true);
	OS.g_signal_connect_closure (textEntryHandle, OS.focus_in_event, display.getClosure (FOCUS_IN_EVENT), true);
}

final private void hookEventsForMenu () {
	OS.g_signal_connect_closure (down.handle, OS.selection_done, display.getClosure (SELECTION_DONE), true);
}

void incrementField(int amount) {
	if (currentField != null) {
		int field = getCalendarField(currentField);
		if (field == Calendar.HOUR && hasAmPm()) {
			int max = calendar.getMaximum(Calendar.HOUR);
			int min = calendar.getMinimum(Calendar.HOUR);
			int value = calendar.get(Calendar.HOUR);
			if ((value == max && amount == 1) || (value == min && amount == -1)) {
				calendar.roll(Calendar.AM_PM, amount);
			}
		}
		if (field > -1) {
			calendar.roll(field, amount);
			updateControl();
			selectField(updateField(currentField));
		}
	}
}

private boolean hasAmPm() {
	AttributedCharacterIterator iterator = dateFormat.formatToCharacterIterator(calendar.getTime());
	while (iterator.current() != CharacterIterator.DONE) {
		for (Attribute attribute : iterator.getAttributes().keySet()) {
			if (Field.AM_PM.equals(attribute)) {
				return true;
			}
		}
		iterator.setIndex(iterator.getRunLimit());
	}
	return false;
}

boolean isDropped () {
	return popupShell.getVisible ();
}

private boolean isCalendar () {
	return ((style & SWT.CALENDAR) != 0);
}

private boolean isDateWithDropDownButton () {
	return ((style & SWT.DROP_DOWN) != 0 && (style & SWT.DATE) != 0);
}

static private boolean isDateWithDropDownButton (int style) {
	return ((style & SWT.DROP_DOWN) != 0 && (style & SWT.DATE) != 0);
}


private boolean isDate () {
	return ((style & SWT.DATE) != 0);
}

private boolean isTime () {
	return ((style & SWT.TIME) != 0);
}

private boolean isReadOnly () {
	return ((style & SWT.READ_ONLY) != 0);
}

private boolean showWeekNumbers() {
	return ((style & SWT.CALENDAR_WEEKNUMBERS) != 0);
}

void initAccessible () {
	Accessible accessible = getAccessible ();
	accessible.addAccessibleListener (new AccessibleAdapter () {
		@Override
		public void getName (AccessibleEvent e) {
			e.result = getSpokenText ();
		}

		@Override
		public void getHelp (AccessibleEvent e) {
			e.result = getToolTipText ();
		}
	});

	accessible.addAccessibleControlListener (new AccessibleControlAdapter () {
		@Override
		public void getChildAtPoint (AccessibleControlEvent e) {
			e.childID = ACC.CHILDID_SELF;
		}

		@Override
		public void getLocation (AccessibleControlEvent e) {
			Rectangle rect = display.map (getParent (), null, getBounds ());
			e.x = rect.x;
			e.y = rect.y;
			e.width = rect.width;
			e.height = rect.height;
		}

		@Override
		public void getChildCount (AccessibleControlEvent e) {
			e.detail = 0;
		}

		@Override
		public void getRole (AccessibleControlEvent e) {
			e.detail = (isCalendar ()) ? ACC.ROLE_LABEL : ACC.ROLE_TEXT;
		}

		@Override
		public void getState (AccessibleControlEvent e) {
			e.detail = ACC.STATE_FOCUSABLE;
			if (hasFocus ()) e.detail |= ACC.STATE_FOCUSED;
		}

		@Override
		public void getSelection (AccessibleControlEvent e) {
			if (hasFocus ()) e.childID = ACC.CHILDID_SELF;
		}

		@Override
		public void getFocus (AccessibleControlEvent e) {
			if (hasFocus ()) e.childID = ACC.CHILDID_SELF;
		}
	});
}

boolean isValidTime (int fieldName, int value) {
	Calendar validCalendar;
	if (isCalendar ()) {
		validCalendar = Calendar.getInstance ();
	} else {
		validCalendar = calendar;
	}
	int min = validCalendar.getActualMinimum (fieldName);
	int max = validCalendar.getActualMaximum (fieldName);
	return value >= min && value <= max;
}

boolean isValidDate (int year, int month, int day) {
	if (year < MIN_YEAR || year > MAX_YEAR) return false;
	Calendar valid = Calendar.getInstance ();
	valid.set (year, month, day);
	return valid.get (Calendar.YEAR) == year
		&& valid.get (Calendar.MONTH) == month
		&& valid.get (Calendar.DAY_OF_MONTH) == day;
}

void popupCalendarEvent (Event event) {
	switch (event.type) {
		case SWT.Dispose:
			if (popupShell != null && !popupShell.isDisposed () && !isDisposed () && getShell () != popupShell.getParent ()) {
				int year = popupCalendar.getYear ();
				int month = popupCalendar.getMonth ();
				int day = popupCalendar.getDay ();
				popupShell = null;
				popupCalendar = null;
				createPopupShell (year, month, day);
			}
			break;
		case SWT.FocusIn: {
			handleFocus (SWT.FocusIn);
			break;
		}
		case SWT.MouseDown: {
			if (event.button != 1) return;
			mdYear = getYear();
			mdMonth = getMonth();
			break;
		}
		case SWT.MouseUp: {
			if (event.button != 1) return;
			/*
			* The drop-down should stay visible when
			* either the year or month is changed.
			*/
			if (mdYear == getYear() && mdMonth == getMonth()) {
				dropDownCalendar (false);
			}
			break;
		}
		case SWT.Selection: {
			int year = popupCalendar.getYear ();
			int month = popupCalendar.getMonth ();
			int day = popupCalendar.getDay ();
			setDate (year, month, day);
			Event e = new Event ();
			e.time = event.time;
			e.stateMask = event.stateMask;
			e.doit = event.doit;
			notifyListeners (SWT.Selection, e);
			event.doit = e.doit;
			break;
		}
		case SWT.Traverse: {
			switch (event.detail) {
				case SWT.TRAVERSE_RETURN:
				case SWT.TRAVERSE_ESCAPE:
				case SWT.TRAVERSE_ARROW_PREVIOUS:
				case SWT.TRAVERSE_ARROW_NEXT:
					event.doit = false;
					break;
				case SWT.TRAVERSE_TAB_NEXT:
				case SWT.TRAVERSE_TAB_PREVIOUS:
//					event.doit = text.traverse (event.detail);
					event.detail = SWT.TRAVERSE_NONE;
					if (event.doit) dropDownCalendar (false);
					return;
				case SWT.TRAVERSE_PAGE_NEXT:
				case SWT.TRAVERSE_PAGE_PREVIOUS:
					return;
			}
			Event e = new Event ();
			e.time = event.time;
			e.detail = event.detail;
			e.doit = event.doit;
			e.character = event.character;
			e.keyCode = event.keyCode;
			notifyListeners (SWT.Traverse, e);
			event.doit = e.doit;
			event.detail = e.detail;
			break;
		}
		case SWT.KeyUp: {
			Event e = new Event ();
			e.time = event.time;
			e.character = event.character;
			e.keyCode = event.keyCode;
			e.stateMask = event.stateMask;
			notifyListeners (SWT.KeyUp, e);
			break;
		}
		case SWT.KeyDown: {
			if (event.character == SWT.ESC) {
				/* Escape key cancels popupCalendar and reverts date */
				popupCalendar.setDate (savedYear, savedMonth, savedDay);
				setDate (savedYear, savedMonth, savedDay);
				dropDownCalendar (false);
			}
			if (event.keyCode == SWT.CR || (event.stateMask & SWT.ALT) != 0 && (event.keyCode == SWT.ARROW_UP || event.keyCode == SWT.ARROW_DOWN)) {
				/* Return, Alt+Down, and Alt+Up cancel popupCalendar and select date. */
				dropDownCalendar (false);
			}
			if (event.keyCode == SWT.SPACE) {
				dropDownCalendar (false);
			}
			/* At this point the widget may have been disposed.
			 * If so, do not continue. */
			if (isDisposed ()) break;
			Event e = new Event ();
			e.time = event.time;
			e.character = event.character;
			e.keyCode = event.keyCode;
			e.stateMask = event.stateMask;
			notifyListeners (SWT.KeyDown, e);
			break;
		}
	}
}

void handleFocus (int type) {
	if (isDisposed ()) return;
	switch (type) {
		case SWT.FocusIn: {
			if (hasFocus) return;
			selectAll ();
			hasFocus = true;
			Shell shell = getShell ();
			shell.removeListener (SWT.Deactivate, popupListener);
			shell.addListener (SWT.Deactivate, popupListener);
			Display display = getDisplay ();
			display.removeFilter (SWT.FocusIn, popupFilter);
			display.addFilter (SWT.FocusIn, popupFilter);
			Event e = new Event ();
			notifyListeners (SWT.FocusIn, e);
			break;
		}
		case SWT.FocusOut: {
			if (!hasFocus) return;
			Control focusControl = getDisplay ().getFocusControl ();
			if (focusControl == down || focusControl == popupCalendar ) return;
			hasFocus = false;
			Shell shell = getShell ();
			shell.removeListener (SWT.Deactivate, popupListener);
			Display display = getDisplay ();
			display.removeFilter (SWT.FocusIn, popupFilter);
			display.removeFilter (SWT.MouseDown, mouseEventListener);
			Event e = new Event ();
			notifyListeners (SWT.FocusOut, e);
			break;
		}
	}
}

void popupShellEvent (Event event) {
	switch (event.type) {
		case SWT.Close:
			event.doit = false;
			dropDownCalendar (false);
			break;
		case SWT.MouseUp:
			dropDownCalendar (false);
			break;
	}
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the control is selected by the user.
 *
 * @param listener the listener which should no longer be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see SelectionListener
 * @see #addSelectionListener
 */
public void removeSelectionListener (SelectionListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Selection, listener);
	eventTable.unhook (SWT.DefaultSelection, listener);
}

/**
 * selects the first occurrence of the given field
 *
 * @param field
 */
void selectField(Field field) {
	AttributedCharacterIterator iterator = dateFormat.formatToCharacterIterator(calendar.getTime());
	while (iterator.current() != CharacterIterator.DONE) {
		for (Attribute attribute : iterator.getAttributes().keySet()) {
			if (attribute.equals(field)) {
				selectField(getFieldPosition(field, iterator));
				return;
			}
		}
		iterator.setIndex(iterator.getRunLimit());
	}
}

/**
 * Selects the given field at the given start/end coordinates
 *
 * @param field
 * @param start
 * @param end
 */
void selectField(FieldPosition fieldPosition) {
	boolean sameField = isSameField(fieldPosition, currentField);
	if (sameField) {
		if (typeBufferPos > -1) {
			typeBufferPos = 0;
		}
	} else {
		typeBufferPos = -1;
		commitData();
		fieldPosition = updateField(fieldPosition);
	}
	Point pt = getSelection();
	int start = fieldPosition.getBeginIndex();
	int end = fieldPosition.getEndIndex();
	if (sameField && start == pt.x && end == pt.y) {
		return;
	}
	currentField = fieldPosition;
	display.syncExec(() -> {
		if (textEntryHandle != 0) {
			String value = getText(getText(), start, end - 1);
			int s = value.lastIndexOf(' ');
			s = (s == -1) ? start : start + s + 1;
			setSelection(s, end);
		}
	});
}

void sendSelectionEvent () {
	int [] y = new int [1];
	int [] m = new int [1];
	int [] d = new int [1];
	GTK.gtk_calendar_get_date (calendarHandle, y, m, d);
	//TODO: hours, minutes, seconds?
	if (d[0] != day ||
		m[0] != month ||
		y[0] != year) {
		year = y[0];
		month = m[0];
		day = d[0];
		/* Highlight the current (today) date */
		if (year == Calendar.getInstance ().get (Calendar.YEAR) && month == Calendar.getInstance ().get (Calendar.MONTH)) {
			GTK.gtk_calendar_mark_day (calendarHandle, Calendar.getInstance ().get (Calendar.DAY_OF_MONTH));
		} else {
			GTK.gtk_calendar_clear_marks (calendarHandle);
		}
		sendSelectionEvent (SWT.Selection);
	}
}

@Override
public void setBackground (Color color) {
	super.setBackground (color);
	if (!GTK.GTK3) {
		if ((isCalendar ()) && color == null) {
			GTK.gtk_widget_modify_base (containerHandle, 0, null);
		}
	}
	bg = color;
	if (popupCalendar != null) popupCalendar.setBackground (color);
}

@Override
void setBackgroundGdkColor (GdkColor color) {
	assert !GTK.GTK3 : "GTK2 code was run by GTK3";
	if (isCalendar ()) {
		GTK.gtk_widget_modify_base (containerHandle, 0, color);
	} else {
		super.setBackgroundGdkColor (color);
	}
}

@Override
void setBackgroundGdkRGBA (GdkRGBA rgba) {
	assert GTK.GTK3 : "GTK3 code was run by GTK2";
	super.setBackgroundGdkRGBA(rgba);
	if (calendarHandle != 0) {
		setBackgroundGdkRGBA (calendarHandle, rgba);
	}
	super.setBackgroundGdkRGBA(rgba);

}

@Override
void setBackgroundGdkRGBA (long /*int*/ context, long /*int*/ handle, GdkRGBA rgba) {
	assert GTK.GTK3 : "GTK3 code was run by GTK2";

	// We need to override here because DateTime widgets use "background" instead of
	// "background-color" as their CSS property.
	if (GTK.GTK_VERSION >= OS.VERSION(3, 14, 0)) {
    	// Form background string
        String name = GTK.GTK_VERSION >= OS.VERSION(3, 20, 0) ? display.gtk_widget_class_get_css_name(handle)
        		: display.gtk_widget_get_name(handle);
        String css = name + " {background: " + display.gtk_rgba_to_css_string (rgba) + ";}\n" +
        		name + ":selected" + " {background: " + display.gtk_rgba_to_css_string(display.COLOR_LIST_SELECTION_RGBA) + ";}";

        // Cache background
        cssBackground = css;

        // Apply background color and any cached foreground color
        String finalCss = display.gtk_css_create_css_color_string (cssBackground, cssForeground, SWT.BACKGROUND);
        gtk_css_provider_load_from_css (context, finalCss);
    } else {
    	super.setBackgroundGdkRGBA(context, handle, rgba);
    }
}

@Override
public void setEnabled (boolean enabled){
	super.setEnabled (enabled);
	if (isDateWithDropDownButton ())
		down.setEnabled (enabled);
}

@Override
public void setFont (Font font) {
	super.setFont (font);
	this.font = font;
	if (popupCalendar != null) popupCalendar.setFont (font);
	redraw ();
}

@Override
void setForegroundGdkColor (GdkColor color) {
	assert !GTK.GTK3 : "GTK2 code was run by GTK3";
	setForegroundColor (containerHandle, color, false);
}

@Override
void setForegroundGdkRGBA (GdkRGBA rgba) {
	assert GTK.GTK3 : "GTK3 code was run by GTK2";
	setForegroundGdkRGBA (containerHandle, rgba);
}

@Override
public void setForeground (Color color) {
	super.setForeground (color);
	fg = color;
	if (popupCalendar != null) popupCalendar.setForeground (color);
}

void setFieldOfInternalDataStructure(FieldPosition field, int value) {
	int calendarField = getCalendarField(field);
	if (calendar.get(calendarField) == value)
		return;
	if (calendarField == Calendar.AM_PM && hasAmPm()) {
		calendar.roll(Calendar.HOUR_OF_DAY, 12);
	}
	calendar.set(calendarField, value);

	//When dealing with months with 31 days and have days set to 31, then if you change the month
	//to one that has 30 (or less) days, then in calendar only the day is changed but the month stays.
	//e.g 10.31.2014  -> decrement month, becomes:
	//    10.01.2014.
	//To get around this behaviour, we set the field again.
	if (calendar.get(calendarField) != value) {
		calendar.set(calendarField, value);
	}
	sendSelectionEvent (SWT.Selection);
}

/**
 * Sets the receiver's year, month, and day in a single operation.
 * <p>
 * This is the recommended way to set the date, because setting the year,
 * month, and day separately may result in invalid intermediate dates.
 * </p>
 *
 * @param year an integer between 1752 and 9999
 * @param month an integer between 0 and 11
 * @param day a positive integer beginning with 1
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @since 3.4
 */
public void setDate (int year, int month, int day) {
	checkWidget ();
	if (!isValidDate (year, month, day)) return;
	if (isCalendar ()) {
		this.year = year;
		this.month = month;
		this.day = day;
		GTK.gtk_calendar_select_month (calendarHandle, month, year);
		GTK.gtk_calendar_select_day (calendarHandle, day);
	} else {
		calendar.set (year, month, day);
		updateControl ();
	}
}

/**
 * Sets the receiver's date, or day of the month, to the specified day.
 * <p>
 * The first day of the month is 1, and the last day depends on the month and year.
 * If the specified day is not valid for the receiver's month and year, then it is ignored.
 * </p>
 *
 * @param day a positive integer beginning with 1
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see #setDate
 */
public void setDay (int day) {
	checkWidget ();
	if (!isValidDate (getYear (), getMonth (), day)) return;
	if (isCalendar ()) {
		this.day = day;
		GTK.gtk_calendar_select_day (calendarHandle, day);
	} else {
		calendar.set (Calendar.DAY_OF_MONTH, day);
		updateControl ();
	}
}

/**
 * Sets the receiver's hours.
 * <p>
 * Hours is an integer between 0 and 23.
 * </p>
 *
 * @param hours an integer between 0 and 23
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void setHours (int hours) {
	checkWidget ();
	if (!isValidTime (Calendar.HOUR_OF_DAY, hours)) return;
	if (isCalendar ()) {
		this.hours = hours;
	} else {
		calendar.set (Calendar.HOUR_OF_DAY, hours);
		updateControl ();
	}
}

@Override
public void setMenu (Menu menu) {
	super.setMenu (menu);
	if (down != null) down.setMenu (menu);
}

/**
 * Sets the receiver's minutes.
 * <p>
 * Minutes is an integer between 0 and 59.
 * </p>
 *
 * @param minutes an integer between 0 and 59
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void setMinutes (int minutes) {
	checkWidget ();
	if (!isValidTime (Calendar.MINUTE, minutes)) return;
	if (isCalendar ()) {
		this.minutes = minutes;
	} else {
		calendar.set (Calendar.MINUTE, minutes);
		updateControl ();
	}
}

/**
 * Sets the receiver's month.
 * <p>
 * The first month of the year is 0, and the last month is 11.
 * If the specified month is not valid for the receiver's day and year, then it is ignored.
 * </p>
 *
 * @param month an integer between 0 and 11
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see #setDate
 */
public void setMonth (int month) {
	checkWidget ();
	if (!isValidDate (getYear (), month, getDay ())) return;
	if (isCalendar ()) {
		this.month = month;
		GTK.gtk_calendar_select_month (calendarHandle, month, year);
	} else {
		calendar.set (Calendar.MONTH, month);
		updateControl ();
	}
}

/**
 * Sets the receiver's seconds.
 * <p>
 * Seconds is an integer between 0 and 59.
 * </p>
 *
 * @param seconds an integer between 0 and 59
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void setSeconds (int seconds) {
	checkWidget ();
	if (!isValidTime (Calendar.SECOND, seconds)) return;
	if (isCalendar ()) {
		this.seconds = seconds;
	} else {
		calendar.set (Calendar.SECOND, seconds);
		updateControl ();
	}
}

/**
 * Sets the receiver's hours, minutes, and seconds in a single operation.
 *
 * @param hours an integer between 0 and 23
 * @param minutes an integer between 0 and 59
 * @param seconds an integer between 0 and 59
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @since 3.4
 */
public void setTime (int hours, int minutes, int seconds) {
	checkWidget ();
	if (!isValidTime (Calendar.HOUR_OF_DAY, hours)) return;
	if (!isValidTime (Calendar.MINUTE, minutes)) return;
	if (!isValidTime (Calendar.SECOND, seconds)) return;
	if (isCalendar ()) {
		this.hours = hours;
		this.minutes = minutes;
		this.seconds = seconds;
	} else {
		calendar.set (Calendar.HOUR_OF_DAY, hours);
		calendar.set (Calendar.MINUTE, minutes);
		calendar.set (Calendar.SECOND, seconds);
		updateControl ();
	}
}

/**
 * Sets the receiver's year.
 * <p>
 * The first year is 1752 and the last year is 9999.
 * If the specified year is not valid for the receiver's day and month, then it is ignored.
 * </p>
 *
 * @param year an integer between 1752 and 9999
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see #setDate
 */
public void setYear (int year) {
	checkWidget ();
	if (!isValidDate (year, getMonth (), getDay ())) return;
	if (isCalendar ()) {
		this.year = year;
		GTK.gtk_calendar_select_month (calendarHandle, month, year);
	} else {
		calendar.set (Calendar.YEAR, year);
		updateControl ();
	}
}

@Override
void setBoundsInPixels (int x, int y, int width, int height) {

	//Date with Drop down is in container. Needs extra handling.
	if (isDateWithDropDownButton () && GTK.GTK3) {
		GtkRequisition requisition = new GtkRequisition ();
		GTK.gtk_widget_get_preferred_size (textEntryHandle, null, requisition);
		int oldHeight = requisition.height; //Entry should not expand vertically. It is single liner.

		int newWidth = width - (down.getSizeInPixels ().x + getGtkBorderPadding ().right);
		GTK.gtk_widget_set_size_request (textEntryHandle, (newWidth >= 0) ? newWidth : 0, oldHeight);
	}

	/*
	 * TAG_GTK_CALENDAR_VERTICAL_FILL_WORKAROUND_394534
	 * Work around a GtkCalendar bug in GTK3:
	 * https://bugzilla.gnome.org/show_bug.cgi?id=737670
	 *
	 * In GTK3.0 - 3.14.2 (but not Gtk2) if the calendar is expanded beyond a certain size,
	 * (e.g in the case of 'Vertical fill' in ControlExample, then the days shift down
	 * and they become un-selectable. e.g, see screen shot:
	 * https://bug737670.bugzilla-attachments.gnome.org/attachment.cgi?id=287470
	 *
	 * To work around this, if gtk 3.0 - 3.14.2 is used, do not allow the calendar to expand beyond it's preffered
	 * native height.
	 */
	int fixedGtkVersion = OS.VERSION (3, 14, 2);
	if (isCalendar () && GTK.GTK3 && (GTK.GTK_VERSION < fixedGtkVersion)) {
			int calendarPrefferedVerticalSize = computeSizeInPixels (SWT.DEFAULT, SWT.DEFAULT, true).y;
			if (height > calendarPrefferedVerticalSize) {
				height = calendarPrefferedVerticalSize;
		}
	}
	super.setBoundsInPixels (x, y, width, height);

}

/**
 * Usually called when control is resized or first initialized.
 */
private void setDropDownButtonSize () {
	Rectangle rect = getClientAreaInPixels ();
	int parentWidth = rect.width;
	int parentHeight = rect.height;
	Point buttonSize = down.computeSizeInPixels (SWT.DEFAULT, parentHeight);

	//TAG_GTK3__NO_VERTICAL_FILL_ADJUSTMENT
	int dateEntryHeight = computeNativeSize (textEntryHandle, SWT.DEFAULT, SWT.DEFAULT, false).y;
	int newHeight = dateEntryHeight;

	//Move button a little closer to entry field, by amount of padding.
	int newXpos = parentWidth - buttonSize.x - getGtkBorderPadding().left - getGtkBorderPadding().right;

	int newYPos = parentHeight/2 - dateEntryHeight/2;
	down.setBoundsInPixels (newXpos, newYPos, buttonSize.x, newHeight);
}

/**
 * Gets the border padding structure, which can be used to determine the inner padding of the text field.
 * Note, this function returns the correct padding only under GTK3.
 * Under Gtk2, it returns a constant.
 * @return GtkBorder object that holds the padding values.
 */
GtkBorder getGtkBorderPadding () {
	if (GTK.GTK3) {
		//In Gtk3, acquire border.
		GtkBorder gtkBorderPadding = new GtkBorder ();
		long /*int*/ context = GTK.gtk_widget_get_style_context (textEntryHandle);
		if (GTK.GTK_VERSION < OS.VERSION(3, 18 , 0)) {
			GTK.gtk_style_context_get_padding (context, GTK.GTK_STATE_FLAG_NORMAL, gtkBorderPadding);
		} else {
			GTK.gtk_style_context_get_padding (context, GTK.gtk_widget_get_state_flags(textEntryHandle), gtkBorderPadding);
		}
		return gtkBorderPadding;
	} else {
		//in GTK2 hard code the padding
		GtkBorder padding = new GtkBorder ();
		padding.bottom = padding.top = padding.left = padding.right = GTK2_MANUAL_BORDER_PADDING;
		return padding;
	}
}

boolean onNumberKeyInput(int key) {
	if (currentField == null) {
		return false;
	}
	int fieldName = getCalendarField(currentField);
	StringBuffer prefix = new StringBuffer();
	StringBuffer current = new StringBuffer();
	StringBuffer suffix = new StringBuffer();

	AttributedCharacterIterator iterator = dateFormat.formatToCharacterIterator(calendar.getTime());
	char c = iterator.first();
	do {
		if (isSameField(currentField, getFieldPosition(iterator))) {
			current.append(c);
		} else if (current.length() == 0) {
			prefix.append(c);
		} else {
			suffix.append(c);
		}
	} while ((c = iterator.next()) != CharacterIterator.DONE);

	if (typeBufferPos < 0) {
		typeBuffer.setLength(0);
		typeBuffer.append(current);
		typeBufferPos = 0;
	}
	if (key == GDK.GDK_BackSpace) {
		if (typeBufferPos > 0 && typeBufferPos <= typeBuffer.length()) {
			typeBuffer.deleteCharAt(typeBufferPos - 1);
			typeBufferPos--;
		}
	} else if (key == GDK.GDK_Delete) {
		if (typeBufferPos >= 0 && typeBufferPos < typeBuffer.length()) {
			typeBuffer.deleteCharAt(typeBufferPos);
		}
	} else {
		char newText = keyToString(key);
		if (!Character.isAlphabetic(newText) && !Character.isDigit(newText)) {
			return false;
		}
		if (fieldName == Calendar.AM_PM) {
			if (dateFormat instanceof SimpleDateFormat) {
				String[] amPmStrings = ((SimpleDateFormat) dateFormat).getDateFormatSymbols().getAmPmStrings();
				if (amPmStrings[Calendar.AM].charAt(0) == newText) {
					setTextField(currentField, Calendar.AM);
					return false;
				} else if (amPmStrings[Calendar.PM].charAt(0) == newText) {
					setTextField(currentField, Calendar.PM);
					return false;
				}
			}
		}
		if (typeBufferPos < typeBuffer.length()) {
			typeBuffer.replace(typeBufferPos, typeBufferPos + 1, Character.toString(newText));
		} else {
			typeBuffer.append(newText);
		}
		typeBufferPos++;
	}
	StringBuffer newText = new StringBuffer(prefix);
	newText.append(typeBuffer);
	newText.append(suffix);
	setText(newText.toString());
	setSelection(prefix.length() + typeBufferPos, prefix.length() + typeBuffer.length());
	currentField.setBeginIndex(prefix.length());
	currentField.setEndIndex(prefix.length() + typeBuffer.length());
	return false;
}

private char keyToString(int key) {
	// If numberpad keys were pressed.
	if (key >= GDK.GDK_KP_0 && key <= GDK.GDK_KP_9) {
		// convert numberpad button to regular key;
		key -= 65408;
	}
	return (char) key;
}

void updateControl() {
	if ((isDate() || isTime()) && textEntryHandle != 0) {
		setText(getFormattedString());
	}
	redraw ();
}

@Override
void register () {
	super.register ();
	if (handle != 0 && display.getWidget(handle) == null) display.addWidget(handle, this);
	if (containerHandle != 0 && containerHandle != handle) display.addWidget (containerHandle, this);
	if (textEntryHandle != 0 && textEntryHandle != containerHandle) display.addWidget (textEntryHandle, this);
}

@Override
GdkRGBA defaultBackground () {
	return display.getSystemColor(SWT.COLOR_LIST_BACKGROUND).handleRGBA;
}

@Override
void deregister () {
	super.deregister ();
	if (handle != 0 && display.getWidget(handle) != null) display.removeWidget(handle);
	if (containerHandle != 0 && containerHandle != handle) display.removeWidget (containerHandle);
	if (textEntryHandle != 0 && textEntryHandle != containerHandle) display.removeWidget (textEntryHandle);
}

int getArrow(long /*int*/ widget) {
	int adj_value = (int) GTK.gtk_adjustment_get_value(GTK.gtk_spin_button_get_adjustment(widget));
	int new_value = 0;
	if (isDate()) {
		FieldPosition firstField = getNextField(null);
		new_value = calendar.get(getCalendarField(firstField));
	} else if (isTime()) {
		new_value = getHours();
		if (hasAmPm()) {
			// as getHours () has 24h format but spinner 12h format, new_value needs to be
			// converted to 12h format
			if (getHours() > 12) {
				new_value = getHours() - 12;
			}
			if (new_value == 0)
				new_value = 12;
		}
	}
	if (adj_value == 0 && firstTime)
		return 0;
	firstTime = false;
	if (adj_value == new_value)
		return 0;
	return adj_value > new_value ? SWT.ARROW_UP : SWT.ARROW_DOWN;
}

/**
 * Calculates appropriate width of GtkEntry and
 * adds Date/Time string to the Date/Time Spinner
 */
void setText (String dateTimeText) {
	if (dateTimeText != null){
		byte [] dateTimeConverted = Converter.wcsToMbcs (dateTimeText, true);
		//note, this is ignored if the control is in a fill-layout.
		GTK.gtk_entry_set_width_chars (textEntryHandle, dateTimeText.length ());
		GTK.gtk_entry_set_text (textEntryHandle, dateTimeConverted);
		if (popupCalendar != null && calendar != null) {
			Date parse;
			try {
				parse = dateFormat.parse(dateTimeText);
			} catch(ParseException e) {
				//not a valid date (yet), return for now
				return;
			}
			Calendar clone = (Calendar) calendar.clone();
			clone.setTime(parse);
			try {
				popupCalendar.setDate (clone.get(Calendar.YEAR), clone.get(Calendar.MONTH), clone.get(Calendar.DAY_OF_MONTH));
			} catch(SWTException e) {
				if (e.code == SWT.ERROR_WIDGET_DISPOSED) {
					//the calendar popup was disposed in the meantime so nothing to update
					return;
				}
				throw e;
			}
		}
	}
}

@Override
long /*int*/ gtk_key_press_event (long /*int*/ widget, long /*int*/ event) {
	if (!isReadOnly () && (isTime () || isDate ())) {
		GdkEventKey keyEvent = new GdkEventKey ();
		OS.memmove (keyEvent, event, GdkEventKey.sizeof);
		int key = keyEvent.keyval;
		switch (key) {
		case GDK.GDK_Up:
		case GDK.GDK_KP_Up:
			incrementField(+1);
			commitData();
			break;
		case GDK.GDK_Down:
		case GDK.GDK_KP_Down:
			incrementField(-1);
			commitData();
			break;
		case GDK.GDK_Tab:
		case GDK.GDK_Right:
		case GDK.GDK_KP_Right:
			selectField(getNextField(currentField));
			sendEvent(SWT.Traverse);
			break;
		case GDK.GDK_Left:
		case GDK.GDK_KP_Left:
			selectField(getPreviousField(currentField));
			sendEvent(SWT.Traverse);
			break;
		case GDK.GDK_Home:
		case GDK.GDK_KP_Home:
			/* Set the value of the current field to its minimum */
			if (currentField != null) {
				setTextField(currentField, calendar.getActualMinimum(getCalendarField(currentField)));
			}
			break;
		case GDK.GDK_End:
		case GDK.GDK_KP_End:
			/* Set the value of the current field to its maximum */
			if (currentField != null) {
				setTextField(currentField, calendar.getActualMaximum(getCalendarField(currentField)));
			}
			break;
		default:
			onNumberKeyInput(key);
		}
	}
	return 1;
}

void commitData() {
	try {
		Date date = dateFormat.parse(getText());
		calendar.setTime(date);
	} catch (ParseException e) {
		// invalid value, input will reset...
	}
	updateControl();
}

/** returns selected text **/
Point getSelection () {
	checkWidget ();
	Point selection;
	int [] start = new int [1];
	int [] end = new int [1];
	GTK.gtk_editable_get_selection_bounds (textEntryHandle, start, end);
	long /*int*/ ptr = GTK.gtk_entry_get_text (textEntryHandle);
	start[0] = (int)/*64*/OS.g_utf8_offset_to_utf16_offset (ptr, start[0]);
	end[0] = (int)/*64*/OS.g_utf8_offset_to_utf16_offset (ptr, end[0]);
	selection = new Point (start [0], end [0]);
	return selection;

}

/**
 * Returns a string containing a copy of the contents of the
 * receiver's text field, or an empty string if there are no
 * contents.
 *
 * @return Spinner's text
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
String getText () {
	checkWidget ();
	if (textEntryHandle != 0) {
		long /*int*/ str = GTK.gtk_entry_get_text (textEntryHandle);
		if (str == 0) return "";
		int length = C.strlen (str);
		byte [] buffer = new byte [length];
		C.memmove (buffer, str, length);
		return new String (Converter.mbcsToWcs (buffer));
	}
		return "";
}

/**
 * returns GtkEntry starting from index and ending with index
 * provided by the user
 */
String getText (String str,int start, int end) {
	checkWidget ();
	if (!(start <= end && 0 <= end)) return "";
	int length = str.length ();
	end = Math.min (end, length - 1);
	if (start > end) return "";
	start = Math.max (0, start);
	/*
	* NOTE: The current implementation uses substring ()
	* which can reference a potentially large character
	* array.
	*/
	return str.substring (start, end + 1);
}

void setSelection (int start, int end) {
	checkWidget ();
	long /*int*/ ptr = GTK.gtk_entry_get_text (textEntryHandle);
	start = (int)/*64*/OS.g_utf16_offset_to_utf8_offset (ptr, start);
	end = (int)/*64*/OS.g_utf16_offset_to_utf8_offset (ptr, end);
	GTK.gtk_editable_set_position (textEntryHandle, start);
	GTK.gtk_editable_select_region (textEntryHandle, start, end);
}

void setTextField(FieldPosition field, int value) {
	int validValue = validateValueBounds(field, value);
	setFieldOfInternalDataStructure(field, validValue);
	setFieldOfInternalDataStructure(field, value);
	updateControl();
	if (currentField != null) {
		selectField(currentField);
	}
}

private int validateValueBounds(FieldPosition field, int value) {
	int calendarField = getCalendarField(field);
	int max = calendar.getActualMaximum (calendarField);
	int min = calendar.getActualMinimum (calendarField);
	if (calendarField == Calendar.YEAR) {
		max = MAX_YEAR;
		min = MIN_YEAR;
		/* Special case: convert 1 or 2-digit years into reasonable 4-digit years. */
		int currentYear = Calendar.getInstance ().get (Calendar.YEAR);
		int currentCentury = (currentYear / 100) * 100;
		if (value < (currentYear + 30) % 100) value += currentCentury;
		else if (value < 100) value += currentCentury - 100;
	}
	if (value > max) value = min; // wrap
	if (value < min) value = max; // wrap
	return value;
}

@Override
long /*int*/ gtk_button_release_event (long /*int*/ widget, long /*int*/ event) {
	if (isDate () || isTime ()) {
		GdkEventButton gdkEvent = getEventInfoFromOS (event);
		if (gdkEvent.button == 1) { // left mouse button.
			onTextMouseClick (gdkEvent);
		}
	}
	return super.gtk_button_release_event (widget, event);
}

private GdkEventButton getEventInfoFromOS (long /*int*/ nativeEventPointer) {
	// create place holder.
	GdkEventButton localEventCopy = new GdkEventButton ();

	// copy data in memory from OS to local JAVA space.
	OS.memmove (localEventCopy, nativeEventPointer, GdkEventButton.sizeof);
	return localEventCopy;
}
/**
 * Output signal is called when Spinner's arrow buttons are triggered,
 * usually by clicking the mouse on the [gtk2: up/down] [gtk3: +/-] buttons.
 * On every click output is called twice presenting current and previous value.
 * This method compares two values and determines if Up or down arrow was called.
 */
@Override
long /*int*/ gtk_output (long /*int*/ widget) {
	if (calendar == null) {
		return 0; //Guard: Object not fully initialized yet.
	}
	int arrowType = getArrow(widget);
	switch (arrowType) {
	case SWT.ARROW_UP: // Gtk2 arrow up. Gtk3 "+" button.
		commitData();
		incrementField(+1);
		break;
	case SWT.ARROW_DOWN: // Gtk2 arrow down. Gtk3 "-" button.
		commitData();
		incrementField(-1);
		break;
	}
	return 1;
}

void replaceCurrentlySelectedTextRegion (String string) {
	checkWidget ();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	byte [] buffer = Converter.wcsToMbcs (string, false);
	int [] start = new int [1], end = new int [1];
	GTK.gtk_editable_get_selection_bounds (textEntryHandle, start, end);
	GTK.gtk_editable_delete_selection (textEntryHandle);
	GTK.gtk_editable_insert_text (textEntryHandle, buffer, buffer.length, start);
	GTK.gtk_editable_set_position (textEntryHandle, start [0]);
}

void onTextMouseClick(GdkEventButton event) {
	if (calendar == null) {
		return; // Guard: Object not fully initialized yet.
	}
	int clickPosition = getSelection().x;
	AttributedCharacterIterator iterator = dateFormat.formatToCharacterIterator(calendar.getTime());
	iterator.first();
	int pos = 0;
	do {
		FieldPosition position = getFieldPosition(iterator);
		iterator.setIndex(iterator.getRunLimit());
		if (isSameField(position, currentField)) {
			// use the current field instead then!
			position = currentField;
		}
		int fieldWidth = position.getEndIndex() - position.getBeginIndex();
		pos += fieldWidth;
		if (position.getFieldAttribute() == null) {
			continue;
		}
		if (pos >= clickPosition) {
			FieldPosition selectField = new FieldPosition(position.getFieldAttribute());
			selectField.setBeginIndex(pos - fieldWidth);
			selectField.setEndIndex(pos);
			selectField(selectField);
			break;
		}
	} while (iterator.current() != CharacterIterator.DONE);

}

String getText (int start, int end) {
	checkWidget ();
	if (!(start <= end && 0 <= end)) return "";
	String str = getText ();
	int length = str.length ();
	end = Math.min (end, length - 1);
	if (start > end) return "";
	start = Math.max (0, start);
	/*
	* NOTE: The current implementation uses substring ()
	* which can reference a potentially large character
	* array.
	*/
	return str.substring (start, end + 1);
}

void selectAll () {
	checkWidget ();
	if (textEntryHandle != 0)
		GTK.gtk_editable_select_region (textEntryHandle, 0, -1);
}


void hideDateTime () {
	if (isDate () || isTime ()){
		GTK.gtk_widget_hide (fixedHandle);
	}
}

@Override
void releaseWidget () {
	super.releaseWidget ();
	if (fixedHandle != 0)
		hideDateTime ();
}

/**
 * Returns a field with updated positionla data
 *
 * @param field
 * @return
 */
private FieldPosition updateField(FieldPosition field) {
	AttributedCharacterIterator iterator = dateFormat.formatToCharacterIterator(calendar.getTime());
	while (iterator.current() != CharacterIterator.DONE) {
		FieldPosition current = getFieldPosition(iterator);
		iterator.setIndex(iterator.getRunLimit());
		if (field == null || isSameField(current, field)) {
			return current;
		}
	}
	return field;
}

/**
 * Given a {@link FieldPosition} searches the next field in the format string
 *
 * @param field
 *            the Field to start from
 * @return the next {@link FieldPosition}
 */
private FieldPosition getNextField(FieldPosition field) {
	AttributedCharacterIterator iterator = dateFormat.formatToCharacterIterator(calendar.getTime());
	FieldPosition first = null;
	boolean found = false;
	while (iterator.current() != CharacterIterator.DONE) {
		FieldPosition current = getFieldPosition(iterator);
		iterator.setIndex(iterator.getRunLimit());
		if (current.getFieldAttribute() == null) {
			continue;
		}
		if (found) {
			return current;
		}
		if (first == null) {
			first = current;
		}
		if (isSameField(current, field)) {
			found = true;
		}
	}
	return first;
}

/**
 *
 * @param field
 * @return the next field of the given one
 */
private FieldPosition getPreviousField(FieldPosition field) {
	AttributedCharacterIterator iterator = dateFormat.formatToCharacterIterator(calendar.getTime());
	FieldPosition last = null;
	do {
		FieldPosition current = getFieldPosition(iterator);
		if (isSameField(current, field)) {
			if (last != null) {
				return last;
			}
		}
		if (current.getFieldAttribute() != null) {
			last = current;
		}
		iterator.setIndex(iterator.getRunLimit());
	} while (iterator.current() != CharacterIterator.DONE);
	return last;
}

/**
 * Searches the current postion of the iterator for a {@link Field} and
 * constructs a {@link FieldPosition} from it
 *
 * @param iterator
 *            the iterator to use
 * @return a new {@link FieldPosition}
 */
private static FieldPosition getFieldPosition(AttributedCharacterIterator iterator) {
	Set<Attribute> keySet = iterator.getAttributes().keySet();
	for (Attribute attribute : keySet) {
		if (attribute instanceof Field) {
			return getFieldPosition((Field) attribute, iterator);
		}
	}
	return getFieldPosition((Field) null, iterator);
}

/**
 * creates a {@link FieldPosition} out of a {@link Field} and and a
 * {@link AttributedCharacterIterator}s current position
 *
 * @param field
 *            the field to use
 * @param iterator
 *            the iterator to extract the data from
 * @return a {@link FieldPosition} init to this Field and begin/end index
 */
private static FieldPosition getFieldPosition(Field field, AttributedCharacterIterator iterator) {
	FieldPosition position = new FieldPosition(field);
	position.setBeginIndex(iterator.getRunStart());
	position.setEndIndex(iterator.getRunLimit());
	return position;
}

/**
 * Check if the given {@link FieldPosition} are considdered "the same", this is
 * when both are not <code>null</code> and reference the same
 * {@link java.text.Format.Field} attribute, or both of them have no
 * fieldattribute and have the same position
 *
 * @param p1
 *            first position to compare
 * @param p2
 *            second position to compare
 * @return <code>true</code> if considered the same, <code>false</code>
 *         otherwise
 */
private static boolean isSameField(FieldPosition p1, FieldPosition p2) {
	if (p1 == p2) {
		return true;
	}
	if (p1 == null || p2 == null) {
		return false;
	}
	if (p1.getFieldAttribute() == null && p2.getFieldAttribute() == null) {
		return p1.equals(p2);
	}
	if (p1.getFieldAttribute() == null) {
		return false;
	}
	return p1.getFieldAttribute().equals(p2.getFieldAttribute());
}

/**
 * Extracts the calendarfield for the given fieldposition
 *
 * @param fieldPosition
 * @return the {@link Calendar} field or -1 if this is not a valid Fieldposition
 */
private static int getCalendarField(FieldPosition fieldPosition) {
	if ((fieldPosition.getFieldAttribute() instanceof Field)) {
		return getCalendarField((Field) fieldPosition.getFieldAttribute());
	} else {
		return -1;
	}
}

/**
 * Extracts the calendarfield transforming HOUR1 types to HOUR0
 *
 * @param field
 * @return the calendarfield coresponding to the {@link Field}
 */
private static int getCalendarField(Field field) {
	if (Field.HOUR1.equals(field)) {
		field = Field.HOUR0;
	} else if (Field.HOUR_OF_DAY1.equals(field)) {
		field = Field.HOUR_OF_DAY0;
	}
	return field.getCalendarField();
}

}