bundles/org.eclipse.swt/Eclipse SWT/gtk1x/org/eclipse/swt/widgets/Slider.java - platform/eclipse.platform.swt - Git at Google

 package org.eclipse.swt.widgets;

 /*
  * (c) Copyright IBM Corp. 2000, 2001.
  * All Rights Reserved
  */

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

 /**
  * Instances of this class are selectable user interface
  * objects that represent a range of positive, numeric values.
  * <p>
  * At any given moment, a given slider will have a
  * single <em>selection</em> that is considered to be its
  * value, which is constrained to be within the range of
  * values the slider represents (that is, between its
  * <em>minimum</em> and <em>maximum</em> values).
  * </p><p>
  * Typically, sliders will be made up of five areas:
  * <ol>
  * <li>an arrow button for decrementing the value</li>
  * <li>a page decrement area for decrementing the value by a larger amount</li>
  * <li>a <em>thumb</em> for modifying the value by mouse dragging</li>
  * <li>a page increment area for incrementing the value by a larger amount</li>
  * <li>an arrow button for incrementing the value</li>
  * </ol>
  * Based on their style, sliders are either <code>HORIZONTAL</code>
  * (which have left and right facing buttons for incrementing and
  * decrementing the value) or <code>VERTICAL</code> (which have
  * up and down facing buttons for incrementing and decrementing
  * the value).
  * </p><p>
  * On some platforms, the size of the slider's thumb can be
  * varied relative to the magnitude of the range of values it
  * represents (that is, relative to the difference between its
  * maximum and minimum values). Typically, this is used to
  * indicate some proportional value such as the ratio of the
  * visible area of a document to the total amount of space that
  * it would take to display it. SWT supports setting the thumb
  * size even if the underlying platform does not, but in this
  * case the appearance of the slider will not change.
  * </p>
  * <dl>
  * <dt><b>Styles:</b></dt>
  * <dd>HORIZONTAL, VERTICAL</dd>
  * <dt><b>Events:</b></dt>
  * <dd>Selection</dd>
  * </dl>
  * <p>
  * IMPORTANT: This class is <em>not</em> intended to be subclassed.
  *
  * @see ScrollBar
  */

 public class Slider extends Control {

 /**
  * 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
  * for all SWT widget classes should include a comment which
  * describes the style constants which are applicable to the class.
  * </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
  * @see Widget#checkSubclass
  * @see Widget#getStyle
  */
 public Slider (Composite parent, int style) {
 	super (parent, checkStyle (style));
 }

 /**
  * Adds the listener to the collection of listeners who will
  * be notified when the receiver's value changes, by sending
  * it one of the messages defined in the <code>SelectionListener</code>
  * interface.
  * <p>
  * When <code>widgetSelected</code> is called, the event object detail field contains one of the following values:
  * <code>0</code> - for the end of a drag.
  * <code>SWT.DRAG</code>.
  * <code>SWT.HOME</code>.
  * <code>SWT.END</code>.
  * <code>SWT.ARROW_DOWN</code>.
  * <code>SWT.ARROW_UP</code>.
  * <code>SWT.PAGE_DOWN</code>.
  * <code>SWT.PAGE_UP</code>.
  * <code>widgetDefaultSelected</code> is not called.
  * </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);
 }

 static int checkStyle (int style) {
 	return checkBits (style, SWT.HORIZONTAL, SWT.VERTICAL, 0, 0, 0, 0);
 }

 void createHandle (int index) {
 	state |= HANDLE;
 	int hAdjustment = OS.gtk_adjustment_new (0, 0, 100, 1, 10, 10);
 	if (hAdjustment == 0) error (SWT.ERROR_NO_HANDLES);
 	if ((style & SWT.HORIZONTAL) != 0) {
 		handle = OS.gtk_hscrollbar_new (hAdjustment);
 	} else {
 		handle = OS.gtk_vscrollbar_new (hAdjustment);
 	}
 	if (handle == 0) error (SWT.ERROR_NO_HANDLES);
 }

 void setHandleStyle() {}

 void showHandle() {
 	OS.gtk_widget_show (handle);
 	OS.gtk_widget_realize (handle);
 }

 void hookEvents () {
 	super.hookEvents ();
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	signal_connect (hAdjustment, "value_changed", SWT.Selection, 2);
 }

 void register () {
 	super.register ();
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	WidgetTable.put (hAdjustment, this);
 }

 void deregister () {
 	super.deregister ();
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	WidgetTable.remove (hAdjustment);
 	/*
 	* This code is intentionally commented.
 	*/
 //	OS.gtk_object_unref (hAdjustment);
 //	OS.gtk_object_destroy (hAdjustment);
 }

 public Point computeSize (int wHint, int hHint, boolean changed) {
 	checkWidget ();
 	// We are interested in the preferred size.
 	// The native widget gives us what it thinks the minimum reasonable
 	// size; we'll say we prefer to be twice that long, and exactly
 	// that wide.
 	int x,y;
 	Point size = super.computeSize (wHint, hHint, changed);
 	if (hHint==SWT.DEFAULT) {
 		x = size.x;
 		if ((style & SWT.HORIZONTAL) != 0) x = 2*x;
 	} else x = hHint;
 	if (wHint==SWT.DEFAULT) {
 		y = size.y;
 		if ((style & SWT.VERTICAL) != 0) y = 2*y;
 	} else y = wHint;

 	return new Point(x,y);
 }

 /**
  * Returns the amount that the receiver's value will be
  * modified by when the up/down (or right/left) arrows
  * are pressed.
  *
  * @return the increment
  *
  * @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 getIncrement () {
 	checkWidget ();
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	GtkAdjustment adjustment = new GtkAdjustment ();
 	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
 	return (int) adjustment.step_increment;
 }

 /**
  * Returns the maximum value which the receiver will allow.
  *
  * @return the maximum
  *
  * @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 getMaximum () {
 	checkWidget ();
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	GtkAdjustment adjustment = new GtkAdjustment ();
 	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
 	return (int) adjustment.upper;
 }

 /**
  * Returns the minimum value which the receiver will allow.
  *
  * @return the minimum
  *
  * @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 getMinimum () {
 	checkWidget ();
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	GtkAdjustment adjustment = new GtkAdjustment ();
 	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
 	return (int) adjustment.lower;
 }

 /**
  * Returns the amount that the receiver's value will be
  * modified by when the page increment/decrement areas
  * are selected.
  *
  * @return the page increment
  *
  * @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 getPageIncrement () {
 	checkWidget ();
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	GtkAdjustment adjustment = new GtkAdjustment ();
 	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
 	return (int) adjustment.page_increment;
 }

 /**
  * Returns the single <em>selection</em> that is the receiver's value.
  *
  * @return the selection
  *
  * @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 getSelection () {
 	checkWidget ();
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	GtkAdjustment adjustment = new GtkAdjustment ();
 	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
 	return (int) adjustment.value;
 }

 /**
  * Returns the size of the receiver's thumb relative to the
  * difference between its maximum and minimum values.
  *
  * @return the thumb value
  *
  * @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 getThumb () {
 	checkWidget ();
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	GtkAdjustment adjustment = new GtkAdjustment ();
 	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
 	return (int) adjustment.page_size;
 }

 int processSelection (int int0, int int1, int int2) {
 	postEvent (SWT.Selection);
 	return 0;
 }

 /**
  * Removes the listener from the collection of listeners who will
  * be notified when the receiver's value changes.
  *
  * @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);
 }

 /**
  * Sets the amount that the receiver's value will be
  * modified by when the up/down (or right/left) arrows
  * are pressed to the argument, which must be at least
  * one.
  *
  * @param value the new increment (must be greater than zero)
  *
  * @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 setIncrement (int value) {
 	checkWidget();
 	if (value < 1) return;
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	GtkAdjustment adjustment = new GtkAdjustment ();
 	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
 	adjustment.step_increment = (float) value;
 	OS.memmove (hAdjustment, adjustment, GtkAdjustment.sizeof);
 	OS.gtk_adjustment_changed (hAdjustment);
 }

 /**
  * Sets the maximum value which the receiver will allow
  * to be the argument which must be greater than or
  * equal to zero.
  *
  * @param value the new maximum (must be zero or greater)
  *
  * @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 setMaximum (int value) {
 	checkWidget ();
 	if (value < 0) return;
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	GtkAdjustment adjustment = new GtkAdjustment ();
 	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
 	adjustment.upper = (float) value;
 	OS.memmove (hAdjustment, adjustment, GtkAdjustment.sizeof);
 	OS.gtk_adjustment_changed (hAdjustment);
 }

 /**
  * Sets the minimum value which the receiver will allow
  * to be the argument which must be greater than or
  * equal to zero.
  *
  * @param value the new minimum (must be zero or greater)
  *
  * @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 setMinimum (int value) {
 	checkWidget ();
 	if (value < 0) return;
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	GtkAdjustment adjustment = new GtkAdjustment ();
 	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
 	adjustment.lower = (float) value;
 	OS.memmove (hAdjustment, adjustment, GtkAdjustment.sizeof);
 	OS.gtk_adjustment_changed (hAdjustment);
 }

 /**
  * Sets the amount that the receiver's value will be
  * modified by when the page increment/decrement areas
  * are selected to the argument, which must be at least
  * one.
  *
  * @return the page increment (must be greater than zero)
  *
  * @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 setPageIncrement (int value) {
 	checkWidget ();
 	if (value < 1) return;
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	GtkAdjustment adjustment = new GtkAdjustment ();
 	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
 	adjustment.page_increment = (float) value;
 	OS.memmove (hAdjustment, adjustment, GtkAdjustment.sizeof);
 	OS.gtk_adjustment_changed (hAdjustment);
 }

 /**
  * Sets the single <em>selection</em> that is the receiver's
  * value to the argument which must be greater than or equal
  * to zero.
  *
  * @param value the new selection (must be zero or greater)
  *
  * @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 setSelection (int value) {
 	checkWidget ();
 	if (value < 0) return;
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	OS.gtk_signal_handler_block_by_data (hAdjustment, SWT.Selection);
 	OS.gtk_adjustment_set_value (hAdjustment, value);
 	OS.gtk_signal_handler_unblock_by_data (hAdjustment, SWT.Selection);
 }

 /**
  * Sets the size of the receiver's thumb relative to the
  * difference between its maximum and minimum values to the
  * argument which must be at least one.
  *
  * @param value the new thumb value (must be at least one)
  *
  * @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 ScrollBar
  */
 public void setThumb (int value) {
 	checkWidget ();
 	if (value < 1) return;
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	GtkAdjustment adjustment = new GtkAdjustment ();
 	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
 	adjustment.page_size = (float) value;
 	OS.memmove (hAdjustment, adjustment, GtkAdjustment.sizeof);
 	OS.gtk_adjustment_changed (hAdjustment);
 }

 /**
  * Sets the receiver's selection, minimum value, maximum
  * value, thumb, increment and page increment all at once.
  * <p>
  * Note: This is equivalent to setting the values individually
  * using the appropriate methods, but may be implemented in a
  * more efficient fashion on some platforms.
  * </p>
  *
  * @param selection the new selection value
  * @param minimum the new minimum value
  * @param maximum the new maximum value
  * @param thumb the new thumb value
  * @param increment the new increment value
  * @param pageIncrement the new pageIncrement value
  *
  * @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 setValues (int selection, int minimum, int maximum, int thumb, int increment, int pageIncrement) {
 	checkWidget ();
 	if (selection < 0) return;
 	if (minimum < 0) return;
 	if (maximum < 0) return;
 	if (thumb < 1) return;
 	if (maximum - minimum - thumb < 0) return;
 	if (increment < 1) return;
 	if (pageIncrement < 1) return;
 	int hAdjustment = OS.gtk_range_get_adjustment (handle);
 	GtkAdjustment adjustment = new GtkAdjustment ();
 	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
 	adjustment.value = (float) selection;
 	adjustment.lower = (float) minimum;
 	adjustment.upper = (float) maximum;
 	adjustment.page_size = (float) thumb;
 	adjustment.step_increment = (float) increment;
 	adjustment.page_increment = (float) pageIncrement;
 	OS.memmove (hAdjustment, adjustment, GtkAdjustment.sizeof);
 	OS.gtk_adjustment_changed (hAdjustment);
 	OS.gtk_adjustment_value_changed (hAdjustment);
 }

 }
	package org.eclipse.swt.widgets;

	/*
	* (c) Copyright IBM Corp. 2000, 2001.
	* All Rights Reserved
	*/

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

	/**
	* Instances of this class are selectable user interface
	* objects that represent a range of positive, numeric values.
	* <p>
	* At any given moment, a given slider will have a
	* single <em>selection</em> that is considered to be its
	* value, which is constrained to be within the range of
	* values the slider represents (that is, between its
	* <em>minimum</em> and <em>maximum</em> values).
	* </p><p>
	* Typically, sliders will be made up of five areas:
	* <ol>
	* <li>an arrow button for decrementing the value</li>
	* <li>a page decrement area for decrementing the value by a larger amount</li>
	* <li>a <em>thumb</em> for modifying the value by mouse dragging</li>
	* <li>a page increment area for incrementing the value by a larger amount</li>
	* <li>an arrow button for incrementing the value</li>
	* </ol>
	* Based on their style, sliders are either <code>HORIZONTAL</code>
	* (which have left and right facing buttons for incrementing and
	* decrementing the value) or <code>VERTICAL</code> (which have
	* up and down facing buttons for incrementing and decrementing
	* the value).
	* </p><p>
	* On some platforms, the size of the slider's thumb can be
	* varied relative to the magnitude of the range of values it
	* represents (that is, relative to the difference between its
	* maximum and minimum values). Typically, this is used to
	* indicate some proportional value such as the ratio of the
	* visible area of a document to the total amount of space that
	* it would take to display it. SWT supports setting the thumb
	* size even if the underlying platform does not, but in this
	* case the appearance of the slider will not change.
	* </p>
	* <dl>
	* <dt><b>Styles:</b></dt>
	* <dd>HORIZONTAL, VERTICAL</dd>
	* <dt><b>Events:</b></dt>
	* <dd>Selection</dd>
	* </dl>
	* <p>
	* IMPORTANT: This class is <em>not</em> intended to be subclassed.
	*
	* @see ScrollBar
	*/

	public class Slider extends Control {

	/**
	* 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
	* for all SWT widget classes should include a comment which
	* describes the style constants which are applicable to the class.
	* </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
	* @see Widget#checkSubclass
	* @see Widget#getStyle
	*/
	public Slider (Composite parent, int style) {
	super (parent, checkStyle (style));
	}

	/**
	* Adds the listener to the collection of listeners who will
	* be notified when the receiver's value changes, by sending
	* it one of the messages defined in the <code>SelectionListener</code>
	* interface.
	* <p>
	* When <code>widgetSelected</code> is called, the event object detail field contains one of the following values:
	* <code>0</code> - for the end of a drag.
	* <code>SWT.DRAG</code>.
	* <code>SWT.HOME</code>.
	* <code>SWT.END</code>.
	* <code>SWT.ARROW_DOWN</code>.
	* <code>SWT.ARROW_UP</code>.
	* <code>SWT.PAGE_DOWN</code>.
	* <code>SWT.PAGE_UP</code>.
	* <code>widgetDefaultSelected</code> is not called.
	* </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);
	}

	static int checkStyle (int style) {
	return checkBits (style, SWT.HORIZONTAL, SWT.VERTICAL, 0, 0, 0, 0);
	}

	void createHandle (int index) {
	state \|= HANDLE;
	int hAdjustment = OS.gtk_adjustment_new (0, 0, 100, 1, 10, 10);
	if (hAdjustment == 0) error (SWT.ERROR_NO_HANDLES);
	if ((style & SWT.HORIZONTAL) != 0) {
	handle = OS.gtk_hscrollbar_new (hAdjustment);
	} else {
	handle = OS.gtk_vscrollbar_new (hAdjustment);
	}
	if (handle == 0) error (SWT.ERROR_NO_HANDLES);
	}

	void setHandleStyle() {}

	void showHandle() {
	OS.gtk_widget_show (handle);
	OS.gtk_widget_realize (handle);
	}

	void hookEvents () {
	super.hookEvents ();
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	signal_connect (hAdjustment, "value_changed", SWT.Selection, 2);
	}

	void register () {
	super.register ();
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	WidgetTable.put (hAdjustment, this);
	}

	void deregister () {
	super.deregister ();
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	WidgetTable.remove (hAdjustment);
	/*
	* This code is intentionally commented.
	*/
	// OS.gtk_object_unref (hAdjustment);
	// OS.gtk_object_destroy (hAdjustment);
	}

	public Point computeSize (int wHint, int hHint, boolean changed) {
	checkWidget ();
	// We are interested in the preferred size.
	// The native widget gives us what it thinks the minimum reasonable
	// size; we'll say we prefer to be twice that long, and exactly
	// that wide.
	int x,y;
	Point size = super.computeSize (wHint, hHint, changed);
	if (hHint==SWT.DEFAULT) {
	x = size.x;
	if ((style & SWT.HORIZONTAL) != 0) x = 2*x;
	} else x = hHint;
	if (wHint==SWT.DEFAULT) {
	y = size.y;
	if ((style & SWT.VERTICAL) != 0) y = 2*y;
	} else y = wHint;

	return new Point(x,y);
	}

	/**
	* Returns the amount that the receiver's value will be
	* modified by when the up/down (or right/left) arrows
	* are pressed.
	*
	* @return the increment
	*
	* @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 getIncrement () {
	checkWidget ();
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	GtkAdjustment adjustment = new GtkAdjustment ();
	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
	return (int) adjustment.step_increment;
	}

	/**
	* Returns the maximum value which the receiver will allow.
	*
	* @return the maximum
	*
	* @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 getMaximum () {
	checkWidget ();
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	GtkAdjustment adjustment = new GtkAdjustment ();
	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
	return (int) adjustment.upper;
	}

	/**
	* Returns the minimum value which the receiver will allow.
	*
	* @return the minimum
	*
	* @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 getMinimum () {
	checkWidget ();
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	GtkAdjustment adjustment = new GtkAdjustment ();
	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
	return (int) adjustment.lower;
	}

	/**
	* Returns the amount that the receiver's value will be
	* modified by when the page increment/decrement areas
	* are selected.
	*
	* @return the page increment
	*
	* @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 getPageIncrement () {
	checkWidget ();
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	GtkAdjustment adjustment = new GtkAdjustment ();
	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
	return (int) adjustment.page_increment;
	}

	/**
	* Returns the single <em>selection</em> that is the receiver's value.
	*
	* @return the selection
	*
	* @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 getSelection () {
	checkWidget ();
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	GtkAdjustment adjustment = new GtkAdjustment ();
	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
	return (int) adjustment.value;
	}

	/**
	* Returns the size of the receiver's thumb relative to the
	* difference between its maximum and minimum values.
	*
	* @return the thumb value
	*
	* @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 getThumb () {
	checkWidget ();
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	GtkAdjustment adjustment = new GtkAdjustment ();
	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
	return (int) adjustment.page_size;
	}

	int processSelection (int int0, int int1, int int2) {
	postEvent (SWT.Selection);
	return 0;
	}

	/**
	* Removes the listener from the collection of listeners who will
	* be notified when the receiver's value changes.
	*
	* @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);
	}

	/**
	* Sets the amount that the receiver's value will be
	* modified by when the up/down (or right/left) arrows
	* are pressed to the argument, which must be at least
	* one.
	*
	* @param value the new increment (must be greater than zero)
	*
	* @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 setIncrement (int value) {
	checkWidget();
	if (value < 1) return;
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	GtkAdjustment adjustment = new GtkAdjustment ();
	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
	adjustment.step_increment = (float) value;
	OS.memmove (hAdjustment, adjustment, GtkAdjustment.sizeof);
	OS.gtk_adjustment_changed (hAdjustment);
	}

	/**
	* Sets the maximum value which the receiver will allow
	* to be the argument which must be greater than or
	* equal to zero.
	*
	* @param value the new maximum (must be zero or greater)
	*
	* @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 setMaximum (int value) {
	checkWidget ();
	if (value < 0) return;
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	GtkAdjustment adjustment = new GtkAdjustment ();
	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
	adjustment.upper = (float) value;
	OS.memmove (hAdjustment, adjustment, GtkAdjustment.sizeof);
	OS.gtk_adjustment_changed (hAdjustment);
	}

	/**
	* Sets the minimum value which the receiver will allow
	* to be the argument which must be greater than or
	* equal to zero.
	*
	* @param value the new minimum (must be zero or greater)
	*
	* @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 setMinimum (int value) {
	checkWidget ();
	if (value < 0) return;
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	GtkAdjustment adjustment = new GtkAdjustment ();
	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
	adjustment.lower = (float) value;
	OS.memmove (hAdjustment, adjustment, GtkAdjustment.sizeof);
	OS.gtk_adjustment_changed (hAdjustment);
	}

	/**
	* Sets the amount that the receiver's value will be
	* modified by when the page increment/decrement areas
	* are selected to the argument, which must be at least
	* one.
	*
	* @return the page increment (must be greater than zero)
	*
	* @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 setPageIncrement (int value) {
	checkWidget ();
	if (value < 1) return;
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	GtkAdjustment adjustment = new GtkAdjustment ();
	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
	adjustment.page_increment = (float) value;
	OS.memmove (hAdjustment, adjustment, GtkAdjustment.sizeof);
	OS.gtk_adjustment_changed (hAdjustment);
	}

	/**
	* Sets the single <em>selection</em> that is the receiver's
	* value to the argument which must be greater than or equal
	* to zero.
	*
	* @param value the new selection (must be zero or greater)
	*
	* @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 setSelection (int value) {
	checkWidget ();
	if (value < 0) return;
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	OS.gtk_signal_handler_block_by_data (hAdjustment, SWT.Selection);
	OS.gtk_adjustment_set_value (hAdjustment, value);
	OS.gtk_signal_handler_unblock_by_data (hAdjustment, SWT.Selection);
	}

	/**
	* Sets the size of the receiver's thumb relative to the
	* difference between its maximum and minimum values to the
	* argument which must be at least one.
	*
	* @param value the new thumb value (must be at least one)
	*
	* @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 ScrollBar
	*/
	public void setThumb (int value) {
	checkWidget ();
	if (value < 1) return;
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	GtkAdjustment adjustment = new GtkAdjustment ();
	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
	adjustment.page_size = (float) value;
	OS.memmove (hAdjustment, adjustment, GtkAdjustment.sizeof);
	OS.gtk_adjustment_changed (hAdjustment);
	}

	/**
	* Sets the receiver's selection, minimum value, maximum
	* value, thumb, increment and page increment all at once.
	* <p>
	* Note: This is equivalent to setting the values individually
	* using the appropriate methods, but may be implemented in a
	* more efficient fashion on some platforms.
	* </p>
	*
	* @param selection the new selection value
	* @param minimum the new minimum value
	* @param maximum the new maximum value
	* @param thumb the new thumb value
	* @param increment the new increment value
	* @param pageIncrement the new pageIncrement value
	*
	* @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 setValues (int selection, int minimum, int maximum, int thumb, int increment, int pageIncrement) {
	checkWidget ();
	if (selection < 0) return;
	if (minimum < 0) return;
	if (maximum < 0) return;
	if (thumb < 1) return;
	if (maximum - minimum - thumb < 0) return;
	if (increment < 1) return;
	if (pageIncrement < 1) return;
	int hAdjustment = OS.gtk_range_get_adjustment (handle);
	GtkAdjustment adjustment = new GtkAdjustment ();
	OS.memmove (adjustment, hAdjustment, GtkAdjustment.sizeof);
	adjustment.value = (float) selection;
	adjustment.lower = (float) minimum;
	adjustment.upper = (float) maximum;
	adjustment.page_size = (float) thumb;
	adjustment.step_increment = (float) increment;
	adjustment.page_increment = (float) pageIncrement;
	OS.memmove (hAdjustment, adjustment, GtkAdjustment.sizeof);
	OS.gtk_adjustment_changed (hAdjustment);
	OS.gtk_adjustment_value_changed (hAdjustment);
	}

	}