*/public int getSelection () {	checkWidget();	SCROLLINFO info = new SCROLLINFO ();	info.cbSize = SCROLLINFO.sizeof;	info.fMask = OS.SIF_POS;	int hwnd = hwndScrollBar ();	int type = scrollBarType ();	OS.GetScrollInfo (hwnd, type, info);	return info.nPos;}/** * Returns a point describing the receiver's size. The * x coordinate of the result is the width of the receiver. * The y coordinate of the result is the height of the * receiver. * * @return the receiver's size * * @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 Point getSize () {	checkWidget();	parent.forceResize ();	RECT rect = new RECT ();	OS.GetClientRect (parent.handle, rect);	int width, height;	if ((style & SWT.HORIZONTAL) != 0) {		width = rect.right - rect.left;		height = OS.GetSystemMetrics (OS.SM_CYHSCROLL);	} else {		width = OS.GetSystemMetrics (OS.SM_CXVSCROLL);		height = rect.bottom - rect.top;	}	return new Point (width, height);}/** * Answers 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> * * @see ScrollBar */public int getThumb () {	checkWidget();	SCROLLINFO info = new SCROLLINFO ();	info.cbSize = SCROLLINFO.sizeof;	info.fMask = OS.SIF_PAGE;	int hwnd = hwndScrollBar ();	int type = scrollBarType ();	OS.GetScrollInfo (hwnd, type, info);	if (info.nPage != 0) --info.nPage;	return info.nPage;}/** * Returns <code>true</code> if the receiver is visible, and * <code>false</code> otherwise. * <p> * If one of the receiver's ancestors is not visible or some * other condition makes the receiver not visible, this method * may still indicate that it is considered visible even though * it may not actually be showing. * </p> * * @return the receiver's visibility state * * @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 boolean getVisible () {	checkWidget();	return (state & HIDDEN) == 0;}int hwndScrollBar () {	return parent.handle;}/** * Returns <code>true</code> if the receiver is enabled and all * of the receiver's ancestors are enabled, and <code>false</code> * otherwise. A disabled control is typically not selectable from the * user interface and draws with an inactive or "grayed" look. * * @return the receiver's enabled state * * @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 #getEnabled */public boolean isEnabled () {	checkWidget();	return getEnabled () && parent.isEnabled ();}/** * Returns <code>true</code> if the receiver is visible and all * of the receiver's ancestors are visible and <code>false</code> * otherwise. * * @return the receiver's visibility state * * @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 #getVisible */public boolean isVisible () {	checkWidget();	return getVisible () && parent.isVisible ();}void releaseChild () {	super.releaseChild ();	if (parent.horizontalBar == this) parent.horizontalBar = null;	if (parent.verticalBar == this) parent.verticalBar = null;}void releaseWidget () {	super.releaseWidget ();	parent = null;}/** * 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);	}int scrollBarType () {	if ((style & SWT.VERTICAL) != 0) return OS.SB_VERT;	/*	* This line is intentionally commented.  There should	* only ever be HORIZONTAL and VERTICAL scroll bars.	* The commented code reminds us that this is the case	* and that the default style is HORIZONTAL.	*/	//	if ((style & SWT.HORIZONTAL) != 0) return OS.SB_HORZ;	return OS.SB_HORZ;}/** * Enables the receiver if the argument is <code>true</code>, * and disables it otherwise. A disabled control is typically * not selectable from the user interface and draws with an * inactive or "grayed" look. * * @param enabled the new enabled state * * @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 setEnabled (boolean enabled) {	checkWidget();	/*	* This line is intentionally commented.  Currently	* always show scrollbar as being enabled and visible.	*///	if (OS.IsWinCE) error (SWT.ERROR_NOT_IMPLEMENTED);	if (!OS.IsWinCE) {		int hwnd = hwndScrollBar (), type = scrollBarType ();		int flags = enabled ? OS.ESB_ENABLE_BOTH : OS.ESB_DISABLE_BOTH;		OS.EnableScrollBar (hwnd, type, flags);		state &= ~DISABLED;		if (!enabled) state |= DISABLED;	}}/** * 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;	increment = value;}/** * Sets the maximum. If this value is negative or less than or * equal to the minimum, the value is ignored. If necessary, first * the thumb and then the selection are adjusted to fit within the * new range. * * @param value the new 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 void setMaximum (int value) {	checkWidget();	if (value < 0) return;	SCROLLINFO info = new SCROLLINFO ();	info.cbSize = SCROLLINFO.sizeof;	int hwnd = hwndScrollBar (), type = scrollBarType ();	info.fMask = OS.SIF_RANGE | OS.SIF_DISABLENOSCROLL;	OS.GetScrollInfo (hwnd, type, info);	if (value - info.nMin - info.nPage < 1) return;	info.nMax = value;	OS.SetScrollInfo (hwnd, type, info, (state & DISABLED) == 0);		/*	* Bug in Windows.  For some reason, when the widget	* is a standard scroll bar, and SetScrollInfo () is	* called with SIF_RANGE or SIF_PAGE, the widget is	* incorrectly made visible so that the next time the	* widget is resized (or another scroll bar operation	* is performed), the scroll bar draws.  The fix is	* to hide the scroll bar (again) when already hidden.	*/	if ((state & HIDDEN) != 0) {		/*		* This line is intentionally commented.  Currently		* always show scrollbar as being enabled and visible.		*///		if (OS.IsWinCE) error (SWT.ERROR_NOT_IMPLEMENTED);		if (!OS.IsWinCE) {			OS.ShowScrollBar (hwnd, type, false);		}	}			/*	* Feature in Windows.  Using SIF_DISABLENOSCROLL,	* SetScrollInfo () can change enabled and disabled	* state of the scroll bar causing a scroll bar that	* was disabled by the application to become enabled.	* The fix is to disable the scroll bar (again) when	* the application has disabled the scroll bar.	*/	if ((state & DISABLED) != 0) {		/*		* This line is intentionally commented.  Currently		* always show scrollbar as being enabled and visible.		*///		if (OS.IsWinCE) error (SWT.ERROR_NOT_IMPLEMENTED);		if (!OS.IsWinCE) {			OS.EnableScrollBar (hwnd, type, OS.ESB_DISABLE_BOTH);		}	}}/** * Sets the minimum value. If this value is negative or greater * than or equal to the maximum, the value is ignored. If necessary, * first the thumb and then the selection are adjusted to fit within * the new range. * * @param value the new 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 void setMinimum (int value) {	checkWidget();	if (value < 0) return;	SCROLLINFO info = new SCROLLINFO ();	info.cbSize = SCROLLINFO.sizeof;	int hwnd = hwndScrollBar (), type = scrollBarType ();	info.fMask = OS.SIF_RANGE | OS.SIF_DISABLENOSCROLL;	OS.GetScrollInfo (hwnd, type, info);	if (info.nMax - value - info.nPage < 1) return;	info.nMin = value;	OS.SetScrollInfo (hwnd, type, info, true);		/*	* Bug in Windows.  For some reason, when the widget	* is a standard scroll bar, and SetScrollInfo () is	* called with SIF_RANGE or SIF_PAGE, the widget is	* incorrectly made visible so that the next time the	* widget is resized (or another scroll bar operation	* is performed), the scroll bar draws.  The fix is	* to hide the scroll bar (again) when already hidden.	*/	if ((state & HIDDEN) != 0) {		/*		* This line is intentionally commented.  Currently		* always show scrollbar as being enabled and visible.		*///		if (OS.IsWinCE) error (SWT.ERROR_NOT_IMPLEMENTED);		if (!OS.IsWinCE) {			OS.ShowScrollBar (hwnd, type, false);		}	}			/*	* Feature in Windows.  Using SIF_DISABLENOSCROLL,