/******************************************************************************* * Copyright (c) 2000, 2004 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Common Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/cpl-v10.html *  * Contributors: *     IBM Corporation - initial API and implementation *******************************************************************************/package org.eclipse.swt.widgets; import org.eclipse.swt.internal.win32.*;import org.eclipse.swt.*;import org.eclipse.swt.graphics.*;import org.eclipse.swt.events.*;/** * Instances of the receiver represent a selectable user * interface object that present a range of continuous * numeric values. * <dl> * <dt><b>Styles:</b></dt> * <dd>HORIZONTAL, VERTICAL</dd> * <dt><b>Events:</b></dt> * <dd>Selection</dd> * </dl> * <p> * Note: Only one of the styles HORIZONTAL and VERTICAL may be specified. * </p><p> * <p> * IMPORTANT: This class is intended to be subclassed <em>only</em> * within the SWT implementation. * </p> */public class Scale extends Control {	static final int TrackBarProc;	static final TCHAR TrackBarClass = new TCHAR (0, OS.TRACKBAR_CLASS, true);	static {		WNDCLASS lpWndClass = new WNDCLASS ();		OS.GetClassInfo (0, TrackBarClass, lpWndClass);		TrackBarProc = lpWndClass.lpfnWndProc;		/*		* Feature in Windows.  The track bar window class		* does not include CS_DBLCLKS.  This mean that these		* controls will not get double click messages such as		* WM_LBUTTONDBLCLK.  The fix is to register a new 		* window class with CS_DBLCLKS.		* 		* NOTE:  Screen readers look for the exact class name		* of the control in order to provide the correct kind		* of assistance.  Therefore, it is critical that the		* new window class have the same name.  It is possible		* to register a local window class with the same name		* as a global class.  Since bits that affect the class		* are being changed, it is possible that other native		* code, other than SWT, could create a control with		* this class name, and fail unexpectedly.		*/		int hInstance = OS.GetModuleHandle (null);		int hHeap = OS.GetProcessHeap ();		lpWndClass.hInstance = hInstance;		lpWndClass.style &= ~OS.CS_GLOBALCLASS;		lpWndClass.style |= OS.CS_DBLCLKS;		int byteCount = TrackBarClass.length () * TCHAR.sizeof;		int lpszClassName = OS.HeapAlloc (hHeap, OS.HEAP_ZERO_MEMORY, byteCount);		OS.MoveMemory (lpszClassName, TrackBarClass, byteCount);		lpWndClass.lpszClassName = lpszClassName;		OS.RegisterClass (lpWndClass);//		OS.HeapFree (hHeap, 0, lpszClassName);		}/** * 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#HORIZONTAL * @see SWT#VERTICAL * @see Widget#checkSubclass * @see Widget#getStyle */public Scale (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. * * @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 */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);}int callWindowProc (int msg, int wParam, int lParam) {	if (handle == 0) return 0;	return OS.CallWindowProc (TrackBarProc, handle, msg, wParam, lParam);}static int checkStyle (int style) {	return checkBits (style, SWT.HORIZONTAL, SWT.VERTICAL, 0, 0, 0, 0);}public Point computeSize (int wHint, int hHint, boolean changed) {	checkWidget ();	int border = getBorderWidth ();	int width = border * 2, height = border * 2;	RECT rect = new RECT ();	OS.SendMessage (handle, OS.TBM_GETTHUMBRECT, 0, rect);	if ((style & SWT.HORIZONTAL) != 0) {		width += OS.GetSystemMetrics (OS.SM_CXHSCROLL) * 10;		int scrollY = OS.GetSystemMetrics (OS.SM_CYHSCROLL);		height += (rect.top * 2) + scrollY + (scrollY / 3);	} else {		int scrollX = OS.GetSystemMetrics (OS.SM_CXVSCROLL);		width += (rect.left * 2) + scrollX + (scrollX / 3);		height += OS.GetSystemMetrics (OS.SM_CYVSCROLL) * 10;	}	if (wHint != SWT.DEFAULT) width = wHint + (border * 2);	if (hHint != SWT.DEFAULT) height = hHint + (border * 2);	return new Point (width, height);}void createHandle () {	super.createHandle ();	OS.SendMessage (handle, OS.TBM_SETRANGEMAX, 0, 100);	OS.SendMessage (handle, OS.TBM_SETPAGESIZE, 0, 10);	OS.SendMessage (handle, OS.TBM_SETTICFREQ, 10, 0);}int defaultForeground () {	return OS.GetSysColor (OS.COLOR_BTNFACE);}/** * 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 ();	return OS.SendMessage (handle, OS.TBM_GETLINESIZE, 0, 0);}/** * 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 ();	return OS.SendMessage (handle, OS.TBM_GETRANGEMAX, 0, 0);}/** * 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 ();	return OS.SendMessage (handle, OS.TBM_GETRANGEMIN, 0, 0);}/** * Returns the amount that the receiver's value will be * modified by when the page increment/decrement areas * are selected. *