/******************************************************************************* * 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 this class are selectable user interface * objects that represent a range of positive, numeric values.  * <p> * At any given moment, a given scroll bar 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 scroll bar represents (that is, between its * <em>minimum</em> and <em>maximum</em> values). * </p><p> * Typically, scroll bars 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, scroll bars are either <code>HORIZONTAL</code> * (which have a left facing button for decrementing the value and a * right facing button for incrementing it) or <code>VERTICAL</code> * (which have an upward facing button for decrementing the value * and a downward facing buttons for incrementing it). * </p><p> * On some platforms, the size of the scroll bar'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 scroll bar will not change. * </p><p> * Scroll bars are created by specifying either <code>H_SCROLL</code>, * <code>V_SCROLL</code> or both when creating a <code>Scrollable</code>. * They are accessed from the <code>Scrollable</code> using * <code>getHorizontalBar</code> and <code>getVerticalBar</code>. * </p><p> * Note: Scroll bars are not Controls.  On some platforms, scroll bars * that appear as part of some standard controls such as a text or list * have no operating system resources and are not children of the control. * For this reason, scroll bars are treated specially.  To create a control * that looks like a scroll bar but has operating system resources, use * <code>Slider</code>.  * </p> * <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> * IMPORTANT: This class is <em>not</em> intended to be subclassed. * </p> * * @see Slider * @see Scrollable * @see Scrollable#getHorizontalBar * @see Scrollable#getVerticalBar */public class ScrollBar extends Widget {		Scrollable parent;	int increment, pageIncrement;/** * 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 */ScrollBar (Scrollable parent, int style) {	super (parent, checkStyle (style));	this.parent = parent;	createWidget ();}/** * 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 createWidget () {	increment = 1;	pageIncrement = 10;	/*	* Do not set the intial values of the maximum	* or the thumb.  These values normally default	* to 100 and 10 but may have been set already	* by the widget that owns the scroll bar.  For	* example, a scroll bar that is created for a	* list widget, setting these defaults would	* override the initial values provided by the	* list widget.	*/}public void dispose () {	if (isDisposed()) return;	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);	int hwnd = hwndScrollBar (), type = scrollBarType ();	super.dispose ();	if (OS.IsWinCE) {		SCROLLINFO info = new SCROLLINFO ();		info.cbSize = SCROLLINFO.sizeof;		info.fMask = OS.SIF_RANGE | OS.SIF_PAGE;		info.nPage = 101;		info.nMax = 100;		info.nMin = 0;		OS.SetScrollInfo (hwnd, type, info, true);	} else {		OS.ShowScrollBar (hwnd, type, false);	}}/** Not currently used.*/Rectangle getBounds () {//	checkWidget ();	parent.forceResize ();	RECT rect = new RECT ();	OS.GetClientRect (parent.handle, rect);	int x = 0, y = 0, width, height;	if ((style & SWT.HORIZONTAL) != 0) {		y = rect.bottom - rect.top;		width = rect.right - rect.left;		height = OS.GetSystemMetrics (OS.SM_CYHSCROLL);	} else {		x = rect.right - rect.left;		width = OS.GetSystemMetrics (OS.SM_CXVSCROLL);		height = rect.bottom - rect.top;	}	return new Rectangle (x, y, width, height);}/** * Returns <code>true</code> if the receiver is 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 #isEnabled */public boolean getEnabled () {	checkWidget();	return (state & DISABLED) == 0;}/** * 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 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();	SCROLLINFO info = new SCROLLINFO ();	info.cbSize = SCROLLINFO.sizeof;	info.fMask = OS.SIF_RANGE;	int hwnd = hwndScrollBar ();	int type = scrollBarType ();	OS.GetScrollInfo (hwnd, type, info);	return info.nMax;}/** * 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();	SCROLLINFO info = new SCROLLINFO ();	info.cbSize = SCROLLINFO.sizeof;	info.fMask = OS.SIF_RANGE;	int hwnd = hwndScrollBar ();	int type = scrollBarType ();	OS.GetScrollInfo (hwnd, type, info);	return info.nMin;}/** * 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();	return pageIncrement;}/** * Returns the receiver's parent, which must be scrollable. * * @return the receiver's parent * * @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 Scrollable getParent () {	checkWidget();	return parent;}/** * 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>