/******************************************************************************* * 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 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 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 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> * 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 ScrollBar */public class Slider extends Control {	int increment, pageIncrement;	static final int ScrollBarProc;	static final TCHAR ScrollBarClass = new TCHAR (0, "SCROLLBAR", true);	static {		WNDCLASS lpWndClass = new WNDCLASS ();		OS.GetClassInfo (0, ScrollBarClass, lpWndClass);		ScrollBarProc = lpWndClass.lpfnWndProc;	}/** * 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 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);}int callWindowProc (int msg, int wParam, int lParam) {	if (handle == 0) return 0;	/*	* Feature in Windows.  Windows runs a modal message	* loop when the user drags a scroll bar.  This means	* that mouse down events won't get delivered until	* after the loop finishes.  The fix is to run any	* deferred messages, including mouse down messages	* before calling the scroll bar window proc.	*/	switch (msg) {		case OS.WM_LBUTTONDOWN:		case OS.WM_LBUTTONDBLCLK: 			display.runDeferredEvents ();	}	return OS.CallWindowProc (ScrollBarProc, 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;	if ((style & SWT.HORIZONTAL) != 0) {		width += OS.GetSystemMetrics (OS.SM_CXHSCROLL) * 10;		height += OS.GetSystemMetrics (OS.SM_CYHSCROLL);	} else {		width += OS.GetSystemMetrics (OS.SM_CXVSCROLL);		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 createWidget () {	super.createWidget ();	increment = 1;	pageIncrement = 10;	/*	* Set the intial values of the maximum	* to 100 and the thumb to 10.  Note that	* info.nPage needs to be 11 in order to	* get a thumb that is 10.	*/	SCROLLINFO info = new SCROLLINFO ();	info.cbSize = SCROLLINFO.sizeof;	info.fMask = OS.SIF_ALL;	info.nMax = 100;	info.nPage = 11;	OS.SetScrollInfo (handle, OS.SB_CTL, info, true);}int defaultBackground () {	return OS.GetSysColor (OS.COLOR_SCROLLBAR);}int defaultForeground () {	return OS.GetSysColor (OS.COLOR_BTNFACE);}void enableWidget (boolean enabled) {	if (OS.IsWinCE) {		super.enableWidget (enabled);	} else {		int flags = enabled ? OS.ESB_ENABLE_BOTH : OS.ESB_DISABLE_BOTH;		OS.EnableScrollBar (handle, OS.SB_CTL, flags);	}	state &= ~DISABLED;	if (!enabled) state |= DISABLED;}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;	OS.GetScrollInfo (handle, OS.SB_CTL, 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;	OS.GetScrollInfo (handle, OS.SB_CTL, 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 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 ();	SCROLLINFO info = new SCROLLINFO ();	info.cbSize = SCROLLINFO.sizeof;	info.fMask = OS.SIF_POS;	OS.GetScrollInfo (handle, OS.SB_CTL, info);	return info.nPos;}/** * 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 ();	SCROLLINFO info = new SCROLLINFO ();	info.cbSize = SCROLLINFO.sizeof;	info.fMask = OS.SIF_PAGE;	OS.GetScrollInfo (handle, OS.SB_CTL, info);	if (info.nPage != 0) --info.nPage;	return info.nPage;}/** * 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);	}void setBounds (int x, int y, int width, int height, int flags) {	super.setBounds (x, y, width, height, flags);	/*	* Bug in Windows.  If the scroll bar is resized when it has focus,	* the flashing cursor that is used to show that the scroll bar has	* focus is not moved.  The fix is to post a fake WM_SETFOCUS to	* get the scroll bar to recompute the size of the flashing cursor.	*/	if (OS.GetFocus () == handle) {		OS.PostMessage (handle, OS.WM_SETFOCUS, 0, 0);	}}/** * 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, which must be greater than the current 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 setMaximum (int value) {	checkWidget ();	if (value < 0) return;	SCROLLINFO info = new SCROLLINFO ();	info.cbSize = SCROLLINFO.sizeof;	info.fMask = OS.SIF_RANGE | OS.SIF_DISABLENOSCROLL;	OS.GetScrollInfo (handle, OS.SB_CTL, info);	if (value - info.nMin - info.nPage < 1) return;	info.nMax = value;	OS.SetScrollInfo (handle, OS.SB_CTL, info, (state & DISABLED) == 0);			/*	* 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.	*/