org.eclipse.swt.widgets.Slider Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2000, 2012 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-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.
*
* At any given moment, a given slider will have a
* single 'selection' that is considered to be its
* value, which is constrained to be within the range of
* values the slider represents (that is, between its
* minimum and maximum values).
*
* Typically, sliders will be made up of five areas:
*
* - an arrow button for decrementing the value
* - a page decrement area for decrementing the value by a larger amount
* - a thumb for modifying the value by mouse dragging
* - a page increment area for incrementing the value by a larger amount
* - an arrow button for incrementing the value
*
* Based on their style, sliders are either HORIZONTAL
* (which have a left facing button for decrementing the value and a
* right facing button for incrementing it) or VERTICAL
* (which have an upward facing button for decrementing the value
* and a downward facing buttons for incrementing it).
*
* 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.
*
*
* - Styles:
* - HORIZONTAL, VERTICAL
* - Events:
* - Selection
*
*
* Note: Only one of the styles HORIZONTAL and VERTICAL may be specified.
*
* IMPORTANT: This class is not intended to be subclassed.
*
*
* @see ScrollBar
* @see Slider snippets
* @see SWT Example: ControlExample
* @see Sample code and further information
* @noextend This class is not intended to be subclassed by clients.
*/
public class Slider extends Control {
int increment, pageIncrement;
boolean ignoreFocus;
static final int /*long*/ 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.
*
* The style value is either one of the style constants defined in
* class SWT which is applicable to instances of this
* class, or must be built by bitwise OR'ing together
* (that is, using the int "|" operator) two or more
* of those SWT style constants. The class description
* lists the style constants that are applicable to the class.
* Style bits are also inherited from superclasses.
*
*
* @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
* - ERROR_NULL_ARGUMENT - if the parent is null
*
* @exception SWTException
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
* - ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
*
*
* @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 user changes the receiver's value, by sending
* it one of the messages defined in the SelectionListener
* interface.
*
* When widgetSelected is called, the event object detail field contains one of the following values:
* SWT.NONE - for the end of a drag.
* SWT.DRAG.
* SWT.HOME.
* SWT.END.
* SWT.ARROW_DOWN.
* SWT.ARROW_UP.
* SWT.PAGE_DOWN.
* SWT.PAGE_UP.
* widgetDefaultSelected is not called.
*
*
* @param listener the listener which should be notified when the user changes the receiver's value
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the listener is null
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*
* @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 /*long*/ callWindowProc (int /*long*/ hwnd, int msg, int /*long*/ wParam, int /*long*/ 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, hwnd, 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 initial 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) {
super.enableWidget (enabled);
if (!OS.IsWinCE) {
int flags = enabled ? OS.ESB_ENABLE_BOTH : OS.ESB_DISABLE_BOTH;
OS.EnableScrollBar (handle, OS.SB_CTL, flags);
}
if (enabled) {
state &= ~DISABLED;
} else {
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
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public int getIncrement () {
checkWidget ();
return increment;
}
/**
* Returns the maximum value which the receiver will allow.
*
* @return the maximum
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
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
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
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
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public int getPageIncrement () {
checkWidget ();
return pageIncrement;
}
/**
* Returns the 'selection', which is the receiver's value.
*
* @return the selection
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
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 receiver's thumb value.
*
* @return the thumb value
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
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 user changes the receiver's value.
*
* @param listener the listener which should no longer be notified
*
* @exception IllegalArgumentException
* - ERROR_NULL_ARGUMENT - if the listener is null
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*
* @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 send a fake WM_SETFOCUS to
* get the scroll bar to recompute the size of the flashing cursor.
*/
if (OS.GetFocus () == handle) {
ignoreFocus = true;
OS.SendMessage (handle, OS.WM_SETFOCUS, 0, 0);
ignoreFocus = false;
}
}
/**
* 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
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
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
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
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;
SetScrollInfo (handle, OS.SB_CTL, info, true);
}
/**
* 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
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public void setMinimum (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 (info.nMax - value - info.nPage < 1) return;
info.nMin = value;
SetScrollInfo (handle, OS.SB_CTL, info, true);
}
/**
* 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.
*
* @param value the page increment (must be greater than zero)
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public void setPageIncrement (int value) {
checkWidget ();
if (value < 1) return;
pageIncrement = value;
}
boolean SetScrollInfo (int /*long*/ hwnd, int flags, SCROLLINFO info, boolean fRedraw) {
/*
* 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) fRedraw = false;
boolean result = OS.SetScrollInfo (hwnd, flags, info, fRedraw);
if ((state & DISABLED) != 0) {
OS.EnableWindow (handle, false);
if (!OS.IsWinCE) {
OS.EnableScrollBar (handle, OS.SB_CTL, OS.ESB_DISABLE_BOTH);
}
}
/*
* Bug in Windows. If the thumb 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 send a fake WM_SETFOCUS
* to get the scroll bar to recompute the size of the flashing
* cursor.
*/
if (OS.GetFocus () == handle) {
ignoreFocus = true;
OS.SendMessage (handle, OS.WM_SETFOCUS, 0, 0);
ignoreFocus = false;
}
return result;
}
/**
* Sets the 'selection', which 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
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public void setSelection (int value) {
checkWidget ();
SCROLLINFO info = new SCROLLINFO ();
info.cbSize = SCROLLINFO.sizeof;
info.fMask = OS.SIF_POS;
info.nPos = value;
SetScrollInfo (handle, OS.SB_CTL, info, true);
}
/**
* Sets the thumb value. The thumb value should be used to represent
* the size of the visual portion of the current range. This value is
* usually the same as the page increment value.
*
* This new value will be ignored if it is less than one, and will be
* clamped if it exceeds the receiver's current range.
*
*
* @param value the new thumb value, which must be at least one and not
* larger than the size of the current range
*
* @exception SWTException
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public void setThumb (int value) {
checkWidget ();
if (value < 1) return;
SCROLLINFO info = new SCROLLINFO ();
info.cbSize = SCROLLINFO.sizeof;
info.fMask = OS.SIF_PAGE | OS.SIF_RANGE | OS.SIF_DISABLENOSCROLL;
OS.GetScrollInfo (handle, OS.SB_CTL, info);
info.nPage = value;
if (info.nPage != 0) info.nPage++;
SetScrollInfo (handle, OS.SB_CTL, info, true);
}
/**
* Sets the receiver's selection, minimum value, maximum
* value, thumb, increment and page increment all at once.
*
* Note: This is similar to setting the values individually
* using the appropriate methods, but may be implemented in a
* more efficient fashion on some platforms.
*
*
* @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
* - ERROR_WIDGET_DISPOSED - if the receiver has been disposed
* - ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
*
*/
public void setValues (int selection, int minimum, int maximum, int thumb, int increment, int pageIncrement) {
checkWidget ();
if (minimum < 0) return;
if (maximum < 0) return;
if (thumb < 1) return;
if (increment < 1) return;
if (pageIncrement < 1) return;
this.increment = increment;
this.pageIncrement = pageIncrement;
SCROLLINFO info = new SCROLLINFO ();
info.cbSize = SCROLLINFO.sizeof;
info.fMask = OS.SIF_POS | OS.SIF_PAGE | OS.SIF_RANGE | OS.SIF_DISABLENOSCROLL;
info.nPos = selection;
info.nMin = minimum;
info.nMax = maximum;
info.nPage = thumb;
if (info.nPage != 0) info.nPage++;
SetScrollInfo (handle, OS.SB_CTL, info, true);
}
int widgetExtStyle () {
/*
* Bug in Windows. If a scroll bar control is given a border,
* dragging the scroll bar thumb eats away parts of the border
* while the thumb is dragged. The fix is to clear border for
* all scroll bars.
*/
int bits = super.widgetExtStyle ();
if ((style & SWT.BORDER) != 0) bits &= ~OS.WS_EX_CLIENTEDGE;
return bits;
}
int widgetStyle () {
int bits = super.widgetStyle () | OS.WS_TABSTOP;
/*
* Bug in Windows. If a scroll bar control is given a border,
* dragging the scroll bar thumb eats away parts of the border
* while the thumb is dragged. The fix is to clear WS_BORDER.
*/
if ((style & SWT.BORDER) != 0) bits &= ~OS.WS_BORDER;
if ((style & SWT.HORIZONTAL) != 0) return bits | OS.SBS_HORZ;
return bits | OS.SBS_VERT;
}
TCHAR windowClass () {
return ScrollBarClass;
}
int /*long*/ windowProc () {
return ScrollBarProc;
}
LRESULT WM_KEYDOWN (int /*long*/ wParam, int /*long*/ lParam) {
LRESULT result = super.WM_KEYDOWN (wParam, lParam);
if (result != null) return result;
if ((style & SWT.VERTICAL) != 0) return result;
/*
* Bug in Windows. When a horizontal scroll bar is mirrored,
* the native control does not correctly swap the arrow keys.
* The fix is to swap them before calling the scroll bar window
* proc.
*
* NOTE: This fix is not ideal. It breaks when the bug is fixed
* in the operating system.
*/
if ((style & SWT.MIRRORED) != 0) {
switch ((int)/*64*/wParam) {
case OS.VK_LEFT:
case OS.VK_RIGHT: {
int key = wParam == OS.VK_LEFT ? OS.VK_RIGHT : OS.VK_LEFT;
int /*long*/ code = callWindowProc (handle, OS.WM_KEYDOWN, key, lParam);
return new LRESULT (code);
}
}
}
return result;
}
LRESULT WM_LBUTTONDBLCLK (int /*long*/ wParam, int /*long*/ lParam) {
/*
* Feature in Windows. Windows uses the WS_TABSTOP
* style for the scroll bar to decide that focus
* should be set during WM_LBUTTONDBLCLK. This is
* not the desired behavior. The fix is to clear
* and restore WS_TABSTOP so that Windows will not
* assign focus.
*/
int oldBits = OS.GetWindowLong (handle, OS.GWL_STYLE);
int newBits = oldBits & ~OS.WS_TABSTOP;
OS.SetWindowLong (handle, OS.GWL_STYLE, newBits);
LRESULT result = super.WM_LBUTTONDBLCLK (wParam, lParam);
if (isDisposed ()) return LRESULT.ZERO;
OS.SetWindowLong (handle, OS.GWL_STYLE, oldBits);
if (result == LRESULT.ZERO) return result;
/*
* Feature in Windows. Windows runs a modal message loop
* when the user drags a scroll bar that terminates when
* it sees an WM_LBUTTONUP. Unfortunately the WM_LBUTTONUP
* is consumed. The fix is to send a fake mouse up and
* release the automatic capture.
*/
if (!OS.IsWinCE) {
if (OS.GetCapture () == handle) OS.ReleaseCapture ();
if (!sendMouseEvent (SWT.MouseUp, 1, handle, OS.WM_LBUTTONUP, wParam, lParam)) {
return LRESULT.ZERO;
}
}
return result;
}
LRESULT WM_LBUTTONDOWN (int /*long*/ wParam, int /*long*/ lParam) {
/*
* Feature in Windows. Windows uses the WS_TABSTOP
* style for the scroll bar to decide that focus
* should be set during WM_LBUTTONDOWN. This is
* not the desired behavior. The fix is to clear
* and restore WS_TABSTOP so that Windows will not
* assign focus.
*/
int oldBits = OS.GetWindowLong (handle, OS.GWL_STYLE);
int newBits = oldBits & ~OS.WS_TABSTOP;
OS.SetWindowLong (handle, OS.GWL_STYLE, newBits);
LRESULT result = super.WM_LBUTTONDOWN (wParam, lParam);
if (isDisposed ()) return LRESULT.ZERO;
OS.SetWindowLong (handle, OS.GWL_STYLE, oldBits);
if (result == LRESULT.ZERO) return result;
/*
* Feature in Windows. Windows runs a modal message loop
* when the user drags a scroll bar that terminates when
* it sees an WM_LBUTTONUP. Unfortunately the WM_LBUTTONUP
* is consumed. The fix is to send a fake mouse up and
* release the automatic capture.
*/
if (!OS.IsWinCE) {
if (OS.GetCapture () == handle) OS.ReleaseCapture ();
if (!sendMouseEvent (SWT.MouseUp, 1, handle, OS.WM_LBUTTONUP, wParam, lParam)) {
return LRESULT.ONE;
}
}
return result;
}
LRESULT WM_SETFOCUS (int /*long*/ wParam, int /*long*/ lParam) {
if (ignoreFocus) return null;
return super.WM_SETFOCUS (wParam, lParam);
}
LRESULT wmScrollChild (int /*long*/ wParam, int /*long*/ lParam) {
/* Do nothing when scrolling is ending */
int code = OS.LOWORD (wParam);
if (code == OS.SB_ENDSCROLL) return null;
/* Move the thumb */
Event event = new Event ();
SCROLLINFO info = new SCROLLINFO ();
info.cbSize = SCROLLINFO.sizeof;
info.fMask = OS.SIF_TRACKPOS | OS.SIF_POS | OS.SIF_RANGE;
OS.GetScrollInfo (handle, OS.SB_CTL, info);
info.fMask = OS.SIF_POS;
switch (code) {
case OS.SB_THUMBPOSITION:
event.detail = SWT.NONE;
info.nPos = info.nTrackPos;
break;
case OS.SB_THUMBTRACK:
event.detail = SWT.DRAG;
info.nPos = info.nTrackPos;
break;
case OS.SB_TOP:
event.detail = SWT.HOME;
info.nPos = info.nMin;
break;
case OS.SB_BOTTOM:
event.detail = SWT.END;
info.nPos = info.nMax;
break;
case OS.SB_LINEDOWN:
event.detail = SWT.ARROW_DOWN;
info.nPos += increment;
break;
case OS.SB_LINEUP:
event.detail = SWT.ARROW_UP;
info.nPos = Math.max (info.nMin, info.nPos - increment);
break;
case OS.SB_PAGEDOWN:
event.detail = SWT.PAGE_DOWN;
info.nPos += pageIncrement;
break;
case OS.SB_PAGEUP:
event.detail = SWT.PAGE_UP;
info.nPos = Math.max (info.nMin, info.nPos - pageIncrement);
break;
}
OS.SetScrollInfo (handle, OS.SB_CTL, info, true);
/*
* Feature in Windows. Windows runs a modal message
* loop when the user drags a scroll bar. This means
* that selection event must be sent because WM_HSCROLL
* and WM_VSCROLL are sent from the modal message loop
* so that they are delivered during inside the loop.
*/
sendSelectionEvent (SWT.Selection, event, true);
// the widget could be destroyed at this point
return null;
}
}