org.eclipse.swt.widgets
Class Slider

java.lang.Object
  |
  +--org.eclipse.swt.widgets.Widget
        |
        +--org.eclipse.swt.widgets.Control
              |
              +--org.eclipse.swt.widgets.Slider

All Implemented Interfaces:

Drawable

public class Slider

extends Control

Safe: 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:

1. an arrow button for decrementing the value
2. a page decrement area for decrementing the value by a larger amount
3. a thumb for modifying the value by mouse dragging
4. a page increment area for incrementing the value by a larger amount
5. 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 Also:

ScrollBar

Field Summary

(package private) int	increment
(package private) int	pageIncrement
(package private) static org.eclipse.swt.internal.win32.TCHAR	ScrollBarClass
(package private) static int	ScrollBarProc

Fields inherited from class org.eclipse.swt.widgets.Control

ACCENTS, accessible, background, drawCount, foreground, handle, hCursor, layoutData, menu, parent, toolTipText

Fields inherited from class org.eclipse.swt.widgets.Widget

CANVAS, COMCTL32_MAJOR, COMCTL32_MINOR, data, DEFAULT_HEIGHT, DEFAULT_WIDTH, DISABLED, DISPOSED, eventTable, HIDDEN, keys, MAJOR, MINOR, Mnemonic, state, style, values

Constructor Summary

Slider(Composite parent, int style)
Enabled: Constructs a new instance of this class given its parent and a style value describing its behavior and appearance.

Method Summary

void	addSelectionListener(SelectionListener listener) Enabled: 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 SelectionListener interface.
(package private) int	callWindowProc(int msg, int wParam, int lParam)
(package private) static int	checkStyle(int style)
Point	computeSize(int wHint, int hHint, boolean changed) Enabled:
(package private) void	createWidget()
(package private) int	defaultBackground()
(package private) int	defaultForeground()
boolean	getEnabled() Enabled:
int	getIncrement() Enabled: Returns the amount that the receiver's value will be modified by when the up/down (or right/left) arrows are pressed.
int	getMaximum() Enabled: Returns the maximum value which the receiver will allow.
int	getMinimum() Enabled: Returns the minimum value which the receiver will allow.
int	getPageIncrement() Enabled: Returns the amount that the receiver's value will be modified by when the page increment/decrement areas are selected.
int	getSelection() Enabled: Returns the single selection that is the receiver's value.
int	getThumb() Enabled: Returns the size of the receiver's thumb relative to the difference between its maximum and minimum values.
void	removeSelectionListener(SelectionListener listener) Enabled: Removes the listener from the collection of listeners who will be notified when the receiver's value changes.
(package private) void	setBounds(int x, int y, int width, int height, int flags)
void	setEnabled(boolean enabled) Enabled:
void	setIncrement(int value) Enabled: 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.
void	setMaximum(int value) Enabled: Sets the maximum value which the receiver will allow to be the argument which must be greater than or equal to zero.
void	setMinimum(int value) Enabled: Sets the minimum value which the receiver will allow to be the argument which must be greater than or equal to zero.
void	setPageIncrement(int value) Enabled: 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.
void	setSelection(int value) Enabled: Sets the single selection that is the receiver's value to the argument which must be greater than or equal to zero.
void	setThumb(int value) Enabled: Sets the size of the receiver's thumb relative to the difference between its maximum and minimum values to the argument which must be at least one.
void	setValues(int selection, int minimum, int maximum, int thumb, int increment, int pageIncrement) Enabled: Sets the receiver's selection, minimum value, maximum value, thumb, increment and page increment all at once.
(package private) int	widgetExtStyle()
(package private) int	widgetStyle()
(package private) org.eclipse.swt.internal.win32.TCHAR	windowClass()
(package private) int	windowProc()
(package private) org.eclipse.swt.internal.win32.LRESULT	WM_LBUTTONDBLCLK(int wParam, int lParam)
(package private) org.eclipse.swt.internal.win32.LRESULT	WM_LBUTTONDOWN(int wParam, int lParam)
(package private) org.eclipse.swt.internal.win32.LRESULT	wmScrollChild(int wParam, int lParam)

Methods inherited from class org.eclipse.swt.widgets.Control

addControlListener, addFocusListener, addHelpListener, addKeyListener, addMouseListener, addMouseMoveListener, addMouseTrackListener, addPaintListener, addTraverseListener, checkOrientation, computeSize, computeTabGroup, computeTabList, computeTabRoot, createHandle, defaultFont, deregister, destroyWidget, drawBackground, drawBackground, findBrush, findCursor, findMnemonic, fixFocus, forceFocus, forceResize, getAccessible, getBackground, getBackgroundPixel, getBorderWidth, getBounds, getCodePage, getDisplay, getFont, getForeground, getForegroundPixel, getLayoutData, getLocation, getMenu, getParent, getPath, getShell, getSize, getToolTipText, getVisible, hasCursor, hasFocus, internal_dispose_GC, internal_new_GC, isActive, isDisposed, isEnabled, isFocusAncestor, isFocusControl, isReparentable, isShowing, isTabGroup, isTabItem, isVisible, menuShell, mnemonicHit, mnemonicMatch, moveAbove, moveBelow, new_Accessible, pack, pack, redraw, redraw, register, releaseHandle, releaseWidget, removeControlListener, removeFocusListener, removeHelpListener, removeKeyListener, removeMouseListener, removeMouseMoveListener, removeMouseTrackListener, removePaintListener, removeTraverseListener, sendKeyEvent, sendKeyEvent, sendMouseEvent, sendMouseEvent, setBackground, setBackgroundPixel, setBounds, setBounds, setCapture, setCursor, setDefaultFont, setFocus, setFont, setForeground, setForegroundPixel, setLayoutData, setLocation, setLocation, setMenu, setParent, setRadioFocus, setRadioSelection, setRedraw, setSavedFocus, setSize, setSize, setTabGroupFocus, setTabItemFocus, setToolTipText, setVisible, sort, subclass, toControl, toControl, toDisplay, toDisplay, transferActive, transferFocus, translateAccelerator, translateMnemonic, translateMnemonic, translateTraversal, traverse, traverse, traverseEscape, traverseGroup, traverseItem, traverseMnemonic, traversePage, traverseReturn, unsubclass, update, update, updateFont, windowProc, WM_ACTIVATE, WM_CHAR, WM_CLEAR, WM_CLOSE, WM_COMMAND, WM_CONTEXTMENU, WM_CTLCOLOR, WM_CUT, WM_DESTROY, WM_DRAWITEM, WM_ENDSESSION, WM_ERASEBKGND, WM_GETDLGCODE, WM_GETFONT, WM_GETOBJECT, WM_HELP, WM_HOTKEY, WM_HSCROLL, WM_IME_CHAR, WM_IME_COMPOSITION, WM_INITMENUPOPUP, WM_KEYDOWN, WM_KEYUP, WM_KILLFOCUS, WM_LBUTTONUP, WM_MBUTTONDBLCLK, WM_MBUTTONDOWN, WM_MBUTTONUP, WM_MEASUREITEM, WM_MENUCHAR, WM_MENUSELECT, WM_MOUSEACTIVATE, WM_MOUSEHOVER, WM_MOUSELEAVE, WM_MOUSEMOVE, WM_MOUSEWHEEL, WM_MOVE, WM_NCACTIVATE, WM_NCCALCSIZE, WM_NCHITTEST, WM_NOTIFY, WM_PAINT, WM_PALETTECHANGED, WM_PASTE, WM_PRINTCLIENT, WM_QUERYENDSESSION, WM_QUERYNEWPALETTE, WM_QUERYOPEN, WM_RBUTTONDBLCLK, WM_RBUTTONDOWN, WM_RBUTTONUP, WM_SETCURSOR, WM_SETFOCUS, WM_SETFONT, WM_SETREDRAW, WM_SETTINGCHANGE, WM_SHOWWINDOW, WM_SIZE, WM_SYSCHAR, WM_SYSCOLORCHANGE, WM_SYSCOMMAND, WM_SYSKEYDOWN, WM_SYSKEYUP, WM_TIMER, WM_UNDO, WM_VSCROLL, WM_WINDOWPOSCHANGING, wmColorChild, wmCommandChild, wmDrawChild, wmMeasureChild, wmNotifyChild

Methods inherited from class org.eclipse.swt.widgets.Widget

addDisposeListener, addListener, checkBits, checkParent, checkSubclass, checkWidget, dispose, error, filters, getData, getData, getName, getNameText, getStyle, hooks, isListening, isValidSubclass, isValidThread, mbcsToWcs, mbcsToWcs, notifyListeners, postEvent, postEvent, releaseChild, releaseResources, removeDisposeListener, removeListener, removeListener, sendEvent, sendEvent, sendEvent, sendEvent, setData, setData, setInputState, setKeyState, toString, wcsToMbcs, wcsToMbcs

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

increment

int increment

pageIncrement

int pageIncrement

ScrollBarProc

static final int ScrollBarProc

ScrollBarClass

static final org.eclipse.swt.internal.win32.TCHAR ScrollBarClass

Constructor Detail

Slider

public Slider(Composite parent,
              int style)

Enabled: 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.

Parameters:

parent - a composite control which will be the parent of the new instance (cannot be null)

style - the style of control to construct

See Also:

SWT.HORIZONTAL, SWT.VERTICAL, Widget.checkSubclass(), Widget.getStyle()

Method Detail

addSelectionListener

public void addSelectionListener(SelectionListener listener)

Enabled: 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 SelectionListener interface.

When widgetSelected is called, the event object detail field contains one of the following values: 0 - 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.

Parameters:

listener - the listener which should be notified

See Also:

SelectionListener, removeSelectionListener(org.eclipse.swt.events.SelectionListener), SelectionEvent

callWindowProc

int callWindowProc(int msg,
                   int wParam,
                   int lParam)

Specified by:

callWindowProc in class Control

checkStyle

static int checkStyle(int style)

computeSize

public Point computeSize(int wHint,
                         int hHint,
                         boolean changed)

Enabled:

Overrides:

computeSize in class Control

Parameters:

wHint - the width hint (can be SWT.DEFAULT)

hHint - the height hint (can be SWT.DEFAULT)

changed - true if the control's contents have changed, and false otherwise

Returns:

the preferred size of the control.

See Also:

Layout, Control.getBorderWidth(), Control.getBounds(), Control.getSize(), Control.pack(), "computeTrim, getClientArea for controls that implement them"

createWidget

void createWidget()

Overrides:

createWidget in class Control

defaultBackground

int defaultBackground()

Overrides:

defaultBackground in class Control

defaultForeground

int defaultForeground()

Overrides:

defaultForeground in class Control

getEnabled

public boolean getEnabled()

Enabled:

Overrides:

getEnabled in class Control

Returns:

the receiver's enabled state

See Also:

Control.isEnabled()

getIncrement

public int getIncrement()

Enabled: Returns the amount that the receiver's value will be modified by when the up/down (or right/left) arrows are pressed.

Returns:

the increment

getMaximum

public int getMaximum()

Enabled: Returns the maximum value which the receiver will allow.

Returns:

the maximum

getMinimum

public int getMinimum()

Enabled: Returns the minimum value which the receiver will allow.

Returns:

the minimum

getPageIncrement

public int getPageIncrement()

Enabled: Returns the amount that the receiver's value will be modified by when the page increment/decrement areas are selected.

Returns:

the page increment

getSelection

public int getSelection()

Enabled: Returns the single selection that is the receiver's value.

Returns:

the selection

getThumb

public int getThumb()

Enabled: Returns the size of the receiver's thumb relative to the difference between its maximum and minimum values.

Returns:

the thumb value

removeSelectionListener

public void removeSelectionListener(SelectionListener listener)

Enabled: Removes the listener from the collection of listeners who will be notified when the receiver's value changes.

Parameters:

listener - the listener which should no longer be notified

See Also:

SelectionListener, addSelectionListener(org.eclipse.swt.events.SelectionListener)

setBounds

void setBounds(int x,
               int y,
               int width,
               int height,
               int flags)

Overrides:

setBounds in class Control

setEnabled

public void setEnabled(boolean enabled)

Enabled:

Overrides:

setEnabled in class Control

Parameters:

enabled - the new enabled state

setIncrement

public void setIncrement(int value)

Enabled: 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.

Parameters:

value - the new increment (must be greater than zero)

setMaximum

public void setMaximum(int value)

Enabled: Sets the maximum value which the receiver will allow to be the argument which must be greater than or equal to zero.

Parameters:

value - the new maximum (must be zero or greater)

setMinimum

public void setMinimum(int value)

Enabled: Sets the minimum value which the receiver will allow to be the argument which must be greater than or equal to zero.

Parameters:

value - the new minimum (must be zero or greater)

setPageIncrement

public void setPageIncrement(int value)

Enabled: 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.

Returns:

the page increment (must be greater than zero)

setSelection

public void setSelection(int value)

Enabled: Sets the single selection that is the receiver's value to the argument which must be greater than or equal to zero.

Parameters:

value - the new selection (must be zero or greater)

setThumb

public void setThumb(int value)

Enabled: Sets the size of the receiver's thumb relative to the difference between its maximum and minimum values to the argument which must be at least one.

Parameters:

value - the new thumb value (must be at least one)

See Also:

ScrollBar

setValues

public void setValues(int selection,
                      int minimum,
                      int maximum,
                      int thumb,
                      int increment,
                      int pageIncrement)

Enabled: Sets the receiver's selection, minimum value, maximum value, thumb, increment and page increment all at once.

Note: This is equivalent to setting the values individually using the appropriate methods, but may be implemented in a more efficient fashion on some platforms.

Parameters:

selection - the new selection value

minimum - the new minimum value

maximum - the new maximum value

thumb - the new thumb value

increment - the new increment value

pageIncrement - the new pageIncrement value

widgetExtStyle

int widgetExtStyle()

Overrides:

widgetExtStyle in class Control

widgetStyle

int widgetStyle()

Overrides:

widgetStyle in class Control

windowClass

org.eclipse.swt.internal.win32.TCHAR windowClass()

Specified by:

windowClass in class Control

windowProc

int windowProc()

Specified by:

windowProc in class Control

WM_LBUTTONDBLCLK

org.eclipse.swt.internal.win32.LRESULT WM_LBUTTONDBLCLK(int wParam,
                                                        int lParam)

Overrides:

WM_LBUTTONDBLCLK in class Control

WM_LBUTTONDOWN

org.eclipse.swt.internal.win32.LRESULT WM_LBUTTONDOWN(int wParam,
                                                      int lParam)

Overrides:

WM_LBUTTONDOWN in class Control

wmScrollChild

org.eclipse.swt.internal.win32.LRESULT wmScrollChild(int wParam,
                                                     int lParam)

Overrides:

wmScrollChild in class Control