public class Slider extends Control
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:
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.
Note: Only one of the styles HORIZONTAL and VERTICAL may be specified.
IMPORTANT: This class is not intended to be subclassed.
ScrollBar
Constructor and Description |
---|
Slider(Composite parent,
int style)
Constructs a new instance of this class given its parent
and a style value describing its behavior and appearance.
|
Modifier and Type | Method and Description |
---|---|
void |
addSelectionListener(SelectionListener listener)
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. |
Point |
computeSize(int wHint,
int hHint,
boolean changed)
Returns the preferred size of the receiver.
|
<T> T |
getAdapter(java.lang.Class<T> adapter)
Implementation of the
Adaptable interface. |
int |
getIncrement()
Returns the amount that the receiver's value will be
modified by when the up/down (or right/left) arrows
are pressed.
|
int |
getMaximum()
Returns the maximum value which the receiver will allow.
|
int |
getMinimum()
Returns the minimum value which the receiver will allow.
|
int |
getPageIncrement()
Returns the amount that the receiver's value will be
modified by when the page increment/decrement areas
are selected.
|
int |
getSelection()
Returns the 'selection', which is the receiver's value.
|
int |
getThumb()
Returns the size of the receiver's thumb relative to the
difference between its maximum and minimum values.
|
void |
removeSelectionListener(SelectionListener listener)
Removes the listener from the collection of listeners who will
be notified when the user changes the receiver's value.
|
void |
setIncrement(int value)
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)
Sets the maximum.
|
void |
setMinimum(int value)
Sets the minimum value.
|
void |
setPageIncrement(int value)
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)
Sets the 'selection', which is the receiver's
value, to the argument which must be greater than or equal
to zero.
|
void |
setThumb(int value)
Sets the size of the receiver's thumb relative to the
difference between its maximum and minimum values.
|
void |
setValues(int selection,
int minimum,
int maximum,
int thumb,
int increment,
int pageIncrement)
Sets the receiver's selection, minimum value, maximum
value, thumb, increment and page increment all at once.
|
addControlListener, addDragDetectListener, addFocusListener, addGestureListener, addHelpListener, addKeyListener, addMenuDetectListener, addMouseListener, addTouchListener, addTraverseListener, computeSize, forceFocus, getAccessible, getBackground, getBackgroundImage, getBorderWidth, getBounds, getCursor, getEnabled, getFont, getForeground, getLayoutData, getLocation, getMenu, getMonitor, getOrientation, getParent, getShell, getSize, getToolTipText, getTouchEnabled, getVisible, isEnabled, isFocusControl, isReparentable, isVisible, moveAbove, moveBelow, pack, pack, redraw, redraw, removeControlListener, removeDragDetectListener, removeFocusListener, removeGestureListener, removeHelpListener, removeKeyListener, removeMenuDetectListener, removeMouseListener, removeTouchListener, removeTraverseListener, requestLayout, setBackground, setBackgroundImage, setBounds, setBounds, setCursor, setData, setEnabled, setFocus, setFont, setForeground, setLayoutData, setLocation, setLocation, setMenu, setOrientation, setParent, setRedraw, setSize, setSize, setToolTipText, setTouchEnabled, setVisible, toControl, toControl, toDisplay, toDisplay, update
addDisposeListener, addListener, checkSubclass, checkWidget, dispose, getData, getData, getDisplay, getListeners, getStyle, isDisposed, isListening, notifyListeners, removeDisposeListener, removeListener, removeListener, reskin, setData, toString
public Slider(Composite parent, int style)
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.
parent
- a composite control which will be the parent of the new instance (cannot be null)style
- the style of control to constructjava.lang.IllegalArgumentException
- SWTException
- SWT.HORIZONTAL
,
SWT.VERTICAL
,
Widget.checkSubclass()
,
Widget.getStyle()
public void addSelectionListener(SelectionListener listener)
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.
listener
- the listener which should be notified when the user changes the receiver's valuejava.lang.IllegalArgumentException
- SWTException
- SelectionListener
,
removeSelectionListener(org.eclipse.swt.events.SelectionListener)
,
SelectionEvent
public void removeSelectionListener(SelectionListener listener)
listener
- the listener which should no longer be notifiedjava.lang.IllegalArgumentException
- SWTException
- SelectionListener
,
addSelectionListener(org.eclipse.swt.events.SelectionListener)
public Point computeSize(int wHint, int hHint, boolean changed)
Control
The preferred size of a control is the size that it would
best be displayed at. The width hint and height hint arguments
allow the caller to ask a control questions such as "Given a particular
width, how high does the control need to be to show all of the contents?"
To indicate that the caller does not wish to constrain a particular
dimension, the constant SWT.DEFAULT
is passed for the hint.
If the changed flag is true
, it indicates that the receiver's
contents have changed, therefore any caches that a layout manager
containing the control may have been keeping need to be flushed. When the
control is resized, the changed flag will be false
, so layout
manager caches can be retained.
computeSize
in class Control
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
otherwiseLayout
,
Control.getBorderWidth()
,
Control.getBounds()
,
Control.getSize()
,
Control.pack(boolean)
,
"computeTrim, getClientArea for controls that implement them"public int getIncrement()
SWTException
- public int getMaximum()
SWTException
- public int getMinimum()
SWTException
- public int getPageIncrement()
SWTException
- public int getSelection()
SWTException
- public int getThumb()
SWTException
- public void setIncrement(int value)
value
- the new increment (must be greater than zero)SWTException
- public void setMaximum(int value)
value
- the new maximum, which must be greater than the current minimumSWTException
- public void setMinimum(int value)
value
- the new minimumSWTException
- public void setPageIncrement(int value)
value
- the page increment (must be greater than zero)SWTException
- public void setSelection(int value)
value
- the new selection (must be zero or greater)SWTException
- public void setThumb(int value)
value
- the new thumb value, which must be at least one and not
larger than the size of the current rangeSWTException
- public void setValues(int selection, int minimum, int maximum, int thumb, int increment, int pageIncrement)
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.
selection
- the new selection valueminimum
- the new minimum valuemaximum
- the new maximum valuethumb
- the new thumb valueincrement
- the new increment valuepageIncrement
- the new pageIncrement valueSWTException
- public <T> T getAdapter(java.lang.Class<T> adapter)
Widget
Adaptable
interface.
IMPORTANT: This method is not part of the RWT public API. It is marked public only so that it can be shared within the packages provided by RWT. It should never be accessed from application code.
getAdapter
in interface Adaptable
getAdapter
in class Control
adapter
- the lookup classnull
if
there is no adapter associated with the given class.
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