Package org.evoludo.ui

Class Slider

Object

UIObject

Widget

FocusWidget

Slider

All Implemented Interfaces:

ChangeHandler, ClickHandler, HasAllDragAndDropHandlers, HasAllFocusHandlers, HasAllGestureHandlers, HasAllKeyHandlers, HasAllMouseHandlers, HasAllTouchHandlers, HasBlurHandlers, HasChangeHandlers, HasClickHandlers, HasDoubleClickHandlers, HasDragEndHandlers, HasDragEnterHandlers, HasDragHandlers, HasDragLeaveHandlers, HasDragOverHandlers, HasDragStartHandlers, HasDropHandlers, HasFocusHandlers, HasGestureChangeHandlers, HasGestureEndHandlers, HasGestureStartHandlers, HasKeyDownHandlers, HasKeyPressHandlers, HasKeyUpHandlers, HasMouseDownHandlers, HasMouseMoveHandlers, HasMouseOutHandlers, HasMouseOverHandlers, HasMouseUpHandlers, HasMouseWheelHandlers, HasTouchCancelHandlers, HasTouchEndHandlers, HasTouchMoveHandlers, HasTouchStartHandlers, TouchEndHandler, TouchMoveHandler, TouchStartHandler, HasAttachHandlers, EventHandler, HasHandlers, EventListener, Focusable, HasEnabled, HasFocus, HasVisibility, IsWidget, SourcesClickEvents, SourcesFocusEvents, SourcesKeyboardEvents, SourcesMouseEvents, HasInputHandlers, InputHandler

public class Slider
extends FocusWidget
implements HasChangeHandlers, ChangeHandler, ClickHandler, TouchStartHandler, TouchEndHandler, TouchMoveHandler, HasInputHandlers, InputHandler

A standard slider widget. The slider handles both linear and logarithmic scales.

CSS Style Rules

.gwt-Slider

the input element.

Example

 public class SliderExample implements EntryPoint {
        public void onModuleLoad() {
                // Make a new slider and display its value on label.
                VerticalPanel p = new VerticalPanel();
                Label l = new Label("Move slider...");
                Slider s = new Slider();
                s.addChangeHandler(new ChangeHandler() {
                        @Override
                        public void onChange(ChangeEvent event) {
                                l.setText("Slider at " + s.getValue());
                        }
                });
                p.add(l);
                p.add(s);
                // Add it to the root panel.
                RootPanel.get().add(p);
        }
 }
 

Author:

Christoph Hauert

Nested Class Summary

Nested classes/interfaces inherited from class UIObject

UIObject.DebugIdImpl, UIObject.DebugIdImplEnabled

Field Summary

Fields

Modifier and Type	Field	Description
protected double	logBase	For logarithmic sliders this is the base of the logarithm.
protected double	logRange	Helper variable to the logarithm of the slider range.
protected double	max	Maximum value of slider.
protected double	min	Minimum value of slider.
protected boolean	reversed	true if minimum and maximum of slider are reversed.
protected HTML	slider	Reference to slider.
private static final double	SLIDER_MAX	Default maximum value of slider.
private static final double	SLIDER_MIN	Default minimum value of slider.
private static final int	SLIDER_STEPS	Default number of steps between minimum and maximum of slider.
protected int	steps	Number of steps between minimum and maximum value of slider.
protected String	title	Title of slider.

Fields inherited from class UIObject

DEBUG_ID_PREFIX

Constructor Summary

Constructors

Modifier	Constructor	Description
	Slider()	Creates a slider ranging from 0.0 to 100.0 with 100 steps and initial value (0.0+100.0)/2.
	Slider(double min, double max)	Creates a slider ranging from min to max with 100 steps and initial value (min+max)/2.
	Slider(double min, double max, double init, int steps)	Creates a slider ranging from min to max with steps increments and initial value init.
	Slider(double min, double max, ChangeHandler handler)	Creates a slider ranging from min to max with 100 steps and initial value (min+max)/2 as well as a change handler.
	Slider(int min, int max, int init, int steps, ChangeHandler handler)	Creates a slider ranging from min to max with steps increments and initial value init as well as a change handler.
protected	Slider(Element element)	This constructor may be used by subclasses to explicitly use an existing element.
	Slider(ChangeHandler handler)	Creates a slider ranging from 0.0 to 100.0 with 100 steps and initial value (0.0+100.0)/2 as well as a change handler.

Method Summary

Modifier and Type	Method	Description
private void	_update()	Updates the logRange if needed as well as the tooltip of the slider.
HandlerRegistration	addChangeHandler(ChangeHandler handler)
HandlerRegistration	addInputHandler(InputHandler handler)	Adds a InputEvent handler.
protected InputElement	getInputElement()	Get the input element underlying the slider.
double	getValue()	Get the value of slider taking its linear or logarithmic scaling into account.
private double	lin2log(double x)	Helper function to convert from linear to logarithmic scales.
private double	log2lin(double x)	Helper function to convert from logarithmic to linear scales.
void	onChange(ChangeEvent event)
void	onClick(ClickEvent event)
void	onInput(InputEvent event)	Called when a InputEvent is fired.
void	onTouchEnd(TouchEndEvent event)
void	onTouchMove(TouchMoveEvent event)
void	onTouchStart(TouchStartEvent event)
void	setEnabled(boolean enabled)
void	setLinear()	Sets a linear scale for the slider.
void	setLogBase(double base)	Set the base for a logarithmic slider.
void	setRange(double left, double right)	Set left and right values of slider.
void	setSteps(int steps)	Set the number of steps between the minimum and maximum values of the slider.
void	setTitle(String title)
void	setValue(double value)	Set the value of slider taking its linear or logarithmic scaling into account.
private <H extends EventHandler> void	touchSlider(TouchEvent<H> event)	Helper function to update the slider value based on touch events.
protected void	updateTitle()	Updates the tooltip of the slider.
static Slider	wrap(Element element)	Creates a Slider widget that wraps an existing <input> element.

Methods inherited from class FocusWidget

addBlurHandler, addClickHandler, addClickListener, addDoubleClickHandler, addDragEndHandler, addDragEnterHandler, addDragHandler, addDragLeaveHandler, addDragOverHandler, addDragStartHandler, addDropHandler, addFocusHandler, addFocusListener, addGestureChangeHandler, addGestureEndHandler, addGestureStartHandler, addKeyboardListener, addKeyDownHandler, addKeyPressHandler, addKeyUpHandler, addMouseDownHandler, addMouseListener, addMouseMoveHandler, addMouseOutHandler, addMouseOverHandler, addMouseUpHandler, addMouseWheelHandler, addMouseWheelListener, addTouchCancelHandler, addTouchEndHandler, addTouchMoveHandler, addTouchStartHandler, getFocusImpl, getTabIndex, isEnabled, onAttach, removeClickListener, removeFocusListener, removeKeyboardListener, removeMouseListener, removeMouseWheelListener, setAccessKey, setFocus, setTabIndex

Methods inherited from class Widget

addAttachHandler, addBitlessDomHandler, addDomHandler, addHandler, asWidget, asWidgetOrNull, createHandlerManager, delegateEvent, doAttachChildren, doDetachChildren, fireEvent, getHandlerCount, getLayoutData, getParent, isAttached, isOrWasAttached, onBrowserEvent, onDetach, onLoad, onUnload, removeFromParent, setLayoutData, sinkEvents, unsinkEvents

Methods inherited from class UIObject

addStyleDependentName, addStyleName, ensureDebugId, ensureDebugId, ensureDebugId, getAbsoluteLeft, getAbsoluteTop, getElement, getOffsetHeight, getOffsetWidth, getStyleElement, getStyleName, getStyleName, getStylePrimaryName, getStylePrimaryName, getTitle, isVisible, isVisible, onEnsureDebugId, removeStyleDependentName, removeStyleName, resolvePotentialElement, setElement, setElement, setHeight, setPixelSize, setSize, setStyleDependentName, setStyleName, setStyleName, setStyleName, setStyleName, setStylePrimaryName, setStylePrimaryName, setVisible, setVisible, setWidth, sinkBitlessEvent, toString

Methods inherited from class Object

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

Methods inherited from interface HasHandlers

fireEvent

Field Details

SLIDER_MIN

private static final double SLIDER_MIN

Default minimum value of slider.

See Also:

• Constant Field Values

SLIDER_MAX

private static final double SLIDER_MAX

Default maximum value of slider.

See Also:

• Constant Field Values

SLIDER_STEPS

private static final int SLIDER_STEPS

Default number of steps between minimum and maximum of slider.

See Also:

• Constant Field Values

slider

protected HTML slider

Reference to slider. The <input> element.

title

protected String title

Title of slider. This string is displayed as the slider's tooltip and is updated to show the slider's current value.

logBase

protected double logBase

For logarithmic sliders this is the base of the logarithm. For logBase≤0 the slider has a linear scale.

reversed

protected boolean reversed

true if minimum and maximum of slider are reversed.

min

protected double min

Minimum value of slider.

See Also:

• SLIDER_MIN

max

protected double max

Maximum value of slider.

See Also:

• SLIDER_MAX

steps

protected int steps

Number of steps between minimum and maximum value of slider.

See Also:

• SLIDER_STEPS

logRange

protected double logRange

Helper variable to the logarithm of the slider range. Reduces calls to the fairly expensive Math.log(double).

Constructor Details

Slider

public Slider()

Creates a slider ranging from 0.0 to 100.0 with 100 steps and initial value (0.0+100.0)/2.

Slider

public Slider(ChangeHandler handler)

Creates a slider ranging from 0.0 to 100.0 with 100 steps and initial value (0.0+100.0)/2 as well as a change handler.

Parameters:

handler - the change handler

Slider

public Slider(double min,
 double max)

Creates a slider ranging from min to max with 100 steps and initial value (min+max)/2.

Parameters:

min - the minimum value

max - the maximum value

Slider

public Slider(double min,
 double max,
 ChangeHandler handler)

Creates a slider ranging from min to max with 100 steps and initial value (min+max)/2 as well as a change handler.

Parameters:

min - the minimum value

max - the maximum value

handler - the change handler

Slider

public Slider(double min,
 double max,
 double init,
 int steps)

Creates a slider ranging from min to max with steps increments and initial value init.

Parameters:

min - the minimum value

max - the maximum value

init - the initial value

steps - the number of steps

Slider

public Slider(int min,
 int max,
 int init,
 int steps,
 ChangeHandler handler)

Creates a slider ranging from min to max with steps increments and initial value init as well as a change handler.

Parameters:

min - the minimum value

max - the maximum value

init - the initial value

steps - the number of steps

handler - the change handler

Slider

protected Slider(Element element)

This constructor may be used by subclasses to explicitly use an existing element. This element must be a <input> element.

Parameters:

element - the element to be used

Method Details

wrap

public static Slider wrap(Element element)

Creates a Slider widget that wraps an existing <input> element. This element must already be attached to the document. If the element is removed from the document, you must call RootPanel.detachNow(Widget).

Parameters:

element - the element to be wrapped

Returns:

Slider widget wrapping element

getInputElement

protected InputElement getInputElement()

Get the input element underlying the slider.

Returns:

the InputElement

setRange

public void setRange(double left,
 double right)

Set left and right values of slider. Left values that exceed right values are acceptable.

Note: HTML sliders must have the minimum on the left and the maximum on the right. This implementation automatically takes care of the conversion if the maximum is on the left and the minimum on the right.

Parameters:

left - the left slider value

right - the right slider value

setSteps

public void setSteps(int steps)

Set the number of steps between the minimum and maximum values of the slider.

Parameters:

steps - the number of steps

setLogBase

public void setLogBase(double base)

Set the base for a logarithmic slider.

Parameters:

base - the logarithmic base of slider

Throws:

IllegalArgumentException - if base≤0 or the minimum and/or maximum values of the slider are ≤0

setLinear

public void setLinear()

Sets a linear scale for the slider.

_update

private void _update()

Updates the logRange if needed as well as the tooltip of the slider.

lin2log

private double lin2log(double x)

Helper function to convert from linear to logarithmic scales.

Parameters:

x - linear value

Returns:

logarithmic value

log2lin

private double log2lin(double x)

Helper function to convert from logarithmic to linear scales.

Parameters:

x - logarithmic value

Returns:

linear value

setEnabled

public void setEnabled(boolean enabled)

Specified by:

setEnabled in interface HasEnabled

Overrides:

setEnabled in class FocusWidget

getValue

public double getValue()

Get the value of slider taking its linear or logarithmic scaling into account.

Returns:

current value of slider

setValue

public void setValue(double value)

Set the value of slider taking its linear or logarithmic scaling into account.

Parameters:

value - the new value of the slider

setTitle

public void setTitle(String title)

Overrides:

setTitle in class UIObject

updateTitle

protected void updateTitle()

Updates the tooltip of the slider. By default it shows the sliders minimum, maximum and current value.

addInputHandler

public HandlerRegistration addInputHandler(InputHandler handler)

Description copied from interface: HasInputHandlers

Adds a InputEvent handler.

Specified by:

addInputHandler in interface HasInputHandlers

Parameters:

handler - the input handler

Returns:

HandlerRegistration used to remove this handler

onInput

public void onInput(InputEvent event)

Description copied from interface: InputHandler

Called when a InputEvent is fired.

Specified by:

onInput in interface InputHandler

Parameters:

event - the InputEvent that was fired

onClick

public void onClick(ClickEvent event)

Specified by:

onClick in interface ClickHandler

onTouchStart

public void onTouchStart(TouchStartEvent event)

Specified by:

onTouchStart in interface TouchStartHandler

onTouchMove

public void onTouchMove(TouchMoveEvent event)

Specified by:

onTouchMove in interface TouchMoveHandler

onTouchEnd

public void onTouchEnd(TouchEndEvent event)

Specified by:

onTouchEnd in interface TouchEndHandler

touchSlider

private <H extends EventHandler> void touchSlider(TouchEvent<H> event)

Helper function to update the slider value based on touch events.

Type Parameters:

H - the handler type

Parameters:

event - the touch event

addChangeHandler

public HandlerRegistration addChangeHandler(ChangeHandler handler)

Specified by:

addChangeHandler in interface HasChangeHandlers

onChange

public void onChange(ChangeEvent event)

Specified by:

onChange in interface ChangeHandler