com.google.gwt.user.client.ui

Class CheckBox

java.lang.Object

com.google.gwt.user.client.ui.UIObject

com.google.gwt.user.client.ui.Widget

com.google.gwt.user.client.ui.FocusWidget

com.google.gwt.user.client.ui.ButtonBase

com.google.gwt.user.client.ui.CheckBox

All Implemented Interfaces:

IsEditor<LeafValueEditor<java.lang.Boolean>>, HasAllDragAndDropHandlers, HasAllFocusHandlers, HasAllGestureHandlers, HasAllKeyHandlers, HasAllMouseHandlers, HasAllTouchHandlers, HasBlurHandlers, 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, HasAttachHandlers, HasValueChangeHandlers<java.lang.Boolean>, HasHandlers, HasDirectionEstimator, HasSafeHtml, EventListener, TakesValue<java.lang.Boolean>, Focusable, HasDirectionalSafeHtml, HasDirectionalText, HasEnabled, HasFocus, HasHTML, HasName, HasText, HasValue<java.lang.Boolean>, HasVisibility, HasWordWrap, IsWidget, SourcesClickEvents, SourcesFocusEvents, SourcesKeyboardEvents, SourcesMouseEvents

Direct Known Subclasses:

RadioButton

public class CheckBox
extends ButtonBase
implements HasName, HasValue<java.lang.Boolean>, HasWordWrap, HasDirectionalSafeHtml, HasDirectionEstimator, IsEditor<LeafValueEditor<java.lang.Boolean>>

A standard check box widget. This class also serves as a base class for RadioButton.

Built-in Bidi Text Support

This widget is capable of automatically adjusting its direction according to its content. This feature is controlled by setDirectionEstimator(boolean) or passing a DirectionEstimator parameter to the constructor, and is off by default.

CSS Style Rules

.gwt-CheckBox

the outer element

.gwt-CheckBox-disabled

applied when Checkbox is disabled

Example

public class CheckBoxExample implements EntryPoint {

  @Override
  public void onModuleLoad() {
    // Make a new check box, and select it by default.
    CheckBox cb = new CheckBox("Foo");
    cb.setValue(true);

    // Hook up a handler to find out when it's clicked.
    cb.addClickHandler(new ClickHandler() {
      @Override
      public void onClick(ClickEvent event) {
        boolean checked = ((CheckBox) event.getSource()).getValue();
        Window.alert("It is " + (checked ? "" : "not ") + "checked");
      }
    });

    // Add it to the root panel.
    RootPanel.get().add(cb);
  }
}

Nested Class Summary

Nested classes/interfaces inherited from class com.google.gwt.user.client.ui.UIObject

UIObject.DebugIdImpl, UIObject.DebugIdImplEnabled

Field Summary

Fields

Modifier and Type	Field and Description
static DirectionEstimator	DEFAULT_DIRECTION_ESTIMATOR
(package private) DirectionalTextHelper	directionalTextHelper
(package private) InputElement	inputElem
(package private) LabelElement	labelElem

Fields inherited from class com.google.gwt.user.client.ui.Widget

eventsToSink

Fields inherited from class com.google.gwt.user.client.ui.UIObject

DEBUG_ID_PREFIX, MISSING_ELEMENT_ERROR, SETELEMENT_TWICE_ERROR

Constructor Summary

Constructors

Modifier	Constructor and Description
	CheckBox() Creates a check box with no label.
protected	CheckBox(Element elem)
	CheckBox(SafeHtml label) Creates a check box with the specified text label.
	CheckBox(SafeHtml label, DirectionEstimator directionEstimator) Creates a check box with the specified text label.
	CheckBox(SafeHtml label, HasDirection.Direction dir) Creates a check box with the specified text label.
	CheckBox(java.lang.String label) Creates a check box with the specified text label.
	CheckBox(java.lang.String label, boolean asHTML) Creates a check box with the specified text label.
	CheckBox(java.lang.String label, DirectionEstimator directionEstimator) Creates a label with the specified text and a default direction estimator.
	CheckBox(java.lang.String label, HasDirection.Direction dir) Creates a check box with the specified text label.

Method Summary

Modifier and Type	Method and Description
HandlerRegistration	addValueChangeHandler(ValueChangeHandler<java.lang.Boolean> handler) Adds a ValueChangeEvent handler.
LeafValueEditor<java.lang.Boolean>	asEditor() Returns the Editor encapsulated by the view object.
protected void	ensureDomEventHandlers()
DirectionEstimator	getDirectionEstimator() Returns the DirectionEstimator object.
java.lang.String	getFormValue() Returns the value property of the input element that backs this widget.
java.lang.String	getHTML() Gets this object's contents as HTML.
java.lang.String	getName() Gets the widget's name.
int	getTabIndex() Gets the tab index.
java.lang.String	getText() Gets this object's text.
HasDirection.Direction	getTextDirection() Gets the direction of this object's text.
java.lang.Boolean	getValue() Determines whether this check box is currently checked.
boolean	getWordWrap() Gets whether word-wrapping is enabled.
boolean	isChecked() Deprecated. Use getValue() instead
boolean	isEnabled() Gets whether this widget is enabled.
protected void	onEnsureDebugId(java.lang.String baseID) Affected Elements: -label = label next to checkbox.
protected void	onLoad() This method is called when a widget is attached to the browser's document.
protected void	onUnload() This method is called when a widget is detached from the browser's document.
protected void	replaceInputElement(Element elem) Replace the current input element with a new one.
protected void	replaceInputElement(Element elem) Deprecated. Call and use replaceInputElement(Element) instead.
void	setAccessKey(char key) Sets the widget's 'access key'.
void	setChecked(boolean checked) Deprecated. Use setValue(Boolean) instead
void	setDirectionEstimator(boolean enabled) Toggles on / off direction estimation.
void	setDirectionEstimator(DirectionEstimator directionEstimator) Sets the DirectionEstimator object.
void	setEnabled(boolean enabled) Sets whether this widget is enabled.
void	setFocus(boolean focused) Explicitly focus/unfocus this widget.
void	setFormValue(java.lang.String value) Set the value property on the input element that backs this widget.
void	setHTML(SafeHtml html, HasDirection.Direction dir) Sets this object's html, also declaring its direction.
void	setHTML(java.lang.String html) Sets this object's contents via HTML.
void	setName(java.lang.String name) Sets the widget's name.
void	setTabIndex(int index) Sets the widget's position in the tab index.
void	setText(java.lang.String text) Sets this object's text.
void	setText(java.lang.String text, HasDirection.Direction dir) Sets this object's text, also declaring its direction.
void	setValue(java.lang.Boolean value) Checks or unchecks the check box.
void	setValue(java.lang.Boolean value, boolean fireEvents) Checks or unchecks the check box, firing ValueChangeEvent if appropriate.
void	setWordWrap(boolean wrap) Sets whether word-wrapping is enabled.
void	sinkEvents(int eventBitsToAdd) Overridden to defer the call to super.sinkEvents until the first time this widget is attached to the dom, as a performance enhancement.

Methods inherited from class com.google.gwt.user.client.ui.ButtonBase

setHTML

Methods inherited from class com.google.gwt.user.client.ui.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, onAttach, removeClickListener, removeFocusListener, removeKeyboardListener, removeMouseListener, removeMouseWheelListener

Methods inherited from class com.google.gwt.user.client.ui.Widget

addAttachHandler, addBitlessDomHandler, addDomHandler, addHandler, asWidget, asWidgetOrNull, createHandlerManager, delegateEvent, doAttachChildren, doDetachChildren, ensureHandlers, fireEvent, getHandlerCount, getHandlerManager, getLayoutData, getParent, isAttached, isOrWasAttached, onBrowserEvent, onDetach, removeFromParent, replaceElement, setLayoutData, setParent, unsinkEvents

Methods inherited from class com.google.gwt.user.client.ui.UIObject

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.google.gwt.event.shared.HasHandlers

fireEvent

Methods inherited from interface com.google.gwt.safehtml.client.HasSafeHtml

setHTML

Field Detail

DEFAULT_DIRECTION_ESTIMATOR

public static final DirectionEstimator DEFAULT_DIRECTION_ESTIMATOR

directionalTextHelper

final DirectionalTextHelper directionalTextHelper

inputElem

InputElement inputElem

labelElem

LabelElement labelElem

Constructor Detail

CheckBox

public CheckBox()

Creates a check box with no label.

CheckBox

public CheckBox(SafeHtml label)

Creates a check box with the specified text label.

Parameters:

label - the check box's label

CheckBox

public CheckBox(SafeHtml label,
                HasDirection.Direction dir)

Creates a check box with the specified text label.

Parameters:

label - the check box's label

dir - the text's direction. Note that DEFAULT means direction should be inherited from the widget's parent element.

CheckBox

public CheckBox(SafeHtml label,
                DirectionEstimator directionEstimator)

Creates a check box with the specified text label.

Parameters:

label - the check box's label

directionEstimator - A DirectionEstimator object used for automatic direction adjustment. For convenience, DEFAULT_DIRECTION_ESTIMATOR can be used.

CheckBox

public CheckBox(java.lang.String label)

Creates a check box with the specified text label.

Parameters:

label - the check box's label

CheckBox

public CheckBox(java.lang.String label,
                HasDirection.Direction dir)

Creates a check box with the specified text label.

Parameters:

label - the check box's label

dir - the text's direction. Note that DEFAULT means direction should be inherited from the widget's parent element.

CheckBox

public CheckBox(java.lang.String label,
                DirectionEstimator directionEstimator)

Creates a label with the specified text and a default direction estimator.

Parameters:

label - the check box's label

directionEstimator - A DirectionEstimator object used for automatic direction adjustment. For convenience, DEFAULT_DIRECTION_ESTIMATOR can be used.

CheckBox

public CheckBox(java.lang.String label,
                boolean asHTML)

Creates a check box with the specified text label.

Parameters:

label - the check box's label

asHTML - true to treat the specified label as html

CheckBox

protected CheckBox(Element elem)

Method Detail

addValueChangeHandler

public HandlerRegistration addValueChangeHandler(ValueChangeHandler<java.lang.Boolean> handler)

Description copied from interface: HasValueChangeHandlers

Adds a ValueChangeEvent handler.

Specified by:

addValueChangeHandler in interface HasValueChangeHandlers<java.lang.Boolean>

Parameters:

handler - the handler

Returns:

the registration for the event

asEditor

public LeafValueEditor<java.lang.Boolean> asEditor()

Description copied from interface: IsEditor

Returns the Editor encapsulated by the view object.

Specified by:

asEditor in interface IsEditor<LeafValueEditor<java.lang.Boolean>>

Returns:

an Editor of type E

getDirectionEstimator

public DirectionEstimator getDirectionEstimator()

Description copied from interface: HasDirectionEstimator

Returns the DirectionEstimator object.

Specified by:

getDirectionEstimator in interface HasDirectionEstimator

getFormValue

public java.lang.String getFormValue()

Returns the value property of the input element that backs this widget. This is the value that will be associated with the CheckBox name and submitted to the server if a FormPanel that holds it is submitted and the box is checked.

Don't confuse this with getValue(), which returns true or false if the widget is checked.

getHTML

public java.lang.String getHTML()

Description copied from interface: HasHTML

Gets this object's contents as HTML.

Specified by:

getHTML in interface HasHTML

Overrides:

getHTML in class ButtonBase

Returns:

the object's HTML

getName

public java.lang.String getName()

Description copied from interface: HasName

Gets the widget's name.

Specified by:

getName in interface HasName

Returns:

the widget's name

getTabIndex

public int getTabIndex()

Description copied from class: FocusWidget

Gets the tab index.

Specified by:

getTabIndex in interface Focusable

Overrides:

getTabIndex in class FocusWidget

Returns:

the tab index

getText

public java.lang.String getText()

Description copied from interface: HasText

Gets this object's text.

Specified by:

getText in interface HasText

Overrides:

getText in class ButtonBase

Returns:

the object's text

getTextDirection

public HasDirection.Direction getTextDirection()

Description copied from interface: HasDirectionalText

Gets the direction of this object's text.

Specified by:

getTextDirection in interface HasDirectionalText

Returns:

the direction of this object's text

getValue

public java.lang.Boolean getValue()

Determines whether this check box is currently checked.

Note that this does not return the value property of the checkbox input element wrapped by this widget. For access to that property, see getFormValue()

Specified by:

getValue in interface TakesValue<java.lang.Boolean>

Specified by:

getValue in interface HasValue<java.lang.Boolean>

Returns:

true if the check box is checked, false otherwise. Will not return null

See Also:

TakesValue.setValue(V)

getWordWrap

public boolean getWordWrap()

Description copied from interface: HasWordWrap

Gets whether word-wrapping is enabled.

Specified by:

getWordWrap in interface HasWordWrap

Returns:

true if word-wrapping is enabled.

isChecked

@Deprecated
public boolean isChecked()

Deprecated. Use getValue() instead

Determines whether this check box is currently checked.

Returns:

true if the check box is checked

isEnabled

public boolean isEnabled()

Description copied from class: FocusWidget

Gets whether this widget is enabled.

Specified by:

isEnabled in interface HasEnabled

Overrides:

isEnabled in class FocusWidget

Returns:

true if the widget is enabled

setAccessKey

public void setAccessKey(char key)

Description copied from interface: Focusable

Sets the widget's 'access key'. This key is used (in conjunction with a browser-specific modifier key) to automatically focus the widget.

Specified by:

setAccessKey in interface Focusable

Overrides:

setAccessKey in class FocusWidget

Parameters:

key - the widget's access key

setChecked

@Deprecated
public void setChecked(boolean checked)

Deprecated. Use setValue(Boolean) instead

Checks or unchecks this check box. Does not fire ValueChangeEvent. (If you want the event to fire, use setValue(Boolean, boolean))

Parameters:

checked - true to check the check box.

setDirectionEstimator

public void setDirectionEstimator(boolean enabled)

Toggles on / off direction estimation.

See note at setDirectionEstimator(DirectionEstimator).

Specified by:

setDirectionEstimator in interface HasDirectionEstimator

Parameters:

enabled - Whether to enable direction estimation. If true, sets the DirectionEstimator object to a default DirectionEstimator.

setDirectionEstimator

public void setDirectionEstimator(DirectionEstimator directionEstimator)

Sets the DirectionEstimator object.

Note: DirectionEstimator should be set before the label has any content; it's highly recommended to set it using a constructor. Reason: if the label already has non-empty content, this will update its direction according to the new estimator's result. This may cause flicker, and thus should be avoided.

Specified by:

setDirectionEstimator in interface HasDirectionEstimator

Parameters:

directionEstimator - The DirectionEstimator to be set. null means turning off direction estimation.

setEnabled

public void setEnabled(boolean enabled)

Description copied from class: FocusWidget

Sets whether this widget is enabled.

Specified by:

setEnabled in interface HasEnabled

Overrides:

setEnabled in class FocusWidget

Parameters:

enabled - true to enable the widget, false to disable it

setFocus

public void setFocus(boolean focused)

Description copied from interface: Focusable

Explicitly focus/unfocus this widget. Only one widget can have focus at a time, and the widget that does will receive all keyboard events. NOTE: Most browsers fire FocusEvents asynchronously. Especially within GWT tests, you'll need to make your test asynchronous to properly do verifications. See GWTTestCase#delayTestFinish for more information on how to do this.

Specified by:

setFocus in interface Focusable

Overrides:

setFocus in class FocusWidget

Parameters:

focused - whether this widget should take focus or release it

setFormValue

public void setFormValue(java.lang.String value)

Set the value property on the input element that backs this widget. This is the value that will be associated with the CheckBox's name and submitted to the server if a FormPanel that holds it is submitted and the box is checked.

Don't confuse this with setValue(java.lang.Boolean), which actually checks and unchecks the box.

Parameters:

value -

setHTML

public void setHTML(SafeHtml html,
                    HasDirection.Direction dir)

Description copied from interface: HasDirectionalSafeHtml

Sets this object's html, also declaring its direction.

Specified by:

setHTML in interface HasDirectionalSafeHtml

Parameters:

html - the object's new html

dir - the html's direction

setHTML

public void setHTML(java.lang.String html)

Description copied from interface: HasHTML

Sets this object's contents via HTML. Use care when setting an object's HTML; it is an easy way to expose script-based security problems. Consider using HasText.setText(String) whenever possible.

Specified by:

setHTML in interface HasHTML

Overrides:

setHTML in class ButtonBase

Parameters:

html - the object's new HTML

setName

public void setName(java.lang.String name)

Description copied from interface: HasName

Sets the widget's name.

Specified by:

setName in interface HasName

Parameters:

name - the widget's new name

setTabIndex

public void setTabIndex(int index)

Description copied from interface: Focusable

Sets the widget's position in the tab index. If more than one widget has the same tab index, each such widget will receive focus in an arbitrary order. Setting the tab index to -1 will cause this widget to be removed from the tab order.

Specified by:

setTabIndex in interface Focusable

Overrides:

setTabIndex in class FocusWidget

Parameters:

index - the widget's tab index

setText

public void setText(java.lang.String text)

Description copied from interface: HasText

Sets this object's text.

Specified by:

setText in interface HasText

Overrides:

setText in class ButtonBase

Parameters:

text - the object's new text

setText

public void setText(java.lang.String text,
                    HasDirection.Direction dir)

Description copied from interface: HasDirectionalText

Sets this object's text, also declaring its direction.

Specified by:

setText in interface HasDirectionalText

Parameters:

text - the object's new text

dir - the text's direction

setValue

public void setValue(java.lang.Boolean value)

Checks or unchecks the check box.

Note that this does not set the value property of the checkbox input element wrapped by this widget. For access to that property, see setFormValue(String)

Specified by:

setValue in interface TakesValue<java.lang.Boolean>

Specified by:

setValue in interface HasValue<java.lang.Boolean>

Parameters:

value - true to check, false to uncheck; null value implies false

See Also:

TakesValue.getValue()

setValue

public void setValue(java.lang.Boolean value,
                     boolean fireEvents)

Checks or unchecks the check box, firing ValueChangeEvent if appropriate.

Note that this does not set the value property of the checkbox input element wrapped by this widget. For access to that property, see setFormValue(String)

Specified by:

setValue in interface HasValue<java.lang.Boolean>

Parameters:

value - true to check, false to uncheck; null value implies false

fireEvents - If true, and value has changed, fire a ValueChangeEvent

setWordWrap

public void setWordWrap(boolean wrap)

Description copied from interface: HasWordWrap

Sets whether word-wrapping is enabled.

Specified by:

setWordWrap in interface HasWordWrap

Parameters:

wrap - true to enable word-wrapping.

sinkEvents

public void sinkEvents(int eventBitsToAdd)

Description copied from class: Widget

Overridden to defer the call to super.sinkEvents until the first time this widget is attached to the dom, as a performance enhancement. Subclasses wishing to customize sinkEvents can preserve this deferred sink behavior by putting their implementation behind a check of isOrWasAttached():

  @Override
 public void sinkEvents(int eventBitsToAdd) {
   if (isOrWasAttached()) {
     / * customized sink code goes here  */
   } else {
     super.sinkEvents(eventBitsToAdd);
  }
} 

Overrides:

sinkEvents in class Widget

Parameters:

eventBitsToAdd - a bitfield representing the set of events to be added to this element's event set

See Also:

Event

ensureDomEventHandlers

protected void ensureDomEventHandlers()

onEnsureDebugId

protected void onEnsureDebugId(java.lang.String baseID)

Affected Elements:

• -label = label next to checkbox.

Overrides:

onEnsureDebugId in class UIObject

Parameters:

baseID - the base ID used by the main element

See Also:

UIObject.onEnsureDebugId(String)

onLoad

protected void onLoad()

This method is called when a widget is attached to the browser's document. onAttach needs special handling for the CheckBox case. Must still call Widget.onAttach() to preserve the onAttach contract.

Overrides:

onLoad in class Widget

onUnload

protected void onUnload()

This method is called when a widget is detached from the browser's document. Overridden because of IE bug that throws away checked state and in order to clear the event listener off of the inputElem.

Overrides:

onUnload in class Widget

replaceInputElement

protected void replaceInputElement(Element elem)

Replace the current input element with a new one. Preserves all state except for the name property, for nasty reasons related to radio button grouping. (See implementation of RadioButton.setName(java.lang.String).)

Parameters:

elem - the new input element

replaceInputElement

@Deprecated
protected void replaceInputElement(Element elem)

Deprecated. Call and use replaceInputElement(Element) instead.