Event (Google Web Toolkit Javadoc)

java.lang.Object
- com.google.gwt.core.client.JavaScriptObject
- - com.google.gwt.dom.client.NativeEvent
  - - com.google.gwt.user.client.Event

```
public class Event
extends NativeEvent
```
An opaque handle to a native DOM Event. An Event cannot be created directly. Instead, use the Event type when returning a native DOM event from JSNI methods. An Event passed back into JSNI becomes the original DOM event the Event was created from, and can be accessed in JavaScript code as expected. This is typically done by calling methods in the DOM class.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`Event.NativePreviewEvent` Represents a preview of a native `Event`.
`static interface`	`Event.NativePreviewHandler` Handler interface for `Event.NativePreviewEvent` events.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`FOCUSEVENTS` A bit-mask covering both focus events (focus and blur).
`static int`	`GESTUREEVENTS` A bit-mask covering all gesture events (start, change, end).
`(package private) static HandlerManager`	`handlers` The list of `Event.NativePreviewHandler`.
`static int`	`KEYEVENTS` A bit-mask covering all keyboard events (down, up, and press).
`static int`	`MOUSEEVENTS` A bit-mask covering all mouse events (down, up, move, over, and out), but not click, dblclick, or wheel events.
`static int`	`ONBLUR` Fired when an element loses keyboard focus.
`static int`	`ONCHANGE` Fired when the value of an input element changes.
`static int`	`ONCLICK` Fired when the user clicks on an element.
`static int`	`ONCONTEXTMENU` Fired when the user requests an element's context menu (usually by right-clicking).
`static int`	`ONDBLCLICK` Fired when the user double-clicks on an element.
`static int`	`ONERROR` Fired when an image encounters an error.
`static int`	`ONFOCUS` Fired when an element receives keyboard focus.
`static int`	`ONGESTURECHANGE` Fired when the user gesture changes.
`static int`	`ONGESTUREEND` Fired when the user gesture ends.
`static int`	`ONGESTURESTART` Fired when the user gesture starts.
`static int`	`ONKEYDOWN` Fired when the user depresses a key.
`static int`	`ONKEYPRESS` Fired when the a character is generated from a keypress (either directly or through auto-repeat).
`static int`	`ONKEYUP` Fired when the user releases a key.
`static int`	`ONLOAD` Fired when an element (normally an IMG) finishes loading.
`static int`	`ONLOSECAPTURE` Fired when an element that has mouse capture loses it.
`static int`	`ONMOUSEDOWN` Fired when the user depresses a mouse button over an element.
`static int`	`ONMOUSEMOVE` Fired when the mouse is moved within an element's area.
`static int`	`ONMOUSEOUT` Fired when the mouse is moved out of an element's area.
`static int`	`ONMOUSEOVER` Fired when the mouse is moved into an element's area.
`static int`	`ONMOUSEUP` Fired when the user releases a mouse button over an element.
`static int`	`ONMOUSEWHEEL` Fired when the user scrolls the mouse wheel over an element.
`static int`	`ONPASTE` Fired when the user pastes text into an input element.
`static int`	`ONSCROLL` Fired when a scrollable element's scroll offset changes.
`static int`	`ONTOUCHCANCEL` Fired when the user cancels touching an element.
`static int`	`ONTOUCHEND` Fired when the user ends touching an element.
`static int`	`ONTOUCHMOVE` Fired when the user moves while touching an element.
`static int`	`ONTOUCHSTART` Fired when the user starts touching an element.
`static int`	`TOUCHEVENTS` A bit-mask covering all touch events (start, move, end, cancel).
`static int`	`UNDEFINED` Deprecated.

Fields inherited from class com.google.gwt.dom.client.NativeEvent
BUTTON_LEFT, BUTTON_MIDDLE, BUTTON_RIGHT

Constructor Summary

Constructors
Modifier Constructor and Description

protected Event()
Not directly instantiable.

Constructors
Modifier	Constructor and Description
`protected`	`Event()` Not directly instantiable.

Method Summary

Methods
Modifier and Type	Method and Description
`static void`	`addEventPreview(EventPreview preview)` Deprecated. replaced by `addNativePreviewHandler(NativePreviewHandler)`
`static HandlerRegistration`	`addNativePreviewHandler(Event.NativePreviewHandler handler)` Adds a `Event.NativePreviewHandler` that will receive all events before they are fired to their handlers.
`static Event`	`as(NativeEvent event)` Converts the `NativeEvent` to Event.
`void`	`cancelBubble(boolean cancel)` Deprecated. use `NativeEvent.stopPropagation()` instead
`static boolean`	`fireNativePreviewEvent(NativeEvent nativeEvent)` Fire a `Event.NativePreviewEvent` for the native event.
`static Event`	`getCurrentEvent()` Gets the current event that is being fired.
`Element`	`getCurrentTarget()` Deprecated. use `NativeEvent.getCurrentEventTarget()` instead
`static EventListener`	`getEventListener(Element elem)` Gets the `EventListener` that will receive events for the given element.
`static int`	`getEventsSunk(Element elem)` Gets the current set of events sunk by a given element.
`Element`	`getFromElement()` Deprecated. use `NativeEvent.getRelatedEventTarget()` instead
`Element`	`getRelatedTarget()` Deprecated. use `NativeEvent.getRelatedEventTarget()` instead
`boolean`	`getRepeat()` Deprecated. not supported on all browsers
`Element`	`getTarget()` Deprecated. use `NativeEvent.getEventTarget()` instead
`Element`	`getToElement()` Deprecated. use `NativeEvent.getRelatedEventTarget()` instead
`int`	`getTypeInt()` Gets the enumerated type of this event, as defined by `ONCLICK`, `ONMOUSEDOWN`, and so forth.
`static int`	`getTypeInt(java.lang.String typeName)` Gets the enumerated type of this event given a valid event type name.
`static void`	`releaseCapture(Element elem)` Releases mouse capture on the given element.
`static void`	`removeEventPreview(EventPreview preview)` Deprecated. use `HandlerRegistration` returned from `addNativePreviewHandler(NativePreviewHandler)`
`static void`	`setCapture(Element elem)` Sets mouse-capture on the given element.
`static void`	`setEventListener(Element elem, EventListener listener)` Sets the `EventListener` to receive events for the given element.
`static void`	`sinkEvents(Element elem, int eventBits)` Sets the current set of events sunk by a given element.

Methods inherited from class com.google.gwt.dom.client.NativeEvent
getAltKey, getButton, getChangedTouches, getCharCode, getClientX, getClientY, getCtrlKey, getCurrentEventTarget, getDataTransfer, getEventTarget, getKeyCode, getMetaKey, getMouseWheelVelocityY, getRelatedEventTarget, getRotation, getScale, getScreenX, getScreenY, getShiftKey, getString, getTargetTouches, getTouches, getType, preventDefault, stopPropagation

Methods inherited from class com.google.gwt.core.client.JavaScriptObject
cast, createArray, createArray, createFunction, createObject, equals, hashCode, toSource, toString

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - ONBLUR
```
public static final int ONBLUR
```
    Fired when an element loses keyboard focus.
    
    See Also:
    Constant Field Values
  - ONCHANGE
```
public static final int ONCHANGE
```
    Fired when the value of an input element changes.
    
    See Also:
    Constant Field Values
  - ONCLICK
```
public static final int ONCLICK
```
    Fired when the user clicks on an element.
    
    See Also:
    Constant Field Values
  - ONDBLCLICK
```
public static final int ONDBLCLICK
```
    Fired when the user double-clicks on an element.
    
    See Also:
    Constant Field Values
  - ONERROR
```
public static final int ONERROR
```
    Fired when an image encounters an error.
    
    See Also:
    Constant Field Values
  - ONFOCUS
```
public static final int ONFOCUS
```
    Fired when an element receives keyboard focus.
    
    See Also:
    Constant Field Values
  - ONGESTURECHANGE
```
public static final int ONGESTURECHANGE
```
    Fired when the user gesture changes.
    
    See Also:
    Constant Field Values
  - ONGESTUREEND
```
public static final int ONGESTUREEND
```
    Fired when the user gesture ends.
    
    See Also:
    Constant Field Values
  - ONGESTURESTART
```
public static final int ONGESTURESTART
```
    Fired when the user gesture starts.
    
    See Also:
    Constant Field Values
  - ONKEYDOWN
```
public static final int ONKEYDOWN
```
    Fired when the user depresses a key.
    
    See Also:
    Constant Field Values
  - ONKEYPRESS
```
public static final int ONKEYPRESS
```
    Fired when the a character is generated from a keypress (either directly or through auto-repeat).
    
    See Also:
    Constant Field Values
  - ONKEYUP
```
public static final int ONKEYUP
```
    Fired when the user releases a key.
    
    See Also:
    Constant Field Values
  - ONLOAD
```
public static final int ONLOAD
```
    Fired when an element (normally an IMG) finishes loading.
    
    See Also:
    Constant Field Values
  - ONLOSECAPTURE
```
public static final int ONLOSECAPTURE
```
    Fired when an element that has mouse capture loses it.
    
    See Also:
    Constant Field Values
  - ONMOUSEDOWN
```
public static final int ONMOUSEDOWN
```
    Fired when the user depresses a mouse button over an element.
    
    See Also:
    Constant Field Values
  - ONMOUSEMOVE
```
public static final int ONMOUSEMOVE
```
    Fired when the mouse is moved within an element's area.
    
    See Also:
    Constant Field Values
  - ONMOUSEOUT
```
public static final int ONMOUSEOUT
```
    Fired when the mouse is moved out of an element's area.
    
    See Also:
    Constant Field Values
  - ONMOUSEOVER
```
public static final int ONMOUSEOVER
```
    Fired when the mouse is moved into an element's area.
    
    See Also:
    Constant Field Values
  - ONMOUSEUP
```
public static final int ONMOUSEUP
```
    Fired when the user releases a mouse button over an element.
    
    See Also:
    Constant Field Values
  - ONMOUSEWHEEL
```
public static final int ONMOUSEWHEEL
```
    Fired when the user scrolls the mouse wheel over an element.
    
    See Also:
    Constant Field Values
  - ONPASTE
```
public static final int ONPASTE
```
    Fired when the user pastes text into an input element.
    Note: This event is not supported on Firefox 2 and earlier, or Opera 10 and earlier. Be aware that it will not fire on these browser versions.
    
    See Also:
    Constant Field Values
  - ONSCROLL
```
public static final int ONSCROLL
```
    Fired when a scrollable element's scroll offset changes.
    
    See Also:
    Constant Field Values
  - ONTOUCHCANCEL
```
public static final int ONTOUCHCANCEL
```
    Fired when the user cancels touching an element.
    
    See Also:
    Constant Field Values
  - ONTOUCHEND
```
public static final int ONTOUCHEND
```
    Fired when the user ends touching an element.
    
    See Also:
    Constant Field Values
  - ONTOUCHMOVE
```
public static final int ONTOUCHMOVE
```
    Fired when the user moves while touching an element.
    
    See Also:
    Constant Field Values
  - ONTOUCHSTART
```
public static final int ONTOUCHSTART
```
    Fired when the user starts touching an element.
    
    See Also:
    Constant Field Values
  - ONCONTEXTMENU
```
public static final int ONCONTEXTMENU
```
    Fired when the user requests an element's context menu (usually by right-clicking). Note that not all browsers will fire this event (notably Opera, as of 9.5).
    
    See Also:
    Constant Field Values
  - FOCUSEVENTS
```
public static final int FOCUSEVENTS
```
    A bit-mask covering both focus events (focus and blur).
    
    See Also:
    Constant Field Values
  - KEYEVENTS
```
public static final int KEYEVENTS
```
    A bit-mask covering all keyboard events (down, up, and press).
    
    See Also:
    Constant Field Values
  - MOUSEEVENTS
```
public static final int MOUSEEVENTS
```
    A bit-mask covering all mouse events (down, up, move, over, and out), but not click, dblclick, or wheel events.
    
    See Also:
    Constant Field Values
  - TOUCHEVENTS
```
public static final int TOUCHEVENTS
```
    A bit-mask covering all touch events (start, move, end, cancel).
    
    See Also:
    Constant Field Values
  - GESTUREEVENTS
```
public static final int GESTUREEVENTS
```
    A bit-mask covering all gesture events (start, change, end).
    
    See Also:
    Constant Field Values
  - UNDEFINED
```
@Deprecated
public static final int UNDEFINED
```
    Deprecated.
    
    Value returned by accessors when the actual integer value is undefined. In Development Mode, most accessors assert that the requested attribute is reliable across all supported browsers.
    
    See Also:
    Event, Constant Field Values
  - handlers
```
static HandlerManager handlers
```
    The list of Event.NativePreviewHandler. We use a list instead of a handler manager for efficiency and because we want to fire the handlers in reverse order. When the last handler is removed, handlers is reset to null.
- Constructor Detail
  - Event
```
protected Event()
```
    Not directly instantiable. Subclasses should also define a protected no-arg constructor to prevent client code from directly instantiating the class.
- Method Detail
  - addEventPreview
```
@Deprecated
public static void addEventPreview(EventPreview preview)
```
    Deprecated. replaced by addNativePreviewHandler(NativePreviewHandler)
    
    Adds an event preview to the preview stack. As long as this preview remains on the top of the stack, it will receive all events before they are fired to their listeners. Note that the event preview will receive all events, including those received due to bubbling, whereas normal event handlers only receive explicitly sunk events.
    
    Parameters:
    preview - the event preview to be added to the stack.
  - addNativePreviewHandler
```
public static HandlerRegistration addNativePreviewHandler(Event.NativePreviewHandler handler)
```
    Adds a Event.NativePreviewHandler that will receive all events before they are fired to their handlers. Note that the handler will receive all native events, including those received due to bubbling, whereas normal event handlers only receive explicitly sunk events.
    
    Unlike other event handlers, Event.NativePreviewHandler are fired in the reverse order that they are added, such that the last Event.NativePreviewEvent that was added is the first to be fired.
    
    Please note that nondeterministic behavior will result if more than one GWT application registers preview handlers. See issue 3892 for details.
    
    Parameters:
    handler - the Event.NativePreviewHandler
    
    Returns:
    HandlerRegistration used to remove this handler
  - as
```
public static Event as(NativeEvent event)
```
    Converts the NativeEvent to Event. This is always safe.
    
    Parameters:
    event - the event to downcast
  - fireNativePreviewEvent
```
public static boolean fireNativePreviewEvent(NativeEvent nativeEvent)
```
    Fire a Event.NativePreviewEvent for the native event.
    
    Parameters:
    nativeEvent - the native event
    
    Returns:
    true to fire the event normally, false to cancel the event
  - getCurrentEvent
```
public static Event getCurrentEvent()
```
    Gets the current event that is being fired. The current event is only available within the lifetime of the onBrowserEvent function. Once the onBrowserEvent method returns, the current event is reset to null.
    
    Returns:
    the current event
  - getEventListener
```
public static EventListener getEventListener(Element elem)
```
    Gets the EventListener that will receive events for the given element. Only one such listener may exist for a single element.
    
    Parameters:
    elem - the element whose listener is to be set
    
    Returns:
    the element's event listener
  - getEventsSunk
```
public static int getEventsSunk(Element elem)
```
    Gets the current set of events sunk by a given element.
    
    Parameters:
    elem - the element whose events are to be retrieved
    
    Returns:
    a bitfield describing the events sunk on this element (its possible values are described in Event)
  - getTypeInt
```
public static int getTypeInt(java.lang.String typeName)
```
    Gets the enumerated type of this event given a valid event type name.
    
    Parameters:
    typeName - the typeName to be tested
    
    Returns:
    the event's enumerated type, or -1 if not defined
  - releaseCapture
```
public static void releaseCapture(Element elem)
```
    Releases mouse capture on the given element. Calling this method has no effect if the element does not currently have mouse capture.
    
    Parameters:
    elem - the element to release capture
    See Also:
    setCapture(Element)
  - removeEventPreview
```
@Deprecated
public static void removeEventPreview(EventPreview preview)
```
    Deprecated. use HandlerRegistration returned from addNativePreviewHandler(NativePreviewHandler)
    
    Removes an element from the preview stack. This element will no longer capture events, though any preview underneath it will begin to do so.
    
    Parameters:
    preview - the event preview to be removed from the stack
  - setCapture
```
public static void setCapture(Element elem)
```
    Sets mouse-capture on the given element. This element will directly receive all mouse events until releaseCapture(Element) is called on it.
    
    Parameters:
    elem - the element on which to set mouse capture
  - setEventListener
```
public static void setEventListener(Element elem,
                    EventListener listener)
```
    Sets the EventListener to receive events for the given element. Only one such listener may exist for a single element.
    
    Parameters:
    elem - the element whose listener is to be set
    listener - the listener to receive events
  - sinkEvents
```
public static void sinkEvents(Element elem,
              int eventBits)
```
    Sets the current set of events sunk by a given element. These events will be fired to the nearest EventListener specified on any of the element's parents.
    
    Parameters:
    elem - the element whose events are to be retrieved
    eventBits - a bitfield describing the events sunk on this element (its possible values are described in Event)
  - cancelBubble
```
@Deprecated
public final void cancelBubble(boolean cancel)
```
    Deprecated. use NativeEvent.stopPropagation() instead
    
    Cancels bubbling for the given event. This will stop the event from being propagated to parent elements.
    
    Parameters:
    cancel - true to cancel bubbling
  - getCurrentTarget
```
@Deprecated
public final Element getCurrentTarget()
```
    Deprecated. use NativeEvent.getCurrentEventTarget() instead
    
    Gets the current target element of this event. This is the element whose listener fired last, not the element which fired the event initially.
    
    Returns:
    the event's current target element
  - getFromElement
```
@Deprecated
public final Element getFromElement()
```
    Deprecated. use NativeEvent.getRelatedEventTarget() instead
    
    Gets the element from which the mouse pointer was moved (only valid for ONMOUSEOVER).
    
    Returns:
    the element from which the mouse pointer was moved
  - getRelatedTarget
```
@Deprecated
public final Element getRelatedTarget()
```
    Deprecated. use NativeEvent.getRelatedEventTarget() instead
    
    Gets the related target for this event.
    
    Returns:
    the related target
  - getRepeat
```
@Deprecated
public final boolean getRepeat()
```
    Deprecated. not supported on all browsers
    
    Gets the key-repeat state of this event.
    
    Returns:
    true if this key event was an auto-repeat
  - getTarget
```
@Deprecated
public final Element getTarget()
```
    Deprecated. use NativeEvent.getEventTarget() instead
    
    Returns the element that was the actual target of the given event.
    
    Returns:
    the target element
  - getToElement
```
@Deprecated
public final Element getToElement()
```
    Deprecated. use NativeEvent.getRelatedEventTarget() instead
    
    Gets the element to which the mouse pointer was moved (only valid for ONMOUSEOUT).
    
    Returns:
    the element to which the mouse pointer was moved
  - getTypeInt
```
public final int getTypeInt()
```
    Gets the enumerated type of this event, as defined by ONCLICK, ONMOUSEDOWN, and so forth.
    
    Returns:
    the event's enumerated type

Class Event

Nested Class Summary

Field Summary

Fields inherited from class com.google.gwt.dom.client.NativeEvent

Constructor Summary

Method Summary

Methods inherited from class com.google.gwt.dom.client.NativeEvent

Methods inherited from class com.google.gwt.core.client.JavaScriptObject

Methods inherited from class java.lang.Object

Field Detail

ONBLUR

ONCHANGE

ONCLICK

ONDBLCLICK

ONERROR

ONFOCUS

ONGESTURECHANGE

ONGESTUREEND

ONGESTURESTART

ONKEYDOWN

ONKEYPRESS

ONKEYUP

ONLOAD

ONLOSECAPTURE

ONMOUSEDOWN

ONMOUSEMOVE

ONMOUSEOUT

ONMOUSEOVER

ONMOUSEUP

ONMOUSEWHEEL

ONPASTE

ONSCROLL

ONTOUCHCANCEL

ONTOUCHEND

ONTOUCHMOVE

ONTOUCHSTART

ONCONTEXTMENU

FOCUSEVENTS

KEYEVENTS

MOUSEEVENTS

TOUCHEVENTS

GESTUREEVENTS

UNDEFINED

handlers

Constructor Detail

Event

Method Detail

addEventPreview

addNativePreviewHandler

as

fireNativePreviewEvent

getCurrentEvent

getEventListener

getEventsSunk

getTypeInt

releaseCapture

removeEventPreview

setCapture

setEventListener

sinkEvents

cancelBubble

getCurrentTarget

getFromElement

getRelatedTarget

getRepeat

getTarget

getToElement

getTypeInt