Package com.google.gwt.user.client

Class Event

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.

  • Field Details

    • ONBLUR

      public static final int ONBLUR
      Fired when an element loses keyboard focus.
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    • ONCHANGE

      public static final int ONCHANGE
      Fired when the value of an input element changes.
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    • ONCLICK

      public static final int ONCLICK
      Fired when the user clicks on an element.
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    • ONDBLCLICK

      public static final int ONDBLCLICK
      Fired when the user double-clicks on an element.
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    • ONERROR

      public static final int ONERROR
      Fired when an image encounters an error.
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    • ONFOCUS

      public static final int ONFOCUS
      Fired when an element receives keyboard focus.
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    • ONGESTURECHANGE

      public static final int ONGESTURECHANGE
      Fired when the user gesture changes.
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    • ONGESTUREEND

      public static final int ONGESTUREEND
      Fired when the user gesture ends.
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    • ONGESTURESTART

      public static final int ONGESTURESTART
      Fired when the user gesture starts.
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    • ONKEYDOWN

      public static final int ONKEYDOWN
      Fired when the user depresses a key.
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    • ONKEYPRESS

      public static final int ONKEYPRESS
      Fired when the a character is generated from a keypress (either directly or through auto-repeat).
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    • ONKEYUP

      public static final int ONKEYUP
      Fired when the user releases a key.
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    • ONLOAD

      public static final int ONLOAD
      Fired when an element (normally an IMG) finishes loading.
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    • ONLOSECAPTURE

      public static final int ONLOSECAPTURE
      Fired when an element that has mouse capture loses it.
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    • ONMOUSEDOWN

      public static final int ONMOUSEDOWN
      Fired when the user depresses a mouse button over an element.
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    • ONMOUSEMOVE

      public static final int ONMOUSEMOVE
      Fired when the mouse is moved within an element's area.
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    • ONMOUSEOUT

      public static final int ONMOUSEOUT
      Fired when the mouse is moved out of an element's area.
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    • ONMOUSEOVER

      public static final int ONMOUSEOVER
      Fired when the mouse is moved into an element's area.
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    • ONMOUSEUP

      public static final int ONMOUSEUP
      Fired when the user releases a mouse button over an element.
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    • ONMOUSEWHEEL

      public static final int ONMOUSEWHEEL
      Fired when the user scrolls the mouse wheel over an element.
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    • ONPASTE

      public static final int ONPASTE
      Fired when the user pastes text into an input element.
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    • ONSCROLL

      public static final int ONSCROLL
      Fired when a scrollable element's scroll offset changes.
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    • ONTOUCHCANCEL

      public static final int ONTOUCHCANCEL
      Fired when the user cancels touching an element.
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    • ONTOUCHEND

      public static final int ONTOUCHEND
      Fired when the user ends touching an element.
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    • ONTOUCHMOVE

      public static final int ONTOUCHMOVE
      Fired when the user moves while touching an element.
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    • ONTOUCHSTART

      public static final int ONTOUCHSTART
      Fired when the user starts touching an element.
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    • ONCONTEXTMENU

      public static final int ONCONTEXTMENU
      Fired when the user requests an element's context menu (usually by right-clicking).
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    • FOCUSEVENTS

      public static final int FOCUSEVENTS
      A bit-mask covering both focus events (focus and blur).
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    • KEYEVENTS

      public static final int KEYEVENTS
      A bit-mask covering all keyboard events (down, up, and press).
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    • 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.
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    • TOUCHEVENTS

      public static final int TOUCHEVENTS
      A bit-mask covering all touch events (start, move, end, cancel).
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    • GESTUREEVENTS

      public static final int GESTUREEVENTS
      A bit-mask covering all gesture events (start, change, end).
      See Also:

    • 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.
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    • 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 Details

    • 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 Details

    • 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(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:

    • 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