Package com.google.gwt.user.client.ui

Class AbstractNativeScrollbar

java.lang.Object

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

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

com.google.gwt.user.client.ui.AbstractNativeScrollbar

All Implemented Interfaces:

HasScrollHandlers, HasAttachHandlers, HasHandlers, EventListener, HasVisibility, IsWidget

Direct Known Subclasses:

NativeHorizontalScrollbar, NativeVerticalScrollbar

public abstract class AbstractNativeScrollbar
extends Widget
implements HasScrollHandlers

Abstract parent class for scrollbars implemented using the native browser scrollbars.

Nested Class Summary

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

UIObject.DebugIdImpl, UIObject.DebugIdImplEnabled

Field Summary

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

Constructor	Description
AbstractNativeScrollbar()

Method Summary

Modifier and Type	Method	Description
HandlerRegistration	addScrollHandler(ScrollHandler handler)	Adds a ScrollEvent handler.
static int	getNativeScrollbarHeight()	Get the height of a native horizontal scrollbar.
static int	getNativeScrollbarWidth()	Get the width of a native vertical scrollbar.
protected abstract Element	getScrollableElement()	Get the scrollable element.
static boolean	isScrollbarLeftAlignedInRtl()	Check whether or not the native vertical scrollbar is aligned on the left side of the scrollable element in RTL mode.
protected void	onAttach()	This method is called when a widget is attached to the browser's document.
protected void	onDetach()	This method is called when a widget is detached from the browser's document.

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, onLoad, onUnload, removeFromParent, replaceElement, setLayoutData, setParent, sinkEvents, 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, onEnsureDebugId, 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

Constructor Details

AbstractNativeScrollbar

public AbstractNativeScrollbar()

Method Details

getNativeScrollbarHeight

public static int getNativeScrollbarHeight()

Get the height of a native horizontal scrollbar.

This method assumes that all native scrollbars on the page have the same height.

Returns:

the height in pixels

getNativeScrollbarWidth

public static int getNativeScrollbarWidth()

Get the width of a native vertical scrollbar.

This method assumes that all native vertical scrollbars on the page have the same width.

Returns:

the height in pixels

isScrollbarLeftAlignedInRtl

public static boolean isScrollbarLeftAlignedInRtl()

Check whether or not the native vertical scrollbar is aligned on the left side of the scrollable element in RTL mode.

Returns:

true if left aligned, false if not

addScrollHandler

public HandlerRegistration addScrollHandler(ScrollHandler handler)

Description copied from interface: HasScrollHandlers

Adds a ScrollEvent handler.

Specified by:

addScrollHandler in interface HasScrollHandlers

Parameters:

handler - the scroll handler

Returns:

HandlerRegistration used to remove this handler

getScrollableElement

protected abstract Element getScrollableElement()

Get the scrollable element.

Returns:

the scrollable element

onAttach

protected void onAttach()

Description copied from class: Widget

This method is called when a widget is attached to the browser's document. To receive notification after a Widget has been added to the document, override the Widget.onLoad() method or use Widget.addAttachHandler(com.google.gwt.event.logical.shared.AttachEvent.Handler).

It is strongly recommended that you override Widget.onLoad() or Widget.doAttachChildren() instead of this method to avoid inconsistencies between logical and physical attachment states.

Subclasses that override this method must call super.onAttach() to ensure that the Widget has been attached to its underlying Element.

Overrides:

onAttach in class Widget

See Also:

• Widget.onLoad()
• Widget.doAttachChildren()

onDetach

protected void onDetach()

Description copied from class: Widget

This method is called when a widget is detached from the browser's document. To receive notification before a Widget is removed from the document, override the Widget.onUnload() method or use Widget.addAttachHandler(com.google.gwt.event.logical.shared.AttachEvent.Handler).

It is strongly recommended that you override Widget.onUnload() or Widget.doDetachChildren() instead of this method to avoid inconsistencies between logical and physical attachment states.

Subclasses that override this method must call super.onDetach() to ensure that the Widget has been detached from the underlying Element. Failure to do so will result in application memory leaks due to circular references between DOM Elements and JavaScript objects.

Overrides:

onDetach in class Widget

See Also:

• Widget.onUnload()
• Widget.doDetachChildren()