com.vaadin.client.widget.escalator
Class ScrollbarBundle

java.lang.Object
  com.vaadin.client.widget.escalator.ScrollbarBundle

All Implemented Interfaces:

DeferredWorker

Direct Known Subclasses:

ScrollbarBundle.HorizontalScrollbarBundle, ScrollbarBundle.VerticalScrollbarBundle

public abstract class ScrollbarBundle
extends java.lang.Object
implements DeferredWorker

An element-like bundle representing a configurable and visual scrollbar in one axis.

Since:

7.4

Author:

Vaadin Ltd

See Also:

ScrollbarBundle.VerticalScrollbarBundle, ScrollbarBundle.HorizontalScrollbarBundle

Nested Class Summary

static class	ScrollbarBundle.Direction The orientation of the scrollbar.
static class	ScrollbarBundle.HorizontalScrollbarBundle A representation of a single horizontal scrollbar.
static class	ScrollbarBundle.VerticalScrollbarBundle A representation of a single vertical scrollbar.
static class	ScrollbarBundle.VisibilityChangeEvent
static interface	ScrollbarBundle.VisibilityHandler A means to listen to when the scrollbar handle in a ScrollbarBundle either appears or is removed.

Field Summary

protected boolean	isInvisibleScrollbar
protected Element	root
protected Element	scrollSizeElement

Method Summary

com.google.gwt.event.shared.HandlerRegistration	addScrollHandler(ScrollHandler handler) Adds a scroll handler to the scrollbar bundle.
com.google.gwt.event.shared.HandlerRegistration	addVisibilityHandler(ScrollbarBundle.VisibilityHandler handler) Adds handler for the scrollbar handle visibility.
protected void	forceScrollbar(boolean enable) Force the scrollbar to be visible with CSS.
abstract ScrollbarBundle.Direction	getDirection() Returns the scroll direction of this scrollbar bundle.
Element	getElement() Gets the root element of this scrollbar-composition.
protected com.google.gwt.event.shared.HandlerManager	getHandlerManager()
double	getOffsetSize() Gets the length of the scrollbar
double	getScrollbarThickness() Gets the scrollbar's thickness.
double	getScrollPos() Gets the scroll position of the scrollbar in the axis the scrollbar is representing.
double	getScrollSize() Gets the amount of pixels the scrollbar needs to be able to scroll through.
protected abstract void	internalForceScrollbar(boolean enable)
abstract java.lang.String	internalGetOffsetSize()
protected abstract java.lang.String	internalGetScrollbarThickness() Gets the scrollbar's thickness as defined in the DOM.
protected abstract int	internalGetScrollPos() Retrieves the element's scroll position (scrollTop or scrollLeft).
protected abstract java.lang.String	internalGetScrollSize()
protected abstract void	internalSetOffsetSize(double px) Modifies root's dimensions in the axis the scrollbar is representing.
protected abstract void	internalSetScrollbarThickness(double px) Modifies scrollSizeElement's dimensions in the opposite axis to what the scrollbar is representing.
protected abstract void	internalSetScrollPos(int px) Modifies the element's scroll position (scrollTop or scrollLeft).
protected abstract void	internalSetScrollSize(double px) Modifies scrollSizeElement's dimensions in such a way that the scrollbar is able to scroll a certain number of pixels in the axis it is representing.
boolean	isLocked() Checks whether the scrollbar bundle is locked or not.
boolean	isWorkPending() Checks whether there are operations pending for this widget or connector that must be executed before reaching a steady state.
void	onLoad() Should be called whenever this bundle is attached to the DOM (typically, from the onLoad of the containing widget).
void	recalculateMaxScrollPos()
void	setLocked(boolean isLocked) Locks or unlocks the scrollbar bundle.
void	setOffsetSize(double px) Sets the length of the scrollbar.
void	setScrollbarThickness(double px) Sets the scrollbar's thickness.
void	setScrollPos(double px) Sets the scroll position of the scrollbar in the axis the scrollbar is representing.
void	setScrollPosByDelta(double delta) Modifies the scroll position of this scrollbar by a number of pixels.
void	setScrollSize(double px) Sets the amount of pixels the scrollbar needs to be able to scroll through.
void	setStylePrimaryName(java.lang.String primaryStyleName) Sets the primary style name
boolean	showsScrollHandle() Checks whether the scrollbar's handle is visible.

Methods inherited from class java.lang.Object

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

Field Detail

root

protected final Element root

scrollSizeElement

protected final Element scrollSizeElement

isInvisibleScrollbar

protected boolean isInvisibleScrollbar

Method Detail

internalGetScrollSize

protected abstract java.lang.String internalGetScrollSize()

setStylePrimaryName

public void setStylePrimaryName(java.lang.String primaryStyleName)

Sets the primary style name

Parameters:

primaryStyleName - The primary style name to use

getElement

public final Element getElement()

Gets the root element of this scrollbar-composition.

Returns:

the root element

setScrollPosByDelta

public final void setScrollPosByDelta(double delta)

Modifies the scroll position of this scrollbar by a number of pixels.

Note: Even though double values are used, they are currently only used as integers as large int (or small but fast long). This means, all values are truncated to zero decimal places.

Parameters:

delta - the delta in pixels to change the scroll position by

internalSetOffsetSize

protected abstract void internalSetOffsetSize(double px)

Modifies root's dimensions in the axis the scrollbar is representing.

Parameters:

px - the new size of root in the dimension this scrollbar is representing

setOffsetSize

public final void setOffsetSize(double px)

Sets the length of the scrollbar.

Parameters:

px - the length of the scrollbar in pixels

forceScrollbar

protected void forceScrollbar(boolean enable)

Force the scrollbar to be visible with CSS. In practice, this means to set either overflow-x or overflow-y to " scroll" in the scrollbar's direction.

This is an IE8 workaround, since it doesn't always show scrollbars with overflow: auto enabled.

internalForceScrollbar

protected abstract void internalForceScrollbar(boolean enable)

getOffsetSize

public double getOffsetSize()

Gets the length of the scrollbar

Returns:

the length of the scrollbar in pixels

internalGetOffsetSize

public abstract java.lang.String internalGetOffsetSize()

setScrollPos

public final void setScrollPos(double px)

Sets the scroll position of the scrollbar in the axis the scrollbar is representing.

Note: Even though double values are used, they are currently only used as integers as large int (or small but fast long). This means, all values are truncated to zero decimal places.

Parameters:

px - the new scroll position in pixels

onLoad

public void onLoad()

Should be called whenever this bundle is attached to the DOM (typically, from the onLoad of the containing widget). Used to ensure the DOM scroll position is maintained when detaching and reattaching the bundle.

Since:

7.4.1

internalSetScrollPos

protected abstract void internalSetScrollPos(int px)

Modifies the element's scroll position (scrollTop or scrollLeft).

Note: The parameter here is a type of integer (instead of a double) by design. The browsers internally convert all double values into an integer value. To make this fact explicit, this API has chosen to force integers already at this level.

Parameters:

px - integer pixel value to scroll to

getScrollPos

public final double getScrollPos()

Gets the scroll position of the scrollbar in the axis the scrollbar is representing.

Returns:

the new scroll position in pixels

internalGetScrollPos

protected abstract int internalGetScrollPos()

Retrieves the element's scroll position (scrollTop or scrollLeft).

Note: The parameter here is a type of integer (instead of a double) by design. The browsers internally convert all double values into an integer value. To make this fact explicit, this API has chosen to force integers already at this level.

Returns:

integer pixel value of the scroll position

internalSetScrollSize

protected abstract void internalSetScrollSize(double px)

Modifies scrollSizeElement's dimensions in such a way that the scrollbar is able to scroll a certain number of pixels in the axis it is representing.

Parameters:

px - the new size of scrollSizeElement in the dimension this scrollbar is representing

setScrollSize

public final void setScrollSize(double px)

Sets the amount of pixels the scrollbar needs to be able to scroll through.

Parameters:

px - the number of pixels the scrollbar should be able to scroll through

getScrollSize

public double getScrollSize()

Gets the amount of pixels the scrollbar needs to be able to scroll through.

Returns:

the number of pixels the scrollbar should be able to scroll through

internalSetScrollbarThickness

protected abstract void internalSetScrollbarThickness(double px)

Modifies scrollSizeElement's dimensions in the opposite axis to what the scrollbar is representing.

Parameters:

px - the dimension that scrollSizeElement should take in the opposite axis to what the scrollbar is representing

setScrollbarThickness

public final void setScrollbarThickness(double px)

Sets the scrollbar's thickness.

If the thickness is set to 0, the scrollbar will be treated as an "invisible" scrollbar. This means, the DOM structure will be given a non-zero size, but getScrollbarThickness() will still return the value 0.

Parameters:

px - the scrollbar's thickness in pixels

internalGetScrollbarThickness

protected abstract java.lang.String internalGetScrollbarThickness()

Gets the scrollbar's thickness as defined in the DOM.

Returns:

the scrollbar's thickness as defined in the DOM, in pixels

getScrollbarThickness

public final double getScrollbarThickness()

Gets the scrollbar's thickness.

This value will differ from the value in the DOM, if the thickness was set to 0 with setScrollbarThickness(double), as the scrollbar is then treated as "invisible."

Returns:

the scrollbar's thickness in pixels

showsScrollHandle

public boolean showsScrollHandle()

Checks whether the scrollbar's handle is visible.

In other words, this method checks whether the contents is larger than can visually fit in the element.

Returns:

true iff the scrollbar's handle is visible

recalculateMaxScrollPos

public void recalculateMaxScrollPos()

getHandlerManager

protected com.google.gwt.event.shared.HandlerManager getHandlerManager()

addVisibilityHandler

public com.google.gwt.event.shared.HandlerRegistration addVisibilityHandler(ScrollbarBundle.VisibilityHandler handler)

Adds handler for the scrollbar handle visibility.

Parameters:

handler - the ScrollbarBundle.VisibilityHandler to add

Returns:

HandlerRegistration used to remove the handler

setLocked

public void setLocked(boolean isLocked)

Locks or unlocks the scrollbar bundle.

A locked scrollbar bundle will refuse to scroll, both programmatically and via user-triggered events.

Parameters:

isLocked - true to lock, false to unlock

isLocked

public boolean isLocked()

Checks whether the scrollbar bundle is locked or not.

Returns:

true iff the scrollbar bundle is locked

getDirection

public abstract ScrollbarBundle.Direction getDirection()

Returns the scroll direction of this scrollbar bundle.

Returns:

the scroll direction of this scrollbar bundle

addScrollHandler

public com.google.gwt.event.shared.HandlerRegistration addScrollHandler(ScrollHandler handler)

Adds a scroll handler to the scrollbar bundle.

Parameters:

handler - the handler to add

Returns:

the registration object for the handler registration

isWorkPending

public boolean isWorkPending()

Description copied from interface: DeferredWorker

Checks whether there are operations pending for this widget or connector that must be executed before reaching a steady state.

Specified by:

isWorkPending in interface DeferredWorker