com.google.gwt.user.cellview.client

Class Header<H>

java.lang.Object

com.google.gwt.user.cellview.client.Header<H>

Type Parameters:

H - the Cell type

Direct Known Subclasses:

SafeHtmlHeader, TextHeader

public abstract class Header<H>
extends Object

A table column header or footer.

Constructor Summary

Constructors

Constructor and Description
Header(Cell<H> cell) Construct a Header with a given Cell.

Method Summary

Modifier and Type	Method and Description
Cell<H>	getCell() Return the Cell responsible for rendering items in the header.
String	getHeaderStyleNames() Get extra style names that should be applied to a cell in this header.
Object	getKey() Get the key for the header value.
abstract H	getValue() Return the header value.
void	onBrowserEvent(Cell.Context context, Element elem, NativeEvent event) Handle a browser event that took place within the header.
boolean	onPreviewColumnSortEvent(Cell.Context context, Element elem, NativeEvent event) Preview a browser event that may trigger a column sort event.
void	render(Cell.Context context, SafeHtmlBuilder sb) Render the header.
void	setHeaderStyleNames(String styleNames) Set extra style names that should be applied to every cell in this header.
void	setUpdater(ValueUpdater<H> updater) Set the ValueUpdater.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, toString

Constructor Detail

Header

public Header(Cell<H> cell)

Construct a Header with a given Cell.

Parameters:

cell - the Cell responsible for rendering items in the header

Method Detail

getCell

public Cell<H> getCell()

Return the Cell responsible for rendering items in the header.

Returns:

the header Cell

getHeaderStyleNames

public String getHeaderStyleNames()

Get extra style names that should be applied to a cell in this header. May be overridden to get value dependent styles by calling getValue().

Returns:

the extra styles of the given row in a space-separated list, or null if there are no extra styles for the cells in this header

getKey

public Object getKey()

Get the key for the header value. By default, the key is the same as the value. Override this method to return a custom key.

Returns:

the key associated with the value

getValue

public abstract H getValue()

Return the header value.

Returns:

the header value

onBrowserEvent

public void onBrowserEvent(Cell.Context context,
                           Element elem,
                           NativeEvent event)

Handle a browser event that took place within the header.

Parameters:

context - the context of the header

elem - the parent Element

event - the native browser event

onPreviewColumnSortEvent

public boolean onPreviewColumnSortEvent(Cell.Context context,
                                        Element elem,
                                        NativeEvent event)

Preview a browser event that may trigger a column sort event. Return true if the CellTable should proceed with sorting the column. Subclasses can override this method to disable column sort for some click events, or particular header/footer sections.

This method will be invoked even if the header's cell does not consume a click event.

Parameters:

context - the context of the header

elem - the parent Element

event - the native browser event

Returns:

true if the CellTable should continue respond to the event (i.e., if this is a click event on a sortable column's header, fire ColumnSortEvent). False if the CellTable should stop respond to the event.

render

public void render(Cell.Context context,
                   SafeHtmlBuilder sb)

Render the header.

Parameters:

context - the context of the header

sb - a SafeHtmlBuilder to render into

setHeaderStyleNames

public void setHeaderStyleNames(String styleNames)

Set extra style names that should be applied to every cell in this header.

If you want to apply style names based on the header value, override #getHeaderStyleNames(Object) directly.

Parameters:

styleNames - the extra style names to apply in a space-separated list, or null if there are no extra styles for this cell

setUpdater

public void setUpdater(ValueUpdater<H> updater)

Set the ValueUpdater.

Parameters:

updater - the value updater to use