org.eclipse.rwt.lifecycle
Class WidgetUtil

java.lang.Object
  org.eclipse.rwt.lifecycle.WidgetUtil

public final class WidgetUtil
extends java.lang.Object

This is a helper class to obtain different aspects for a widget related to the handling of widgets in RAP.

Since:

1.0

Field Summary

static java.lang.String	CUSTOM_VARIANT Used to mark a widget as belonging to a custom variant using Widget.setData.
static java.lang.String	CUSTOM_WIDGET_ID Note: This constant is provisional and subject to change without further notice.
static java.lang.String	ENABLE_UI_TESTS Note: This constant is provisional and subject to change without further notice.

Method Summary

static Widget	find(Composite root, java.lang.String id) This method searches for a widget with the given id within the widget hierachy starting at root.
static IWidgetAdapter	getAdapter(Widget widget) Returns the according IWidgetAdapter for a specified widget.
static java.lang.String	getId(Widget widget) Returns the id of the given widget that is used to identify the widget on the client.
static AbstractWidgetLCA	getLCA(Widget widget) Returns the AbstractWidgetLCA instance for this widget.
static java.lang.String	getVariant(Widget widget) Returns the widget variant defined for the given widget using Widget.setData().

Methods inherited from class java.lang.Object

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

Field Detail

CUSTOM_VARIANT

public static final java.lang.String CUSTOM_VARIANT

Used to mark a widget as belonging to a custom variant using Widget.setData. For more information on custom widget variants, see the RAP help on theming.

Since:

1.1

See Also:

Widget.setData(String,Object), Constant Field Values

CUSTOM_WIDGET_ID

public static final java.lang.String CUSTOM_WIDGET_ID

Note: This constant is provisional and subject to change without further notice.

By default, the widget-id returned by IWidgetAdapter.getId() is an automatically generated value that is session-wide unique. A custom id can be assigned by using the Widget#setData(String, Object) method and using this constant for the key argument and a string that denotes the new id as the data argument. In addition the system property denoted by ENABLE_UI_TESTS must be set to true.

The id must only contain characters that are valid according to the W3C recommendation for id and name attributes.

It is the clients' responsibility to choose a unique id. Assigning an id that is used by another widget will lead to indeterministic behavior.

The following code would assign the id 'myId' to the widget:

   Widget widget = new ...
   widget.setData( WidgetUtil.CUSTOM_WIDGET_ID, "myId" );
 

Since:

1.1

See Also:

Widget.setData(String,Object), getId(Widget), ENABLE_UI_TESTS, Constant Field Values

ENABLE_UI_TESTS

public static final java.lang.String ENABLE_UI_TESTS

Note: This constant is provisional and subject to change without further notice.

If a system property with this name is set to true, the UI testing support is activated. For all widgets that are rendered to the client, the HTML id attribute is set.

In conjunction with CUSTOM_WIDGET_ID, each widget can be assigned a custom, more human-readable, identifier that is independant if the order in which widgets are created.

Since:

1.1

See Also:

CUSTOM_WIDGET_ID, Constant Field Values

Method Detail

getAdapter

public static IWidgetAdapter getAdapter(Widget widget)

Returns the according IWidgetAdapter for a specified widget.

Parameters:

widget - the widget

Returns:

the IWidgetAdapter instance

getId

public static java.lang.String getId(Widget widget)

Returns the id of the given widget that is used to identify the widget on the client.

Parameters:

widget - the widget to obtain the id for, must not be null

Returns:

the id for the given widget

getVariant

public static java.lang.String getVariant(Widget widget)

Returns the widget variant defined for the given widget using Widget.setData().

Parameters:

widget - the widget whose variant is requested

Returns:

the variant or null if no variant has been specified for the given widget

getLCA

public static AbstractWidgetLCA getLCA(Widget widget)

Returns the AbstractWidgetLCA instance for this widget.

Parameters:

widget - the widget to obtain the life cycle adapter from

Returns:

the life cycle adapter for the given widget

find

public static Widget find(Composite root,
                          java.lang.String id)

This method searches for a widget with the given id within the widget hierachy starting at root.

Parameters:

root - the root widget where to start the search

id - the id of the widget to search for

Returns:

the widget or null if there was no widget found with the given id within the widget hierarchy