net.sf.jguiraffe.gui.builder.components

Class ComponentGroup

java.lang.Object

net.sf.jguiraffe.gui.builder.components.ComponentGroup

public class ComponentGroup
extends Object

This class represents a group of components.

The form builder library supports adding components to logical groups. Logical in this context means that these groups do not have a direct representation on the generated GUI. They exist only during the builder process and can be used to reference components. Examples include constructing radio groups or composite component handlers.

A ComponentGroup instance does not contain the components themselves, but rather their names. For obtaining the corresponding components access to a ComponentBuilderData object is required.

Version:

$Id: ComponentGroup.java 205 2012-01-29 18:29:57Z oheger $

Author:

Oliver Heger

Constructor Summary

Constructors

Constructor and Description
ComponentGroup() Creates a new instance of ComponentGroup.

Method Summary

Modifier and Type	Method and Description
void	addComponent(String name) Adds a component to this group.
static ComponentGroup	createGroup(org.apache.commons.jelly.JellyContext context, String name) Creates a new ComponentGroup instance and stores it in the specified context.
void	enableGroup(ComponentBuilderData data, boolean enabled) Changes the enabled state of this ComponentGroup.
static ComponentGroup	fromBeanContext(BeanContext context, String groupName) Obtains the ComponentGroup with the specified name from the given BeanContext.
static ComponentGroup	fromContext(org.apache.commons.jelly.JellyContext context, String name) Fetches the group with the given name from the specified jelly context.
Map<String,ComponentHandler<?>>	getComponentHandlers(ComponentBuilderData data) Returns a map with the ComponentHandler objects of the components this group refers to.
Set<String>	getComponentNames() Returns a set with the names of all components contained in this group.
Map<String,Object>	getComponents(ComponentBuilderData data) Returns a map with all components this group refers to.
static boolean	groupExists(org.apache.commons.jelly.JellyContext context, String name) Tests whether a group with the specified name exists in the given jelly context.
static boolean	groupExistsInBeanContext(BeanContext context, String groupName) Tests whether a group with the specified name exists in the given BeanContext.
static void	storeGroup(org.apache.commons.jelly.JellyContext context, String name, ComponentGroup group) Stores a component group in the jelly context under a given name.

Methods inherited from class java.lang.Object

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

Constructor Detail

ComponentGroup

public ComponentGroup()

Creates a new instance of ComponentGroup.

Method Detail

getComponentNames

public Set<String> getComponentNames()

Returns a set with the names of all components contained in this group. The order of elements in the set corresponds to the order in which the components have been added to this group.

Returns:

a set with the names of all contained components

addComponent

public void addComponent(String name)

Adds a component to this group.

Parameters:

name - the name of the component to add

getComponents

public Map<String,Object> getComponents(ComponentBuilderData data)
                                 throws FormBuilderException

Returns a map with all components this group refers to. This method looks up all component names in the specified ComponentBuilderData object. The resulting map contains the names of the components as keys and the corresponding component objects as values. If a component name cannot be resolved, a FormBuilderException exception is thrown.

Parameters:

data - the ComponentBuilderData object (must not be null)

Returns:

a map with all components that belong to this group

Throws:

FormBuilderException - if a component cannot be resolved

IllegalArgumentException - if the ComponentBuilderData object is null

getComponentHandlers

public Map<String,ComponentHandler<?>> getComponentHandlers(ComponentBuilderData data)
                                                     throws FormBuilderException

Returns a map with the ComponentHandler objects of the components this group refers to. This method works like getComponents(ComponentBuilderData), but the resulting map contains the ComponentHandlers rather than the components themselves.

Parameters:

data - the ComponentBuilderData object (must not be null)

Returns:

a map with all component handlers that belong to this group

Throws:

FormBuilderException - if a component cannot be resolved

IllegalArgumentException - if the ComponentBuilderData object is null

enableGroup

public void enableGroup(ComponentBuilderData data,
                        boolean enabled)
                 throws FormBuilderException

Changes the enabled state of this ComponentGroup. This method obtains the ComponentHandler objects for all components that belong to this group. Then it calls the setEnabled() method on all these handlers.

Parameters:

data - the ComponentBuilderData object (must not be null)

enabled - the new enabled flag

Throws:

FormBuilderException - if a component cannot be resolved

IllegalArgumentException - if the ComponentBuilderData object is null

See Also:

getComponentHandlers(ComponentBuilderData)

fromContext

public static ComponentGroup fromContext(org.apache.commons.jelly.JellyContext context,
                                         String name)
                                  throws NoSuchElementException

Fetches the group with the given name from the specified jelly context. If the group does not exist, an exception will be thrown.

Parameters:

context - the jelly context (must not be null

name - the name of the desired group

Returns:

the group with this name

Throws:

IllegalArgumentException - if the context is null

NoSuchElementException - if there is no such group

groupExists

public static boolean groupExists(org.apache.commons.jelly.JellyContext context,
                                  String name)

Tests whether a group with the specified name exists in the given jelly context. Note that ComponentGroup objects are not stored under their name in the context, but a specific prefix is used. So always this method has to be used to check the existence of a group rather than testing the context directly.

Parameters:

context - the jelly context

name - the name of the group

Returns:

true if there is such a group, false otherwise

Throws:

IllegalArgumentException - if the context is null

storeGroup

public static void storeGroup(org.apache.commons.jelly.JellyContext context,
                              String name,
                              ComponentGroup group)

Stores a component group in the jelly context under a given name.

Parameters:

context - the context

name - the group's name

group - the group to store (if null , the group will be removed if it exists)

createGroup

public static ComponentGroup createGroup(org.apache.commons.jelly.JellyContext context,
                                         String name)
                                  throws FormBuilderException

Creates a new ComponentGroup instance and stores it in the specified context. This is a convenience method which performs the following steps:

1. It checks whether already a group with the specified name exists in the context. If this is the case, an exception is thrown.
2. Otherwise a new ComponentGroup instance is created.
3. The new instance is stored in the context under the specified name.
4. The newly created instance is returned.

Parameters:

context - the Jelly context (must not be null

name - the name of the new ComponentGroup (must not be null)

Returns:

the newly created ComponentGroup instance

Throws:

FormBuilderException - if a group with this name already exists

IllegalArgumentException - if the group name or the context is null

fromBeanContext

public static ComponentGroup fromBeanContext(BeanContext context,
                                             String groupName)

Obtains the ComponentGroup with the specified name from the given BeanContext. This method is similar to fromContext(JellyContext, String), but the ComponentGroup is resolved from a BeanContext object. This can be useful if the group is to be obtained after a builder operation. In this case, the Jelly context may not be available directly, but it can be accessed through the BeanContext returned by the builder.

Parameters:

context - the BeanContext

groupName - the name of the group to be obtained

Returns:

the corresponding ComponentGroup instance

Throws:

IllegalArgumentException - if the BeanContext is null

InjectionException - if the group cannot be resolved

groupExistsInBeanContext

public static boolean groupExistsInBeanContext(BeanContext context,
                                               String groupName)

Tests whether a group with the specified name exists in the given BeanContext. Works like groupExists(JellyContext, String), but checks the given BeanContext.

Parameters:

context - the BeanContext

groupName - the name of the group in question

Returns:

a flag whether this ComponentGroup can be found in this BeanContext

Throws:

IllegalArgumentException - if the BeanContext is null