net.sf.jguiraffe.gui.forms

Interface ComponentHandler<T>

Type Parameters:

T - the data type used by this component handler

All Known Subinterfaces:

CompositeComponentHandler<T,S>, ListComponentHandler, ProgressBarHandler, StaticTextHandler, TableHandler, TextHandler, TreeHandler

All Known Implementing Classes:

AbstractCompositeComponentHandler, AbstractRadioButtonHandler, BooleanRadioButtonHandler, ComponentHandlerImpl, DefaultRadioButtonHandler, SwingButtonHandler

public interface ComponentHandler<T>

Definition of an interface for accessing GUI components independently from their type.

This interface represents a Java GUI widget like a text field or a checkbox. There will be concrete implementations for real components, which implement data exchange.

The form framework uses implementations of this interface to transfer data from and to GUI components. The details of this data transfer are hidden by concrete implementations. This makes it possible for instance to read a complete form and store the entered data in a bean.

Version:

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

Author:

Oliver Heger

Method Summary

Modifier and Type	Method and Description
Object	getComponent() Returns a reference to the real component that is wrapped by this component handler.
T	getData() Returns the data of the wrapped component.
Object	getOuterComponent() Returns the outer most component, which is the component to be added to the enclosing container.
Class<?>	getType() Returns the data type used by this component.
boolean	isEnabled() Returns a flag whether this component is enabled.
void	setData(T data) Sets the data of the wrapped component.
void	setEnabled(boolean f) Allows to set the enabled flag.

Method Detail

getComponent

Object getComponent()

Returns a reference to the real component that is wrapped by this component handler.

Returns:

the underlying component

getOuterComponent

Object getOuterComponent()

Returns the outer most component, which is the component to be added to the enclosing container. It may sometimes be necessary that for one GUI widget not a single component can be created, but multiple ones are necessary. An example would be a text area in Swing, which is comprised of the Swing text area itself plus a scroll pane object. In this example the outer component would be the scroll pane, the component (returned by getComponent() would be the text area. The mechanism with the outer component allows a GUI library specific implementation to construct composite components for certain complex widgets, but from the client's view they behave like a single one.

Returns:

the outer component

getData

T getData()

Returns the data of the wrapped component. This is the data the user has entered, e.g. text.

Returns:

the component's data

setData

void setData(T data)

Sets the data of the wrapped component. This method can be used to initialize GUI widgets, e.g. to set default text at start up.

Parameters:

data - the data to set

getType

Class<?> getType()

Returns the data type used by this component. The Class object returned here determines, which type is allowed for the getData() and setData() methods. It depends on the concrete GUI component. For text fields it will be a string, for checkboxes probably a boolean etc.

Returns:

the data type used by this component

isEnabled

boolean isEnabled()

Returns a flag whether this component is enabled.

Returns:

the enabled flag

setEnabled

void setEnabled(boolean f)

Allows to set the enabled flag. A disabled component cannot be focused and does not accept user input.

Parameters:

f - the value of the enabled flag