Package com.w4t

This is the base package for the W4 Toolkit library, containing elementary components, layout manager and interface definitions.


Interface Summary
Area Defines the interface for parts of a WebContainer, when it is divided and layouted by a WebLayout.
Concealer A class implements the Concealer interface to indicate that a developement tool should leave the internal structure of a instance of this class unchanged.
MessageForm This Interface has to be implemented by a WebForm which is used as a message form in a w4t application.
SimpleComponent WebComponents which are a representation of simple HTML tags implement this interface.
Validatable classes that implement this are validatable, which means that they can be asked to validate their internals from outside.
ValidatableComponent classes that implement this can be asked to validate their internals (for instance the value of a Webcomponent) against a Validator which can be set.
Validator classes that implement this know how to validate a given input string.
WebErrorForm This Interface has to be implemented by a WebForm which is used as an error form in a W4 Toolkit application.
WebLayout Defines the interface for classes that know how to layout WebContainers.

Class Summary
Browser Subclasses of Browser represent vendor-specific and version-specific information about the web browser that is used on the client side to display the pages from the current session.
ColumnEventAdapter Deprecated. No longer supported.
ColumnProperties A properties class for columns on a WebDataBaseTable.
Command the abstract superclass of all Command objects handled in the W4TContexts command repository.
Decorator This abstract class is a Wrapper for a WebComponent.
Message Messages are added to the request's message queue by means of the W4TContext and displayed in a message box (a special pop up window).
Position This is a helping class for the constraints used in the WebGridLayout.
Style This is a helping class for W4 components to create Cascading Style Sheets entries.
W4TContext The W4TContext is a central place to go for functionality that applies to or retrieves information from the whole web application, like opening pooled connections, loading WebForms, getting global statistics etc.
WebAnchor A WebAnchor is a component which branches to a location that is reachable for the displaying browser, as URL of files, websites, or other WebAnchors on the same form.
WebBorderComponent A WebBorderComponent contains a WebComponent as content, which is displayed with borders around it.
WebBorderLayout Defines the WebBorderLayout.
WebButton A WebButton is used for submitting forms.
WebCardLayout A WebCardLayout treats each WebComponent in the WebContainer to which this layout belongs as a card.
WebCheckBox A WebCheckBox is a graphical WebComponent which can be either in an "on" (checked) or "off" (unchecked) state.
WebComponent The abstract superclass of all WebComponents.
WebComponentProperties This is the superclass of all property setting classes like Style, WindowProperties etc.
WebComponentStatistics A WebComponentStatistics encapsulates statistical information about the web application that is currently running: how many WebComponents of which types have been created, how many sessions currently are on the web application, memory usage, application uptime etc.
WebConnection The WebConnection class is the counterpart of the java.sql.Connection for W4 Toolkit applications.
WebContainer A WebContainer is a WebComponent, which contains other WebComponents.
WebDataBaseSource A WebDataBaseSource is a com.w4t.WebDataSource implementation which provides data of database query results to databound WebComponents.
WebDataBaseSourceExt A WebDataBaseSourceExt is a WebDataBaseSource which implements the java.sql.ResultSet Interface.
WebDataBaseTable A WebDataBaseTable is a configurable databound table.
WebDataBoundComponent WebDataBoundComponent is the abstract super class of all databound WebComponents.
WebDataSource WebDataSource objects are used to provide bound components automatically with data from the underlying model classes.
WebFlowLayout Defines the WebFlowLayout.
WebForm WebForm is the top-level container in all W4 Toolkit applications.
WebGridLayout Defines the WebGridLayout.
WebImage A WebImage encapsulates the HTML <img> element.
WebLabel A WebLabel is used for placing Strings into a Container.
WebObject Implements some basic functionality which is common to every WebObject based component.
WebPanel This is the simplest container class.
WebRadioButton A WebRadioButton is a s a graphical WebComponent which can be either in an "on" (checked) or "off" (unchecked) state.
WebRadioButtonGroup A WebRadioButtonGroup is a logical grouping of WebRadioButtons.
WebSelect A WebSelect presents a list of items for selection as a pop-up (default) or a as a list box with scrollbars.
WebText A WebText is a text WebComponent that allows the editing of a single line of text.
WebTextArea A WebTextArea is a text WebComponent that allows the editing of a multiple line of text.
WindowProperties WindowProperties encapsulates information about browser windows, like size, position etc..

Package com.w4t Description

This is the base package for the W4 Toolkit library, containing elementary components, layout manager and interface definitions.

The only top-level container in W4 Toolkit applications is the WebForm. See the documentation of this class in order to get started.


Texts that appear on the user interface of a W4 Toolkit application can be internationalized by using the following technique:

Property URIs

All UI texts (i.e. the values of WebLabels, labels of WebButtons, tree leaves and nodes etc.) as well as some other String settings, like the character set on a WebForm, can be optionally set as a property URI specifying a key in a resource bundle.

During rendering the property URI is resolved by the library and the value in the resource bundle is rendered into the HTML output in place of the property URI.

URIs used within W4 Toolkit have the format


or slightly more formally expressed:

  propertyURI    ::= <scheme>://<propertyKey>@<bundleBaseName>
  scheme         ::= property
  name           ::= <identifier>
  bundleBaseName ::= <identifier>

See also RFC 2396 - Uniform Resource Identifiers (URI): Generic Syntax.

You can also access the resolver from within Java code via W4TContext.resolve(String).


W4 Toolkit uses the locale that is sent by the browser for resolving. Which file of the resource bundle is used is then determined by the standard rules (see the ResourceBundle.getBundle() documentation). The locale of the browser can be queried by calling W4TContext.getBrowser().getLocale().

The locale that is to be used for resolving can be overriden by the TODO# method.