Visual Java Overview
Visual Java enables you to easily design graphical user interfaces
(GUIs) and integrate them into your projects.
The Visual menu in the Java WorkShop menu bar is described
in The Visual Menu.
Types of GUIs
You can use Visual Java to build GUIs for both applets and standalone projects.
You can create three different types of GUI containers:
- Frames
Frames are top-level application windows with a title and a
border. A frame should be used as the main container for:
- A standalone application
- An applet whose GUI exists outside of the browser,
not within the page
Frames are the only types of containers to which you
can add menu bars.
- Panels
Panels are containers that do not create separate windows
of their own. A panel should be used as the main container
for applets that display their GUIs in a browser page or
applet viewer.
- Dialog Boxes
Dialog boxes are pop-up windows that are activated from frames and
panels.
The panel is the default main container in Visual Java.
When you start a new project, Visual Java automatically
opens a layout window with a panel GUI in it. Choose
Visual=>Main Container to change the type of a selected
GUI.
If you run a project whose top-level container is a panel
as a standalone application, Visual Java automatically
creates a frame in which the panel can run.
When you create a container it is entered in the container list
(the large text area to the right of the component palette).
Selecting a container in the list brings its layout window
to the front of the display.
Layout
Visual Java uses a grid system that enables you to place
GUI components, such as buttons and text fields, in the
cells of a grid. You can nest grids within cells
of other grids. The components provided on the Visual Java
palette are analogs of Java AWT (Abstract Windowing
Toolkit) components.
The grid-based system provides a layout paradigm in which
the GUI components are laid out relative to each
other (as opposed to some other systems in which components are
laid out in absolute positions). Relative layout
works well in the Java multiplatform environment because
components in the different native window toolkits vary in size and appearance.
Components
All Visual Java components (including containers) have
attributes associated with them that you can use to modify
the components. You can change the attributes by selecting
the component in the layout grid and choosing
Visual=>Edit Attributes.
Select containers (frames, panels, and dialog boxes) by
clicking in the blue area around the grid or by clicking on
their names in the containers list (next to the component
palette on the Visual Java control panel).
All of the Visual Java components, including their
special attributes are described in Visual Java Components.
Attributes common to most components are described in Laying Out GUI Interfaces.
There are two shortcut methods for opening the Attributes Editor:
- Select the component, and then click on the
icon in the Visual Java tool bar.
- Click the right mouse button on the edge of a selected component.
Some customized components are also available using the
Custom button and menu. They are described in Custom Button and Menu.
Operations
Visual Java provides an operations editor that assists you
in associating event filters and actions (callbacks) to your
components. The operations editor is available from the
attributes editor. See
Operations (Filters and Actions) for more information.
Generate the GUI
Once you have laid out the GUI to your satisfaction, you
can choose Visual=>Generate to generate the
Java source code that implements the GUI. This process is
described in Generate Java Source
Code.
The generated code is based on the information displayed in
your layout, it includes changes made since you last saved
the layout.
Note that the GUI is automatically generated from your most
recently saved layout whenever you build the project using
the Build Manager. It is generally unnecessary for you to
explicitly generate the interface.
Build the Project
After you have saved the GUI interface, use the
Build Manager to compile the project. The Build Manager
automatically generates Java source files from the most
recently saved layout file
(<ProjectName>.gui
), and adds
the new source files to the project.
Run the Project
After you have built the project, you can run it by clicking
on the Project Tester icon
If your program is a standalone application, or if it is an
applet that will run on Netscape Navigator, please read
about Visual Java Runtime Classes.
Groups and Shadows
Visual Java components are implemented as shadow
classes (wrappers) of AWT components.
Groups are collections of shadow classes and other groups.
Applications created using Visual Java are actually
groups. Each Java WorkShop project contains one (and only
one) group, however, projects can contain other projects.
For information about groups and shadows, see Using Groups and
Shadows (Basic) and Using Groups
and Shadows (Advanced).
Visual Java API Documentation
The following are links to documents that describe
the Visual Java API:
See also:
- The Visual Menu
- Visual Java Components
- Laying Out GUI Interfaces
- Generating Java Source Code
- Adding Operations (Filters and
Actions)
- Visual Java Runtime Classes
- Creating Menus
- Adding Custom Components and Windows
- Using Groups and Shadows (Basic)
- Using Groups and Shadows (Advanced)
- Visual Java API Documentation
- Visual Java
Runtime Packages
- Class
Hierarchy
- Index of
all Fields and Methods