Java Reference
In-Depth Information
Packages > <default package>
node (Fig. 25.6). If you specified a package name for the
app class in Fig. 25.5, then that package's name will appear rather than
<default package>
.
Expanded node
Collapsed node
Fig. 25.6
|
NetBeans
Projects
window.
NetBeans creates and opens three files for a
JavaFX FXML Application
project:
•
Welcome.fxml
—This file contains the FXML markup for the GUI. By default,
the IDE creates a GUI containing a
Button
and a
Label
.
•
Welcome.java
—This is the main class that creates the GUI from the FXML file
and displays the GUI in a window.
•
WelcomeController.java
—This is the class in which you'd define the GUI's
event handlers that allow the app to respond to user interactions with the GUI.
In Section 25.5, when we present an app with event handlers, we'll discuss the main app
class and the controller class in detail. For the
Welcome
app, you will not edit any of these
files in NetBeans, so you can close them. You do not need the
WelcomeController.java
file in this app, so you can right click the file in the
Projects
window and select
Delete
to
remove it. Click
Yes
in the confirmation dialog to delete the file.
One way to use an image in your app is to add its file to the project, then display it on an
ImageView
. The
bug.png
image you'll use for this app is located in the
images
subfolder
of this chapter's examples folder. Locate the
images
folder on your file system, then drag
bug.png
onto the project's
<default package>
node to add the file to the project.
You'll now open JavaFX Scene Builder so that you can create this app's GUI. To do so,
right click
Welcome.fxml
in the
Projects
window, then select
Open
to view the FXML file
in Scene Builder (Fig. 25.7).
Deleting the Default Controls
The FXML file provided by NetBeans contains a default GUI consisting of a
Button
con-
trol and a
Label
control. The
Welcome
app will not use these default controls, so you can
delete them. To do so, click each in the content panel (or in the
Hierarchy
window at the
bottom-left of Scene Builder's window), then press the
Backspace
or
Delete
key. In each
case, Scene Builder displays the warning “
Some components have an fx:id. Do you really
want to delete them?
”. This means that there could be Java code in the project that refers