Java Reference
In-Depth Information
areavailablepriortocalling
pack()
,andchangingthemaftercalling
pack()
would
require another call to
pack()
to ensure that the GUI is properly sized.
Compile
Listing 7-6
and run this application.
Figure 7-13
shows the resulting GUI.
Figure 7-13.
A tooltip appears when you move the mouse cursor over a textfield.
Note
TempVerter
demonstrates some of Swing's many components, which are
located in the
javax.swing
package. Other components that you'll find useful in-
clude
JScrollPane
(Swing'sversionof
ScrollPane
),
JTextArea
(Swing'sver-
sion of
TextArea
), and
JOptionPane
(a class that makes it easy to pop up a
standard dialog box that prompts users for a value or informs them of something).
JOptionPane
declares
showConfirmDialog()
,
showInputDialog()
,
showMessageDialog()
,and
showOptionDialog()
classmethodstoaskcon-
firmingquestions(yes/no/cancel),promptforinput,telltheuseraboutsomethingthat
has happened, and combine confirmation with input and message display.
TempVerter Meets JLayer
Suppose you plan to distribute your Swing application as shareware (see
ht-
tp://en.wikipedia.org/wiki/Shareware
)
andwanttodisplayatranslucent
UNREGISTEREDmessageovertheGUIuntiltheuserregisterstheircopy.Youcould
accomplishthistaskbyworkingwiththeglasspanedirectly,oryoucouldworkwiththe
javax.swing.JLayer
class, which is new in Java 7.
JLayer
'sJavadocdescribesthisclassas“auniversaldecoratorforSwingcompon-
ents, which enables you to implement various advanced painting effects as well as re-
ceive notifications of all
AWTEvent
s generated within its borders.”
JLayer
works
with a glass pane on your behalf.