In this magercise, you'll learn about adding an Icon, or
small image, to a JButton and placing components within a
JFrame. You'll create two buttons with images on them and
respond to the selection of each. In addition to physically selecting
the button with a mouse, you'll support keyboard selection through
accelerators.
Magercise 3 Prerequisites
None.
Skeleton Code
FirstSwing.java
Resources
Tasks
-
Import the swing package.
-
Define two
Icon instance variables in class
FirstSwing called bee and dog.
Then, load the bee.gif and dog.gif image files.
-
Create buttons
top and bottom with icons
bee and dog.
-
Add an accelerator for each button.
-
When working with a
JFrame, you add components to an internal
area of the JFrame, instead of the actual frame. Get a reference
to this Container via the getContentPane() method.
-
To have the buttons appear one on top of each other, modify the skeleton's
constructor so that it sets the content's layout to
GridLayout with
2 rows and 1 column.
-
Add the buttons to the grid layout.
-
Save everything and compile the program. Then run it to see the results.
Clicking a button or using the accelerator displays a message to the screen.
As a precaution, the Save command appends a "1"
to the end of the filename you want to save. This can help
prevent you from accidently overwriting your source code.
Note: The accelerator key is ALT under Win32 and Solaris.
Where help exists, the task numbers above are linked to the
step-by-step
help page.
The following JavaTM source file represents
a solution to this Magercise.
