Swing Hacks

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Chapter 7, Text

#51 Write Backward Text

HACK

(flipping them around the axis, so that the pixels furthest to the right are

now furthest to the left), and translating by the width of the component (so

the pixels move from negative coordinates, where they wouldn’t be seen,

back into positive space). This transformation is illustrated in Figure 7-8.

Mirror, Mirror on the Wall

The following main( ) method provides a trivial setup of a frame in which

you can view the backward

JLabel. The result is shown in Figure 7-9.

public static void main (String[] args) {

BackwardsJLabel field =

new BackwardsJLabel ("Through the looking glass");

JFrame frame = new JFrame("Backwards Text");

frame.getContentPane( ).add (field);

frame.pack( );

frame.setVisible(true);

}

Because the transformation is simple and limited to the paint( ) method, it

seems like something you could do anywhere. You can easily create a

BackwardsJTextField that uses exactly the same paint( ) method in a trivi-

ally overridden

JTextField—honestly, it’s so trivial that it’s not worth list-

ing here; just set up the trivial “call

super” constructors, copy over this

paint( ) method, and tweak the main( ) method to show the text field

instead of the label. The result will look like Figure 7-10.

Figure 7-8. Mirror image as scale-and-translate AffineTransform

Figure 7-9. JLabel rendered as mirror image

Figure 7-10. JTextField rendered as mirror image ...