asked on

JTextField

if I used a JTextField, is there any way that I can limit how many characters can be inputed to the text field? I want a max of 5 chars to be entered into the text field, and I dont want to have to check the length and pop up a dialog telling the user they've exceeded 5 chars, I just want to flat out limit it.

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moirafish

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mrquija

ASKER

Moirafish, thank you for your wonderful help. Question, how does your class know how long to construct the textfield? Is there anyway that I can change the width of the jtextfield to whatever I specify?

mrquija

ASKER

Nevamind, I used

super.setColumns(int width)

to do what I needed to do. Thanks again

moirafish

Thanks for the points :-)

The easiest thing to do for the width is just set the column number of the JTextField..

in the constructor
public MaxCharsField(int maxchars)
do
super(maxchars);

this means the preferred size of the JTextField will fit maxchars characters
but since the default font of JTextField is variable font, maxchars characters doesn’t always fit the field…
eg: @@@@@ would fill a maxchars 5 field but 11111 would half fill it.

you could set the font to a fixed font such as in MaxCharsField constructor do:

Font monoFont = new Font("Monospaced", Font.PLAIN, 12);
this.setFont(monoFont);

& then the sizing seems to work better if you make maxchars+1 columns, ie.
super(maxchars+1);

hope you find something that works!
Moira