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Thread: Please help

  1. #1
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    Question Please help

    I have a big problem when creating the calculator in Jcreator.the thing is after running the program, when I press the decimal point for anytime(even more than once) it displays in the text field.I tried to solve this & failed.please can some one give me a solution for this.It's better if you can provide me the codings.

  2. #2
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    Default Re: Please help

    If you want to ignore the decimal point key if there is already a decimal point displayed in the text field, use a DocumentFilter, something like this:
    ...
    JTextField textField = new JTextField();
    PlainDocument doc = new PlainDocument();     // or whatever document type you require
     
    doc.setDocumentFilter(new DocumentFilter() {
        @Override
        public void replace(FilterBypass fb, int offset, int length, String text, AttributeSet attrs)
                throws BadLocationException
        {
            // get document text
            Document currentDoc = fb.getDocument();
            String docText = currentDoc.getText(0, currentDoc.getLength());
     
            // return if both current and new text have a decimal point
            if (text.contains(".") && docText.contains(".")) {
                System.out.println("Decimal point already entered!");
                return;
            }
            // allow the new text
            super.replace(fb, offset, length, text, attrs);
        }
    });
    textField.setDocument(doc);
    If that's not what you wanted, you'll have to explain a bit more clearly.

  3. The Following User Says Thank You to dlorde For This Useful Post:

    prasansani (May 30th, 2010)

  4. #3
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    Default Re: Please help

    Quote Originally Posted by prasansani View Post
    I have a big problem when creating the calculator in Jcreator.the thing is after running the program, when I press the decimal point for anytime(even more than once) it displays in the text field.I tried to solve this & failed.please can some one give me a solution for this.It's better if you can provide me the codings.
    Well, you could try to get it to reset the TF to zero if it's pushed more than once or something.

    Also, what's wrong with that? Just make sure it'll output "Error" or something if the user does that.