CODEWITHSUNDEEP
javaswingjtextarea
FirmView
FirmView

Reputation: 3150

getting the changed lines jtextarea

I am doing a text editor which needs custom validation. Since, the content is very large i thought of validating only the lines which are changed or added. The validation errors are shown by the line numbers, like "Line: 10 cannot exceed 15 chars"

  1. For single lines, every time the user changes iam validating the current line, keeping the row number as reference. - solved

  2. The user can copy text and paste - multiple lines. for this, thought of getSelectionStart and getSelectionEnd. Is there a way of getting the row numbers from getSelectionStart and getSelectionEnd, so i can get starting row and ending row?

After some exprements i thought selecting the lines which are visible will solve my above statated No. 2 problem.

Rectangle would solve in getting the x, y cordinates of viewable region and wrote the code, i think i am almost finished. But, i am not getting the end row number correctly,

      [code]
    //editor is jtextarea
      Rectangle r = editor.getVisibleRect();
      Point top = new Point(r.x, r.y);
      Point bottom = new Point(r.x, r.y + r.height);
      int startRow = editor.viewToModel(top); /* this is working. it shows 0 at           initial, then after the line reaches the end and when the scrollbar gets displayed, it shows the numbers correctly, 1,2,3...*/
     int endRow = editor.viewToModel(bottom); /* this is not working, when we type, it is taking column numbers */
     editorLineNo.setText(" START ROW " + startRow + " END ROW" + endRow);
     [/code]

     What is needed is, start row number and end row number from the viewable area  of jtextarea

Upvotes: 2

Views: 277

Answers (2)

StanislavL
StanislavL

Reputation: 57421

Utilities.getRowStart() / getRowEnd() passing the offsets.

Upvotes: 3

camickr
camickr

Reputation: 324207

Is there a way of getting the row numbers ...

Element root = textArea.getDocument().getDefaultRootElement();
int row = root.getElementIndex( selectionStart ) + 1;

Upvotes: 4

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