A method to truncate a string to fit within a TextView in a specific number of lines.

Text Truncate for Text View

    private boolean truncated = false;
    private int numLines = 0;
    private static final String mEllipsis = "\u2026";
    /**
     * Truncate a string to fit within a TextView in a certain number of lines.
     */
    protected String truncate(String original, TextView tv, int maxLines) {

        StringBuffer buffer = new StringBuffer();
        numLines = 0;

        //calculate the available width of the TextView
        int tvWidth = tv.getMeasuredWidth() - tv.getCompoundPaddingLeft() - tv.getCompoundPaddingRight();

        //first split the string into multiple lines delimited by \n, then iterate through each line
        String[] lines = original.split("\n");

        Log.d(TAG, "maxLines=" + maxLines);
        for (int i = 0; i < lines.length; i++) {
            String line = lines[i];
            Log.d(TAG, "current line=" + line);

            //measure the total width this line would take up without any wrapping
            float lineWidth = tv.getPaint().measureText(line);

            //count the number of wrapped lines added by the current line if wrapped within the given width
            numLines += Math.ceil(lineWidth / tvWidth);

            Log.d(TAG, "numLines=" + numLines);
            //this line will not fit in the TextView, need to truncate the line itself
            if (numLines > maxLines) {
                //calculate the number of lines that are still available in the TextView
                int linesLeft = maxLines - (numLines - (int)Math.ceil(lineWidth / tvWidth));

                //fit the current line within the remaining number of lines, truncating and adding ellipsis if needed
                String truncatedLine = TextUtils.ellipsize(line, tv.getPaint(), (tvWidth - tv.getPaint().measureText(mEllipsis)) * linesLeft, TruncateAt.END).toString();

                //if this line was truncated
                if (!truncatedLine.equals(line)) {
                    buffer.append(truncatedLine);
                    //if this line was able to fit within the remaining number of lines
                } else {
                    buffer.append(line);
                }
                //the overall string was truncated
                truncated = true;
                break;

                //this line will fit within and fill up all the lines remaining in the TextView
            } else if (numLines == maxLines) {
                buffer.append(line);

                //if there are more lines after this
                if (i < lines.length-1) {
                    truncated = true;
                }
                break;

                //this line will fit within but NOT fill up all the lines remaining (there will be empty lines after after this)
            } else { // if (numLines < maxLines)
                buffer.append(line);
                //if there are more lines and the next line is not just an empty line
                if (i < lines.length-2 && !lines[i+1].equals("")) {
                    buffer.append("\n");
                }
                continue;
            }
        }
        return buffer.toString();
    }