StringIndexOutOfBoundsException in breakText()

[GoogleCodeExporter]

This code is bug prone (line 514, method 

while( input.charAt(pos) != ' ' ) {
    pos--;
}

Under some cases, if there's no space at all, you can easily go below the 
range. The while() should be rather:

while( (pos >= 0) && (input.charAt(pos) != ' ' ) )

Original issue reported on code.google.com by [email protected] on 27 Feb 2012 at 11:17

[GoogleCodeExporter]

The error still occurs even with the above proposed fix. How about this?

if (input.substring(0, pos).matches("\\s") {
  while ((pos >= 0) && (input.charAt(pos) != ' ')) {
    pos--;
  }
}

Not sure about the performance implications though..

Original comment by [email protected] on 12 Sep 2012 at 8:33

[GoogleCodeExporter]

I have tried all solutions provided above but this problem is still not solved, 
this is buggy code.

Original comment by mohdtausif25 on 13 Sep 2012 at 7:22

[GoogleCodeExporter]

[deleted comment]

[GoogleCodeExporter]

why do we have to find the blank space using the while loop?
cant we use lastindex of instead?


i tried to fix the error using the code below. but then the string started to 
overlap and then i modified a bit more and now i get a blank string
else {
   // Backup until we are at a space.
   pos = input.lastIndexOf(" ");
   // This line includes up to the space.
   if(-1 != pos){
             if(maxWidth > pos){
             mLines.add(new int[] { posStartThisLine, pos });
         }else{
                 mLines.add(new int[] { posStartThisLine, maxWidth });
         pos = maxWidth;
          }                              
     }                       
    }

i cant work through it as i cant understand the logic used here, can anyone 
help me with the same

Original comment by [email protected] on 21 Feb 2013 at 7:46

[GoogleCodeExporter]

i think i figured out a work around, it works for me, but more testing is 
required.

// Start breaking.
                int posStartThisLine = -1;
                float lengthThisLine = 0.0f;
                boolean breakWords = true;
                int pos = 0;
                int backup = 0;
                while (pos < input.length()) {


                    if (posStartThisLine == -1) {
                        posStartThisLine = pos;
                    }

                    if (mLines.size() == maxLines) {
                        mRequiredEllipsis = true;
                        break;
                    }

                    float widthOfChar = tp.measureText(input.charAt(pos) + "");
                    boolean newLineRequired = false;

                    // Check for a new line character or if we've run over max width.
                    if (input.charAt(pos) == '\n') {
                        newLineRequired = true;

                        // We want the current line to go up to the character right before the
                        // new line char, and we want the next line to start at the char after
                        // this new line char.
                        mLines.add(new int[] { posStartThisLine, pos-1 });
                    }
                    else if (lengthThisLine + widthOfChar >= maxWidth) {
                        newLineRequired = true;
                        // We need to backup if we are in the middle of a word.
                        if (input.charAt(pos) == ' ' || breakWords == false) {
                            // Backup one character, because it doesn't fit on this line.
                            pos--;

                            // So this line includes up to the character before the space.
                            mLines.add(new int[] { posStartThisLine, pos });
                        }
                        else {
                            // Backup until we are at a space.
                            backup = pos;
                            while( input.charAt(pos) != ' ' ) {
                                pos--;
                                if(pos == -1){
                                    break;
                                }
                            }
//                         while( (pos >= 0) && (input.charAt(pos) != ' ' ) ) {
//                              pos--;
//                          }
                            // This line includes up to the space.
                            if(-1 != pos){
                                mLines.add(new int[] { posStartThisLine, pos });
                                }else{
                                    mLines.add(new int[] { posStartThisLine,backup });

                            }                       
                        }
                    }

                    if (newLineRequired) {
                        // The next cycle should reset the position if it sees it's -1 (to whatever i is).
                        posStartThisLine = -1;

                        // Reset line length for next iteration.
                        lengthThisLine = 0.0f;

                        // When we get to the last line, subtract the width of the ellipsis.
                        if (mLines.size() == maxLines - 1) {
                            maxWidth -= (mLengthEllipsis + mLengthEllipsisMore);
                            // We also don't need to break on a full word, it'll look a little
                            // cleaner if all breaks on the final lines break in the middle of
                            // the last word.
                            breakWords = false;                        
                           }
                        if(pos == -1){
                            breakWords = true;
                            pos = backup;
                        }else{
                            breakWords = false;
                        }

                    }
                    else {
                        lengthThisLine += widthOfChar;

                        // If we're on the last character of the input string, add on whatever we have leftover.
                        if (pos == input.length() - 1) {
                            mLines.add(new int[] { posStartThisLine, pos });
                        }
                    }

                    pos++;
                }

Original comment by [email protected] on 21 Feb 2013 at 11:57