Android stackoverflow using while loop

Question

I'm using this method to shrink TextView text as it's name suggests:

public static float shrinkTextToFit(String caller, float availableWidth, TextView textView, float startingTextSize, float minimumTextSize) {
    startingTextSize = textView.getTextSize() < startingTextSize ? textView.getTextSize() : startingTextSize;
    Log.i("123", "=========================");
    Log.i("123", caller + " called shrinkTextToFit");
    CharSequence text = textView.getText();
    float textSize = startingTextSize;
    textView.setTextSize(startingTextSize);
    while (!TextUtils.equals(text, (TextUtils.ellipsize(text, textView.getPaint(), availableWidth, TextUtils.TruncateAt.END)))) {
        textSize -= 2;
        Log.i("123", "textSize: " + textSize);
        if ((textSize <= minimumTextSize) || (textSize <= 0)) {
            break;
        } else {
            textView.setTextSize(textSize);
        }
    }
    return textSize;
}

And I'm having a stack-overflow only with this devices (and some times it doesn't happen):

Samsung GT-I9192
Samsung GT-I9300
LG-D290

OS versions: 4.4.2, 4.3

10  at android.widget.TextView.sendAfterTextChanged(TextView.java:8503)
11  at android.widget.TextView$ChangeWatcher.afterTextChanged(TextView.java:10633)
12  at android.text.SpannableStringBuilder.sendAfterTextChanged(SpannableStringBuilder.java:970)
13  at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:497)
14  at android.text.SpannableStringBuilder.append(SpannableStringBuilder.java:247)
15  at android.text.TextUtils.ellipsize(TextUtils.java:1185)
16  at android.text.TextUtils.ellipsize(TextUtils.java:1079)
17  at android.text.TextUtils.ellipsize(TextUtils.java:1054)
18  at app.utils.Utils.float shrinkTextToFit(float,android.widget.TextView,float,float)

I'm calling this function inside TextWatcher afterTextChanged() and yes that could be the problem, but the idea is to shrink the text size while its being inserted.

@Override
public void afterTextChanged(Editable s) {
    mEditText.removeTextChangedListener(mTextWatcher);
    Utils.shrinkTextToFit("watcher", mAvailableWidth, mEditText, 50, 10);
    mEditText.addTextChangedListener(mTextWatcher);
}

Example Logs:

Start to type letters (scroll to read all the log):

08-01 14:48:50.284    watcher called shrinkTextToFit
08-01 14:48:50.676    =========================
08-01 14:48:50.677    watcher called shrinkTextToFit
08-01 14:48:51.749    =========================
08-01 14:48:51.749    watcher called shrinkTextToFit
08-01 14:48:51.749    textSize: 48.0
08-01 14:48:51.750    textSize: 46.0
08-01 14:48:51.751    textSize: 44.0
08-01 14:48:51.752    textSize: 42.0
08-01 14:48:52.500    =========================
08-01 14:48:52.501    watcher called shrinkTextToFit
08-01 14:48:52.501    textSize: 48.0
08-01 14:48:52.501    textSize: 46.0
08-01 14:48:52.501    textSize: 44.0
08-01 14:48:52.501    textSize: 42.0
08-01 14:48:52.501    textSize: 40.0
08-01 14:48:52.503    textSize: 38.0
08-01 14:48:52.504    textSize: 36.0
08-01 14:48:53.013    =========================
08-01 14:48:53.013    watcher called shrinkTextToFit
08-01 14:48:53.013    textSize: 48.0
08-01 14:48:53.013    textSize: 46.0
08-01 14:48:53.013    textSize: 44.0
08-01 14:48:53.014    textSize: 42.0
08-01 14:48:53.015    textSize: 40.0
08-01 14:48:53.015    textSize: 38.0
08-01 14:48:53.015    textSize: 36.0
08-01 14:48:53.016    textSize: 34.0
08-01 14:48:53.017    textSize: 32.0
08-01 14:48:53.020    textSize: 30.0
08-01 14:48:59.948    =========================
08-01 14:48:59.949    watcher called shrinkTextToFit
08-01 14:48:59.949    textSize: 48.0
08-01 14:48:59.949    textSize: 46.0
08-01 14:48:59.949    textSize: 44.0
08-01 14:48:59.949    textSize: 42.0
08-01 14:48:59.950    textSize: 40.0
08-01 14:48:59.950    textSize: 38.0
08-01 14:48:59.950    textSize: 36.0
08-01 14:48:59.950    textSize: 34.0
08-01 14:48:59.951    textSize: 32.0
08-01 14:48:59.951    textSize: 30.0
08-01 14:48:59.951    textSize: 28.0

Start to erase letters:

08-01 14:48:59.953    =========================
08-01 14:48:59.953    watcher called shrinkTextToFit
08-01 14:48:59.954    textSize: 48.0
08-01 14:48:59.954    textSize: 46.0
08-01 14:48:59.954    textSize: 44.0
08-01 14:48:59.954    textSize: 42.0
08-01 14:48:59.954    textSize: 40.0
08-01 14:48:59.954    textSize: 38.0
08-01 14:48:59.954    textSize: 36.0
08-01 14:48:59.954    textSize: 34.0
08-01 14:48:59.954    textSize: 32.0
08-01 14:48:59.954    textSize: 30.0
08-01 14:49:00.116    =========================
08-01 14:49:00.116    watcher called shrinkTextToFit
08-01 14:49:00.116    textSize: 48.0
08-01 14:49:00.117    textSize: 46.0
08-01 14:49:00.117    textSize: 44.0
08-01 14:49:00.117    textSize: 42.0
08-01 14:49:00.117    textSize: 40.0
08-01 14:49:00.117    textSize: 38.0
08-01 14:49:00.117    textSize: 36.0
08-01 14:49:00.121    =========================
08-01 14:49:00.121    watcher called shrinkTextToFit
08-01 14:49:00.121    textSize: 48.0
08-01 14:49:00.121    textSize: 46.0
08-01 14:49:00.121    textSize: 44.0
08-01 14:49:00.121    textSize: 42.0
08-01 14:49:00.284    =========================
08-01 14:49:00.284    watcher called shrinkTextToFit
08-01 14:49:00.288    =========================
08-01 14:49:00.288    watcher called shrinkTextToFit
08-01 14:49:00.444    =========================

What am I doing wrong and how can I improve this solution to prevent this exceptions?

Just a guess, but when you modify the text in your method, this might again lead to your method being called which then modifies the text, which again... — Florian Schaetz, Jul 31 '15 at 10:25
@FlorianSchaetz inside `afterTextChanged()` I'm doing: `removeTextChangedListener(mTextWatcher)`, call my function, and then `addTextChangedListener(mTextWatcher)`. I think this prevents that situation but I might be wrong. — GuilhE, Jul 31 '15 at 10:29
Debugging the app or adding log statements will probably show you what is happening? — Christine, Jul 31 '15 at 15:41
I don't think removing the textchangelistener and re-adding it doesn't solve that problem. You're going to get the call again in the next pass. My guess is you're effectively calling this text change loop constantly without an exit. Although I don't see what in the code provided would cause that (unless `setTextSize()` throws it in to this loop). — DeeV, Jul 31 '15 at 15:42

score 1 · Answer 1 · answered Aug 13 '15 at 17:45

1

I think you should do the math for textsize, and run your setTextSize one time.

Even if you use some kind of temporary view to do the work against, get the size from that. Instead of calling against the view with the eventlistener on it.

answered Aug 13 '15 at 17:45

Justin Mecham

29
2

I'll try that approach and update the post with the results. Thanks ;) – GuilhE Aug 13 '15 at 17:53

score 1 · Accepted Answer · answered Oct 12 '15 at 13:18

I've found the solution, or so it seams, and it's quite odd and strange. So I've noticed something weird wile I was debugging (because for the first time I could reproduce this error):

I've noticed when the text was "green" the text was being "well parsed":

but some times the text wasn't "green", specially if the text was somenthing like "... / ...":

And that was causing the StackOverflow because TextUtils.ellipsize wasn't returning and the debugger was acting a bit strange too.

Changing this:

CharSequence text = textView.getText();

To this:

CharSequence text = textView.getText().toString();

Is the solution.
And now it's working. Thanks IntelliJ for being the best IDE ever :)

Android stackoverflow using while loop

2 Answers2