Android NumberPicker with Formatter doesn't format on first rendering

Question

I have a NumberPicker that has a formatter that formats the displayed numbers either when the NumberPicker spins or when a value is entered manually. This works fine, but when the NumberPicker is first shown and I initialize it with setValue(0) the 0 does not get formatted (it should display as "-" instead of 0). As soon as I spin the NumberPicker from that point on everything works.

How can I force the NumberPicker to format always - Both on first rendering and also when I enter a number manually with the keyboard?

This is my formatter

public class PickerFormatter implements Formatter {

 private String mSingle;
 private String mMultiple;

 public PickerFormatter(String single, String multiple) {
    mSingle = single;
    mMultiple = multiple;
 }

 @Override
 public String format(int num) {
    if (num == 0) {
        return "-";
    }
    if (num == 1) {
        return num + " " + mSingle;
    }
    return num + " " + mMultiple;
 }

}

I add my formatter to the picker with setFormatter(), this is all I do to the picker.

    picker.setMaxValue(max);
    picker.setMinValue(min);
    picker.setFormatter(new PickerFormatter(single, multiple));
    picker.setWrapSelectorWheel(wrap);

added some code, but the code is not the issue, the numberpicker just doesnt execute the code on first render — A. Steenbergen, Jul 17 '13 at 21:00
im a bit new to this but can you call format() from the constructor function? I don't think it is called initially. Would that help? — Ankit Aggarwal, Jul 18 '13 at 05:51
I've just googled it and found this issue report on the Android project: http://code.google.com/p/android/issues/detail?id=35482 Let's wait for a fix. — georgepiva, Sep 04 '13 at 18:14

score 29 · Answer 1 · edited May 23 '17 at 10:31

29

dgel's solution doesn't work for me: when I tap on the picker, formatting disappears again. This bug is caused by input filter set on EditText inside NumberPicker when setDisplayValues isn't used. So I came up with this workaround:

Field f = NumberPicker.class.getDeclaredField("mInputText");
f.setAccessible(true);
EditText inputText = (EditText)f.get(mPicker);
inputText.setFilters(new InputFilter[0]);

edited May 23 '17 at 10:31

Community

1
1

answered Nov 07 '14 at 09:12

torvin

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1

Worked for me on API 25. Thanks! – rjr-apps Dec 21 '17 at 21:39

score 27 · Answer 2 · edited May 23 '17 at 12:02

27

I also encountered this annoying little bug. Used a technique from this answer to come up with a nasty but effective fix.

NumberPicker picker = (NumberPicker)view.findViewById(id.picker);
picker.setMinValue(1);
picker.setMaxValue(5);
picker.setWrapSelectorWheel(false);
picker.setFormatter(new NumberPicker.Formatter() {
    @Override
    public String format(int value) {
        return my_formatter(value);
    }
});

try {
    Method method = picker.getClass().getDeclaredMethod("changeValueByOne", boolean.class);
    method.setAccessible(true);
    method.invoke(picker, true);
} catch (NoSuchMethodException e) {
    e.printStackTrace();
} catch (IllegalArgumentException e) {
    e.printStackTrace();
} catch (IllegalAccessException e) {
    e.printStackTrace();
} catch (InvocationTargetException e) {
    e.printStackTrace();
}

Calling that private changeValueByOne method immediately after instantiating my number picker seems to kick the formatter enough to behave how it should. The number picker comes up nice and clean with the first value formatted correctly. Like I said, nasty but effective.

edited May 23 '17 at 12:02

Community

1
1

answered Sep 30 '13 at 21:20

dgel

16,352
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13

Somehow in Android programming you have to use nasty hacks very often. – A. Steenbergen Oct 12 '13 at 15:36
1

can't believe, that this is not yet fixed. – Sebastian Hojas Mar 16 '14 at 18:46
3

this bug was reported 2 years ago... are you kidding me google? still an issue on android 4.4.2 – serine Jun 04 '14 at 14:24
2

Doesn't work for me: whenever I tap on the picker, formatting disappears again. I came up with another [solution](http://stackoverflow.com/a/26797732/332528) – torvin Nov 07 '14 at 09:12
4

Indeed - this is still present in Marshmallow :( – Nathan Osman Oct 13 '15 at 06:25
1

Still not fixed, but the method changeValueByOne() is missing in newer SDKs, so this exact solution no longer works. :-/ – osxdirk Jan 12 '16 at 16:49
Today 11th Nov 2016 Still issue exists :-( – Maveňツ Nov 01 '16 at 12:16
It's nice to have some good guys saving you a lot of trouble like this=) – RexSplode Mar 06 '17 at 13:49
5

Android 7.1.1 and the bug seems to be completely unnoticed still. – Andrew No Apr 20 '17 at 01:23
8

Elon Musk launched a tesla into the space and this issue still exists. – Karl-John Chow Apr 26 '18 at 09:11

score 12 · Answer 3 · answered Mar 04 '14 at 21:59

12

I had the same problem and I used the setDisplayedValues() method instead.

int max = 99;
String[] values = new String[99];
values[0] = “-” + mSingle
values[1] = 
for(int i=2; i<=max; i++){
    makeNames[i] = String.valueOf(i) + mMultiple;
}
picker.setMinValue(0);
picker.setMaxValue(max);
picker.setDisplayedValues(values)

This doesn't allow the user to set the value manually in the picker though.

answered Mar 04 '14 at 21:59

Lumbi

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From the [Android Developer Reference](https://developer.android.com/reference/android/widget/NumberPicker.html): Note: The length of the displayed values array set via setDisplayedValues(String[]) must be equal to the range of selectable numbers which is equal to getMaxValue() - getMinValue() + 1. – MikeJfromVA Apr 05 '18 at 17:06

Sebastian · Answer 4 · 2018-03-07T21:45:38.120

The following solution worked out for me for APIs 18-26 without using reflection, and without using setDisplayedValues().

It consists of two steps:

Make sure the first element shows by setting it's visibility to invisible (I used Layout Inspector to see the difference with when it shows, it's not logical but View.INVISIBLE actually makes the view visible).

private void initNumberPicker() {
 // Inflate or create your BugFixNumberPicker class
 // Do your initialization on bugFixNumberPicker...

 bugFixNumberPicker.setFormatter(new NumberPicker.Formatter() {
    @Override
    public String format(final int value) {
        // Format to your needs
        return aFormatMethod(value);
    }
 });

 // Fix for bug in Android Picker where the first element is not shown
 View firstItem = bugFixNumberPicker.getChildAt(0);
  if (firstItem != null) {
    firstItem.setVisibility(View.INVISIBLE);
  }
}

Subclass NumberPicker and make sure no click events go through so the glitch where picker elements disapear on touch can't happen.

public class BugFixNumberPicker extends NumberPicker {

 public BugFixNumberPicker(Context context) {
    super(context);
 }

 public BugFixNumberPicker(Context context, AttributeSet attrs) {
    super(context, attrs);
 }

 public BugFixNumberPicker(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
 }

 @Override
 public boolean performClick() {
    return false;
 }

 @Override
 public boolean performLongClick() {
    return false;
 }

 @Override
 public boolean onInterceptTouchEvent(MotionEvent event) {
    return false;
 }
}

Nikolai · Answer 5 · 2020-02-25T12:46:50.810

6

Here's my solution based on answers by torvin and Sebastian. You don't have to subclass anything or use reflection.

View editView = numberPicker.getChildAt(0);

if (editView instanceof EditText) {
    // Remove default input filter
    ((EditText) editView).setFilters(new InputFilter[0]);
}

edited Feb 25 '20 at 12:46

answered Jan 07 '19 at 23:18

Nikolai

821
3
17
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1

Thanks for this solution this worked for me using databindings, a numberpicker and a formatter also including unicode signs. – Dimitri Williams Dec 13 '21 at 20:51

score 4 · Answer 6 · edited Dec 11 '13 at 19:05

Calling the private method changeValueByOne() via reflection as described in an earlier answer works for me on API Level 16 (Android 4.1.2 and up), but it does not seem to help on API Level 15 (Android 4.0.3), however!

What works for me on API Level 15 (and up) is to use your own custom formatter to create String array and pass that with the method setDisplayedValues() to the number picker.

See also: Android 3.x and 4.x NumberPicker Example

Christopher Chua · Answer 7 · 2018-05-29T23:38:33.540

4

The answer provided by NoActivity worked for me but I only had to do:

View firstItem = bugFixNumberPicker.getChildAt(0);
if (firstItem != null) {
  firstItem.setVisibility(View.INVISIBLE);
}

to fix the issue. I did not need to subclass NumberPicker. I did not see the issue where picker elements disappear on touch.

edited May 29 '18 at 23:38

answered May 29 '18 at 23:31

Christopher Chua

181
1
8

I can confirm the formatted elements disappear on touch (tested on Lollipop). – Nikolai Jan 07 '19 at 23:09
This is the best working answer, (for me) the accepted one works as well, but using with compose , the text color disappears. – Narek Hayrapetyan Dec 27 '22 at 15:03

score 3 · Accepted Answer · answered Jan 06 '21 at 21:01

3

Kotlin version based on Nikolai's answer

private fun initNumberPicker() {
    nrPicker.children.iterator().forEach {
        if (it is EditText) it.filters = arrayOfNulls(0)    // remove default input filter
    }
}

answered Jan 06 '21 at 21:01

Emanuel Moecklin

28,488
11
69
85

score 1 · Answer 9 · answered Nov 04 '14 at 12:00

1

I managed to fix it by calling

picker.invalidate();

just after setting the formatter.

answered Nov 04 '14 at 12:00

user1504495

666
8
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score 0 · Answer 10 · answered Oct 25 '19 at 19:16

Improved Nikolai answer if selected index is not 0. Not to great for performances but fix the problem..

for(index in numberPicker.minValue..numberPicker.maxValue) {

        val editView = numberPicker.getChildAt(index-numberPicker.minValue)
        if (editView != null && editView is EditText) {
            // Remove default input filter
            (editView as EditText).filters = arrayOfNulls(0)
        }
    }

Android NumberPicker with Formatter doesn't format on first rendering

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