Android NumberPicker: Set min, max, default from XML

Question

Is there a way to set the minimum, maximum and default values of a NumberPicker from the XML Layout?

I'm doing it from within the Activity code:

np = (NumberPicker) findViewById(R.id.np);
np.setMaxValue(120);
np.setMinValue(0);
np.setValue(30);

XML is obviously more appropriate , because it defines property, not behaviour.

Is there a way to set these using the XML layout?

You might need to Customize NumberPicker and then use it MyNumberPicker everywhere...and in the Constructor of MyNumberPicker get all attribute set and set values... — MKJParekh, Sep 07 '12 at 13:02
@MKJParekh do you know how to set setMaxValue setMinValue for Time picker? http://stackoverflow.com/questions/20188983/how-to-set-the-setmaxvalue-setminvalue-for-time-picker-dailog-fragment — LOG_TAG, Nov 25 '13 at 10:01

score 60 · Accepted Answer · edited Oct 08 '16 at 21:56

60

I had the same problem, this is how I solved it (according to the comment of MKJParekh):

I created my own NumberPicker-Class

package com.exaple.project;

import android.annotation.TargetApi;
import android.content.Context;
import android.os.Build;
import android.util.AttributeSet;
import android.widget.NumberPicker;

@TargetApi(Build.VERSION_CODES.HONEYCOMB)//For backward-compability
public class MyNumberPicker extends NumberPicker {

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

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

    public MyNumberPicker(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        processAttributeSet(attrs);
    }
    private void processAttributeSet(AttributeSet attrs) {
        //This method reads the parameters given in the xml file and sets the properties according to it
        this.setMinValue(attrs.getAttributeIntValue(null, "min", 0));
        this.setMaxValue(attrs.getAttributeIntValue(null, "max", 0));
    }
}

Now you can use this NumberPicker in your xml layout file

<com.exaple.project.myNumberPicker
    android:id="@+id/numberPicker1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:orientation="vertical"
    max="100"
    min="1" />

Thanks to MKJParekh for his useful comment

edited Oct 08 '16 at 21:56

Defuera

5,356
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answered Jan 05 '13 at 17:19

MazeChaZer

1,228
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4

Works great, thanks for sharing. Pay attention when using the graphical layout editor in Eclipse: if you change anything here, the custom properties like min and max will get deleted and you have to add them manually again. – pgruetter May 13 '14 at 20:15
3

Note that it is good to define the custom XML attributes in `res/values/attrs.xml` as described in the [docs](https://developer.android.com/training/custom-views/create-view.html#customattr). This also enables IDEs / layout editors to recognize the custom attributes. The docs also say the `AttributeSet` shouldn't be used directly (as here), instead one should retrieve a `TypedArray`. – user905686 Sep 21 '16 at 21:24
Thanks for sharing. Very surprised Google "forgot" to place these fundamental properties into the base class. – TomDK Aug 21 '19 at 03:46
thanks a lot, you can also override setValue so you can set inside XML file. – Mohamed AbdelraZek Nov 04 '19 at 18:29
@MazeChaZer - I think [my answer](https://stackoverflow.com/a/48219853/2957169) should just be a comment under yours. If you want to merge it into your answer, then I will delete mine. – charles-allen Oct 18 '21 at 00:26

score 10 · Answer 2 · answered Feb 04 '21 at 04:48

10

You can try this:

<NumberPicker
  android:id="@+id/number_picker"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  app:minValue="@{0}"
  app:maxValue="@{120}"
  app:value="@{30}"/>

This works as part of Android Databinding. So, you might want to set it to true in your app level build.gradle.

android {
    ...

    dataBinding {
        enabled true
    }
}

answered Feb 04 '21 at 04:48

Namitha Reval

551
1
7
13

ERROR:activity_main.xml:27: AAPT: error: attribute minValue (aka com.example.autovolumeadjusterbyspeed:minValue) not found. – Ronen Festinger Apr 28 '22 at 18:20
Is dataBinding enabled to true in build.gradle? – Namitha Reval May 04 '22 at 07:56
yes, it fails in build time. – Ronen Festinger May 04 '22 at 10:48

score 7 · Answer 3 · edited Oct 16 '21 at 23:18

Here is an updated version that follows the Android Docs
(and thus supports theming & Android Studio designer preview)

values/attrs.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <declare-styleable name="NumberPickerWithXml">
        <attr name="maxValue" format="integer" />
        <attr name="minValue" format="integer" />
        <attr name="defaultValue" format="integer" />
    </declare-styleable>

</resources>

NumberPickerWithXml.kt:

package com.example.library.ui

import android.content.Context
import android.util.AttributeSet
import android.widget.NumberPicker
import com.example.library.ui.R

class NumberPickerWithXml : NumberPicker {

    constructor(context: Context) : super(context)

    constructor(context: Context, attrs: AttributeSet) : super(context, attrs) {
        processXmlAttributes(attrs)
    }

    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int) : super(context, attrs, defStyleAttr) {
        processXmlAttributes(attrs, defStyleAttr)
    }

    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int, defStyleRes: Int) : super(context, attrs, defStyleAttr, defStyleRes) {
        processXmlAttributes(attrs, defStyleAttr, defStyleRes)
    }

    private fun processXmlAttributes(attrs: AttributeSet, defStyleAttr: Int = 0, defStyleRes: Int = 0) {
        val attributes = context.theme.obtainStyledAttributes(attrs, R.styleable.NumberPickerWithXml, defStyleAttr, defStyleRes)

        try {
            this.minValue = attributes.getInt(R.styleable.NumberPickerWithXml_minValue, 0)
            this.maxValue = attributes.getInt(R.styleable.NumberPickerWithXml_maxValue, 0)
            this.value = attributes.getInt(R.styleable.NumberPickerWithXml_defaultValue, 0)
        } finally {
            attributes.recycle()
        }
    }

}

...or NumberPickerWithXml.java (untested):

package com.example.library.ui

import android.content.Context;
import android.util.AttributeSet;
import android.widget.NumberPicker;
import com.example.library.ui.R;

public class NumberPickerWithXml extends NumberPicker {

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

    public NumberPickerWithXml(Context context, AttributeSet attrs) {
        super(context, attrs);
        processXmlAttributes(attrs, 0, 0);
    }

    public NumberPickerWithXml(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        processXmlAttributes(attrs, defStyleAttr, 0);
    }

    public NumberPickerWithXml(Context context, AttributeSet attrs, int: defStyleAttr, int: defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        processXmlAttributes(attrs, defStyleAttr, defStyleRes);
    }

    private void processXmlAttributes(AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        TypedArray attributes = getContext().getTheme().obtainStyledAttributes(attrs, R.styleable.NumberPickerWithXml, defStyleAttr, defStyleRes);

        try {
            this.setMinValue(attributes.getInt(R.styleable.NumberPickerWithXml_minValue, 0));
            this.setMaxValue(attributes.getInt(R.styleable.NumberPickerWithXml_maxValue, 0));
            this.setValue(attributes.getInt(R.styleable.NumberPickerWithXml_defaultValue, 0));
        } finally {
            attributes.recycle();
        }
    }

}

Usage in your layout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:custom="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools">

    <com.example.library.ui.NumberPickerWithXml
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        custom:defaultValue="30"
        custom:maxValue="120"
        custom:minValue="0" />

</LinearLayout>

A super easy way to verify your Java code would be to throw it in a Java file in Android Studio. It would have pointed out all of the errors really fast. — Abandoned Cart, Oct 16 '21 at 23:19
@AbandonedCart - Thanks for fixing it! The Java version was a bit of an after-thought; it didn't cross my mind that I could just add a Java file to my pure Kotlin project! On reflection today, I think my answer should just be a comment under MazeChaZer's answer. — charles-allen, Oct 18 '21 at 00:21
Personally, I preferred this one. It was much more complete and easier to follow, both of which may have been lost as a comment. — Abandoned Cart, Oct 18 '21 at 01:31

Android NumberPicker: Set min, max, default from XML

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