Is there a way to define a min and max value for EditText in Android?

Question

First make this class :

package com.test;

import android.text.InputFilter;
import android.text.Spanned;

public class InputFilterMinMax implements InputFilter {

    private int min, max;

    public InputFilterMinMax(int min, int max) {
        this.min = min;
        this.max = max;
    }

    public InputFilterMinMax(String min, String max) {
        this.min = Integer.parseInt(min);
        this.max = Integer.parseInt(max);
    }

    @Override
    public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {   
        try {
            int input = Integer.parseInt(dest.toString() + source.toString());
            if (isInRange(min, max, input))
                return null;
        } catch (NumberFormatException nfe) { }     
        return "";
    }

    private boolean isInRange(int a, int b, int c) {
        return b > a ? c >= a && c <= b : c >= b && c <= a;
    }
}

Then use this from your Activity :

EditText et = (EditText) findViewById(R.id.myEditText);
et.setFilters(new InputFilter[]{ new InputFilterMinMax("1", "12")});

This will allow user to enter values from 1 to 12 only.

EDIT :

Set your edittext with android:inputType="number".

You can find more details at https://www.techcompose.com/how-to-set-minimum-and-maximum-value-in-edittext-in-android-app-development/.

Thanks.

There is a small error in Pratik's code. For instance, if a value is 10 and you add a 1 at the beginning to make 110, the filter function would treat the new value as 101.

See below for a fix to this:

@Override
public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
    try {
        // Removes string that is to be replaced from destination
        // and adds the new string in.
        String newVal = dest.subSequence(0, dstart)
                // Note that below "toString()" is the only required:
                + source.subSequence(start, end).toString()
                + dest.subSequence(dend, dest.length());
        int input = Integer.parseInt(newVal);
        if (isInRange(min, max, input))
            return null;
    } catch (NumberFormatException nfe) { }
    return "";
}

Of what i've seen of @Patrik's solution and @Zac's addition, the code provided still has a big problem :

If min==3 then it's impossible to type any number starting with 1 or 2 (ex: 15, 23)
If min>=10 then it's impossible to type anything as every number will have to start with 1,2,3...

In my understanding we cannot achieve the min-max limitation of an EditText's value with simple use of the class InputFilterMinMax, at least not for the min Value, because when user is typing a positive number, the value goes growing and we can easily perform an on-the-fly test to check if it's reached the limit or went outside the range and block entries that do not comply. Testing the min value is a different story as we cannot be sure if the user has finished typing or not and therefore cannot decide if we should block or not.

It's not exactly what OP requested but for validation purposes i've combined in my solution an InputFilter to test max values, with an OnFocusChangeListener to re-test for min value when the EditText loses the focus assuming the user's finished typing and it's something like this :

package test;


import android.text.InputFilter;

import android.text.Spanned;

public class InputFilterMax implements InputFilter {

private int max;

public InputFilterMax(int max) {
    this.max = max;
}

public InputFilterMax(String max) {
    this.max = Integer.parseInt(max);
}

@Override
public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {   
    try {
        String replacement = source.subSequence(start, end).toString(); 

        String newVal = dest.toString().substring(0, dstart) + replacement +dest.toString().substring(dend, dest.toString().length());

        int input = Integer.parseInt(newVal);

        if (input<=max)
            return null;
    } catch (NumberFormatException nfe) { }   
//Maybe notify user that the value is not good      
return "";
}
}

And OnFocusChangeListenerMin

package test;

import android.text.TextUtils;
import android.view.View;
import android.view.View.OnFocusChangeListener;

public class OnFocusChangeListenerMin implements OnFocusChangeListener {

private int min;

public OnFocusChangeListenerMin(int min) {
    this.min = min;
}

public OnFocusChangeListenerMin(String min) {
    this.min = Integer.parseInt(min);
}


@Override
public void onFocusChange(View v, boolean hasFocus) {
    if(!hasFocus) {
        String val = ((EditText)v).getText().toString();
        if(!TextUtils.isEmpty(val)){
            if(Integer.valueOf(val)<min){
                //Notify user that the value is not good
            }

        }
    }
}
}

Then in Activity set the InputFilterMax and theOnFocusChangeListenerMin to EditText note : You can 2 both min and max in onFocusChangeListener.

mQteEditText.setOnFocusChangeListener( new OnFocusChangeListenerMin('20');
mQteEditText.setFilters(new InputFilter[]{new InputFilterMax(getActivity(),'50')});

Kotlin if any one needs it (Use Utilities)

class InputFilterMinMax: InputFilter {
    private var min:Int = 0
    private var max:Int = 0
    constructor(min:Int, max:Int) {
        this.min = min
        this.max = max
    }
    constructor(min:String, max:String) {
        this.min = Integer.parseInt(min)
        this.max = Integer.parseInt(max)
    }
    override fun filter(source:CharSequence, start:Int, end:Int, dest: Spanned, dstart:Int, dend:Int): CharSequence? {
        try
        {
            val input = Integer.parseInt(dest.toString() + source.toString())
            if (isInRange(min, max, input))
                return null
        }
        catch (nfe:NumberFormatException) {}
        return ""
    }
    private fun isInRange(a:Int, b:Int, c:Int):Boolean {
        return if (b > a) c in a..b else c in b..a
    }
}

Then use this from your Kotlin class

percentage_edit_text.filters = arrayOf(Utilities.InputFilterMinMax(1, 100))

This EditText allows from 1 to 100.

Then use this from your XML

android:inputType="number"

Extension of Pratik's and Zac's answer. Zac fixed a small bug of Pratik's in his answer. But I notcied that code doesn't support negative values, it will throw a NumberFormatException. To fix that, and allow the MIN to be negative, use the following code.

Add this line (In bold) between the other two lines:

newVal = newVal.substring(0, dstart) + source.toString()+ newVal.substring(dstart, newVal.length());

if(newVal.equalsIgnoreCase("-") && min < 0)return null;

int input = Integer.parseInt(newVal);

public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
    try {
        // Remove the string out of destination that is to be replaced
        String newVal = dest.toString().substring(0, dstart) + dest.toString().substring(dend, dest.toString().length());
        // Add the new string in
        newVal = newVal.substring(0, dstart) + source.toString() + newVal.substring(dstart, newVal.length());
        //****Add this line (below) to allow Negative values***// 
        if(newVal.equalsIgnoreCase("-") && min < 0)return null;
        int input = Integer.parseInt(newVal);
        if (isInRange(min, max, input))
            return null;
    } catch (NumberFormatException nfe) {
        nfe.printStackTrace();
    }
    return "";
}

If you need range with negative numbers like -90:90, you can use this solution.

public class InputFilterMinMax implements InputFilter {

private int min, max;

public InputFilterMinMax(int min, int max) {
    this.min = min;
    this.max = max;
}

public InputFilterMinMax(String min, String max) {
    this.min = Integer.parseInt(min);
    this.max = Integer.parseInt(max);
}

@Override
public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
    try {
        String stringInput = dest.toString() + source.toString();
        int value;
        if (stringInput.length() == 1 && stringInput.charAt(0) == '-') {
            value = -1;
        } else {
            value = Integer.parseInt(stringInput);
        }
        if (isInRange(min, max, value))
            return null;
    } catch (NumberFormatException nfe) {
    }
    return "";
}

private boolean isInRange(int min, int max, int value) {
    return max > min ? value >= min && value <= max : value >= max && value <= min;
}
}