Material Design - Text field input - Over/under character or word count (android.support.design.widget.TextInputLayout) http://www.google.com/design/spec/patterns/errors.html#errors-user-input-errors

activity_test.xml

<?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"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:orientation="vertical"
	android:padding="24dp"
	>

	<android.support.design.widget.TextInputLayout
		android:id="@+id/text1"
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:orientation="vertical"
		>
		<EditText
			android:layout_width="match_parent"
			android:layout_height="wrap_content"
			android:hint="Text Hint 1"
			android:singleLine="true"
			/>
	</android.support.design.widget.TextInputLayout>
	<android.support.design.widget.TextInputLayout
		android:id="@+id/text2"
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:orientation="vertical"
		>
		<EditText
			android:id="@+id/text"
			android:layout_width="match_parent"
			android:layout_height="wrap_content"
			android:hint="Text Hint 2"
			/>
	</android.support.design.widget.TextInputLayout>
</LinearLayout>

CharacterCountErrorWatcher.java

import android.graphics.Color;
import android.support.design.widget.TextInputLayout;
import android.text.Editable;
import android.text.Layout;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
import android.text.TextWatcher;
import android.text.style.AlignmentSpan;
import android.text.style.ForegroundColorSpan;


/**
 * Material Design Guidlines:
 * http://www.google.com/design/spec/patterns/errors.html#errors-user-input-errors
 * see section headed "Text field input - Over/under character or word count"
 *
 * @author Simon Lightfoot <simon@demondevelopers.com>
 */
public class CharacterCountErrorWatcher
	implements TextWatcher
{
	private final TextInputLayout mTextInputLayout;
	private final ForegroundColorSpan mNormalTextAppearance;
	private final AlignmentSpan mAlignmentSpan = new AlignmentSpan.Standard(Layout.Alignment.ALIGN_OPPOSITE);
	private final SpannableStringBuilder mErrorText = new SpannableStringBuilder();
	private int mMinLen;
	private int mMaxLen;

	public CharacterCountErrorWatcher(TextInputLayout textInputLayout, int minLen, int maxLen)
	{
		mTextInputLayout = textInputLayout;
		mNormalTextAppearance = new ForegroundColorSpan(Color.GRAY);
		mMinLen = minLen;
		mMaxLen = maxLen;
		updateErrorText();
	}

	private void updateErrorText()
	{
		mErrorText.clear();
		mErrorText.clearSpans();
		final int length = mTextInputLayout.getEditText().length();
		if(length > 0){
			mErrorText.append(String.valueOf(length));
			mErrorText.append(" / ");
			mErrorText.append(String.valueOf(mMaxLen));
			mErrorText.setSpan(mAlignmentSpan, 0, mErrorText.length(),
				Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
			if(hasValidLength()){
				mErrorText.setSpan(mNormalTextAppearance, 0, mErrorText.length(),
					Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
			}
		}
		mTextInputLayout.setError(mErrorText);
	}

	public boolean hasValidLength()
	{
		final int length = mTextInputLayout.getEditText().length();
		return (length >= mMinLen && length <= mMaxLen);
	}

	@Override
	public void afterTextChanged(Editable s)
	{
		updateErrorText();
	}

	@Override
	public void beforeTextChanged(CharSequence s, int start, int count, int after)
	{
		//
	}

	@Override
	public void onTextChanged(CharSequence s, int start, int before, int count)
	{
		//
	}
}

TestActivity.java

import android.os.Bundle;
import android.support.design.widget.TextInputLayout;
import android.support.v7.app.AppCompatActivity;


public class TestActivity extends AppCompatActivity
{
	@Override
	protected void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_test);

		TextInputLayout text1 = (TextInputLayout) findViewById(R.id.text1);
		TextInputLayout text2 = (TextInputLayout) findViewById(R.id.text2);

		text1.getEditText().addTextChangedListener(new CharacterCountErrorWatcher(text1, 0, 10));
		text2.getEditText().addTextChangedListener(new CharacterCountErrorWatcher(text2, 5, 10));
	}
}

Example of a single-line with character counter with user input text	Example of a single-line with character counter with error text

Example of a multi-line with character counter with user input text	Example of a multi-line with character counter with error text

Now obsolete. See
https://developer.android.com/reference/android/support/design/widget/TextInputLayout.html#setCounterEnabled(boolean)
and
https://developer.android.com/reference/android/support/design/widget/TextInputLayout.html#setCounterMaxLength(int)

Hi,

I'm trying to implement the same kind of TextInputLayout with an EditText. My purpose is to display the error message to the right just as you have done here. Even with your method, I'm unable to do that. If you have time, could you please respond to this: http://stackoverflow.com/questions/42575825/textinputlayout-error-right-align

Can you post the updated code please?

https://developer.android.com/reference/android/support/design/widget/TextInputLayout.html#setCounterEnabled(boolean)