CreditCardView.java

package com.flutterwave.raveandroid.card;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.text.InputType;
import android.util.AttributeSet;
import android.util.Log;
import android.util.SparseArray;

import com.flutterwave.raveandroid.R;
import com.google.android.material.textfield.TextInputEditText;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Created by hamzafetuga on 24/07/2017.
 */

public class CreditCardView extends TextInputEditText {


    private SparseArray<Pattern> mCCPatterns = null;
    //default credit card image
    private final int mDefaultDrawableResId = R.drawable.ic_credit_card;
    private int mCurrentDrawableResId = 0;
    private Drawable mCurrentDrawable;
    String lastFormattedText;

    public CreditCardView(Context context) {
        super(context);
        init();
    }

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

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

    private void init() {
        lastFormattedText = "";

        if (mCCPatterns == null) {
            mCCPatterns = new SparseArray<>();
            // With spaces for credit card masking
            mCCPatterns.put(R.drawable.ic_visa, Pattern.compile(
                    "^4[0-9]{2,12}(?:[0-9]{3})?$"));
            mCCPatterns.put(R.drawable.ic_master_card, Pattern.compile(
                    "^5[1-5][0-9]{1,14}$"));
            mCCPatterns.put(R.drawable.ic_american_express, Pattern.compile(
                    "^3[47][0-9]{1,13}$"));
            ///^([506]{3})([0-9]{1,16})$/
            mCCPatterns.put(R.drawable.ic_verve_logo, Pattern.compile(
                    "^([506]{3})([0-9]{1,16})$"
            ));
        }

        setInputType(InputType.TYPE_CLASS_PHONE);
        addTextChangedListener(new CreditCardTextWatcher());
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        if (mCurrentDrawable == null) {
            return;
        }

        int rightOffset = 0;
        if (getError() != null && getError().length() > 0) {
            rightOffset = (int) getResources().getDisplayMetrics().density * 32;
        }

        int right = getWidth() - getPaddingRight() - rightOffset;

        int top = getPaddingTop();
        int bottom = getHeight() - getPaddingBottom();
        float ratio = (float) mCurrentDrawable.getIntrinsicWidth() / (float) mCurrentDrawable.getIntrinsicHeight();
        //int left = right - mCurrentDrawable.getIntrinsicWidth(); //If images are correct size.
        int left = (int) (right - ((bottom - top) * ratio)); //scale image depeding on height available.
        mCurrentDrawable.setBounds(left, top, right, bottom);

        mCurrentDrawable.draw(canvas);
    }

    @Override
    protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {

        if (mCCPatterns == null) {
            init();
        }
//
        String actualText = text.toString().replaceAll("\\s", "");

        Log.d("actual", actualText);

        if (lengthBefore == actualText.length()) {
            return;
        }

        int mDrawableResId = 0;
        for (int i = 0; i < mCCPatterns.size(); i++) {
            int key = mCCPatterns.keyAt(i);
            // get the object by the key.
            Pattern p = mCCPatterns.get(key);
            Matcher m = p.matcher(actualText);
            if (m.find()) {
                mDrawableResId = key;
                break;
            }
        }
        if (mDrawableResId > 0 && mDrawableResId !=
                mCurrentDrawableResId) {
            mCurrentDrawableResId = mDrawableResId;
        } else if (mDrawableResId == 0) {
            mCurrentDrawableResId = mDefaultDrawableResId;
        }
        mCurrentDrawable = getResources()
                .getDrawable(mCurrentDrawableResId);

    }

}