QRCode Generation

README.txt

Usage:
imageView.setImageBitmap(QRCodeHandler.generateQRCode(bill,getScreenRes()));

//Utility Function
public int getScreenRes() {
        DisplayMetrics metrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(metrics);
        return metrics.densityDpi;
}

Contents.java

import android.provider.ContactsContract;

public class Contents {
    private Contents() {
    }

    public static final class Type {

        // Plain text. Use Intent.putExtra(DATA, string). This can be used for URLs too, but string
        // must include "http://" or "https://".
        public static final String TEXT = "TEXT_TYPE";

        // An email type. Use Intent.putExtra(DATA, string) where string is the email address.
        public static final String EMAIL = "EMAIL_TYPE";

        // Use Intent.putExtra(DATA, string) where string is the phone number to call.
        public static final String PHONE = "PHONE_TYPE";

        // An SMS type. Use Intent.putExtra(DATA, string) where string is the number to SMS.
        public static final String SMS = "SMS_TYPE";


        //  A contact. Send a request to encode it as follows:
        //  <p/>
        //  import android.provider.Contacts;
        //  <p/>
        //  Intent intent = new Intent(Intents.Encode.ACTION); intent.putExtra(Intents.Encode.TYPE,
        //  CONTACT); Bundle bundle = new Bundle(); bundle.putString(Contacts.Intents.Insert.NAME,
        //  "Jenny"); bundle.putString(Contacts.Intents.Insert.PHONE, "8675309");
        //  bundle.putString(Contacts.Intents.Insert.EMAIL, "jenny@the80s.com");
        //  bundle.putString(Contacts.Intents.Insert.POSTAL, "123 Fake St. San Francisco, CA 94102");
        //  intent.putExtra(Intents.Encode.DATA, bundle);

        public static final String CONTACT = "CONTACT_TYPE";


        // A geographic location. Use as follows:
        // Bundle bundle = new Bundle();
        // bundle.putFloat("LAT", latitude);
        // bundle.putFloat("LONG", longitude);
        // intent.putExtra(Intents.Encode.DATA, bundle);

        public static final String LOCATION = "LOCATION_TYPE";

        private Type() {
        }
    }

    public static final String URL_KEY = "URL_KEY";

    public static final String NOTE_KEY = "NOTE_KEY";

    // When using Type.CONTACT, these arrays provide the keys for adding or retrieving multiple
    // phone numbers and addresses.
    public static final String[] PHONE_KEYS = {
            ContactsContract.Intents.Insert.PHONE, ContactsContract.Intents.Insert.SECONDARY_PHONE,
            ContactsContract.Intents.Insert.TERTIARY_PHONE
    };

    public static final String[] PHONE_TYPE_KEYS = {
            ContactsContract.Intents.Insert.PHONE_TYPE,
            ContactsContract.Intents.Insert.SECONDARY_PHONE_TYPE,
            ContactsContract.Intents.Insert.TERTIARY_PHONE_TYPE
    };

    public static final String[] EMAIL_KEYS = {
            ContactsContract.Intents.Insert.EMAIL, ContactsContract.Intents.Insert.SECONDARY_EMAIL,
            ContactsContract.Intents.Insert.TERTIARY_EMAIL
    };

    public static final String[] EMAIL_TYPE_KEYS = {
            ContactsContract.Intents.Insert.EMAIL_TYPE,
            ContactsContract.Intents.Insert.SECONDARY_EMAIL_TYPE,
            ContactsContract.Intents.Insert.TERTIARY_EMAIL_TYPE
    };
}

QRCodeEncoder.java

import android.graphics.Bitmap;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.telephony.PhoneNumberUtils;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;

import java.util.Collection;
import java.util.EnumMap;
import java.util.HashSet;
import java.util.Map;

public class QRCodeEncoder {
    private static final int WHITE = 0xFFFFFFFF;
    private static final int BLACK = 0xFF000000;

    private int dimension = Integer.MIN_VALUE;
    private String contents = null;
    private String displayContents = null;
    private String title = null;
    private BarcodeFormat format = null;
    private boolean encoded = false;

    public QRCodeEncoder(String data, Bundle bundle, String type, String format, int dimension) {
        this.dimension = dimension;
        encoded = encodeContents(data, bundle, type, format);
    }

    public String getContents() {
        return contents;
    }

    public String getDisplayContents() {
        return displayContents;
    }

    public String getTitle() {
        return title;
    }

    private boolean encodeContents(String data, Bundle bundle, String type, String formatString) {
        // Default to QR_CODE if no format given.
        format = null;
        if (formatString != null) {
            try {
                format = BarcodeFormat.valueOf(formatString);
            } catch (IllegalArgumentException iae) {
                // Ignore it then
            }
        }
        if (format == null || format == BarcodeFormat.QR_CODE) {
            this.format = BarcodeFormat.QR_CODE;
            encodeQRCodeContents(data, bundle, type);
        } else if (data != null && data.length() > 0) {
            contents = data;
            displayContents = data;
            title = "Text";
        }
        return contents != null && contents.length() > 0;
    }

    private void encodeQRCodeContents(String data, Bundle bundle, String type) {
        if (type.equals(Contents.Type.TEXT)) {
            if (data != null && data.length() > 0) {
                contents = data;
                displayContents = data;
                title = "Text";
            }
        } else if (type.equals(Contents.Type.EMAIL)) {
            data = trim(data);
            if (data != null) {
                contents = "mailto:" + data;
                displayContents = data;
                title = "E-Mail";
            }
        } else if (type.equals(Contents.Type.PHONE)) {
            data = trim(data);
            if (data != null) {
                contents = "tel:" + data;
                displayContents = PhoneNumberUtils.formatNumber(data);
                title = "Phone";
            }
        } else if (type.equals(Contents.Type.SMS)) {
            data = trim(data);
            if (data != null) {
                contents = "sms:" + data;
                displayContents = PhoneNumberUtils.formatNumber(data);
                title = "SMS";
            }
        } else if (type.equals(Contents.Type.CONTACT)) {
            if (bundle != null) {
                StringBuilder newContents = new StringBuilder(100);
                StringBuilder newDisplayContents = new StringBuilder(100);

                newContents.append("MECARD:");

                String name = trim(bundle.getString(ContactsContract.Intents.Insert.NAME));
                if (name != null) {
                    newContents.append("N:").append(escapeMECARD(name)).append(';');
                    newDisplayContents.append(name);
                }

                String address = trim(bundle.getString(ContactsContract.Intents.Insert.POSTAL));
                if (address != null) {
                    newContents.append("ADR:").append(escapeMECARD(address)).append(';');
                    newDisplayContents.append('\n').append(address);
                }

                Collection<String> uniquePhones = new HashSet<String>(Contents.PHONE_KEYS.length);
                for (int x = 0; x < Contents.PHONE_KEYS.length; x++) {
                    String phone = trim(bundle.getString(Contents.PHONE_KEYS[x]));
                    if (phone != null) {
                        uniquePhones.add(phone);
                    }
                }
                for (String phone : uniquePhones) {
                    newContents.append("TEL:").append(escapeMECARD(phone)).append(';');
                    newDisplayContents.append('\n').append(PhoneNumberUtils.formatNumber(phone));
                }

                Collection<String> uniqueEmails = new HashSet<String>(Contents.EMAIL_KEYS.length);
                for (int x = 0; x < Contents.EMAIL_KEYS.length; x++) {
                    String email = trim(bundle.getString(Contents.EMAIL_KEYS[x]));
                    if (email != null) {
                        uniqueEmails.add(email);
                    }
                }
                for (String email : uniqueEmails) {
                    newContents.append("EMAIL:").append(escapeMECARD(email)).append(';');
                    newDisplayContents.append('\n').append(email);
                }

                String url = trim(bundle.getString(Contents.URL_KEY));
                if (url != null) {
                    // escapeMECARD(url) -> wrong escape e.g. http\://zxing.google.com
                    newContents.append("URL:").append(url).append(';');
                    newDisplayContents.append('\n').append(url);
                }

                String note = trim(bundle.getString(Contents.NOTE_KEY));
                if (note != null) {
                    newContents.append("NOTE:").append(escapeMECARD(note)).append(';');
                    newDisplayContents.append('\n').append(note);
                }

                // Make sure we've encoded at least one field.
                if (newDisplayContents.length() > 0) {
                    newContents.append(';');
                    contents = newContents.toString();
                    displayContents = newDisplayContents.toString();
                    title = "Contact";
                } else {
                    contents = null;
                    displayContents = null;
                }

            }
        } else if (type.equals(Contents.Type.LOCATION)) {
            if (bundle != null) {
                // These must use Bundle.getFloat(), not getDouble(), it's part of the API.
                float latitude = bundle.getFloat("LAT", Float.MAX_VALUE);
                float longitude = bundle.getFloat("LONG", Float.MAX_VALUE);
                if (latitude != Float.MAX_VALUE && longitude != Float.MAX_VALUE) {
                    contents = "geo:" + latitude + ',' + longitude;
                    displayContents = latitude + "," + longitude;
                    title = "Location";
                }
            }
        }
    }

    public Bitmap encodeAsBitmap() throws WriterException {
        if (!encoded) return null;

        Map<EncodeHintType, Object> hints = null;
        String encoding = guessAppropriateEncoding(contents);
        if (encoding != null) {
            hints = new EnumMap<EncodeHintType, Object>(EncodeHintType.class);
            hints.put(EncodeHintType.CHARACTER_SET, encoding);
        }
        MultiFormatWriter writer = new MultiFormatWriter();
        BitMatrix result = writer.encode(contents, format, dimension, dimension, hints);
        int width = result.getWidth();
        int height = result.getHeight();
        int[] pixels = new int[width * height];
        // All are 0, or black, by default
        for (int y = 0; y < height; y++) {
            int offset = y * width;
            for (int x = 0; x < width; x++) {
                pixels[offset + x] = result.get(x, y) ? BLACK : WHITE;
            }
        }

        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
        return bitmap;
    }

    private static String guessAppropriateEncoding(CharSequence contents) {
        // Very crude at the moment
        for (int i = 0; i < contents.length(); i++) {
            if (contents.charAt(i) > 0xFF) {
                return "UTF-8";
            }
        }
        return null;
    }

    private static String trim(String s) {
        if (s == null) {
            return null;
        }
        String result = s.trim();
        return result.length() == 0 ? null : result;
    }

    private static String escapeMECARD(String input) {
        if (input == null || (input.indexOf(':') < 0 && input.indexOf(';') < 0)) {
            return input;
        }
        int length = input.length();
        StringBuilder result = new StringBuilder(length);
        for (int i = 0; i < length; i++) {
            char c = input.charAt(i);
            if (c == ':' || c == ';') {
                result.append('\\');
            }
            result.append(c);
        }
        return result.toString();
    }
}

QRCodeHandler.java

import android.graphics.Bitmap;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.WriterException;

public class QRCodeHandler {
    public static Bitmap generateQRCode(String BILL_CONTENTS, int SCREEN_RESOLUTION) throws WriterException {

        int imageSize;
        //Just random guesses
        if (SCREEN_RESOLUTION > 400){
            imageSize = 700;
        }else if (SCREEN_RESOLUTION > 300 && SCREEN_RESOLUTION < 400)
            imageSize = 500;
        else
            imageSize = 350;

        QRCodeEncoder qrCodeEncoder = new QRCodeEncoder(BILL_CONTENTS+"",
                null,
                Contents.Type.TEXT,
                BarcodeFormat.QR_CODE.toString(),
                imageSize);

        return qrCodeEncoder.encodeAsBitmap();
    }
}