LayTray/app/src/main/java/space/neothefox/laytray/IconService.java

package space.neothefox.laytray;

import android.accessibilityservice.AccessibilityService;
import android.accessibilityservice.AccessibilityServiceInfo;
import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.Context;
import android.content.SharedPreferences;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.RectF;
import android.graphics.drawable.Icon;
import android.os.Build;
import android.preference.PreferenceManager;
import android.util.Log;
import android.view.accessibility.AccessibilityEvent;

import static android.graphics.Paint.ANTI_ALIAS_FLAG;


@SuppressWarnings("SuspiciousNameCombination")
public class IconService extends AccessibilityService
implements SharedPreferences.OnSharedPreferenceChangeListener
{

    public static final String TAG = "layicon";
    public static final String channelId = "space.neothefox.laytray.IC";
    private final AccessibilityServiceInfo serviceInfo = new AccessibilityServiceInfo();

    private SharedPreferences layouts;
    private SharedPreferences options;
    private String lastToast;

    private NotificationManager iconManager;
    private NotificationChannel iconChannel;

    @Override
    protected void onServiceConnected()
    {
        super.onServiceConnected();
        Log.d(TAG, "Icon service started");
        serviceInfo.eventTypes = AccessibilityEvent.TYPE_NOTIFICATION_STATE_CHANGED;
        serviceInfo.packageNames = new String[] {"com.blackberry.keyboard"};
        serviceInfo.feedbackType = AccessibilityServiceInfo.FEEDBACK_VISUAL;
        serviceInfo.notificationTimeout = 100;
        this.setServiceInfo(serviceInfo);
        layouts = getSharedPreferences("layouts", 0);
        options = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
        lastToast = "EMPT";
        options.registerOnSharedPreferenceChangeListener(this);

        iconManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
        {
            try
            {
                iconChannel = iconManager.getNotificationChannel(channelId);
            }
            catch (NullPointerException e)
            {
                Log.d(TAG, "No NotificationChannel found");
            }
            if(iconChannel == null) {
                iconChannel = new NotificationChannel(
                        channelId,
                        getString(R.string.title_icon_channel),
                        NotificationManager.IMPORTANCE_LOW);
                iconChannel.setShowBadge(false);
                iconChannel.enableLights(false);
                iconChannel.enableVibration(false);
                iconChannel.setLockscreenVisibility(Notification.VISIBILITY_SECRET);
                iconManager.createNotificationChannel(iconChannel);
            }
        }
    }

    private void updateNotification(String toast)
    {
        Notification indicator;
        String textIcon = layouts.getString(toast,"EMPT");
        if(textIcon.equals("EMPT"))
        {
            SharedPreferences.Editor layoutsEditor = layouts.edit();
            layoutsEditor.putString(toast, "??");
            layoutsEditor.apply();
            textIcon = "??";
        }
        Icon smallIcon = Icon.createWithBitmap(textAsBitmap(textIcon,
                                                            Integer.parseInt(options.getString("textSize", "48")),
                                                            options.getBoolean("textFakeBold", true),
                                                            Integer.parseInt(options.getString("textMode", "0")),
                                                            Color.WHITE));

        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
        {
            indicator = new Notification.Builder(this, channelId)
                    .setSmallIcon(smallIcon)
                    .setContentTitle(toast)
                    .setOngoing(true)
                    .setVisibility(Notification.VISIBILITY_SECRET)
                    .build();
        }
        else
        {
            indicator = new Notification.Builder(this)
                    .setSmallIcon(smallIcon)
                    .setContentTitle(toast)
                    .setOngoing(true)
                    .setPriority(Integer.parseInt(options.getString("notificationImportance", "0")))
                    .setVisibility(Notification.VISIBILITY_SECRET)
                    .build();
        }
        iconManager.notify(0, indicator);
        return;
    }

    //Borrowed from Ted Hopp from StackOverflow
    public static Bitmap textAsBitmap(String text, float textSize, boolean fakeBold, int mode, int textColor)
    {
        Paint paint = new Paint(ANTI_ALIAS_FLAG);
        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_OUT));
        paint.setTextSize(textSize);
        paint.setFakeBoldText(fakeBold);
        paint.setColor(textColor);
        switch (mode)
        {
            case 1: {
                int width = 48;
                int height = 48;
                Bitmap image = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
                Canvas canvas = new Canvas(image);
                canvas.drawCircle(width / 2f, height / 2f, width / 2f, paint);
                paint.setAlpha(255);
                paint.setColor(Color.TRANSPARENT);
                paint.setTextSize(textSize);
                paint.setTextAlign(Paint.Align.CENTER);
                canvas.drawText(text, width/2f, ((height/2f) - (paint.descent()+paint.ascent())/2f), paint);
                return image;
            }

            case 2: {
                int width = 48;
                int height = 48;
                Bitmap image = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
                Canvas canvas = new Canvas(image);
                canvas.drawRoundRect(new RectF(0, 0, height, width), 5, 5, paint);
                paint.setAlpha(255);
                paint.setColor(Color.TRANSPARENT);
                paint.setTextSize(textSize);
                paint.setTextAlign(Paint.Align.CENTER);
                canvas.drawText(text, width / 2f, ((height/2f) - (paint.descent()+paint.ascent())/2f), paint);
                return image;
            }

            case 3: {
                int width = 48;
                int height = 48;
                Bitmap image = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
                Canvas canvas = new Canvas(image);
                canvas.drawRoundRect(new RectF(0, 0, height, width), 5, 5, paint);
                paint.setAlpha(255);
                paint.setColor(Color.TRANSPARENT);
                canvas.drawRoundRect(new RectF(2,2,height-2,width-2), 5, 5, paint);
                paint.setColor(textColor);
                paint.setTextSize(textSize);
                paint.setTextAlign(Paint.Align.CENTER);
                canvas.drawText(text, width / 2f, ((height/2f) - (paint.descent()+paint.ascent())/2f), paint);
                return image;
            }

            case 0:
            default:
                paint.setTextAlign(Paint.Align.LEFT);
                float baseline = -paint.ascent(); // ascent() is negative
                int width = (int) (paint.measureText(text) + 0.5f); // round
                int height = (int) (baseline + paint.descent() + 0.5f);
                Bitmap image = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
                Canvas canvas = new Canvas(image);
                canvas.drawText(text, 0, baseline, paint);
                return image;
        }
    }

    @Override
    public void onAccessibilityEvent(AccessibilityEvent event)
    {

        Log.d(TAG, event.toString());
        if(event.getEventType() == AccessibilityEvent.TYPE_NOTIFICATION_STATE_CHANGED)
        {
            Log.d(TAG, "Caught a Toast: ");
            Log.d(TAG, (String)event.getPackageName());
            lastToast = (String)event.getText().get(0);
            Log.d(TAG, lastToast);

            updateNotification(lastToast);
        }
        else
            Log.d(TAG, "Caution! This service had been tampered with!");

    }

    @Override
    public void onInterrupt()
    {
    }

    @Override
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key)
    {
        options = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
        updateNotification(lastToast);
    }
}