пытаясь упростить проблему с интро-макетом

Question

Я работаю над очень большим проектом, и мне сказали писать код очень и очень эффективно. Я обычно писал свой код, но я хочу, чтобы макет вступления также использовал mvvm. как я могу это сделать?

моя обычная активность приветствия ниже

t?

моя обычная активность приветствия ниже

public class WelcomeActivity extends AppCompatActivity {
    private ViewPager viewPager;
    private MyViewPagerAdapter myViewPagerAdapter;
    private LinearLayout dotsLayout;
    private TextView[] dots;
    private int[] layouts;
    //private Button btnSkip, btnNext;
    private LoginSession prefManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Checking for first time launch - before calling setContentView()
        prefManager = new LoginSession(this);
        if (!prefManager.isFirstTimeLaunch()) {
            launchHomeScreen();
            finish();
        }

        // Making notification bar transparent
        if (Build.VERSION.SDK_INT >= 21) {
            getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
        }

        setContentView(R.layout.activity_welcome);

        viewPager = (ViewPager) findViewById(R.id.view_pager);
        dotsLayout = (LinearLayout) findViewById(R.id.layoutDots);
        /*btnSkip = (Button) findViewById(R.id.btn_skip);
        btnNext = (Button) findViewById(R.id.btn_next);*/


        // layouts of all welcome sliders
        // add few more layouts if you want
        layouts = new int[]{
                R.layout.welcome_slide1,
                R.layout.welcome_slide2,
                R.layout.welcome_slide3
        };

        // adding bottom dots
        addBottomDots(0);

        // making notification bar transparent
        changeStatusBarColor();

        myViewPagerAdapter = new MyViewPagerAdapter();
        viewPager.setAdapter(myViewPagerAdapter);
        viewPager.addOnPageChangeListener(viewPagerPageChangeListener);

       /* btnSkip.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                launchHomeScreen();
            }
        });

        btnNext.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // checking for last page
                // if last page home screen will be launched
                int current = getItem(+1);
                if (current < layouts.length) {
                    // move to next screen
                    viewPager.setCurrentItem(current);
                } else {
                    launchHomeScreen();
                }
            }
        });*/
    }

    private void addBottomDots(int currentPage) {
        dots = new TextView[layouts.length];

        int[] colorsActive = getResources().getIntArray(R.array.array_dot_active);
        int[] colorsInactive = getResources().getIntArray(R.array.array_dot_inactive);

        dotsLayout.removeAllViews();
        for (int i = 0; i < dots.length; i++) {
            dots[i] = new TextView(this);
            dots[i].setText(Html.fromHtml("&#8226;"));
            dots[i].setTextSize(35);
            dots[i].setTextColor(colorsInactive[currentPage]);
            dotsLayout.addView(dots[i]);
        }

        if (dots.length > 0)
            dots[currentPage].setTextColor(colorsActive[currentPage]);
    }

    private int getItem(int i) {
        return viewPager.getCurrentItem() + i;
    }

    private void launchHomeScreen() {
        prefManager.setFirstTimeLaunch(false);
        startActivity(new Intent(WelcomeActivity.this, MainActivity.class));
        finish();
    }

    //  viewpager change listener
    ViewPager.OnPageChangeListener viewPagerPageChangeListener = new ViewPager.OnPageChangeListener() {

        @Override
        public void onPageSelected(int position) {
            addBottomDots(position);

            // changing the next button text 'NEXT' / 'GOT IT'
            if (position == layouts.length - 1) {
                // last page. make button text to GOT IT
                /*btnNext.setText(getString(R.string.start));
                btnSkip.setVisibility(View.GONE);*/
            } else {
                // still pages are left
                /*btnNext.setText(getString(R.string.next));
                btnSkip.setVisibility(View.VISIBLE);*/
            }
        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {

        }

        @Override
        public void onPageScrollStateChanged(int arg0) {

        }
    };

    /**
     * Making notification bar transparent
     */
    private void changeStatusBarColor() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            Window window = getWindow();
            window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            window.setStatusBarColor(Color.TRANSPARENT);
        }
    }

    /**
     * View pager adapter
     */
    public class MyViewPagerAdapter extends PagerAdapter {
        private LayoutInflater layoutInflater;

        public MyViewPagerAdapter() {
        }

        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);

            View view = layoutInflater.inflate(layouts[position], container, false);
            container.addView(view);

            return view;
        }

        @Override
        public int getCount() {
            return layouts.length;
        }

        @Override
        public boolean isViewFromObject(View view, Object obj) {
            return view == obj;
        }


        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            View view = (View) object;
            container.removeView(view);
        }
    }
}

Мои общие предпочтения как показано ниже

publi c class LoginSession {

SharedPreferences pref;

SharedPreferences.Editor editor;

Context _context;

int PRIVATE_MODE = 0;


public LoginSession(Context context) {
    this._context = context;
    pref = _context.getSharedPreferences(Constants.PREF_NAME, PRIVATE_MODE);
    editor = pref.edit();
}

public void createLoginSession(JsonObject jsonObject)
{
    editor.putBoolean(Constants.LOGGED_IN,true);
    editor.putString(Constants.API_TOKEN,jsonObject.get("token_key").getAsString());
    editor.putString(Constants.USERNAME,jsonObject.get("username").getAsString());
    editor.putInt(Constants.ID,jsonObject.get("id").getAsInt());
    editor.commit();
}

public boolean isLoggedIn() {
    return pref.getBoolean(Constants.LOGGED_IN, false);
}

public Map<String, String> getLoginDetails() {
    Map<String, String> logindetailsMap=new HashMap<>();
    logindetailsMap.put(Constants.LOGGED_IN,pref.getString(Constants.LOGGED_IN,null));
    logindetailsMap.put(Constants.USERNAME,pref.getString(Constants.USERNAME,null));
    logindetailsMap.put(Constants.API_TOKEN,pref.getString(Constants.API_TOKEN,null));
    logindetailsMap.put(Constants.ID, String.valueOf(pref.getInt(Constants.ID,0)));
    return logindetailsMap;
}

public void setFirstTimeLaunch(boolean isFirstTime) {
    editor.putBoolean(IS_FIRST_TIME_LAUNCH, isFirstTime);
    editor.commit();
}

public boolean isFirstTimeLaunch() {
    return pref.getBoolean(IS_FIRST_TIME_LAUNCH, true);
}

}