Using Shared preferences to remember the font size that a user prefers in Android

Question

I'm developing a mobile songbook android application. I have enabled text to be zoomed in or out. I want the application to be able to remember the specific font size that a user prefers when a user closes a specific song to another or even better even when a user closes the application and opens it again. Here is how i tried doing it:

public void saveFont(View view){
    SharedPreferences sharedPref = getSharedPreferences("fontsize", Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPref.edit();
    editor.putFloat("fontsize",factor.getInt());
    editor.apply();
}

public void rememberFont(View view){
    SharedPreferences sharedPref = getSharedPreferences("fontsize", Context.MODE_PRIVATE);
    double factor = sharedPref.getString("fontsize","");
    factor.setInt();
}

Here is the entire class:

public class SongbookActivity extends AppCompatActivity {
private TextView wordMeaning;
private TextToSpeech convertToSpeech;
ScaleGestureDetector scaleGestureDetector;
public double factor;

@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_dictionary);

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbarSongActivity);
    TextView textViewTitle = (TextView) toolbar.findViewById(R.id.toolbar_title);
    setSupportActionBar(toolbar);


    Intent intent = getIntent();
    Bundle bundle = intent.getExtras();
    int dictionaryId = bundle.getInt("SONG._ID");
    int id = dictionaryId + 1;


    wordMeaning = (TextView)findViewById(R.id.dictionary);


    String title = bundle.getString("SONG._TITLE");
    String description = bundle.getString("SONG._LYRICS");

    final android.support.v7.app.ActionBar ab = getSupportActionBar();
    ab.setHomeAsUpIndicator(R.drawable.left);
    ab.setTitle(null);
    ab.setDisplayHomeAsUpEnabled(true);


    textViewTitle.setText(title);

    textViewTitle.setSelected(true);
   // textViewTitle.setMovementMethod(new ScrollingMovementMethod());

    wordMeaning.setTextIsSelectable(true);

    registerForContextMenu(wordMeaning);
    wordMeaning.setMovementMethod(new ScrollingMovementMethod());
    wordMeaning.setText(description);
    scaleGestureDetector = new ScaleGestureDetector(this, new simpleOnScaleGestureListener());


    }


//copy text or select
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
    //user has long pressed your TextView
    menu.add(0, v.getId(), 0, "Song copied to Clipboard");

    //cast the received View to TextView so that you can get its text
    TextView yourTextView = (TextView) v;

    //place your TextView's text in clipboard
    ClipboardManager clipboard = (ClipboardManager) getSystemService(CLIPBOARD_SERVICE);
    clipboard.setText(yourTextView.getText());

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onTouchEvent(MotionEvent event) {


    if (event.getPointerCount() > 1) {
        scaleGestureDetector.onTouchEvent(event);
        return true;
    }
    return false;


}

public void saveFont(View view){
    SharedPreferences sharedPref = getSharedPreferences("fontsize", Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPref.edit();
    editor.putFloat("fontsize",factor.getInt());
    editor.apply();
}

public void rememberFont(View view){
    SharedPreferences sharedPref = getSharedPreferences("fontsize", Context.MODE_PRIVATE);
    double factor = sharedPref.getString("fontsize","");
    factor.setInt();
}

public class simpleOnScaleGestureListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {

    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        // TODO Auto-generated method stub
        float size = wordMeaning.getTextSize();
        Log.d("TextSizeStart", String.valueOf(size));

        float factor = detector.getScaleFactor();
        Log.d("Factor", String.valueOf(factor));

        float product = size*factor;
        Log.d("TextSize", String.valueOf(product));
        wordMeaning.setTextSize(TypedValue.COMPLEX_UNIT_PX, product);

        size = wordMeaning.getTextSize();
        Log.d("TextSizeEnd", String.valueOf(size));
        return true;
    }
}



@Override
public boolean onOptionsItemSelected(MenuItem item) {
    double factor = 1;
    float size = wordMeaning.getTextSize();
    saveFont(View view);
    rememberFont(View view);
    Log.d("TextSizeStart", String.valueOf(size));
    switch (item.getItemId()) {
        case R.id.small_layout:
            factor = 0.5;
            break;
        case R.id.medium_layout:
            factor = 0.9;
            break;
        case R.id.large_layout:
            factor = 1.3;
            break;
        case R.id.xlarge_layout:
            factor = 1.8;
            break;
    }



    Log.d("Factor", String.valueOf(factor));

    double product = size*factor;
    Log.d("TextSize", String.valueOf(product));
    wordMeaning.setTextSize(TypedValue.COMPLEX_UNIT_PX, (float)product);

    size = wordMeaning.getTextSize();
    Log.d("TextSizeEnd", String.valueOf(size));
    return super.onOptionsItemSelected(item);



}

}

I'm getting errors when trying to call the method and on the method declaration. i'm a noob at this so please give me all the details you might think can help me, no matter how insignificant it can be.

Answer 1

here you will get all http://developer.android.com/training/basics/data-storage/shared-preferences.html actually you storing in float with int and trying to get in string so try below

public void saveFont(View view){
    SharedPreferences sharedPref = getSharedPreferences("fontsize", Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPref.edit();
    editor.putInt("fontsize",factor.getInt());
    editor.commit();
}

and from getting back

public void rememberFont(View view){
    SharedPreferences sharedPref = getSharedPreferences("fontsize", Context.MODE_PRIVATE);
    int  prevFont = sharedPref.getInt("fontsize",-1);

}

in -1 you can set your default font

Answer 2

Just a "light" how you can do this.

public void setVariable(float myFloat) {
    pref = _context.getSharedPreferences("fontsize", Context.MODE_PRIVATE);
    editor = pref.edit();
    editor.putFloat("fontsize", myFloat);
    editor.commit();
}

public float getVariable() {
    pref = _context.getSharedPreferences("fontsize", Context.MODE_PRIVATE);
    return pref.getFloat("fontsize", 5.5/*a default value*/);
}

_context can be an attribute.

EDIT1 : This class works FINE for me to any 'save' issues. Change this as your need

public class SharedPreferencesManager {

    // Shared Preferences
    private SharedPreferences pref;
    private SharedPreferences.Editor editor;
    private Context _context;

    // Shared pref mode
    private final int PRIVATE_MODE_SHARED_PREF = 0;

    // Shared preferences file name
    private final String PREF_NAME = "blabla";

    /*KEYS para o sharedpreferences*/
    private final String KEY_TO_USE = PREF_NAME + "setFont";


    public SharedPreferencesManager(Context context) {
        this._context = context;
        pref = _context.getSharedPreferences(PREF_NAME, PRIVATE_MODE_SHARED_PREF);
        editor = pref.edit();
    }

    public void setFont(float keySize) {
        editor.putFloat(KEY_TO_USE, keySize);
        editor.commit();
    }

        public boolean getFont() {
        return pref.getFloat(KEY_TO_USE, 15/*your default value is in here (in sp)*/);
    }
}

To use this, just create an object (passing the context[the activity]) and use the method GET in EVERY call/inflate of your EditText/TextView, and set the size like this

myTextView.setTextSize(mSharedPreferencesManagerObject.getVariable())

And to all of this make sense, on EVERY zoom changes, you need to call

mSharedPreference.setVariable(sizeHere)

It HAS to work. If not, the problem is in your "OnZoomChange" logic/semantic.

Answer 3

If you are having trouble with SharedPreferences, try using this . This greatly simplifies the whole process and uses SharedPreferences internally. All you have to do is copy the source file in your project and use it.

Here is an example:

In your activity's onCreate() method, initialize TinyDB.

TinyDB tinyDB = new TinyDB(this);

Then use it like this:

tinyDB.putString("fontSize", "12");

String fontSize = tinyDB.getString("fontSize");

As simple as that. There are many methods which are very useful in day to day development, just go through the source file once. Hope it helps.