Why isn't my spinner updating with my arrayList items?

Question

I have the current method and sActivity has a public arrayList that I want to use. I just can't figure it out, my spinner does not have any values in it. This spinner is in another activity than where I am adding items to the arraylist. So maybe I have to intent.putExtra("arrayL", savedColors) so that i have to send arraylist to this activity...I don't know just guessing. Any help is much appreciated. I have hard coded some ColorSaver objects into the arrayList, so i know there is values in it.

private void addColorNames()
{
    Spinner colorsSpinner = (Spinner) findViewById(R.id.colorsSpinner);

    ArrayAdapter<ColorSaver> dataAdapter 
        = new ArrayAdapter<ColorSaver>
        (RecallActivity.this, android.R.layout.simple_spinner_item, sActivity.savedColors);

    dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    colorsSpinner.setAdapter(dataAdapter);

}//End addColorNames()

public class RecallActivity extends Activity {


ArrayList<String> namesArray = new ArrayList<String>();
SaveActivity sActivity = new SaveActivity();


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_recall);
    // Show the Up button in the action bar.
    setupActionBar();
    final Intent intent1 = new Intent(this, MainActivity.class);
    final Spinner colorList = (Spinner) findViewById(R.id.colorsSpinner);
    Button grabButton = (Button) findViewById(R.id.grabButton);

    //Load the spinner with the saved colors
    addColorNames();


    //namesArray.addAll(sActivity.nameArray);
    //colorsSpinner.add;
    grabButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            // Perform action on click
            //ColorSaver saver = new ColorSaver(colorName, redcolor, greencolor, bluecolor);
            //savedColors.add(saver);
            //startActivity(intent1);
            ColorSaver selectedItem = (ColorSaver) colorList.getSelectedItem();

            int redValue, greenValue, blueValue;
            String name;
            redValue = selectedItem.getRedValue();
            greenValue = selectedItem.getGreenValue();
            blueValue = selectedItem.getBlueValue();
            name = selectedItem.getColorName();
            intent1.putExtra("savedRValue", redValue);
            intent1.putExtra("savedGValue", greenValue);
            intent1.putExtra("savedBValue", blueValue);
            intent1.putExtra("savedName", name);
            startActivity(intent1);


        }//END onClick
    });
}

/**
 * Set up the {@link android.app.ActionBar}.
 */
private void setupActionBar() {

    getActionBar().setDisplayHomeAsUpEnabled(true);

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.recall, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case android.R.id.home:
        // This ID represents the Home or Up button. In the case of this
        // activity, the Up button is shown. Use NavUtils to allow users
        // to navigate up one level in the application structure. For
        // more details, see the Navigation pattern on Android Design:
        //
        // http://developer.android.com/design/patterns/navigation.html#up-vs-back
        //
        NavUtils.navigateUpFromSameTask(this);
        return true;
    }
    return super.onOptionsItemSelected(item);
}// END onOptionsItemSelected(MenuItem item)


public void addColorNames()
{
    Spinner colorsSpinner = (Spinner) findViewById(R.id.colorsSpinner);

    ArrayAdapter<ColorSaver> dataAdapter 
        = new ArrayAdapter<ColorSaver>
        (RecallActivity.this, android.R.layout.simple_spinner_item, sActivity.savedColors);

    dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    colorsSpinner.setAdapter(dataAdapter);

}//End addColorNames()

}//END CLASS

The Class where I am saving items to the array is

public class SaveActivity extends Activity {

private static final String TAG = "Save Activity";
public ArrayList<ColorSaver> savedColors = new ArrayList<ColorSaver>();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_save);
    // Show the Up button in the action bar.
    setupActionBar();

    final Intent intent1 = new Intent(this, MainActivity.class);
    Button saveButton = (Button) findViewById(R.id.saveButton1);
    final EditText nameField = (EditText) findViewById(R.id.colorNameField);
    final Intent intent = new Intent();

    //Making sure the savedColors arrayList has something in it.
    ColorSaver temp = new ColorSaver("TestColor", 180, 80, 255);
    savedColors.add(temp);


    saveButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            // Perform action on click

            int redcolor, greencolor, bluecolor;
            redcolor = intent.getIntExtra("RedValue", 255);
            greencolor = intent.getIntExtra("GreenValue", 255);
            bluecolor = intent.getIntExtra("BlueValue", 255);
            String colorName = nameField.getText().toString();

            ColorSaver saver = new ColorSaver(colorName, redcolor, greencolor, bluecolor);
            savedColors.add(saver);
            Log.i(TAG, savedColors.get(savedColors.size()-1).getColorName());
            startActivity(intent1);

        }
    });

}//END OnCreate()

/**
 * Set up the {@link android.app.ActionBar}.
 */
private void setupActionBar() {

    getActionBar().setDisplayHomeAsUpEnabled(true);

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.save, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case android.R.id.home:
        // This ID represents the Home or Up button. In the case of this
        // activity, the Up button is shown. Use NavUtils to allow users
        // to navigate up one level in the application structure. For
        // more details, see the Navigation pattern on Android Design:
        //
        // http://developer.android.com/design/patterns/navigation.html#up-vs-back
        //
        NavUtils.navigateUpFromSameTask(this);
        return true;
    }
    return super.onOptionsItemSelected(item);
}

}//END CLASS

Answer 1

There is a possibility that the ArrayList from sActivity is null when you access it from another activity.

Check whether it is null or has values inside, or just use Intent to pass the array to the activity with Spinner. (It is safer to use Intent's extra data)