Android how to get next item on array with button click

Question

i want to get the next item on an array on button click.

array is like this :

String[] pickupLinesItems = { "a", "b", "c" };

then i have this for the spinner

public void onItemSelected(org.holoeverywhere.widget.AdapterView<?> parent,
        View view, int position, long id) {

    position = spinner.getSelectedItemPosition();

    SpinnerAdapter adap = spinner.getAdapter();

    if (adap.equals(pickupLinesAdapter)) {
        switch (position) {
        case 0:
            stopPlaying();
            speakMedia = MediaPlayer.create(this, R.raw.a);
            break;
        case 1:
             stopPlaying();
             speakMedia = MediaPlayer.create(this, R.raw.b);
             break;
        case 2:
             stopPlaying();
             speakMedia = MediaPlayer.create(this, R.raw.c);
             break;

        }
    }
}

public void onClick(View v) {
    // TODO Auto-generated method stub
    int index = 0;

    switch (v.getId()) {
    case R.id.next:
        // here i want to go on the next item on array
        break; 
    case R.id.back:
                    // here i wanna go back one item on the array
        break;
    }
}

how would i do this, i've tried everything and cant seem to get it. i tried to do an if statement but nothing.

So, like, if the spinner is on b, you want a button press to change it to c? — Embattled Swag
– Embattled Swag, Commented Feb 14, 2014 at 19:51

user3311655 · Accepted Answer · 2014-02-14 20:26:18Z

3

Need a variable to hold the current index of pickupLinesItems declared at the same scope as String[] pickupLinesItems = { "a", "b", "c" };

For example:

int pickupLinesItemIndex = 0;

Then you could do something like this:

public void onClick(View v) {
    // TODO Auto-generated method stub

    switch (v.getId()) {
    case R.id.next:
        if(pickupLinesItemIndex < pickupLinesItems.length)
        {
          String pickupLine = pickupLinesItemIndex[++pickupLinesItemIndex];
        }
        break; 
    case R.id.back:
        if(pickupLinesItemIndex > 0)
        {
          String pickupLine = pickupLinesItemIndex[--pickupLinesItemIndex];
        }
        break;
    }
}

edited Feb 14, 2014 at 20:26

answered Feb 14, 2014 at 19:56

user3311655

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3 Comments

Shayan Pourvatan Over a year ago

i'm sure you mean ++pickupLinesItemIndex and --pickupLinesItemIndex and you must check pickupLinesItemIndex that not became bigger than size of array or lower than zero

Shayan Pourvatan Over a year ago

you need pickupLinesItems.length - 1 for checking max.

user3204203 Over a year ago

tried this ang nothing happened, doesnt change, doesnt give me an error, nothing.

Embattled Swag · Accepted Answer · 2014-02-14 19:56:23Z

0

Assuming my comment is correct, you could do something like:

//in your onClick
case R.id.next:
    int current = spinner.getSelectedItemPosition();
    spinner.setSelection(current++);
    break;

You could do the same thing in back. Also, make sure to check for boundary conditions (if you're on c, make sure you go to a and not attempt to reach out of the array's bounds).

answered Feb 14, 2014 at 19:56

Embattled Swag

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2 Comments

Blackbelt Over a year ago

I will say current++%3, or he should check for IndexOutOfBoundException

user3204203 Over a year ago

i tried this before and it didnt work then and still doesnt and to be honest i dont know why. it doesnt give me an arror or anything it just doesnt move on to the next.

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