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i have a scrollview with text in it and a button at the bottom. what i want to do is change the text on the button according to the percentage of scrolling done by the user. this is my code: 

public class Verbal extends Activity implements ScrollViewListener {

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.verbal);
    ObservableScrollView scrollview = (ObservableScrollView) findViewById(R.id.scrollview);
    scrollview.setScrollViewListener(this);

}

@Override
public void onScrollChanged(ObservableScrollView scrollView, int x, int y,
        int oldx, int oldy) {
    // TODO Auto-generated method stub
    Button answer = (Button) findViewById(R.id.answernumber);

    int totalHeight = scrollView.getChildAt(0).getHeight();
    int p = (y/totalHeight)*100;

    if (p>3 && p<8)
        answer.setText("1");
    else if (p>8 && p<11)
        answer.setText("2");
    else if (p>11 && p<14)
        answer.setText("3");
    else if (p>14 && p<17)
        answer.setText("4");
    else if (p>17 && p<21) 
        answer.setText("5");
    else if (p>21 && p<25)
        answer.setText("6");
    else if (p>25 && p<29)
        answer.setText("7");
    else if (p>29 && p<31)
        answer.setText("8");
    else if (p>31 && p<35)
        answer.setText("9");
    else if (p>35 && p<39)
        answer.setText("10");
    else if (p>39 && p<45)
        answer.setText("11");
    else if (p>45 && p<50)
        answer.setText("12");
    else if (p>50 && p<56)
        answer.setText("13");
    else if (p>56 && p<62)
        answer.setText("14");
    else if (p>62 && p<67)
        answer.setText("15");
    else if (p>67 && p<72)
        answer.setText("16");
    else if (p>72 && p<78)
        answer.setText("17");
    else if (p>78 && p<83)
        answer.setText("18");
    else if (p>83 && p<86)
        answer.setText("19");
    else if (p>86)
        answer.setText("20");   




}

}

the problem is the text is not changing in the button because initially the value of 'y' is zero so 'p' is also zero. but as the user scrolls down value of 'y' changes and 'p' dosent change. i need to continuously change value of 'p' as 'y' changes. please help me programmatically what to do?

Abhinav Raja
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  • Why do you need to do this? – Daksh Shah Feb 17 '14 at 13:30
  • i have a set of questions in the scroll view. i just want to change number text on button according to what question is the user reading. – Abhinav Raja Feb 17 '14 at 13:32
  • Did you read this(http://stackoverflow.com/questions/19614069/get-percentage-scrolled-of-an-element-with-jquery) maybe it is of some help to you – Daksh Shah Feb 17 '14 at 13:34
  • i think maybe with a do while loop i can get this working but dont know how to use it – Abhinav Raja Feb 17 '14 at 13:52
  • This is how to use do while loop in java: http://docs.oracle.com/javase/tutorial/java/nutsandbolts/while.html and this is wikipedia of do-while: http://en.wikipedia.org/wiki/Do_while_loop – Daksh Shah Feb 17 '14 at 13:54
  • i dont need links. i know what is do while i am just not getting how to use in my code. it shoud be like do {..} while MotionEvent.ACTION_MOVE something like this – Abhinav Raja Feb 17 '14 at 14:00

1 Answers1

3

I think your problem is that you're running a integer division, and thus p is always 0. You have to cast it to double like this:

 double p = ((double)y/(double)totalHeight)*100;
super-qua
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