How to change color of arraylist item in custom listview based on positive or negative value

Question

Im new to android and Im building an app to show stock prices from an XML feed.

I have got an array list containing 3 items. However, I want to change the color of one of the items in the array list to red if its -ve or green if its +ve.

I dont know how to do this or where in my code is best to do it.

Please help....

My Adapter class:

public class TheAdapter extends ArrayAdapter<TheMetal>{

public TheAdapter(Context ctx, int textViewResourceId, List<TheMetal> sites) {
    super(ctx, textViewResourceId, sites);
}



@Override
public View getView(int pos, View convertView, ViewGroup parent){
    RelativeLayout row = (RelativeLayout)convertView;
    Log.i("StackSites", "getView pos = " + pos);
    if(null == row){

        LayoutInflater inflater = (LayoutInflater)parent.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        row = (RelativeLayout)inflater.inflate(R.layout.row_metal, null);
    }




    TextView dispNameTxt = (TextView)row.findViewById(R.id.displayNameText);
    TextView spotPriceTxt = (TextView)row.findViewById(R.id.spotPriceText);
    TextView changeTxt = (TextView)row.findViewById(R.id.changeText);


    dispNameTxt.setText (getItem(pos).getDisplayName());
    spotPriceTxt.setText(getItem(pos).getSpotPrice());
    changeTxt.setText(getItem(pos).getChange());


    return row;

}

My row_metal layout:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="10dp" >



<TextView
    android:id="@+id/displayNameText"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textSize="30sp"
    android:layout_marginLeft="20dp" />

<TextView
    android:id="@+id/spotPriceText"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_toRightOf="@+id/displayNameText"
    android:textSize="19sp"
    android:textStyle="bold"
    android:gravity="right"
    android:layout_alignParentRight="true"
    android:layout_marginRight="30dp" />

<TextView
    android:id="@+id/changeText"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/spotPriceText"
    android:layout_toRightOf="@+id/displayNameText"
    android:textSize="16sp"
    android:gravity="right"
    android:layout_alignParentRight="true"
    android:layout_marginRight="20dp"
    />

Answer 1

It is so simple. You just need to place these line within your getView() method:

        if (Double.parseDouble(getItem(pos).getChange())>=0) {
                     row.setBackgroundColor(Color.parseColor("#00FF00");
                     changeTxt.setTextColor(Color.parseColor("#00FF00"));
                    } else {  
                     row.setBackgroundColor(Color.parseColor("#FF0000");                      
                     changeTxt.setTextColor(Color.parseColor("#FF0000"));
                    }

Answer 2

Change your getView() method to this

@Override  
public View getView(int pos, View convertView, ViewGroup parent){

  if(convertView == null)
    convertView = getLayoutInflater().inflate(R.layout.row_metal, null);


  TextView dispNameTxt = (TextView) convertView .findViewById(R.id.displayNameText);
  TextView spotPriceTxt = (TextView) convertView .findViewById(R.id.spotPriceText);
  TextView changeTxt = (TextView) convertView .findViewById(R.id.changeText);

  dispNameTxt.setText(getItem(pos).getDisplayName());
  spotPriceTxt.setText(getItem(pos).getSpotPrice());
  changeTxt.setText(getItem(pos).getChange());


  if( Double.parseDouble(getItem(pos).getSpotPrice()) >= 0 )
    convertView.setBackgroundColor(Color.GREEN);
  else
    convertView.setBackgroundColor(Color.RED);

  return convertView;
}