Question

In onListItemClick I want to change clicked item background, this is my code:

public void onListItemClick(ListView parent, View v, int position, long id){

    if (position != previous_position){
        v.setBackgroundResource(R.drawable.category_clicked_item_bg);
        if (previous_category != null)
            previous_category.setBackgroundResource(R.drawable.category_item_bg);
        previous_category = v;
        previous_position = position;
    }
}

previous_category and previous_position are protected variables.

The problem is, that on item click multiple items in list are highlighted (more specifically 1 or 2). In list there are 20 rows, if I click one in middle, only one gets highlighted, if I click any row in beginning or end, other row in opposite side gets highlighted with interval 13 rows (that’s probably the reason why pressing middle row don’t highlight second).

I need list to highlight only one row the clicked one, what is the problem?

ADDITIONAL CODE

If that can help, here is also ListView adapter class:

package domehotel.guestbook.page.category;

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import domehotel.guestbook.R;

public class CategoryAdapter extends ArrayAdapter<CategoryItem>{

Context context; 
int layoutResourceId;    
CategoryItem data[] = null;

public CategoryAdapter(Context context, int layoutResourceId, CategoryItem[] data) {
    super(context, layoutResourceId, data);
    this.layoutResourceId = layoutResourceId;
    this.context = context;
    this.data = data;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View row = convertView;
    CategoryHolder holder = null;

    if(row == null)
    {
        LayoutInflater inflater = ((Activity)context).getLayoutInflater();
        row = inflater.inflate(layoutResourceId, parent, false);

        holder = new CategoryHolder();
        holder.category_name = (TextView)row.findViewById(R.id.category_name);

        row.setTag(holder);
    }
    else
    {
        holder = (CategoryHolder)row.getTag();
    }

    CategoryItem category = data[position];
    holder.category_name.setText(category.category_name);

    return row;
}

static class CategoryHolder
{
    TextView category_name;
}
}

Answer 1

In fact you are reusing views. getView takes as 2nd parameter a View named convertView. The ListView calls this method with an old View item (if there is one), which is instantiated (inflated) but not displayed at the moment. Your meth. onListItemClick now sets the backround of one of these Views, but this View will be reused later for another row, without resetting it’s backround.

A possible soloution:

1. The click listener should only store the background color, or a clicked flag, for a clicked position somewhere and then ask the View (row) in question to rerender (it could also save state and then set the background directly).

2. The getView(..) method should always set the background color of a View according to the saved color/state for its position. Set a normal background for positions not marked as clicked or set another background for positions marked as clicked by the click listener.