Question

So I had my listview working perfectly then I decided to add a context menu. As soon as I did that whenever I normal clicked an item in my listview, the entire list gets inverted on the first click. Subsequent clicks do nothing to the order, but when the first item is de-selected again the list returns to normal. When I take out the context menu logic that I added, the list view problem does not go away.

I’ve attached a debugger and the elements in my list adapter are never reordered, and the ListView itself is never set to reverse with .setStackFromBottom()

Here is my onClick listener registered to handle the click events of the list view items:

public void onClick(View v) {  
    ViewHolder holder = (ViewHolder) v.getTag();  
    CheckBox b = holder.box;  
    Boolean check = b.isChecked();  
    b.setChecked(!check);  
    if (!check) {  
       mChecked.add(holder.fu);  
       if (mChecked.size() == 1) {  
         buttonLayout.setVisibility(View.VISIBLE);  
       }  
    } else {  
       mChecked.remove(holder.fu);  
       if (mChecked.size() == 0) {  
         buttonLayout.setVisibility(View.GONE);  
       }  
   }  
}

The viewholder class just holds references to objects I use in the listview for optimizations. I cannot figure out why this is causing my list to invert when displayed, I’ve tried moving the listener to a different view in the layout, I’ve tried re-writing the listener, nothing seems to work! Any advice would be appreciated.

Edit: here is the code for the view holder

/** Class to provide a holder for ListViews. Used for optimization */  
private class ViewHolder {  
    TextView date;  
    TextView gallons;  
    TextView cost;  
    TextView cpg;  
    TextView mpg;  
    CheckBox box;  
    FillUp fu;  
}  

as well as the adapter:

 public class FillUpAdapter extends BaseAdapter {

        ArrayList<FillUp> mElements;
        ArrayList<FillUp> mChecked;
        Context mContext;

        public FillUpAdapter(Context c, ArrayList<FillUp> data) {
            mContext = c;
            mElements = data;
            mChecked = new ArrayList<FillUp>();
        }

        public void clearChecked() {
            mChecked.clear();
        }

        public ArrayList<FillUp> getChecked() {
            return mChecked;
        }

        public boolean remove(FillUp f) {
            mChecked.remove(f);
            return mElements.remove(f);
        }

        @Override
        public int getCount() {
            return mElements.size();
        }

        @Override
        public Object getItem(int arg0) {
            return mElements.get(arg0);
        }

        @Override
        public long getItemId(int arg0) {

            return mElements.get(arg0).getId();
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            LinearLayout layout;
            ViewHolder holder;
            if (convertView != null) {
                layout = (LinearLayout) convertView;
                holder = (ViewHolder) layout.getTag();
            } else {
                layout = (LinearLayout) LayoutInflater.from(mContext).inflate(
                        R.layout.fillup_list_item, parent, false);
                holder = new ViewHolder();
                holder.cost = (TextView) layout
                        .findViewById(R.id.fillUpListTotalValue);
                holder.cpg = (TextView) layout
                        .findViewById(R.id.fillUpListCostPerGal);
                holder.gallons = (TextView) layout
                        .findViewById(R.id.fillUpListGalValue);
                holder.mpg = (TextView) layout
                        .findViewById(R.id.fillUpMPGText);
                holder.date = (TextView) layout
                        .findViewById(R.id.fillUpListDate);
                holder.box = (CheckBox) layout
                        .findViewById(R.id.fillUpListCheckBox);
                holder.fu = (FillUp) getItem(position);
                layout.setTag(holder);

            }

            holder.date.setText(holder.fu.getDate());
            holder.gallons.setText(holder.fu.getGallonsText());
            holder.cpg.setText(holder.fu.getCostText());
            holder.cost.setText(holder.fu.getTotalText());
            holder.mpg.setText(String.format("%03.1f MPG",holder.fu.getMPG()));
            if (convertView != null) {
                holder.box.setChecked(mChecked.contains(holder.fu));
            }

            layout.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    ViewHolder holder = (ViewHolder) v.getTag();
                    CheckBox b = holder.box;
                    Boolean check = b.isChecked();
                    b.setChecked(!check);
                    if (!check) {
                        mChecked.add(holder.fu);
                        if (mChecked.size() == 1) {
                            buttonLayout.setVisibility(View.VISIBLE);
                        }
                    } else {
                        mChecked.remove(holder.fu);
                        if (mChecked.size() == 0) {
                            buttonLayout.setVisibility(View.GONE);
                        }
                    }
                }
            });
            return layout;
        }
}

UPDATE:
Ok, so I’ve narrowed it down to the visibility change on the buttonLayout view, which is a linear layout of buttons on the bottom of the Activity’s layout, underneath the ListView. Whenever I change that view’s visibility to View.VISIBLE (which happens when the first item is checked) the list’s order is reversed. The order is restored when the view’s visibility is set to View.GONE

I have no idea what would cause that though 🙁

Answer 1

After narrowing the scope a bit more, I discovered the problem was not the changing of the visibility of my button bar, but actually the passing around of FillUp objects in holder.fu of my ViewHolder class. By changing that to instead reference the adapter’s getItem(position) method, everything seemed to work out. Quite an odd bug, since the adapter itself was not having the order of the elements changed, but passing around a reference to the object made it very unhappy.