I am having an issue that I have been working on for a while. I am using an ExpandableListView with a ViewHolder. I know that the ExpandableListView reuses Views and that is what I think is happening with the problem that I have.
I have 3 views in the list and if I select 1 then 2 then 3, then everything is fine and it displays the correct child view. Although when I select 3 first, all of the other child views are the same with the same groupPosition. If I select 2 first, then 3 is correct, but 1 displays the third child view.
I want them to be all fixed to the correct groupPosition so that they don't change.
Here is my adapter for the ExpandableListView:
public class MenuListAdapter extends BaseExpandableListAdapter
{
private Context context;
private ArrayList<ListData> listData = new ArrayList<ListData>();
/**
* Constructor for the class.
*
* @param refContext This is a reference to the context of the ExpandableListAdapter being used in.
* @param refListData This is a reference to the ArrayList of ListData that will display the item data of the menu in the list.
*/
public MenuListAdapter(Context refContext, ArrayList<ListData> refListData)
{
context = refContext;
listData = refListData;
}
private static class ViewHolder
{
TextView title;
TextView description;
ImageView image;
ImageButton addItem;
}
@Override
public int getGroupCount()
{
return listData.size();
}
@Override
public int getChildrenCount(int groupPosition)
{
return 1; // There will only ever be 1 child in the group.
}
@Override
public Object getGroup(int groupPosition)
{
return groupPosition;
}
@Override
public Object getChild(int groupPosition, int childPosition)
{
return null;
}
@Override
public long getGroupId(int groupPosition)
{
return groupPosition;
}
@Override
public long getChildId(int groupPosition, int childPosition)
{
return childPosition;
}
@Override
public boolean hasStableIds()
{
return true; // Stops child views from resetting
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent)
{
final ViewHolder holder;
if(convertView == null)
{
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.listview_item, parent, false);
holder = new ViewHolder();
holder.title = (TextView) convertView.findViewById(R.id.titleTextView);
holder.image = (ImageView) convertView.findViewById(R.id.imageImageView);
holder.addItem = (ImageButton) convertView.findViewById(R.id.addItemImageButton);
/* The contents of the item View is set for every View in the list. */
holder.title.setText(listData.get(groupPosition).getTitle());
holder.image.setImageBitmap(listData.get(groupPosition).getImageBitmap());
holder.image.setTag(listData.get(groupPosition).getImageRes()); // Sets tag for image resource.
holder.image.setFocusable(false);// Enables the group view to be in focus in order to still be able to select the image and group.
holder.image.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
Integer imageResource = (Integer) holder.image.getTag(); // Get image resource from tag.
int resource = imageResource.intValue(); // Creates primitive image resource from object Integer.
Intent imageIntent = new Intent(context, ImageActivity.class);
imageIntent.putExtra("image_resource", resource); // Adds image resource as Extra to Intent.
context.startActivity(imageIntent);
}
});
holder.addItem.setFocusable(false); // Enables the group view to be in focus in order to still be able to select the button and group.
holder.addItem.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
/* AlertDialog that allows the user to select how many items they want of the item they selected. */
AlertDialog.Builder alertBuilder = new AlertDialog.Builder(context);
AlertDialog alertDialog;
LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View customView = layoutInflater.inflate(R.layout.item_quantity, null);
final NumberPicker quantityPicker = (NumberPicker) customView.findViewById(R.id.quantityPicker);
quantityPicker.setMinValue(1);
quantityPicker.setMaxValue(10);
quantityPicker.setDescendantFocusability(NumberPicker.FOCUS_BLOCK_DESCENDANTS); // Stops keyboard from appearing.
alertBuilder.setTitle("Select quantity");
alertBuilder.setView(customView);
alertBuilder.setPositiveButton("Confirm", new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int id)
{
int quantityAmount = quantityPicker.getValue(); // Gets value from NumberPicker.
/* Update checkout data. */
MainActivity mainActivity = (MainActivity) context;
mainActivity.updateCheckout(holder.title.getText().toString(), quantityAmount); // Updates checkout with added order.
dialog.cancel(); // Cancels AlertDialog.
Toast.makeText(context, "Order added to checkout!", Toast.LENGTH_SHORT).show();
}
});
alertBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener()
{
@Override
public void onClick(DialogInterface dialog, int which)
{
dialog.cancel(); // Cancels AlertDialog.
}
});
alertDialog = alertBuilder.create(); // Creates the AlertDialog View.
alertDialog.show(); // Shows the AlertDialog View.
}
});
convertView.setTag(holder);
}
else
{
holder = (ViewHolder) convertView.getTag();
}
return convertView;
}
@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent)
{
final ViewHolder holder;
if(convertView == null)
{
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.listview_desc_item, parent, false);
holder = new ViewHolder();
holder.description = (TextView) convertView.findViewById(R.id.descriptionTextView);
holder.description.setText(listData.get(groupPosition).getDescription()); // Sets description of item View.
System.out.println("Group position: " + groupPosition);
System.out.println("Child position: " + childPosition);
convertView.setTag(holder);
}
else
{
holder = (ViewHolder) convertView.getTag();
}
return convertView;
}
@Override
public boolean isChildSelectable(int groupPosition, int childPosition)
{
return false;
}
}
Please can someone help me with this issue.
