I have been struggling with this for a while and can’t find the answer despite looking for a while. I have a custom arrayAdapter which populates my list view with a custom object POI.
package com.WasserSportLotse;
import java.util.ArrayList;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Filter;
import android.widget.ImageView;
import android.widget.TextView;
class poiAdapter extends ArrayAdapter<POI>{
private ArrayList<POI> items;
private Context mContext;
public ArrayList<POI> allItems;
private Filter filter;
public ArrayList<POI> filtered;
public poiAdapter(Context context, int textViewResourceId, ArrayList<POI> items){
super(context, textViewResourceId, items);
mContext = context;
this.items = items;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
if (v == null) {
LayoutInflater vi = (LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.list_items, null);
}
POI poi = items.get(position);
if (poi != null) {
TextView mDistanceTextView = (TextView) v.findViewById(R.id.listitems_distancetxt);
TextView mNameTextView = (TextView) v.findViewById(R.id.listitems_nametxt);
TextView mCategoryTextView = (TextView) v.findViewById(R.id.listitems_categorytxt);
if (mDistanceTextView != null) {
mDistanceTextView.setText(poi.getDistance()+"km");
}
if(mNameTextView != null){
mNameTextView.setText(poi.getName());
}
if(mCategoryTextView != null){
mCategoryTextView.setText(poi.getType());
setImage(poi.getType(), v);
}
}
return v;
}
private void setImage(String type, View v) {
if ("shopping".equals(type)){
ImageView mImage = (ImageView) v.findViewById(R.id.imageView1);
mImage.setImageResource(R.drawable.shopping);
}
if ("liegestelle".equals(type)){
ImageView mImage = (ImageView) v.findViewById(R.id.imageView1);
mImage.setImageResource(R.drawable.liegestelle);
}
if ("restaurant".equals(type)){
ImageView mImage = (ImageView) v.findViewById(R.id.imageView1);
mImage.setImageResource(R.drawable.restaurant);
}
if ("schleuse".equals(type)){
ImageView mImage = (ImageView) v.findViewById(R.id.imageView1);
mImage.setImageResource(R.drawable.schleuse);
}
if ("verein".equals(type)){
ImageView mImage = (ImageView) v.findViewById(R.id.imageView1);
mImage.setImageResource(R.drawable.verein);
}
if ("tankstelle".equals(type)){
ImageView mImage = (ImageView) v.findViewById(R.id.imageView1);
mImage.setImageResource(R.drawable.tankstelle);
}
if ("faekalien".equals(type)){
ImageView mImage = (ImageView) v.findViewById(R.id.imageView1);
mImage.setImageResource(R.drawable.faekalien);
}
if ("werkstatt".equals(type)){
ImageView mImage = (ImageView) v.findViewById(R.id.imageView1);
mImage.setImageResource(R.drawable.werkstatt);
}
if ("uebernachtung".equals(type)){
ImageView mImage = (ImageView) v.findViewById(R.id.imageView1);
mImage.setImageResource(R.drawable.uebernachtung);
}
}
@Override
public Filter getFilter()
{
if(filter == null)
filter = new POITypeFilter();
return filter;
}
private class POITypeFilter extends Filter
{
@Override
protected FilterResults performFiltering(CharSequence constraint) {
// NOTE: this function is *always* called from a background thread, and
// not the UI thread.
constraint = constraint.toString().toLowerCase();
FilterResults result = new FilterResults();
if(constraint != null && constraint.toString().length() > 0)
{
ArrayList<POI> filt = new ArrayList<POI>();
ArrayList<POI> lItems = new ArrayList<POI>();
synchronized (this)
{
lItems.addAll(items);
}
for(int i = 0, l = lItems.size(); i < l; i++)
{
POI m = lItems.get(i);
if(m.getType().toLowerCase().contains(constraint))
filt.add(m);
}
result.count = filt.size();
result.values = filt;
}
else
{
synchronized(this)
{
result.values = items;
result.count = items.size();
}
}
return result;
}
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
// NOTE: this function is *always* called from the UI thread.
filtered = (ArrayList<POI>)results.values;
notifyDataSetChanged();
clear();
for(int i = 0, l = filtered.size(); i < l; i++)
add(filtered.get(i));
notifyDataSetInvalidated();
}
}
}
I am trying to Override the getFilter method so I can filter each POI by POI.type and update the listView. I am calling the getFilter like so
@Override
protected void onRestart() {
super.onRestart();
mAdapter.getFilter().filter(getFilterSettings());
mAdapter.notifyDataSetChanged();
}
This just returns a black screen as if everything has been filtered out. I put breakpoints in over the getFilter but the app does enter into it so I am not sure the app is using this code. Is there something obvious that I am missing?
UPDATE – Half way there
I had a couple of problems here. It looked as tho the app wasn’t calling getFilter as the breakpoints where not stopping there. In fact the Davlik Virtual Machine can only use so many break points (it’s not so many to keep it in mind). It stopped using the breakpoints at exactly the time I use the code I wanted to analyse. I think I was pretty unlucky.
Then where where some problems with the code.I changed
private ArrayList<POI> items;
to public. So it could be read into a new array and that filters the results. Now just to figure out how to make the arrayAdapter to filter again but on the original array. Wow this is turning out to be a long process.
if you want to make a custom filter, all you have to do is create a toString() method on your POI class that returns the value you want to filter by.