I am using an ArrayAdapter with filterable interface to implement search functionality in a listview.My code for adapter is following:
public class FlightsAdapter extends ArrayAdapter<Flight> implements Filterable {
List<Flight> flightLists = new ArrayList<Flight>();
private List<Flight> origFlightList;
private Context context;
Flight flight = null;
public FlightsAdapter(Context context, int textViewResourceId,
List<Flight> fLists) {
super(context, textViewResourceId, fLists);
this.context = context;
this.flightLists = fLists;
}
public void updateFlightList(List<Flight> newData){
this.flightLists.clear();
this.flightLists = newData;
}
public Filter getFilter() {
return new Filter() {
#Override
protected FilterResults performFiltering(CharSequence constraint) {
final FilterResults oReturn = new FilterResults();
final List<Flight> results = new ArrayList<Flight>();
if (origFlightList == null)
origFlightList = flightLists;
if (constraint != null) {
if (origFlightList != null && origFlightList.size() > 0) {
for (final Flight f : origFlightList) {
if (f.getPlace().toLowerCase()
.contains(constraint.toString()))
results.add(f);
}
}
oReturn.values = results;
oReturn.count = results.size();
}
return oReturn;
}
#SuppressWarnings("unchecked")
#Override
protected void publishResults(CharSequence constraint,
FilterResults results) {
flightLists = (ArrayList<Flight>) results.values;
notifyDataSetChanged();
}
};
}
}
getFilter() and publishResults() methods get triggered properly on searching and flightLists get populated with new data but the listview remain same with no items change, I don't know what I am doing wrong in above code, Please help me figure out this problem
Here is the problem
flightLists = (ArrayList<Flight>) results.values;
Replace this with
flightLists.clear();
flightLists.addAll((ArrayList<Flight>) results.values);
See if that fixes your issue.
Later edit (explanation):
When you created your adapter, you gave it a List object. The adapter thus has a reference, a pointer, to that List, from where it takes the data to display.
When you have replaced that reference with a whole other block of memory
flightLists = (ArrayList<Flight>) results.values;
the adapter didn't updated the orignial data set (from where it actually was taking data to display). Thus, notifyDataSetChanged() didn't work.
When updating the data in an adapter, you have to keep the original data structure reference intact. Clearing and populating with another data set is an option. Reinstantiating it (in any way) isn't.
This is basic java.
Related
I followed some youtube tutorial about SQLite and RecyclerView (https://www.youtube.com/watch?v=VQKq9RHMS_0&ab_channel=Stevdza-San) I completed all the things and customize it as I need to my app and everything work fine.
Now all I want to do is add Search Button at the top (Action Bar) that i can search items from my RecyclerView.
So i was try to figure out how to implement it, but I struggle with the filter and all those things. Every tutorials that I saw about this work with List (E) while my CustomeAdpter geting ArrayList and I can't undrstand how to make it work with the ArrayList.
So if some one can help me with that and give me some little guidance I will be grateful
EDIT
I added the getFilter() function in my adapter, but when I try to search something nothing happened in RecyclerView.
I am adding my code: MainActivity.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
activity = MainActivity.this;
noClubsImage = findViewById(R.id.noClubsImage);
noClubsText = findViewById(R.id.noClubsText);
recyclerView = findViewById(R.id.recyclerView);
add_button = findViewById(R.id.add_button);
add_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, AddActivity.class);
activity.startActivityForResult(intent,1);
}
});
myDB = new MyDatabaseHelper(MainActivity.this);
club_id = new ArrayList<>();
club_name = new ArrayList<>();
join_date = new ArrayList<>();
expire_date = new ArrayList<>();
storeDataInArrays();
customAdapter = new CustomAdapter(MainActivity.this, this, club_id, club_name, join_date, expire_date);
recyclerView.setAdapter(customAdapter);
recyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.this));
}
.
.
.
EDIT***
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main_menu, menu);
MenuItem item = menu.findItem(R.id.action_search);
SearchView searchView = (SearchView) item.getActionView();
searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
#Override
public boolean onQueryTextSubmit(String query) {
customAdapter.getFilter().filter(query);
return false;
}
#Override
public boolean onQueryTextChange(String newText) {
customAdapter.getFilter().filter(newText);
return true;
}
});
return super.onCreateOptionsMenu(menu);
}
}
And this is my Adapter:
I added Try & catch function in onBindViewHolder becuase it's crash if not and get this error: "java.lang.IndexOutOfBoundsException: Index: 1, Size: 1"
After adding it, I can search but something very weird, upload some pictures:
When I start the app
Start searching "Yasha" -> it change the two rows
public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.MyViewHolder> implements Filterable{
private Context context;
private Activity activity;
private ArrayList club_id, club_name, join_date,expire_date,list,originalList;
int position;
Animation translate_anim;
CustomAdapter(Activity activity, Context context, ArrayList club_id, ArrayList club_name, ArrayList join_date, ArrayList expire_date){
this.activity = activity;
this.context = context;
this.club_id = club_id;
this.club_name = club_name;
this.join_date = join_date;
this.expire_date = expire_date;
this.list = club_name;
this.originalList = club_name;
}
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(context);
View view = inflater.inflate(R.layout.my_row,parent,false);
return new MyViewHolder(view);
}
public Filter getFilter(){
return new Filter() {
#Override
protected FilterResults performFiltering(CharSequence constraint) {
ArrayList filteredResults = null;
if (constraint.length() == 0) {
filteredResults = club_name;
} else {
filteredResults = getFilteredResults(constraint.toString().toLowerCase());
}
FilterResults results = new FilterResults();
results.values = filteredResults;
Log.d("Test",filteredResults.toString());
return results;
}
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
club_name = (ArrayList<String>) results.values;
notifyDataSetChanged();
}
};
}
protected ArrayList getFilteredResults(String constraint) {
ArrayList results = new ArrayList<>();
for (Object item : originalList) {
if (item.toString().toLowerCase().contains(constraint)) {
results.add(item.toString());
}
}
//Log.d("Test",results.toString());
return results;
}
#Override
public void onBindViewHolder(#NonNull MyViewHolder holder, final int position) {
try{
this.position = position;
holder.club_name_txt.setText(String.valueOf(club_name.get(position)));
holder.join_txt.setText(String.valueOf(join_date.get(position)));
holder.expire_txt.setText(String.valueOf(expire_date.get(position)));
holder.mainLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(context,UpdateActivity.class);
intent.putExtra("club_id",String.valueOf(club_id.get(position)));
intent.putExtra("club_name",String.valueOf(club_name.get(position)));
intent.putExtra("join_date",String.valueOf(join_date.get(position)));
intent.putExtra("expire_date",String.valueOf(expire_date.get(position)));
activity.startActivityForResult(intent,1);
}
});
}catch(Exception ex) {
Log.e("TAG", "EXCEPTION CAUGHT WHILE EXECUTING DATABASE TRANSACTION");
ex.printStackTrace();
}
}
#Override
public int getItemCount() {
return club_id.size();
}
public class MyViewHolder extends RecyclerView.ViewHolder {
LinearLayout mainLayout;
TextView club_id_txt, club_name_txt, join_txt,expire_txt;
public MyViewHolder(#NonNull View itemView) {
super(itemView);
club_name_txt = itemView.findViewById(R.id.club_name_txt);
join_txt = itemView.findViewById(R.id.jDate_txt);
expire_txt = itemView.findViewById(R.id.eDate_txt);
mainLayout = itemView.findViewById(R.id.mainLayout);
translate_anim = AnimationUtils.loadAnimation(context, R.anim.translate_anim);
mainLayout.setAnimation(translate_anim);
}
}}
you have customAdapter.getFilter(); line in both methods of OnQueryTextListener and it returns filter for you. thats all what you have requested, you've never passed a String to this filter. this line should look like this
customAdapter.getFilter().filter(query); // or newText, depend on OnQueryTextListener method
edit due to comments:
remove this try{}catch() and fix your exception. this method is reliable and only your mistake can lead to crash.
you are filtering and publishing only one of arrays (club_name = (ArrayList<String>) results.values;), but still you are informing adapter that list have number of items equal to club_id.size(); in getItemCount. thats why you are getting IndexOutOfBoundsException - club_id is untouched and have multiple items, even after filtering when club_name have only few or one item inside. you should filter all four arrays, in fact this should be one array with custom object carrying all four params
some tutorial for fixing:
keep your data in some additional arrays which will stay untouched and keep all data even after filtering. for start make "original" and "working" arrays
CustomAdapter(Activity activity, Context context, ArrayList club_id, ArrayList club_name, ArrayList join_date, ArrayList expire_date){
this.activity = activity;
this.context = context;
this.club_id_org = club_id;
this.club_name_org = club_name;
this.join_date_org = join_date;
this.expire_date_org = expire_date;
this.club_id = new ArrayList<>();
this.club_id.addAll(this.club_id_org);
this.club_name = new ArrayList<>();
this.club_name.addAll(this.club_name_org);
this.join_date = new ArrayList<>();
this.join_date.addAll(this.join_date_org);
this.expire_date = new ArrayList<>();
this.expire_date.addAll(this.expire_date_org);
}
note how much duplicated code we have in here, thats why this should be one ArrayList with some custom object... but nvm, lets stay (for now) with four arrays
dont use this construction: this.list = club_name; - this makes list and club_name are same arrays (objects), when you remove some item from one then it will be removed from second (in fact same) array, and we need here two separated arrays (x4)
now all arrays with _org suffix are carrying whole lists, but adapter should work on "working" arrays, these without _org, like you have currently in code
now filtering: in performFiltering you should create, again, four temporary arrays and fill them with filtered items. for filtering iterate through _org arrays, these with all items
#Override
protected FilterResults performFiltering(CharSequence constraint) {
ArrayList club_id_temp = new Arraylist<>(),
club_name_temp = new Arraylist<>(),
join_date_temp = new Arraylist<>(),
expire_date_temp = new Arraylist<>();
if (constraint.length() == 0) {
club_id_temp.addAll(club_id_org);
club_name_temp.addAll(club_name_org);
join_date_temp.addAll(join_date_org);
expire_date_temp.addAll(expire_date_org);
} else {
for(int i=0; i<club_name_org.size(); i++){
if(club_name_org.get(i).toLowerCase().contains(constraint.toLowerCase())){
club_id_temp.add(club_id_org.get(i));
club_name_temp.add(club_name_org.get(i));
join_date_temp.add(join_date_org.get(i));
expire_date_temp.add(expire_date_org.get(i));
}
}
}
FilterResults results = new FilterResults();
results.values = ...
and now we have a small problem... results.values can carry only one object, e.g. one ArrayList and you have four... lets make come class carrying all four for your purposes, declare such e.g. on the bottom of adapter (just before last bracket closing whole adapter })
public static class TempArrays{
public ArrayList club_id, club_name, join_date, expire_date;
}
and pack all four filtered arrays into:
FilterResults results = new FilterResults();
TempArrays ta = new TempArrays();
ta.club_id = club_id_temp;
ta.club_name = club_name_temp;
ta.join_date = join_date_temp;
ta.expire_date = expire_date_temp;
results.values = ta;
return results;
}
and unpack this construction in publishResults:
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
TempArrays ta = (TempArrays) results.values;
club_id = ta.club_id;
club_name = ta.club_name;
join_date = ta.join_date;
expire_date = ta.expire_date;
notifyDataSetChanged();
}
again: four arrays isn't proper way, look how much duplicated lines we have here... + some small workaround for passing all four after filtering instead of one... in fact there should be some ClubModel class, similar to this
public static class ClubModel{
public String club_id, club_name, join_date, expire_date;
}
and then you may work on one array with ClubModel items, instead of four arrays. check out POJO definition
I have an listview with filter. When I input some words in an edittext that I used as a filter for example "david", it works well, items in the list are filtered and it will show all item that contains "david". But when I delete some words, for example "dav", the list is still filtered, but it filtered from the last filtered by "david".
Let's say I had 40 items, filtered by "david", it becomes 24 items. Then I filtered it again with "dav", it filtered from the "24 items" one, not the "40 items" one.
Here is my custom adapter:
public class WRegistrantListAdapter extends ArrayAdapter<Registrant> {
private Context mContext;
private int mResource;
private List<Registrant> mOriginalList;
private List<Registrant> mFilteredList;
public WRegistrantListAdapter(Context context, int resource, ArrayList<Registrant> oobjects, int workshopItemId) {
super(context, resource, oobjects);
mContext = context;
mResource = resource;
mFilteredList = oobjects;
}
#NonNull
#Override
public View getView(int position, #Nullable View convertView, #NonNull ViewGroup parent) {
//contains code for displaying item.
}
#NonNull
#Override
public Filter getFilter() {
return new Filter() {
#Override
protected FilterResults performFiltering(CharSequence charSequence) {
FilterResults result = new FilterResults();
String constraint = charSequence.toString().toLowerCase();
if (mOriginalList == null) {
mOriginalList = mFilteredList;
Toast.makeText(mContext, String.valueOf(mOriginalList.size()), Toast.LENGTH_SHORT).show();
}
if (constraint == null || constraint.isEmpty() || constraint.equals("")) {
result.values = mOriginalList;
result.count = mOriginalList.size();
} else {
List<Registrant> list = new ArrayList<>();
int max = mOriginalList.size();
for (int cont = 0; cont < max; cont++) {
Registrant item = mOriginalList.get(cont);
boolean contains =
item.getRegistrantName().toLowerCase().contains(constraint) ||
item.getRegistrantNumber().toLowerCase().contains(constraint);
if (contains) {
list.add(mOriginalList.get(cont));
}
}
result.values = list;
result.count = list.size();
}
return result;
}
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
clear();
addAll((ArrayList<Registrant>) results.values);
notifyDataSetChanged();
}
};
}
}
Which part in the filtering is wrong? Any help would be much appreciated. Hope my explanation is not confusing because English is not my mother language.
You need two different lists for filtering, so try change mOriginalList = mFilteredList; to mOriginalList = new ArrayList<>(mFilteredList); may solve the issue.
Explanations:
mOriginalList = mFilteredList; is same list with two different names. It is helpful in modular program, just like mFilteredList = oobjects; in your adapter constructor.
mOriginalList = new ArrayList<>(mFilteredList); is to make a shallow copy of mFilteredList and store it as mOriginalList, so the lists are different.
Shallow and Deep Copy:
Example: If your custom class, Registrant, contains a public field (List, Map or custom object etc., that requires new for creation) named sample. Under shallow copy, mOriginalList = new ArrayList<>(mFilteredList);, mOriginalList.get(i) is a copy of mFilteredList.get(i) and they are 2 different Registrant objects. But mOriginalList.get(i).sample and mFilteredList.get(i).sample is the same object.
If you need mOriginalList.get(i).sample and mFilteredList.get(i).sample to be different objects, then it is called deep copy. There is no ready method to make deep copy, you have to make your own method according to your custom class. But up to now, I never have a case that needs deep copy.
Hope that helps!
You should keep two separate lists in your adapter such as,
private List<Registrant> mOriginalList = new ArrayList();
private List<Registrant> mFilteredList = new ArrayList();
public WRegistrantListAdapter(Context context, int resource, ArrayList<Registrant> oobjects, int workshopItemId) {
super(context, resource, oobjects);
mContext = context;
mResource = resource;
mFilteredList.addAll(oobjects);
mOriginalList.addAll(oobjects);
}
Initially, both of them should have the same value and you will use filteredList for showing your data. Later in the filter, you should publish your data like
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
filteredList.clear();
filteredList.addAll((ArrayList<Registrant>) results.values);
notifyDataSetChanged();
}
A complete example is can be found in Filter ListView with arrayadapter
It seems that this should be easy.
I have an Android app with a list using an ArrayAdapter. It works. I replace the ArrayAdapter with a custom sub-class. It works. I add a inner class that is a sub-class of Filter and mark the ArrayAdaptor sub-class as implementing Fiterable. And it works fine, except that it does not filter.
What is the magic word I have to say here?
None of the methods in the Filter sub-class are being invoked.
public class XYZListAdapter extends ArrayAdapter<XYZListFragment.XYZItem> implements Filterable {
private List<XYZListFragment.XYZItem> sourceObjects;
private Context sourceContext;
private XYZFilter xyzFilter;
public XYZListAdapter(Context context, int resource, int textViewResourceId, List<XYZListFragment.XYZItem> objects) {
super(context, resource, textViewResourceId, objects);
sourceObjects = new ArrayList<>(objects);
sourceContext = context;
}
public View getView(int position, View convertView, ViewGroup parent) {
Log.i("XYZAdapter", "getView");
View v = convertView;
if (v == null) {
v = ((LayoutInflater)sourceContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(R.layout.fragment_xyz_list_item, parent, false);
}
XYZListFragment.XYZItem mItem = sourceObjects.get(position);
if (mItem != null) {
TextView t = (TextView)v.findViewById(R.id.xyz_list_item_name_view);
if (t != null) {
t.setText(mItem.name());
}
}
return v;
}
#Override
public Filter getFilter() {
Log.i("XYZAdapter", "getFilter");
if (xyzFilter == null)
xyzFilter = new XYZFilter();
return xyzFilter;
}
private class XYZFilter extends Filter {
#Override
protected FilterResults performFiltering(CharSequence constraint) {
Log.i("XYZFilter", "perform");
FilterResults results = new FilterResults();
if (constraint == null || constraint.length() == 0) {
results.values = sourceObjects;
results.count = sourceObjects.size();
}
else {
List<XYZListFragment.XYZItem> nextXYZList = new ArrayList<>();
for (XYZListFragment.XYZItem p : sourceObjects) {
if (p.name().toUpperCase().startsWith(constraint.toString().toUpperCase()))
nextXYZList.add(p);
}
results.values = nextXYZList;
results.count = nextXYZList.size();
}
return results;
}
#Override
#SuppressWarnings("unchecked")
protected void publishResults(CharSequence constraint, FilterResults results) {
Log.i("XYZFilter", "publish");
if (results.count == 0)
notifyDataSetInvalidated();
else {
sourceObjects = (List<XYZListFragment.XYZItem>) results.values;
notifyDataSetChanged();
}
}
}
}
It doesn't work because you shouldn't subclass the ArrayAdapter if you want to customize it's filtering logic. You would need to implement an adapter from scratch using the BaseAdapter.
Basically, the ArrayAdapter internally tracks its own list of objects. However you are only updating your list of objects in the subclass. You need to update the internal list as well. Otherwise the adapter is not aware of the change.
There are other issues. For instance, the performFiltering() method executes on a background thread. That means you need to synchronize any changes done to the list. The ArrayAdapter already does this internally...and you have no way of accessing the sync lock object it uses...which makes it impossible for you to safely sync.
Also, your filtering solution doesn't seem to provide a solution for restoring the list back to its original state after the filtering is cleared out.
You can read more about the problems with ArrayAdapter filtering here. General rule of thumb. When using the ArrayAdapter don't create your own list to track the data and don't customize the filtering. Optionally, you can use something like the AbsArrayAdapter which is just like an ArrayAdapter but lets you define the filtering logic for you.
I have AutoCompleteTextView attached to my view, and used ArrayAdapter to populate for list of items. But I am unaware of how to add header and footer view for AutocompleteTextView drop down's item.
I know we can add header and footer in listview.
Any suggestions ?
On an AutoCompleteTextView, you don't have direct access to the DropDownListView, that's why you cannot add header and footer views there.
A solution to your problem will be to use 2 types of views in your list, and set the first/last row to have the header's/footer's layout. This can be done on the adapter, which you create yourself.
Here's some info about how to provide different layouts for different rows in a list view:
Android ListView with different layouts for each row
Android provided methods like addHeaderView(View v) and addFooterView(View v) to define headers and footers for the ListViews.
To find an answer on your question, I can refer you to Android: Adding static header to the top of a ListActivity.
Good luck!
private class PlacesAutoCompleteAdapter extends ArrayAdapter<String> implements Filterable {
private ArrayList<String> resultList;
public PlacesAutoCompleteAdapter(Context context, int textViewResourceId) {
super(context, textViewResourceId);
}
#Override
public int getCount() {
return resultList.size();
}
#Override
public String getItem(int index) {
return resultList.get(index);
}
#Override
public Filter getFilter() {
Filter filter = new Filter() {
#Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults filterResults = new FilterResults();
if (constraint != null) {
// Retrieve the autocomplete results.
resultList = autocomplete(constraint.toString());
// Assign the data to the FilterResults
filterResults.values = resultList;
filterResults.count = resultList.size();
}
return filterResults;
}
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
if (results != null && results.count > 0) {
notifyDataSetChanged();
}
else {
notifyDataSetInvalidated();
}
}};
return filter;
}
}
where autocomplete function should return the arraylist of string
can someone please give me an link of filling AutoCompleteTextView using BaseAdapter in android for phone contacts.
Thanks
user750716 is wrong.
You can fill AutoCompleteTextView with BaseAdapter. You just need to remember that BaseAdapter has to implement Filterable.
In Adapter create your ArrayList of Objects.
Implement getView with whatever View you want and fill it with objects.get(position) info.
Implement getItem(int position) returning a string (name of clicked object)
In the same adapter add stuff for filtering:
public Filter getFilter() {
return new MyFilter();
}
private class MyFilter extends Filter {
#Override
protected FilterResults performFiltering(CharSequence filterString) {
// this will be done in different thread
// so you could even download this data from internet
FilterResults results = new FilterResults();
ArrayList<myObject> allMatching = new ArrayList<myObject>()
// find all matching objects here and add
// them to allMatching, use filterString.
results.values = allMatching;
results.count = allMatching.size();
return results;
}
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
objects.clear();
ArrayList<myObject> allMatching = (ArrayList<myObject>) results.values;
if (allMatching != null && !allMatching.isEmpty()) {
objects = allMatching;
}
notifyDataSetChanged();
}
}
This is not possible with an BaseAdapter but you can use a CursorAdapter with no SQLite DB in the background. In the function runQueryOnBackgroundThread you can create an MatrixCursor.
Something like this:
String[] tableCols = new String[] { "_id", "keyword" };
MatrixCursor cursor = new MatrixCursor(tableCols);
cursor.addRow(new Object[] { 1, "went" });
cursor.addRow(new Object[] { 2, "gone" });
I have done this in my morphological analyzer.