List View Filter Android
Solution 1
Add an EditText on top of your listview in its .xml layout file. And in your activity/fragment..
lv = (ListView) findViewById(R.id.list_view);
inputSearch = (EditText) findViewById(R.id.inputSearch);
// Adding items to listview
adapter = new ArrayAdapter<String>(this, R.layout.list_item, R.id.product_name, products);
lv.setAdapter(adapter);
inputSearch.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
// When user changed the Text
MainActivity.this.adapter.getFilter().filter(cs);
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) { }
@Override
public void afterTextChanged(Editable arg0) {}
});
The basic here is to add an OnTextChangeListener to your edit text and inside its callback method apply filter to your listview's adapter.
EDIT
To get filter to your custom BaseAdapter you"ll need to implement Filterable interface.
class CustomAdapter extends BaseAdapter implements Filterable {
public View getView(){
...
}
public Integer getCount()
{
...
}
@Override
public Filter getFilter() {
Filter filter = new Filter() {
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
arrayListNames = (List<String>) results.values;
notifyDataSetChanged();
}
@Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults results = new FilterResults();
ArrayList<String> FilteredArrayNames = new ArrayList<String>();
// perform your search here using the searchConstraint String.
constraint = constraint.toString().toLowerCase();
for (int i = 0; i < mDatabaseOfNames.size(); i++) {
String dataNames = mDatabaseOfNames.get(i);
if (dataNames.toLowerCase().startsWith(constraint.toString())) {
FilteredArrayNames.add(dataNames);
}
}
results.count = FilteredArrayNames.size();
results.values = FilteredArrayNames;
Log.e("VALUES", results.values.toString());
return results;
}
};
return filter;
}
}
Inside performFiltering() you need to do actual comparison of the search query to values in your database. It will pass its result to publishResults() method.
Solution 2
Implement your adapter Filterable:
public class vJournalAdapter extends ArrayAdapter<JournalModel> implements Filterable{
private ArrayList<JournalModel> items;
private Context mContext;
....
then create your Filter class:
private class JournalFilter extends Filter{
@Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults result = new FilterResults();
List<JournalModel> allJournals = getAllJournals();
if(constraint == null || constraint.length() == 0){
result.values = allJournals;
result.count = allJournals.size();
}else{
ArrayList<JournalModel> filteredList = new ArrayList<JournalModel>();
for(JournalModel j: allJournals){
if(j.source.title.contains(constraint))
filteredList.add(j);
}
result.values = filteredList;
result.count = filteredList.size();
}
return result;
}
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
if (results.count == 0) {
notifyDataSetInvalidated();
} else {
items = (ArrayList<JournalModel>) results.values;
notifyDataSetChanged();
}
}
}
this way, your adapter is Filterable, you can pass filter item to adapter's filter and do the work. I hope this will be helpful.
Solution 3
In case anyone are still interested in this subject, I find that the best approach for filtering lists is to create a generic Filter class and use it with some base reflection/generics techniques contained in the Java old school SDK package. Here's what I did:
public class GenericListFilter<T> extends Filter {
/**
* Copycat constructor
* @param list the original list to be used
*/
public GenericListFilter (List<T> list, String reflectMethodName, ArrayAdapter<T> adapter) {
super ();
mInternalList = new ArrayList<>(list);
mAdapterUsed = adapter;
try {
ParameterizedType stringListType = (ParameterizedType)
getClass().getField("mInternalList").getGenericType();
mCompairMethod =
stringListType.getActualTypeArguments()[0].getClass().getMethod(reflectMethodName);
}
catch (Exception ex) {
Log.w("GenericListFilter", ex.getMessage(), ex);
try {
if (mInternalList.size() > 0) {
T type = mInternalList.get(0);
mCompairMethod = type.getClass().getMethod(reflectMethodName);
}
}
catch (Exception e) {
Log.e("GenericListFilter", e.getMessage(), e);
}
}
}
/**
* Let's filter the data with the given constraint
* @param constraint
* @return
*/
@Override protected FilterResults performFiltering(CharSequence constraint) {
FilterResults results = new FilterResults();
List<T> filteredContents = new ArrayList<>();
if ( constraint.length() > 0 ) {
try {
for (T obj : mInternalList) {
String result = (String) mCompairMethod.invoke(obj);
if (result.toLowerCase().startsWith(constraint.toString().toLowerCase())) {
filteredContents.add(obj);
}
}
}
catch (Exception ex) {
Log.e("GenericListFilter", ex.getMessage(), ex);
}
}
else {
filteredContents.addAll(mInternalList);
}
results.values = filteredContents;
results.count = filteredContents.size();
return results;
}
/**
* Publish the filtering adapter list
* @param constraint
* @param results
*/
@Override protected void publishResults(CharSequence constraint, FilterResults results) {
mAdapterUsed.clear();
mAdapterUsed.addAll((List<T>) results.values);
if ( results.count == 0 ) {
mAdapterUsed.notifyDataSetInvalidated();
}
else {
mAdapterUsed.notifyDataSetChanged();
}
}
// class properties
private ArrayAdapter<T> mAdapterUsed;
private List<T> mInternalList;
private Method mCompairMethod;
}
And afterwards, the only thing you need to do is to create the filter as a member class (possibly within the View's "onCreate") passing your adapter reference, your list, and the method to be called for filtering:
this.mFilter = new GenericFilter<MyObjectBean> (list, "getName", adapter);
The only thing missing now, is to override the "getFilter" method in the adapter class:
@Override public Filter getFilter () {
return MyViewClass.this.mFilter;
}
All done! You should successfully filter your list - Of course, you should also implement your filter algorithm the best way that describes your need, the code bellow is just an example.. Hope it helped, take care.
Amira Elsayed Ismail
God put me on earth to accomplish a certain number of things, right now I am so far behind, I will never die.
Updated on May 30, 2020Comments
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Amira Elsayed Ismail almost 4 years
I have created a list view in android and I want to add edit text above the list and when the user enter text the list will be filtered according to user input
can anyone tell me please if there is a way to filter the list adapter in android ?
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Amira Elsayed Ismail over 11 yearsI have created a custom adapter that extends BaseAdapter and inside it I have defined a Vector of my object that will be shown in the list, when I try to use the above code I couldn't find getFilter method in my Adapter, so could you please tell me if I have to implement any interface ??
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Purush Pawar over 11 yearsFiltering the data in case of BaseAdapter is a bit tricky. You will have to implement Filterable interface to your implementation of BaseAdapter. You will have then getFilter() method and inside it you have to implement two callback methods to work with; void publishResults() and FilterResults performFiltering(CharSequence constraint).
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Amira Elsayed Ismail over 11 yearscan you support with a simple example please ?
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Purush Pawar over 11 yearsYes. Check EDIT section of my answer.
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Amira Elsayed Ismail over 11 yearsThank you very much, it is just what I need, but I have one more problem that when I use back space the list not returned back to it's original data, so can you please help in this problem ?
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Purush Pawar over 11 yearsI suggest you to post another question on SO regarding this. Because it is not a proper way to keep asking different questions into same post. Well , as a heads up , just copy the whole arraylist into another temporary arraylist first and inside onPerformFiltering() method use this temporary list for searching. This will solve your problem. And please upvote and/or accept the answer if it helped you.
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Purush Pawar about 10 yearsIts an ArrayList of the current contents of the ListView. Basically, the data set of your adapter.
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Cruces about 8 yearsI don't know about android, but I remember being told to try to avoid reflection if possible in c# because it is quite resource intensive (I usually work on windows mobile applications so this could be a problem) , does this apply on android? or does reflection have the same effect as building an actual class without generics? I was thinking of creating a template for filterable and just adding the class and method used as parameters
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Iman Marashi almost 8 yearsUse import android.widget.Filter;
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jbrios777 almost 8 yearsYes, you're correct. The same applies here, reflection gives a weight to the program processing, but in this case it's a very simple use of it, and because we are using it with a generic/template notation, it also helps the compiler. Good luck!
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Alexey over 5 yearsN.B. You may have problems with obfuscation(dexguard/proguard) if you use reflection.