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POExtending ArrayAdapter in android
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  1. POExtending ArrayAdapter in android
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    copied!<p>I need to override a <code>getFilter()</code> method from the class <code>ArrayAdapter</code> and i found the source code from <a href="https://github.com/android/platform_frameworks_base/blob/master/core/java/android/widget/ArrayAdapter.java" rel="noreferrer">here in the github</a> </p> <pre><code>//package name import java.util.ArrayList; import java.util.Arrays; import java.util.List; import android.content.Context; import android.util.Log; import android.widget.ArrayAdapter; import android.widget.Filter; import android.widget.Filterable; public class CustomAdapter&lt;T&gt; extends ArrayAdapter&lt;T&gt; implements Filterable{ private ArrayList&lt;T&gt; mOriginalValues; private List&lt;T&gt; mObjects; private CustomFilter mFilter; private final Object mLock = new Object(); public CustomAdapter(Context context, int textViewResourceId, T[] objects) { super(context, textViewResourceId, objects); mObjects = Arrays.asList(objects); // TODO Auto-generated constructor stub } @Override public Filter getFilter() { // TODO Auto-generated method stub if (mFilter == null) { mFilter = new CustomFilter(); } return mFilter; } private class CustomFilter extends Filter { @Override protected FilterResults performFiltering(CharSequence prefix) { FilterResults results = new FilterResults(); Log.d("bajji", "its ---&gt; " + prefix); if (mOriginalValues == null) { synchronized (mLock) { mOriginalValues = new ArrayList&lt;T&gt;(mObjects); } } if (prefix == null || prefix.length() == 0) { ArrayList&lt;T&gt; list; synchronized (mLock) { list = new ArrayList&lt;T&gt;(mOriginalValues); } results.values = list; results.count = list.size(); } else { String prefixString = prefix.toString().toLowerCase(); ArrayList&lt;T&gt; values; synchronized (mLock) { values = new ArrayList&lt;T&gt;(mOriginalValues); } final int count = values.size(); final ArrayList&lt;T&gt; newValues = new ArrayList&lt;T&gt;(); final ArrayList&lt;T&gt; approxValues = new ArrayList&lt;T&gt;(); final ArrayList&lt;T&gt; secondApproxValues = new ArrayList&lt;T&gt;(); for (int i = 0; i &lt; count; i++) { final T value = values.get(i); final String valueText = value.toString().toLowerCase(); boolean flag = true; // First match against the whole, non-splitted value if (valueText.startsWith(prefixString)) { newValues.add(value); flag = false; } else { final String[] words = valueText.split(" "); final int wordCount = words.length; // Start at index 0, in case valueText starts with space(s) for (int k = 0; k &lt; wordCount; k++) { if (words[k].startsWith(prefixString)) { newValues.add(value); flag = false; break; } } } if(flag) { if(approxMatch(valueText, prefixString) &lt;= 3) { //change the stuff and do a levi work approxValues.add(value); } else { final String[] words = valueText.split(" "); final int wordCount = words.length; // Start at index 0, in case valueText starts with space(s) for (int k = 0; k &lt; wordCount; k++) { if(approxMatch(words[k], prefixString) &lt;= 3) { //leve work secondApproxValues.add(value); break; } } } } } newValues.addAll(approxValues); newValues.addAll(secondApproxValues); results.values = newValues; results.count = newValues.size(); } return results; } @Override protected void publishResults(CharSequence constraint, FilterResults results) { //noinspection unchecked mObjects = (List&lt;T&gt;) results.values; if (results.count &gt; 0) { notifyDataSetChanged(); } else { notifyDataSetInvalidated(); } } } private int approxMatch (String s, String t) { // an approxmimate string matching algo return p; } } </code></pre> <p>The problem is the getFilter method has a object of a private inner class <code>ArrayFilter</code> which has a method <code>peformFiltering</code> and i need to put a different code there so i have to overide the class. And i get an exception in the method. </p> <p>In the derived class which extends ArrayAdapter i created a private inner class which is similar to <code>ArrayFilter</code> and called it <code>MyFilter</code> and i get the same exception again in the method <code>performFiltering</code>.</p> <p>I found a solution to solve my problem. I copied all the code in <code>ArrayAdapter</code> class and created a new class called <code>MyAdapter</code> and i altered some code inside the inner class <code>ArrayFilter</code> and the app works the way i wanted it to. But i feel its not the best solution.</p> <p>Android has various api levels so if the array adapter is changed in different api level then i have to add those changes in my codes to. So i feel the best way is to extend the class <code>ArrayAdapter</code> to create <code>MyAdapter</code> rather than just copying and pasting the code from the <code>ArrayAdapter</code></p> <p>How can i override the inner private class of a parent class..?</p> <p>Edit: The exception i get.. <img src="https://i.stack.imgur.com/IbUXw.png" alt="Exception"></p> <p>Edit2: Now i added the full code in the question. and it works perfectly if i copy and edit the array adapter.. the problem is only when i extend..!! now the code and search is working perfectly. I checked it with <code>Log.i</code>.. but the drop down list for auto complete suggestion in UI is not working.. i only get for the first character i type the next character filtering takes place but UI update is not taking place.</p>
 

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