refactor

library/src/se/emilsjolander/stickylistheaders/ExpandableStickyListHeadersListView.java

@@ -3,8 +3,6 @@
 import android.content.Context;
 import android.util.AttributeSet;
 import android.view.View;
-
-import android.widget.SectionIndexer;
 import java.util.List;
 
 /**
@@ -54,8 +52,8 @@ public ExpandableStickyListHeadersAdapter getAdapter() {
 
     @Override
     public void setAdapter(StickyListHeadersAdapter adapter) {
-        mExpandableStickyListHeadersAdapter = (adapter instanceof SectionIndexer) ?
-            new SectionIndexingExpandableStickyListHeadersAdapter(adapter) :
+        mExpandableStickyListHeadersAdapter = (adapter instanceof SectionIndexingStickyListHeadersAdapter) ?
+            new SectionIndexingExpandableStickyListHeadersAdapter(((SectionIndexingStickyListHeadersAdapter) adapter)) :
             new ExpandableStickyListHeadersAdapter(adapter);
         super.setAdapter(mExpandableStickyListHeadersAdapter);
     }

library/src/se/emilsjolander/stickylistheaders/SectionIndexingExpandableStickyListHeadersAdapter.java

@@ -4,23 +4,26 @@
 
 public class SectionIndexingExpandableStickyListHeadersAdapter extends ExpandableStickyListHeadersAdapter implements SectionIndexer {
 
-	SectionIndexingExpandableStickyListHeadersAdapter(StickyListHeadersAdapter innerAdapter) {
+	SectionIndexingExpandableStickyListHeadersAdapter(SectionIndexingStickyListHeadersAdapter innerAdapter) {
 		super(innerAdapter);
-		if (!(innerAdapter instanceof SectionIndexer)) throw new IllegalArgumentException("Wrapped adapter must implement SectionIndexer");
 	}
 
 	@Override
 	public Object[] getSections() {
-		return ((SectionIndexer) mInnerAdapter).getSections();
+		return getAdapter().getSections();
 	}
 
 	@Override
 	public int getPositionForSection(int sectionIndex) {
-		return ((SectionIndexer) mInnerAdapter).getPositionForSection(sectionIndex);
+		return getAdapter().getPositionForSection(sectionIndex);
 	}
 
 	@Override
 	public int getSectionForPosition(int position) {
-		return ((SectionIndexer) mInnerAdapter).getSectionForPosition(position);
+		return getAdapter().getSectionForPosition(position);
+	}
+
+	private SectionIndexingStickyListHeadersAdapter getAdapter() {
+		return ((SectionIndexingStickyListHeadersAdapter) mInnerAdapter);
 	}
 }

library/src/se/emilsjolander/stickylistheaders/SectionIndexingStickyListHeadersAdapter.java

@@ -0,0 +1,5 @@
+package se.emilsjolander.stickylistheaders;
+
+import android.widget.SectionIndexer;
+
+public interface SectionIndexingStickyListHeadersAdapter extends StickyListHeadersAdapter, SectionIndexer {}

sample/src/se/emilsjolander/stickylistheaders/sample/TestBaseAdapter.java

@@ -5,15 +5,11 @@
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.BaseAdapter;
-import android.widget.SectionIndexer;
 import android.widget.TextView;
-
 import java.util.ArrayList;
+import se.emilsjolander.stickylistheaders.SectionIndexingStickyListHeadersAdapter;
 
-import se.emilsjolander.stickylistheaders.StickyListHeadersAdapter;
-
-public class TestBaseAdapter extends BaseAdapter implements
-        StickyListHeadersAdapter, SectionIndexer {
+public class TestBaseAdapter extends BaseAdapter implements SectionIndexingStickyListHeadersAdapter {
 
     private final Context mContext;
     private String[] mCountries;