Bug: Fixes Item not staying pinned

example/src/main/java/de/halfbit/pinnedsection/examples/PinnedSectionListActivity.java

@@ -44,13 +44,17 @@ public class PinnedSectionListActivity extends ListActivity implements OnClickLi
 
     static class SimpleAdapter extends ArrayAdapter<Item> implements PinnedSectionListAdapter {
 
+        int currentPinned;
+        int headerItems;
+
         private static final int[] COLORS = new int[] {
             R.color.green_light, R.color.orange_light,
             R.color.blue_light, R.color.red_light };
 
-        public SimpleAdapter(Context context, int resource, int textViewResourceId) {
+        public SimpleAdapter(Context context, int resource, int textViewResourceId, int headerItems) {
             super(context, resource, textViewResourceId);
             generateDataset('A', 'Z', false);
+            this.headerItems = headerItems;
         }
 
         public void generateDataset(char from, char to, boolean clear) {
@@ -90,7 +94,12 @@ protected void onSectionAdded(Item section, int sectionPosition) { }
             Item item = getItem(position);
             if (item.type == Item.SECTION) {
                 //view.setOnClickListener(PinnedSectionListActivity.this);
-                view.setBackgroundColor(parent.getResources().getColor(COLORS[item.sectionPosition % COLORS.length]));
+                // If there are header Views, the position received does not include these
+                if(highlightActive && (position + headerItems) == currentPinned) {
+                    view.setBackgroundColor(parent.getResources().getColor(R.color.pink_light));
+                } else {
+                    view.setBackgroundColor(parent.getResources().getColor(COLORS[item.sectionPosition % COLORS.length]));
+                }
             }
             return view;
         }
@@ -108,14 +117,23 @@ public boolean isItemViewTypePinned(int viewType) {
             return viewType == Item.SECTION;
         }
 
+        @Override
+        public void pinnedItemChanged(int position) {
+            // Record the current pinned item and redraw
+            if(highlightActive) {
+                currentPinned = position;
+                notifyDataSetChanged();
+            }
+        }
+
     }
 
     static class FastScrollAdapter extends SimpleAdapter implements SectionIndexer {
 
         private Item[] sections;
 
-        public FastScrollAdapter(Context context, int resource, int textViewResourceId) {
-            super(context, resource, textViewResourceId);
+        public FastScrollAdapter(Context context, int resource, int textViewResourceId, int headerItems) {
+            super(context, resource, textViewResourceId, headerItems);
         }
 
         @Override protected void prepareSections(int sectionsNumber) {
@@ -172,6 +190,7 @@ public Item(int type, String text) {
 	private boolean isFastScroll;
 	private boolean addPadding;
 	private boolean isShadowVisible = true;
+	private static boolean highlightActive = false;
 	private int mDatasetUpdateCount;
 
 	@Override
@@ -183,6 +202,7 @@ protected void onCreate(Bundle savedInstanceState) {
 		    addPadding = savedInstanceState.getBoolean("addPadding");
 		    isShadowVisible = savedInstanceState.getBoolean("isShadowVisible");
 		    hasHeaderAndFooter = savedInstanceState.getBoolean("hasHeaderAndFooter");
+		    highlightActive = savedInstanceState.getBoolean("highlightActive");
 		}
 		initializeHeaderAndFooter();
 		initializeAdapter();
@@ -196,6 +216,7 @@ protected void onSaveInstanceState(Bundle outState) {
 	    outState.putBoolean("addPadding", addPadding);
 	    outState.putBoolean("isShadowVisible", isShadowVisible);
 	    outState.putBoolean("hasHeaderAndFooter", hasHeaderAndFooter);
+	    outState.putBoolean("highlightActive", highlightActive);
 	}
 
 	@Override
@@ -214,6 +235,7 @@ public boolean onCreateOptionsMenu(Menu menu) {
 		menu.getItem(0).setChecked(isFastScroll);
 		menu.getItem(1).setChecked(addPadding);
 		menu.getItem(2).setChecked(isShadowVisible);
+		menu.getItem(3).setChecked(highlightActive);
 		return true;
 	}
 
@@ -240,6 +262,10 @@ public boolean onOptionsItemSelected(MenuItem item) {
     	        item.setChecked(hasHeaderAndFooter);
     	        initializeHeaderAndFooter();
     	        break;
+			case R.id.action_highlight_active:
+				highlightActive = !highlightActive;
+				item.setChecked(highlightActive);
+				break;
     	    case R.id.action_updateDataset:
     	    	updateDataset();
     	    	break;
@@ -293,9 +319,9 @@ private void initializeAdapter() {
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
                 getListView().setFastScrollAlwaysVisible(true);
             }
-            setListAdapter(new FastScrollAdapter(this, android.R.layout.simple_list_item_1, android.R.id.text1));
+            setListAdapter(new FastScrollAdapter(this, android.R.layout.simple_list_item_1, android.R.id.text1, getListView().getHeaderViewsCount()));
         } else {
-            setListAdapter(new SimpleAdapter(this, android.R.layout.simple_list_item_1, android.R.id.text1));
+            setListAdapter(new SimpleAdapter(this, android.R.layout.simple_list_item_1, android.R.id.text1, getListView().getHeaderViewsCount()));
         }
     }
 

example/src/main/res/menu/main.xml

@@ -24,6 +24,12 @@
         android:title="@string/action_showHeaderAndFooter"
         android:checkable="true"/>
 
+    <item
+        android:id="@+id/action_highlight_active"
+        android:showAsAction="never"
+        android:title="@string/action_highlight_active"
+        android:checkable="true" />
+
     <item
         android:id="@+id/action_updateDataset"
         android:showAsAction="never"

example/src/main/res/values/colors.xml

@@ -4,7 +4,8 @@
     <color name="green_light">#ff99cc00</color>
     <color name="orange_light">#ffffbb33</color>
     <color name="blue_light">#ff33b5e5</color>
-
+    <color name="pink_light">#ffff00fc</color>
+
     <!-- Went to: $android-sdk > Android:v14 > res > values > colors.xml and copied the colors-->
 
 </resources>

example/src/main/res/values/strings.xml

@@ -7,5 +7,6 @@
     <string name="action_showShadow">Show shadow</string>
     <string name="action_showHeaderAndFooter">Show Header &amp; Footer</string>
     <string name="action_updateDataset">Update dataset</string>
+    <string name="action_highlight_active">Highlight active item</string>
 
 </resources>

library/src/main/java/de/halfbit/pinnedsection/PinnedSectionListView.java

@@ -49,6 +49,8 @@ public class PinnedSectionListView extends ListView {
 	public interface PinnedSectionListAdapter extends ListAdapter {
 		/** This method shall return 'true' if views of given type has to be pinned. */
 		boolean isItemViewTypePinned(int viewType);
+		/** This method notifies the adapter that the pinned item has changed. */
+		void pinnedItemChanged(int position);
 	}
 
 	/** Wrapper class for pinned section view and its position in the list. */
@@ -84,6 +86,9 @@ static class PinnedSection {
     /** Pinned view Y-translation. We use it to stick pinned view to the next section. */
     int mTranslateY;
 
+    /** Position of the current pinned item, so we can tell when it changes. */
+    int currentPinned;
+
 	/** Scroll listener which does the magic */
 	private final OnScrollListener mOnScrollListener = new OnScrollListener() {
 
@@ -104,6 +109,8 @@ public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCoun
             ListAdapter adapter = getAdapter();
             if (adapter == null || visibleItemCount == 0) return; // nothing to do
 
+            int sectionPosition = findCurrentSectionPosition(firstVisibleItem);
+
             final boolean isFirstVisibleItemSection =
                     isItemViewTypePinned(adapter, adapter.getItemViewType(firstVisibleItem));
 
@@ -116,7 +123,6 @@ public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCoun
                 }
 
             } else { // section is not at the first visible position
-                int sectionPosition = findCurrentSectionPosition(firstVisibleItem);
                 if (sectionPosition > -1) { // we have section position
                     ensureShadowForPosition(sectionPosition, firstVisibleItem, visibleItemCount);
                 } else { // there is no section for the first visible item, destroy shadow
@@ -236,10 +242,6 @@ void destroyPinnedShadow() {
 
 	/** Makes sure we have an actual pinned shadow for given position. */
     void ensureShadowForPosition(int sectionPosition, int firstVisibleItem, int visibleItemCount) {
-        if (visibleItemCount < 2) { // no need for creating shadow at all, we have a single visible item
-            destroyPinnedShadow();
-            return;
-        }
 
         if (mPinnedSection != null
                 && mPinnedSection.position != sectionPosition) { // invalidate shadow, if required
@@ -305,18 +307,30 @@ int findCurrentSectionPosition(int fromPosition) {
 			int itemPosition = indexer.getPositionForSection(sectionPosition);
 			int typeView = adapter.getItemViewType(itemPosition);
 			if (isItemViewTypePinned(adapter, typeView)) {
+				checkPinnedItemChange(adapter, itemPosition);
 				return itemPosition;
 			} // else, no luck
 		}
 
 		// try slow way by looking through to the next section item above
 		for (int position=fromPosition; position>=0; position--) {
 			int viewType = adapter.getItemViewType(position);
-			if (isItemViewTypePinned(adapter, viewType)) return position;
+			if (isItemViewTypePinned(adapter, viewType)) {
+				checkPinnedItemChange(adapter, position);
+				return position;
+			}
 		}
 		return -1; // no candidate found
 	}
 
+	/* If the current item has changed, notify the adapter by calling its interface method. */
+	void checkPinnedItemChange(ListAdapter adapter, int position) {
+		if(currentPinned != position) {
+			currentPinned = position;
+			pinnedItemChanged(adapter, position);
+		}
+	}
+
 	void recreatePinnedShadow() {
 	    destroyPinnedShadow();
         ListAdapter adapter = getAdapter();
@@ -520,4 +534,11 @@ public static boolean isItemViewTypePinned(ListAdapter adapter, int viewType) {
         return ((PinnedSectionListAdapter) adapter).isItemViewTypePinned(viewType);
     }
 
+    public static void pinnedItemChanged(ListAdapter adapter, int position) {
+		if (adapter instanceof HeaderViewListAdapter) {
+			adapter = ((HeaderViewListAdapter)adapter).getWrappedAdapter();
+		}
+		((PinnedSectionListAdapter) adapter).pinnedItemChanged(position);
+    }
+
 }