Add the ability to show/hide headers on demand.

library/res/values/attrs.xml

@@ -29,6 +29,7 @@
 
         <!-- StickyListHeaders attributes -->
         <attr name="hasStickyHeaders" format="boolean" />
+        <attr name="showHeaders" format="boolean" />
         <attr name="isDrawingListUnderStickyHeader" format="boolean" />
     </declare-styleable>
 

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

@@ -90,6 +90,7 @@ void onStickyHeaderChanged(StickyListHeadersListView l, View header,
     /* --- Settings --- */
     private boolean mAreHeadersSticky = true;
     private boolean mClippingToPadding = true;
+    private boolean mShowHeaders = true;
     private boolean mIsDrawingListUnderStickyHeader = true;
     private int mStickyHeaderTopOffset = 0;
     private int mPaddingLeft = 0;
@@ -102,6 +103,7 @@ void onStickyHeaderChanged(StickyListHeadersListView l, View header,
     private OnStickyHeaderOffsetChangedListener mOnStickyHeaderOffsetChangedListener;
     private OnStickyHeaderChangedListener mOnStickyHeaderChangedListener;
     private AdapterWrapperDataSetObserver mDataSetObserver;
+    private StickyListHeadersAdapter mOriginalAdapter;
     private Drawable mDivider;
     private int mDividerHeight;
 
@@ -205,6 +207,7 @@ public StickyListHeadersListView(Context context, AttributeSet attrs, int defSty
 
                 // -- StickyListHeaders attributes --
                 mAreHeadersSticky = a.getBoolean(R.styleable.StickyListHeadersListView_hasStickyHeaders, true);
+                mShowHeaders = a.getBoolean(R.styleable.StickyListHeadersListView_showHeaders, mShowHeaders);
                 mIsDrawingListUnderStickyHeader = a.getBoolean(
                         R.styleable.StickyListHeadersListView_isDrawingListUnderStickyHeader,
                         true);
@@ -290,7 +293,7 @@ private void clearHeader() {
 
     private void updateOrClearHeader(int firstVisiblePosition) {
         final int adapterCount = mAdapter == null ? 0 : mAdapter.getCount();
-        if (adapterCount == 0 || !mAreHeadersSticky) {
+        if (adapterCount == 0 || !mAreHeadersSticky || !mShowHeaders) {
             return;
         }
 
@@ -659,6 +662,18 @@ public void setAdapter(StickyListHeadersAdapter adapter) {
         if (mAdapter != null) {
             mAdapter.unregisterDataSetObserver(mDataSetObserver);
         }
+        mOriginalAdapter = adapter;
+        if(!mShowHeaders) {
+            mAdapter = null;
+            mList.setAdapter(adapter);
+            mList.setDivider(mDivider);
+			mList.setDividerHeight(mDividerHeight);
+			clearHeader();
+            return;
+        } else {
+            mList.setDivider(null);
+			mList.setDividerHeight(0);
+		}
 
         if (adapter instanceof SectionIndexer) {
             mAdapter = new SectionIndexerAdapterWrapper(getContext(), adapter);
@@ -1077,4 +1092,21 @@ public void setBlockLayoutChildren(boolean blockLayoutChildren) {
         mList.setBlockLayoutChildren(blockLayoutChildren);
     }
 
+    /**
+     * Shows or hides all headers, when changed the scroll would be reset.
+     */
+    public void setShowHeaders(boolean value) {
+        mShowHeaders = value;
+        if (!mShowHeaders && !mAreHeadersSticky) {
+            clearHeader();
+        } else {
+            updateOrClearHeader(mList.getFixedFirstVisibleItem());
+        }
+        setAdapter(mOriginalAdapter);
+    }
+
+    public boolean showHeaders() {
+        return mShowHeaders;
+    }
+
 }

sample/res/layout/main.xml

@@ -102,6 +102,13 @@
                     android:id="@+id/sticky_checkBox"
                     android:checked="true"/>
 
+            <CheckBox
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:text="@string/show_header"
+                    android:id="@+id/show_checkBox"
+                    android:checked="true"/>
+
             <CheckBox
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"

sample/res/values/strings.xml

@@ -14,6 +14,7 @@
     <string name="update_list">Update list</string>
     <string name="clear_list">Clear list</string>
     <string name="sticky_header">Sticky header</string>
+    <string name="show_header">Show header</string>
     <string name="fade_header">Fade header</string>
     <string name="draw_behind_header">Draw behind header</string>
     <string name="fast_scroll">Fast scroll</string>

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

@@ -41,6 +41,7 @@ public class TestActivity extends ActionBarActivity implements
     private Button clearButton;
 
     private CheckBox stickyCheckBox;
+    private CheckBox showCheckBox;
     private CheckBox fadeCheckBox;
     private CheckBox drawBehindCheckBox;
     private CheckBox fastScrollCheckBox;
@@ -104,6 +105,8 @@ public void run() {
 
         stickyCheckBox = (CheckBox) findViewById(R.id.sticky_checkBox);
         stickyCheckBox.setOnCheckedChangeListener(checkBoxListener);
+        showCheckBox = (CheckBox) findViewById(R.id.show_checkBox);
+        showCheckBox.setOnCheckedChangeListener(checkBoxListener);
         fadeCheckBox = (CheckBox) findViewById(R.id.fade_checkBox);
         fadeCheckBox.setOnCheckedChangeListener(checkBoxListener);
         drawBehindCheckBox = (CheckBox) findViewById(R.id.draw_behind_checkBox);
@@ -153,6 +156,9 @@ public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                     stickyList.setFastScrollEnabled(isChecked);
                     stickyList.setFastScrollAlwaysVisible(isChecked);
                     break;
+                case R.id.show_checkBox:
+                    stickyList.setShowHeaders(isChecked);
+                    break;
             }
         }
     };