Bug 1220928 - Handle configuration changes. r=sebastian

MozReview-Commit-ID: E5MoWlcMCdj

--HG--
extra : rebase_source : 006266b04f760acfead496d0d97ab01fde44900d

mobile/android/base/java/org/mozilla/gecko/home/CombinedHistoryAdapter.java

@@ -47,6 +47,7 @@ public class CombinedHistoryAdapter extends RecyclerView.Adapter<CombinedHistory
 
     private List<RemoteClient> remoteClients = Collections.emptyList();
     private List<RemoteTab> clientChildren;
+    private int remoteClientIndexOfParent = -1;
     private Cursor historyCursor;
 
     // Maintain group collapsed and hidden state. Only accessed from the UI thread.
@@ -61,9 +62,7 @@ public class CombinedHistoryAdapter extends RecyclerView.Adapter<CombinedHistory
 
     private final Context context;
 
-    private boolean inChildView = false;
-
-    public CombinedHistoryAdapter(Context context) {
+    public CombinedHistoryAdapter(Context context, int savedParentIndex) {
         super();
         this.context = context;
         sectionHeaders = new SparseArray<>();
@@ -76,6 +75,7 @@ public class CombinedHistoryAdapter extends RecyclerView.Adapter<CombinedHistory
         if (sState == null) {
             sState = new RemoteTabsExpandableListState(GeckoSharedPrefs.forProfile(context));
         }
+        remoteClientIndexOfParent = savedParentIndex;
     }
 
     public void setClients(List<RemoteClient> clients) {
@@ -184,22 +184,30 @@ public class CombinedHistoryAdapter extends RecyclerView.Adapter<CombinedHistory
         return null;
     }
 
+    public int getParentIndex() {
+        return remoteClientIndexOfParent;
+    }
+
+    private boolean isInChildView() {
+        return remoteClientIndexOfParent != -1;
+    }
+
     public void showChildView(int parentPosition) {
         if (clientChildren == null) {
             clientChildren = new ArrayList<>();
         }
         // Handle "back" view.
         clientChildren.add(null);
-        clientChildren.addAll(remoteClients.get(transformAdapterPositionForDataStructure(ItemType.CLIENT, parentPosition)).tabs);
-        inChildView = true;
+        remoteClientIndexOfParent = transformAdapterPositionForDataStructure(ItemType.CLIENT, parentPosition);
+        clientChildren.addAll(remoteClients.get(remoteClientIndexOfParent).tabs);
         notifyDataSetChanged();
     }
 
     public boolean exitChildView() {
-        if (!inChildView) {
+        if (!isInChildView()) {
             return false;
         }
-        inChildView = false;
+        remoteClientIndexOfParent = -1;
         clientChildren.clear();
         notifyDataSetChanged();
         return true;
@@ -285,7 +293,7 @@ public class CombinedHistoryAdapter extends RecyclerView.Adapter<CombinedHistory
 
     @Override
     public int getItemViewType(int position) {
-        if (inChildView) {
+        if (isInChildView()) {
             if (position == 0) {
                 return ItemType.itemTypeToViewType(ItemType.NAVIGATION_BACK);
             }
@@ -310,8 +318,13 @@ public class CombinedHistoryAdapter extends RecyclerView.Adapter<CombinedHistory
 
     @Override
     public int getItemCount() {
-        if (inChildView) {
-            return (clientChildren == null) ? 0 : clientChildren.size();
+        if (isInChildView()) {
+            if (clientChildren == null) {
+                clientChildren = new ArrayList<>();
+                clientChildren.add(null);
+                clientChildren.addAll(remoteClients.get(remoteClientIndexOfParent).tabs);
+            }
+            return clientChildren.size();
         } else {
             final int historySize = historyCursor == null ? 0 : historyCursor.getCount();
             return remoteClients.size() + historySize + sectionHeaders.size();

mobile/android/base/java/org/mozilla/gecko/home/CombinedHistoryPanel.java

@@ -9,6 +9,7 @@ import android.app.AlertDialog;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.DialogInterface;
+import android.content.res.Configuration;
 import android.database.Cursor;
 import android.os.Bundle;
 import android.support.v4.app.LoaderManager;
@@ -82,6 +83,7 @@ public class CombinedHistoryPanel extends HomeFragment implements RemoteClientsD
     private CombinedHistoryRecyclerView mRecyclerView;
     private CombinedHistoryAdapter mAdapter;
     private CursorLoaderCallbacks mCursorLoaderCallbacks;
+    private int mSavedParentIndex = -1;
 
     private OnPanelLevelChangeListener.PanelLevel mPanelLevel = OnPanelLevelChangeListener.PanelLevel.PARENT;
     private Button mPanelFooterButton;
@@ -106,7 +108,7 @@ public class CombinedHistoryPanel extends HomeFragment implements RemoteClientsD
         super.onViewCreated(view, savedInstanceState);
 
         mRecyclerView = (CombinedHistoryRecyclerView) view.findViewById(R.id.combined_recycler_view);
-        mAdapter = new CombinedHistoryAdapter(getContext());
+        mAdapter = new CombinedHistoryAdapter(getContext(), mSavedParentIndex);
         mRecyclerView.setAdapter(mAdapter);
         mRecyclerView.setItemAnimator(new DefaultItemAnimator());
         mRecyclerView.addItemDecoration(new DividerItemDecoration(getContext()));
@@ -125,6 +127,17 @@ public class CombinedHistoryPanel extends HomeFragment implements RemoteClientsD
         mCursorLoaderCallbacks = new CursorLoaderCallbacks();
     }
 
+    @Override
+    public void onConfigurationChanged(Configuration newConfig) {
+        super.onConfigurationChanged(newConfig);
+
+        if (isVisible()) {
+            // The parent stack is saved just so that the folder state can be
+            // restored on rotation.
+            mSavedParentIndex = mAdapter.getParentIndex();
+        }
+    }
+
     @Override
     protected void load() {
         getLoaderManager().initLoader(LOADER_ID_HISTORY, null, mCursorLoaderCallbacks);
@@ -285,7 +298,7 @@ public class CombinedHistoryPanel extends HomeFragment implements RemoteClientsD
                     break;
 
                 case CHILD:
-                    final JSONArray tabUrls = ((CombinedHistoryAdapter) mRecyclerView.getAdapter()).getCurrentChildTabs();
+                    final JSONArray tabUrls = mAdapter.getCurrentChildTabs();
                     if (tabUrls != null) {
                         final JSONObject message = new JSONObject();
                         try {
@@ -425,7 +438,7 @@ public class CombinedHistoryPanel extends HomeFragment implements RemoteClientsD
 
         final int itemId = item.getItemId();
         if (itemId == R.id.home_remote_tabs_hide_client) {
-            ((CombinedHistoryAdapter) mRecyclerView.getAdapter()).removeItem(info.position);
+            mAdapter.removeItem(info.position);
             return true;
         }
 
@@ -452,7 +465,7 @@ public class CombinedHistoryPanel extends HomeFragment implements RemoteClientsD
 
     @Override
     public void onClients(List<RemoteClient> clients) {
-        ((CombinedHistoryAdapter) mRecyclerView.getAdapter()).unhideClients(clients);
+        mAdapter.unhideClients(clients);
     }
 
     /**