trying to get rid of parcelable

Author: vivchar

example/src/main/java/com/github/vivchar/example/pages/github/GithubFragment.java

@@ -59,6 +59,8 @@ public class GithubFragment extends BaseScreenFragment {
 	private GridLayoutManager mLayoutManager;
 	private SwipeRefreshLayout mSwipeToRefresh;
 	private GithubPresenter mGithubPresenter;
+	@Nullable
+	private Bundle mSavedInstanceState;
 
 	@Nullable
 	@Override
@@ -123,7 +125,14 @@ public void onLoadMore(final int page, final int totalItemsCount) {
 	@Override
 	public void onViewStateRestored(@Nullable final Bundle savedInstanceState) {
 		super.onViewStateRestored(savedInstanceState);
-		mRecyclerViewAdapter.onRestoreInstanceState(savedInstanceState);
+		mSavedInstanceState = savedInstanceState;
+	}
+
+	@Override
+	public void onResume() {
+		super.onResume();
+		mRecyclerViewAdapter.onRestoreInstanceState(mSavedInstanceState);
+		mSavedInstanceState = null;
 	}
 
 	@Override

example/src/main/java/com/github/vivchar/example/pages/github/items/list/RecyclerViewState.java

@@ -7,25 +7,21 @@
 import com.github.vivchar.rendererrecyclerviewadapter.CompositeViewState;
 import com.github.vivchar.rendererrecyclerviewadapter.ViewState;
 
+import java.io.Serializable;
 import java.util.HashMap;
 
 /**
  * Created by Vivchar Vitaly on 21.10.17.
  */
 
-public class RecyclerViewState extends CompositeViewState<RecyclerViewHolder> {
-
-	@NonNull
-	private final HashMap<Integer, ViewState> mViewStates;
+public class RecyclerViewState extends CompositeViewState<RecyclerViewHolder> implements Serializable {
 
 	public RecyclerViewState(@NonNull final CompositeViewHolder holder) {
 		super(holder);
-		mViewStates = holder.getAdapter().getStates();
 	}
 
 	@Override
 	public void restore(@NonNull final RecyclerViewHolder holder) {
 		super.restore(holder);
-		holder.getAdapter().setStates(mViewStates);
 	}
 }

example/src/main/java/com/github/vivchar/example/pages/github/items/stargazer/StargazerViewState.java

@@ -4,11 +4,13 @@
 
 import com.github.vivchar.rendererrecyclerviewadapter.ViewState;
 
+import java.io.Serializable;
+
 /**
  * Created by Vivchar Vitaly on 21.10.17.
  */
 
-public class StargazerViewState implements ViewState<StargazerViewHolder> {
+public class StargazerViewState implements ViewState<StargazerViewHolder>, Serializable {
 
 	private static final String TAG = StargazerViewState.class.getSimpleName();
 	private final int mVisibility;

example/src/main/java/com/github/vivchar/example/pages/simple/ViewStateFragment.java

@@ -33,6 +33,8 @@ public class ViewStateFragment extends BaseScreenFragment {
 
 	private final YourDataProvider mYourDataProvider = new YourDataProvider();
 	private RendererRecyclerViewAdapter mRecyclerViewAdapter;
+	@Nullable
+	private Bundle mSavedInstanceState;
 
 	@Nullable
 	@Override
@@ -77,7 +79,14 @@ public int createViewStateID(@NonNull final StateViewModel model) {
 	@Override
 	public void onViewStateRestored(@Nullable final Bundle savedInstanceState) {
 		super.onViewStateRestored(savedInstanceState);
-		mRecyclerViewAdapter.onRestoreInstanceState(savedInstanceState);
+		mSavedInstanceState = savedInstanceState;
+	}
+
+	@Override
+	public void onResume() {
+		super.onResume();
+		mRecyclerViewAdapter.onRestoreInstanceState(mSavedInstanceState);
+		mSavedInstanceState = null;
 	}
 
 	@Override

rendererrecyclerviewadapter/src/main/java/com/github/vivchar/rendererrecyclerviewadapter/CompositeViewState.java

@@ -1,23 +1,49 @@
 package com.github.vivchar.rendererrecyclerviewadapter;
 
-import android.os.Parcelable;
 import android.support.annotation.NonNull;
+import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.RecyclerView;
+import android.util.Log;
+import android.view.View;
+
+import java.io.Serializable;
+import java.util.HashMap;
 
 /**
  * Created by Vivchar Vitaly on 20.10.17.
- *
  */
-public class CompositeViewState <VH extends CompositeViewHolder> implements ViewState<VH> {
+public class CompositeViewState <VH extends CompositeViewHolder> implements ViewState<VH>, Serializable {
 
 	@NonNull
-	protected final Parcelable mLayoutManagerState;
+	protected HashMap<Integer, ViewState> mViewStates;
+	protected int mPosition;
+	protected int mTopOffset;
+	protected int mLeftOffset;
 
 	public <VH extends CompositeViewHolder> CompositeViewState(@NonNull final VH holder) {
-		mLayoutManagerState = holder.getRecyclerView().getLayoutManager().onSaveInstanceState();
+		mViewStates = holder.getAdapter().getStates();
+		final RecyclerView.LayoutManager layoutManager = holder.getRecyclerView().getLayoutManager();
+		if (layoutManager instanceof LinearLayoutManager) {
+			/* To get rid of Parcelable, https://stackoverflow.com/a/35287828/4894238 */
+			mPosition = ((LinearLayoutManager) layoutManager).findFirstVisibleItemPosition();
+			final View item = holder.getRecyclerView().getChildAt(0);
+			mTopOffset = (item == null) ? 0 : (item.getTop() - holder.getRecyclerView().getPaddingTop());
+			mLeftOffset = (item == null) ? 0 : (item.getLeft() - holder.getRecyclerView().getPaddingLeft());
+			Log.d("###", "save mPosition: " + mPosition + " mTopOffset: " + mTopOffset);
+		} else {
+			mPosition = 0;
+			mTopOffset = 0;
+		}
 	}
 
 	@Override
 	public void restore(@NonNull final VH holder) {
-		holder.getRecyclerView().getLayoutManager().onRestoreInstanceState(mLayoutManagerState);
+		holder.getAdapter().setStates(mViewStates);
+
+		final RecyclerView.LayoutManager layoutManager = holder.getRecyclerView().getLayoutManager();
+		if (mPosition != -1 && layoutManager instanceof LinearLayoutManager) {
+			Log.d("###", "restore mPosition: " + mPosition + " mTopOffset: " + mTopOffset);
+			((LinearLayoutManager) layoutManager).scrollToPositionWithOffset(mPosition, Math.max(mTopOffset, mLeftOffset));
+		}
 	}
 }