Port AudioPlayer's viewpager to ViewPager2, improve RTL support

4 files changed, 39 insertions, 32 deletions

diff --git a/app/build.gradle b/app/build.gradle
index 6fb84c29a..b400b8700 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -142,6 +142,7 @@ dependencies {
     implementation "androidx.preference:preference:1.1.0"
     implementation "androidx.gridlayout:gridlayout:1.0.0"
     implementation "androidx.recyclerview:recyclerview:1.1.0"
+    implementation "androidx.viewpager2:viewpager2:1.0.0"
     implementation "androidx.coordinatorlayout:coordinatorlayout:1.1.0"
     implementation "androidx.media:media:1.1.0"
     implementation "androidx.work:work-runtime:$workManagerVersion"
diff --git a/app/src/main/java/de/danoeh/antennapod/fragment/AudioPlayerFragment.java b/app/src/main/java/de/danoeh/antennapod/fragment/AudioPlayerFragment.java
index 7f0326019..e57ea63dc 100644
--- a/app/src/main/java/de/danoeh/antennapod/fragment/AudioPlayerFragment.java
+++ b/app/src/main/java/de/danoeh/antennapod/fragment/AudioPlayerFragment.java
@@ -13,20 +13,28 @@ import android.widget.ImageButton;
 import android.widget.ProgressBar;
 import android.widget.SeekBar;
 import android.widget.TextView;
+
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.widget.Toolbar;
 import androidx.fragment.app.Fragment;
-import androidx.fragment.app.FragmentManager;
-import androidx.fragment.app.FragmentPagerAdapter;
-import androidx.viewpager.widget.ViewPager;
+import androidx.viewpager2.adapter.FragmentStateAdapter;
+import androidx.viewpager2.widget.ViewPager2;
+
 import com.google.android.material.bottomsheet.BottomSheetBehavior;
+
+import org.greenrobot.eventbus.EventBus;
+import org.greenrobot.eventbus.Subscribe;
+import org.greenrobot.eventbus.ThreadMode;
+
+import java.text.DecimalFormat;
+
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.activity.CastEnabledActivity;
 import de.danoeh.antennapod.activity.MainActivity;
 import de.danoeh.antennapod.core.event.FavoritesEvent;
 import de.danoeh.antennapod.core.event.PlaybackPositionEvent;
-import de.danoeh.antennapod.core.feed.Chapter;
 import de.danoeh.antennapod.core.feed.FeedItem;
 import de.danoeh.antennapod.core.feed.FeedMedia;
 import de.danoeh.antennapod.core.feed.util.PlaybackSpeedUtils;
@@ -50,12 +58,6 @@ import io.reactivex.Maybe;
 import io.reactivex.android.schedulers.AndroidSchedulers;
 import io.reactivex.disposables.Disposable;
 import io.reactivex.schedulers.Schedulers;
-import org.greenrobot.eventbus.EventBus;
-import org.greenrobot.eventbus.Subscribe;
-import org.greenrobot.eventbus.ThreadMode;
-
-import java.text.DecimalFormat;
-import java.util.List;
 
 /**
  * Shows the audio player.
@@ -73,7 +75,7 @@ public class AudioPlayerFragment extends Fragment implements
 
     PlaybackSpeedIndicatorView butPlaybackSpeed;
     TextView txtvPlaybackSpeed;
-    private ViewPager pager;
+    private ViewPager2 pager;
     private PagerIndicatorView pageIndicator;
     private TextView txtvPosition;
     private TextView txtvLength;
@@ -127,11 +129,10 @@ public class AudioPlayerFragment extends Fragment implements
         sbPosition.setOnSeekBarChangeListener(this);
 
         pager = root.findViewById(R.id.pager);
-        AudioPlayerPagerAdapter pagerAdapter = new AudioPlayerPagerAdapter(getChildFragmentManager());
-        pager.setAdapter(pagerAdapter);
+        pager.setAdapter(new AudioPlayerPagerAdapter(this));
         // Required for getChildAt(int) in ViewPagerBottomSheetBehavior to return the correct page
-        pager.setOffscreenPageLimit(NUM_CONTENT_FRAGMENTS);
-        pager.addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
+        // pager.setOffscreenPageLimit(NUM_CONTENT_FRAGMENTS);
+        pager.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback() {
             @Override
             public void onPageSelected(int position) {
                 pager.post(() -> ((MainActivity) getActivity()).getBottomSheet().updateScrollingChild());
@@ -502,30 +503,30 @@ public class AudioPlayerFragment extends Fragment implements
         return false;
     }
 
-    private static class AudioPlayerPagerAdapter extends FragmentPagerAdapter {
+    private static class AudioPlayerPagerAdapter extends FragmentStateAdapter {
         private static final String TAG = "AudioPlayerPagerAdapter";
 
-        public AudioPlayerPagerAdapter(FragmentManager fm) {
-            super(fm);
+        public AudioPlayerPagerAdapter(@NonNull Fragment fragment) {
+            super(fragment);
         }
 
+        @NonNull
         @Override
-        public Fragment getItem(int position) {
+        public Fragment createFragment(int position) {
             Log.d(TAG, "getItem(" + position + ")");
             switch (position) {
                 case POS_COVER:
                     return new CoverFragment();
                 case POS_DESCR:
                     return new ItemDescriptionFragment();
+                default:
                 case POS_CHAPTERS:
                     return new ChaptersFragment();
-                default:
-                    return null;
             }
         }
 
         @Override
-        public int getCount() {
+        public int getItemCount() {
             return NUM_CONTENT_FRAGMENTS;
         }
     }
diff --git a/app/src/main/java/de/danoeh/antennapod/view/PagerIndicatorView.java b/app/src/main/java/de/danoeh/antennapod/view/PagerIndicatorView.java
index 53a95eede..780ee0d88 100644
--- a/app/src/main/java/de/danoeh/antennapod/view/PagerIndicatorView.java
+++ b/app/src/main/java/de/danoeh/antennapod/view/PagerIndicatorView.java
@@ -1,15 +1,17 @@
 package de.danoeh.antennapod.view;
 
+import android.animation.ArgbEvaluator;
 import android.content.Context;
 import android.content.res.TypedArray;
-import android.database.DataSetObserver;
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.util.AttributeSet;
 import android.view.View;
+
 import androidx.annotation.Nullable;
-import androidx.vectordrawable.graphics.drawable.ArgbEvaluator;
-import androidx.viewpager.widget.ViewPager;
+import androidx.core.view.ViewCompat;
+import androidx.recyclerview.widget.RecyclerView;
+import androidx.viewpager2.widget.ViewPager2;
 
 public class PagerIndicatorView extends View {
     private final Paint paint = new Paint();
@@ -38,26 +40,29 @@ public class PagerIndicatorView extends View {
         paint.setAntiAlias(true);
         paint.setStyle(Paint.Style.FILL);
 
-        int[] colorAttrs = new int[] { android.R.attr.textColorSecondary };
+        int[] colorAttrs = new int[]{android.R.attr.textColorSecondary};
         TypedArray a = getContext().obtainStyledAttributes(colorAttrs);
         circleColorHighlight = a.getColor(0, 0xffffffff);
         circleColor = (Integer) new ArgbEvaluator().evaluate(0.8f, 0x00ffffff, circleColorHighlight);
         a.recycle();
     }
 
-    public void setViewPager(ViewPager pager) {
-        numPages = pager.getAdapter().getCount();
-        pager.getAdapter().registerDataSetObserver(new DataSetObserver() {
+    public void setViewPager(ViewPager2 pager) {
+        numPages = pager.getAdapter().getItemCount();
+        pager.getAdapter().registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() {
             @Override
             public void onChanged() {
-                numPages = pager.getAdapter().getCount();
+                numPages = pager.getAdapter().getItemCount();
                 invalidate();
             }
         });
-        pager.addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
+        pager.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback() {
             @Override
             public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
                 PagerIndicatorView.this.position = position + positionOffset;
+                if (ViewCompat.getLayoutDirection(pager) == ViewCompat.LAYOUT_DIRECTION_RTL) {
+                    PagerIndicatorView.this.position = numPages - 1 - PagerIndicatorView.this.position;
+                }
                 invalidate();
             }
         });
diff --git a/app/src/main/res/layout/audioplayer_fragment.xml b/app/src/main/res/layout/audioplayer_fragment.xml
index d01228d27..a9e9137f2 100644
--- a/app/src/main/res/layout/audioplayer_fragment.xml
+++ b/app/src/main/res/layout/audioplayer_fragment.xml
@@ -34,7 +34,7 @@
             tools:background="@android:color/holo_green_light"
             android:elevation="8dp"/>
 
-    <androidx.viewpager.widget.ViewPager
+    <androidx.viewpager2.widget.ViewPager2
             android:id="@+id/pager"
             android:layout_width="match_parent"
             android:layout_height="0dp"