Add RTL layout support

app/src/debug/AndroidManifest.xml

@@ -6,5 +6,6 @@
 
     <application
         android:name=".DebugApp"
-        tools:replace="android:name" />
+        tools:replace="android:name"
+        android:supportsRtl="true" />
 </manifest>

app/src/main/AndroidManifest.xml

@@ -23,6 +23,7 @@
         android:label="@string/app_name"
         android:logo="@mipmap/ic_launcher"
         android:theme="@style/OpeningTheme"
+        android:supportsRtl="true"
         android:resizeableActivity="true"
         tools:ignore="AllowBackup">
         <activity

app/src/main/java/org/schabi/newpipe/fragments/MainFragment.java

@@ -27,6 +27,7 @@
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.settings.tabs.Tab;
 import org.schabi.newpipe.settings.tabs.TabsManager;
+import org.schabi.newpipe.util.LocalizeLayoutUtils;
 import org.schabi.newpipe.util.NavigationHelper;
 import org.schabi.newpipe.util.ServiceHelper;
 
@@ -160,26 +161,38 @@ private void setupTabs() {
         tabsList.clear();
         tabsList.addAll(tabsManager.getTabs());
 
+        final boolean isRTL = LocalizeLayoutUtils.isRTL(getContext());
+
         if (pagerAdapter == null || !pagerAdapter.sameTabs(tabsList)) {
             pagerAdapter = new SelectedTabsPagerAdapter(requireContext(),
-                    getChildFragmentManager(), tabsList);
+                    getChildFragmentManager(), tabsList, isRTL);
         }
 
         binding.pager.setAdapter(null);
         binding.pager.setOffscreenPageLimit(tabsList.size());
         binding.pager.setAdapter(pagerAdapter);
 
-        updateTabsIconAndDescription();
+        if (isRTL) {
+            binding.mainTabLayout.getTabAt(pagerAdapter.getCount() - 1).select();
+        }
+
+        updateTabsIconAndDescription(isRTL);
         updateTitleForTab(binding.pager.getCurrentItem());
 
         hasTabsChanged = false;
     }
 
-    private void updateTabsIconAndDescription() {
+    private void updateTabsIconAndDescription(final boolean isRTL) {
         for (int i = 0; i < tabsList.size(); i++) {
             final TabLayout.Tab tabToSet = binding.mainTabLayout.getTabAt(i);
             if (tabToSet != null) {
-                final Tab tab = tabsList.get(i);
+                final Tab tab = tabsList.get(
+                        LocalizeLayoutUtils.getLayoutPosition(
+                                isRTL,
+                                tabsList.size(),
+                                i)
+                );
+
                 tabToSet.setIcon(tab.getTabIconRes(requireContext()));
                 tabToSet.setContentDescription(tab.getTabName(requireContext()));
             }
@@ -199,7 +212,8 @@ public void onTabSelected(final TabLayout.Tab selectedTab) {
     }
 
     @Override
-    public void onTabUnselected(final TabLayout.Tab tab) { }
+    public void onTabUnselected(final TabLayout.Tab tab) {
+    }
 
     @Override
     public void onTabReselected(final TabLayout.Tab tab) {
@@ -213,19 +227,27 @@ private static final class SelectedTabsPagerAdapter
             extends FragmentStatePagerAdapterMenuWorkaround {
         private final Context context;
         private final List<Tab> internalTabsList;
+        private boolean isRTL;
 
         private SelectedTabsPagerAdapter(final Context context,
                                          final FragmentManager fragmentManager,
-                                         final List<Tab> tabsList) {
+                                         final List<Tab> tabsList,
+                                         final boolean isRTL) {
             super(fragmentManager, BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT);
             this.context = context;
             this.internalTabsList = new ArrayList<>(tabsList);
+            this.isRTL = isRTL;
         }
 
         @NonNull
         @Override
         public Fragment getItem(final int position) {
-            final Tab tab = internalTabsList.get(position);
+            final Tab tab = internalTabsList.get(
+                    LocalizeLayoutUtils.getLayoutPosition(
+                            isRTL,
+                            internalTabsList.size(),
+                            position)
+            );
 
             final Fragment fragment;
             try {

app/src/main/java/org/schabi/newpipe/fragments/detail/TabAdapter.java

@@ -8,26 +8,30 @@
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentPagerAdapter;
 
+import org.schabi.newpipe.util.LocalizeLayoutUtils;
+
 import java.util.ArrayList;
 import java.util.List;
 
 public class TabAdapter extends FragmentPagerAdapter {
     private final List<Fragment> mFragmentList = new ArrayList<>();
     private final List<String> mFragmentTitleList = new ArrayList<>();
     private final FragmentManager fragmentManager;
+    private boolean isRTL;
 
-    public TabAdapter(final FragmentManager fm) {
+    public TabAdapter(final FragmentManager fm, final boolean isRTL) {
         // if changed to BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT => crash if enqueueing stream in
         // the background and then clicking on it to open VideoDetailFragment:
         // "Cannot setMaxLifecycle for Fragment not attached to FragmentManager"
         super(fm, BEHAVIOR_SET_USER_VISIBLE_HINT);
         this.fragmentManager = fm;
+        this.isRTL = isRTL;
     }
 
     @NonNull
     @Override
     public Fragment getItem(final int position) {
-        return mFragmentList.get(position);
+        return mFragmentList.get(getLayoutPosition(position));
     }
 
     @Override
@@ -46,16 +50,18 @@ public void clearAllItems() {
     }
 
     public void removeItem(final int position) {
-        mFragmentList.remove(position == 0 ? 0 : position - 1);
-        mFragmentTitleList.remove(position == 0 ? 0 : position - 1);
+        final int newPosition = getLayoutPosition(position);
+
+        mFragmentList.remove(newPosition == 0 ? 0 : newPosition - 1);
+        mFragmentTitleList.remove(newPosition == 0 ? 0 : newPosition - 1);
     }
 
     public void updateItem(final int position, final Fragment fragment) {
-        mFragmentList.set(position, fragment);
+        mFragmentList.set(getLayoutPosition(position), fragment);
     }
 
     public void updateItem(final String title, final Fragment fragment) {
-        final int index = mFragmentTitleList.indexOf(title);
+        final int index = getLayoutPosition(mFragmentTitleList.indexOf(title));
         if (index != -1) {
             updateItem(index, fragment);
         }
@@ -64,22 +70,23 @@ public void updateItem(final String title, final Fragment fragment) {
     @Override
     public int getItemPosition(@NonNull final Object object) {
         if (mFragmentList.contains(object)) {
-            return mFragmentList.indexOf(object);
+            return getLayoutPosition(mFragmentList.indexOf(object));
         } else {
             return POSITION_NONE;
         }
     }
 
     public int getItemPositionByTitle(final String title) {
-        return mFragmentTitleList.indexOf(title);
+        return getLayoutPosition(mFragmentTitleList.indexOf(title));
     }
 
     @Nullable
     public String getItemTitle(final int position) {
         if (position < 0 || position >= mFragmentTitleList.size()) {
             return null;
         }
-        return mFragmentTitleList.get(position);
+
+        return mFragmentTitleList.get(getLayoutPosition(position));
     }
 
     public void notifyDataSetUpdate() {
@@ -93,4 +100,7 @@ public void destroyItem(@NonNull final ViewGroup container,
         fragmentManager.beginTransaction().remove((Fragment) object).commitNowAllowingStateLoss();
     }
 
+    private int getLayoutPosition(final int position) {
+        return LocalizeLayoutUtils.getLayoutPosition(isRTL, mFragmentList.size(), position);
+    }
 }

app/src/main/java/org/schabi/newpipe/fragments/detail/VideoDetailFragment.java

@@ -91,6 +91,7 @@
 import org.schabi.newpipe.util.ExtractorHelper;
 import org.schabi.newpipe.util.ListHelper;
 import org.schabi.newpipe.util.Localization;
+import org.schabi.newpipe.util.LocalizeLayoutUtils;
 import org.schabi.newpipe.util.NavigationHelper;
 import org.schabi.newpipe.util.PermissionHelper;
 import org.schabi.newpipe.util.PicassoHelper;
@@ -603,10 +604,6 @@ public void onViewCreated(@NonNull final View rootView, final Bundle savedInstan
     protected void initViews(final View rootView, final Bundle savedInstanceState) {
         super.initViews(rootView, savedInstanceState);
 
-        pageAdapter = new TabAdapter(getChildFragmentManager());
-        binding.viewPager.setAdapter(pageAdapter);
-        binding.tabLayout.setupWithViewPager(binding.viewPager);
-
         binding.detailThumbnailRootLayout.requestFocus();
 
         binding.detailControlsPlayWithKodi.setVisibility(
@@ -621,6 +618,13 @@ protected void initViews(final View rootView, final Bundle savedInstanceState) {
                         : View.GONE
         );
 
+        pageAdapter = new TabAdapter(
+                getChildFragmentManager(),
+                LocalizeLayoutUtils.isRTL(getContext())
+        );
+        binding.viewPager.setAdapter(pageAdapter);
+        binding.tabLayout.setupWithViewPager(binding.viewPager);
+
         if (DeviceUtils.isTv(getContext())) {
             // remove ripple effects from detail controls
             final int transparent = ContextCompat.getColor(requireContext(),
@@ -985,8 +989,12 @@ private void initTabs() {
      * {@link #tabContentDescriptions}, which are all set in {@link #initTabs()}.
      */
     private void updateTabIconsAndContentDescriptions() {
+        final boolean isRTL = LocalizeLayoutUtils.isRTL(getContext());
+
         for (int i = 0; i < tabIcons.size(); ++i) {
-            final TabLayout.Tab tab = binding.tabLayout.getTabAt(i);
+            final TabLayout.Tab tab = binding.tabLayout.getTabAt(
+                    LocalizeLayoutUtils.getLayoutPosition(
+                            isRTL, tabIcons.size(), i));
             if (tab != null) {
                 tab.setIcon(tabIcons.get(i));
                 tab.setContentDescription(tabContentDescriptions.get(i));

app/src/main/java/org/schabi/newpipe/fragments/list/search/SearchFragment.java

@@ -1089,7 +1089,7 @@ public int getSuggestionMovementFlags(@NonNull final RecyclerView.ViewHolder vie
 
         final SuggestionItem item = suggestionListAdapter.getItem(position);
         return item.fromHistory ? makeMovementFlags(0,
-                ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT) : 0;
+                ItemTouchHelper.START | ItemTouchHelper.END) : 0;
     }
 
     public void onSuggestionItemSwiped(@NonNull final RecyclerView.ViewHolder viewHolder) {

app/src/main/java/org/schabi/newpipe/local/playlist/LocalPlaylistFragment.java

@@ -683,7 +683,7 @@ private void saveImmediate() {
     private ItemTouchHelper.SimpleCallback getItemTouchCallback() {
         int directions = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
         if (shouldUseGridLayout(requireContext())) {
-            directions |= ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
+            directions |= ItemTouchHelper.START | ItemTouchHelper.END;
         }
         return new ItemTouchHelper.SimpleCallback(directions,
                 ItemTouchHelper.ACTION_STATE_IDLE) {

app/src/main/java/org/schabi/newpipe/local/subscription/decoration/FeedGroupCarouselDecoration.kt

@@ -5,31 +5,47 @@ import android.graphics.Rect
 import android.view.View
 import androidx.recyclerview.widget.RecyclerView
 import org.schabi.newpipe.R
+import org.schabi.newpipe.util.LocalizeLayoutUtils
 
 class FeedGroupCarouselDecoration(context: Context) : RecyclerView.ItemDecoration() {
 
     private val marginStartEnd: Int
     private val marginTopBottom: Int
     private val marginBetweenItems: Int
+    private val isRTL: Boolean
 
     init {
         with(context.resources) {
             marginStartEnd = getDimensionPixelOffset(R.dimen.feed_group_carousel_start_end_margin)
             marginTopBottom = getDimensionPixelOffset(R.dimen.feed_group_carousel_top_bottom_margin)
             marginBetweenItems = getDimensionPixelOffset(R.dimen.feed_group_carousel_between_items_margin)
         }
+
+        isRTL = LocalizeLayoutUtils.isRTL(context)
     }
 
     override fun getItemOffsets(outRect: Rect, child: View, parent: RecyclerView, state: RecyclerView.State) {
         val childAdapterPosition = parent.getChildAdapterPosition(child)
         val childAdapterCount = parent.adapter?.itemCount ?: 0
 
-        outRect.set(marginBetweenItems, marginTopBottom, 0, marginTopBottom)
+        outRect.set(0, marginTopBottom, 0, marginTopBottom)
+
+        if (isRTL) {
+            outRect.right = marginBetweenItems
+
+            if (childAdapterPosition == 0) {
+                outRect.right = marginStartEnd
+            } else if (childAdapterPosition == childAdapterCount - 1) {
+                outRect.left = marginStartEnd
+            }
+        } else {
+            outRect.left = marginBetweenItems
 
-        if (childAdapterPosition == 0) {
-            outRect.left = marginStartEnd
-        } else if (childAdapterPosition == childAdapterCount - 1) {
-            outRect.right = marginStartEnd
+            if (childAdapterPosition == 0) {
+                outRect.left = marginStartEnd
+            } else if (childAdapterPosition == childAdapterCount - 1) {
+                outRect.right = marginStartEnd
+            }
         }
     }
 }

app/src/main/java/org/schabi/newpipe/player/helper/PlayerHelper.java

@@ -514,7 +514,7 @@ public static WindowManager.LayoutParams retrievePopupLayoutParamsFromPrefs(
                 popupLayoutParamType(),
                 IDLE_WINDOW_FLAGS,
                 PixelFormat.TRANSLUCENT);
-        popupLayoutParams.gravity = Gravity.LEFT | Gravity.TOP;
+        popupLayoutParams.gravity = Gravity.START | Gravity.TOP;
         popupLayoutParams.softInputMode = WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE;
 
         final int centerX = (int) (player.getScreenWidth() / 2f - popupWidth / 2f);
@@ -558,7 +558,7 @@ public static WindowManager.LayoutParams buildCloseOverlayLayoutParams() {
                 flags,
                 PixelFormat.TRANSLUCENT);
 
-        closeOverlayLayoutParams.gravity = Gravity.LEFT | Gravity.TOP;
+        closeOverlayLayoutParams.gravity = Gravity.START | Gravity.TOP;
         closeOverlayLayoutParams.softInputMode =
                 WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE;
         return closeOverlayLayoutParams;

app/src/main/java/org/schabi/newpipe/player/playqueue/PlayQueueItemTouchCallback.java

@@ -8,7 +8,7 @@ public abstract class PlayQueueItemTouchCallback extends ItemTouchHelper.SimpleC
     private static final int MAXIMUM_INITIAL_DRAG_VELOCITY = 25;
 
     public PlayQueueItemTouchCallback() {
-        super(ItemTouchHelper.UP | ItemTouchHelper.DOWN, ItemTouchHelper.RIGHT);
+        super(ItemTouchHelper.UP | ItemTouchHelper.DOWN, ItemTouchHelper.END);
     }
 
     public abstract void onMove(int sourceIndex, int targetIndex);

app/src/main/java/org/schabi/newpipe/util/CommentTextOnTouchListener.java

@@ -35,7 +35,7 @@ public boolean onTouch(final View v, final MotionEvent event) {
                 int x = (int) event.getX();
                 int y = (int) event.getY();
 
-                x -= widget.getTotalPaddingLeft();
+                x -= widget.getTotalPaddingStart();
                 y -= widget.getTotalPaddingTop();
 
                 x += widget.getScrollX();

app/src/main/java/org/schabi/newpipe/util/LocalizeLayoutUtils.java

@@ -0,0 +1,29 @@
+package org.schabi.newpipe.util;
+
+import android.content.Context;
+import android.content.res.Configuration;
+import android.view.View;
+
+public final class LocalizeLayoutUtils {
+    private LocalizeLayoutUtils() { }
+
+    private static Boolean isRTL = null;
+
+    public static int getLayoutPosition(final boolean isRtl, final int count, final int position) {
+        return isRtl
+                ? count - 1 - position
+                : position;
+    }
+
+    public static boolean isRTL(final Context context) {
+        if (isRTL != null) {
+            return isRTL;
+        }
+
+        final Configuration config = context.getResources().getConfiguration();
+
+        isRTL = config.getLayoutDirection() == View.LAYOUT_DIRECTION_RTL;
+
+        return isRTL;
+    }
+}

app/src/main/res/drawable/ic_play_arrow_shadow.xml

@@ -1,7 +1,6 @@
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
     android:width="24dp"
     android:height="24dp"
-    android:autoMirrored="true"
     android:viewportWidth="80"
     android:viewportHeight="80">
     <path