Android: Use SwipeRefreshLayout in MainActivity

The main reason why I'm adding this isn't actually to allow
users to swipe down to refresh, it's to add a loading indicator.
Considering that the Storage Access Framework can be slow for
folders with many items (many subfolders?), not showing a
loading indicator might give users the impression that adding
a folder resulted in nothing happening even though Dolphin is
scanning for games in the background. But I suppose letting
users swipe down to refresh is a nice bonus with the change.

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/adapters/PlatformPagerAdapter.java

@@ -10,6 +10,7 @@ import androidx.annotation.NonNull;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentPagerAdapter;
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 
 import org.dolphinemu.dolphinemu.R;
 import org.dolphinemu.dolphinemu.ui.platform.Platform;
@@ -18,6 +19,7 @@ import org.dolphinemu.dolphinemu.ui.platform.PlatformGamesFragment;
 public class PlatformPagerAdapter extends FragmentPagerAdapter
 {
   private Context mContext;
+  private SwipeRefreshLayout.OnRefreshListener mOnRefreshListener;
 
   private final static int[] TAB_ICONS =
           {
@@ -26,17 +28,19 @@ public class PlatformPagerAdapter extends FragmentPagerAdapter
                   R.drawable.ic_folder
           };
 
-  public PlatformPagerAdapter(FragmentManager fm, Context context)
+  public PlatformPagerAdapter(FragmentManager fm, Context context,
+          SwipeRefreshLayout.OnRefreshListener onRefreshListener)
   {
     super(fm, BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT);
     mContext = context;
+    mOnRefreshListener = onRefreshListener;
   }
 
   @NonNull
   @Override
   public Fragment getItem(int position)
   {
-    return PlatformGamesFragment.newInstance(Platform.fromPosition(position));
+    return PlatformGamesFragment.newInstance(Platform.fromPosition(position), mOnRefreshListener);
   }
 
   @Override

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/ui/main/MainActivity.java

@@ -13,6 +13,7 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 import androidx.viewpager.widget.ViewPager;
 
 import com.google.android.material.floatingactionbutton.FloatingActionButton;
@@ -39,7 +40,8 @@ import org.dolphinemu.dolphinemu.utils.StartupHandler;
  * The main Activity of the Lollipop style UI. Manages several PlatformGamesFragments, which
  * individually display a grid of available games for each Fragment, in a tabbed layout.
  */
-public final class MainActivity extends AppCompatActivity implements MainView
+public final class MainActivity extends AppCompatActivity
+        implements MainView, SwipeRefreshLayout.OnRefreshListener
 {
   private ViewPager mViewPager;
   private Toolbar mToolbar;
@@ -97,7 +99,11 @@ public final class MainActivity extends AppCompatActivity implements MainView
 
     if (sShouldRescanLibrary && !cacheAlreadyLoading)
     {
+      new AfterDirectoryInitializationRunner().run(this, false, () ->
+      {
+        setRefreshing(true);
         GameFileCacheService.startRescan(this);
+      });
     }
 
     sShouldRescanLibrary = true;
@@ -267,6 +273,28 @@ public final class MainActivity extends AppCompatActivity implements MainView
     return mPresenter.handleOptionSelection(item.getItemId(), this);
   }
 
+  /**
+   * Called when the user requests a refresh by swiping down.
+   */
+  @Override
+  public void onRefresh()
+  {
+    setRefreshing(true);
+    GameFileCacheService.startRescan(this);
+  }
+
+  /**
+   * Shows or hides the loading indicator.
+   */
+  @Override
+  public void setRefreshing(boolean refreshing)
+  {
+    forEachPlatformGamesView(view -> view.setRefreshing(refreshing));
+  }
+
+  /**
+   * To be called when the game file cache is updated.
+   */
   @Override
   public void showGames()
   {
@@ -297,7 +325,7 @@ public final class MainActivity extends AppCompatActivity implements MainView
   private void setPlatformTabsAndStartGameFileCacheService()
   {
     PlatformPagerAdapter platformPagerAdapter = new PlatformPagerAdapter(
-            getSupportFragmentManager(), this);
+            getSupportFragmentManager(), this, this);
     mViewPager.setAdapter(platformPagerAdapter);
     mViewPager.setOffscreenPageLimit(platformPagerAdapter.getCount());
     mTabLayout.setupWithViewPager(mViewPager);

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/ui/main/MainPresenter.java

@@ -54,12 +54,21 @@ public final class MainPresenter
 
     IntentFilter filter = new IntentFilter();
     filter.addAction(GameFileCacheService.CACHE_UPDATED);
+    filter.addAction(GameFileCacheService.DONE_LOADING);
     mBroadcastReceiver = new BroadcastReceiver()
     {
       @Override
       public void onReceive(Context context, Intent intent)
       {
+        switch (intent.getAction())
+        {
+          case GameFileCacheService.CACHE_UPDATED:
             mView.showGames();
+            break;
+          case GameFileCacheService.DONE_LOADING:
+            mView.setRefreshing(false);
+            break;
+        }
       }
     };
     LocalBroadcastManager.getInstance(mContext).registerReceiver(mBroadcastReceiver, filter);
@@ -87,6 +96,7 @@ public final class MainPresenter
         return true;
 
       case R.id.menu_refresh:
+        mView.setRefreshing(true);
         GameFileCacheService.startRescan(context);
         return true;
 

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/ui/main/MainView.java

@@ -23,6 +23,11 @@ public interface MainView
 
   void launchOpenFileActivity(int requestCode);
 
+  /**
+   * Shows or hides the loading indicator.
+   */
+  void setRefreshing(boolean refreshing);
+
   /**
    * To be called when the game file cache is updated.
    */

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/ui/main/TvMainActivity.java

@@ -4,6 +4,7 @@ import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.Bundle;
+import android.util.TypedValue;
 import android.widget.Toast;
 
 import androidx.annotation.NonNull;
@@ -15,6 +16,7 @@ import androidx.leanback.widget.ArrayObjectAdapter;
 import androidx.leanback.widget.HeaderItem;
 import androidx.leanback.widget.ListRow;
 import androidx.leanback.widget.ListRowPresenter;
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 
 import org.dolphinemu.dolphinemu.R;
 import org.dolphinemu.dolphinemu.activities.EmulationActivity;
@@ -26,6 +28,7 @@ import org.dolphinemu.dolphinemu.model.GameFile;
 import org.dolphinemu.dolphinemu.model.TvSettingsItem;
 import org.dolphinemu.dolphinemu.services.GameFileCacheService;
 import org.dolphinemu.dolphinemu.ui.platform.Platform;
+import org.dolphinemu.dolphinemu.utils.AfterDirectoryInitializationRunner;
 import org.dolphinemu.dolphinemu.utils.DirectoryInitialization;
 import org.dolphinemu.dolphinemu.utils.FileBrowserHelper;
 import org.dolphinemu.dolphinemu.utils.PermissionsHandler;
@@ -36,12 +39,15 @@ import org.dolphinemu.dolphinemu.viewholders.TvGameViewHolder;
 import java.util.ArrayList;
 import java.util.Collection;
 
-public final class TvMainActivity extends FragmentActivity implements MainView
+public final class TvMainActivity extends FragmentActivity
+        implements MainView, SwipeRefreshLayout.OnRefreshListener
 {
   private static boolean sShouldRescanLibrary = true;
 
   private final MainPresenter mPresenter = new MainPresenter(this, this);
 
+  private SwipeRefreshLayout mSwipeRefresh;
+
   private BrowseSupportFragment mBrowseFragment;
 
   private final ArrayList<ArrayObjectAdapter> mGameRows = new ArrayList<>();
@@ -84,7 +90,11 @@ public final class TvMainActivity extends FragmentActivity implements MainView
 
     if (sShouldRescanLibrary && !cacheAlreadyLoading)
     {
+      new AfterDirectoryInitializationRunner().run(this, false, () ->
+      {
+        setRefreshing(true);
         GameFileCacheService.startRescan(this);
+      });
     }
 
     sShouldRescanLibrary = true;
@@ -117,6 +127,16 @@ public final class TvMainActivity extends FragmentActivity implements MainView
 
   void setupUI()
   {
+    mSwipeRefresh = findViewById(R.id.swipe_refresh);
+
+    TypedValue typedValue = new TypedValue();
+    getTheme().resolveAttribute(R.attr.colorPrimary, typedValue, true);
+    mSwipeRefresh.setColorSchemeColors(typedValue.data);
+
+    mSwipeRefresh.setOnRefreshListener(this);
+
+    setRefreshing(GameFileCacheService.isLoading());
+
     final FragmentManager fragmentManager = getSupportFragmentManager();
     mBrowseFragment = new BrowseSupportFragment();
     fragmentManager
@@ -188,6 +208,15 @@ public final class TvMainActivity extends FragmentActivity implements MainView
     startActivityForResult(intent, requestCode);
   }
 
+  /**
+   * Shows or hides the loading indicator.
+   */
+  @Override
+  public void setRefreshing(boolean refreshing)
+  {
+    mSwipeRefresh.setRefreshing(refreshing);
+  }
+
   @Override
   public void showGames()
   {
@@ -277,6 +306,16 @@ public final class TvMainActivity extends FragmentActivity implements MainView
     }
   }
 
+  /**
+   * Called when the user requests a refresh by swiping down.
+   */
+  @Override
+  public void onRefresh()
+  {
+    setRefreshing(true);
+    GameFileCacheService.startRescan(this);
+  }
+
   private void buildRowsAdapter()
   {
     ArrayObjectAdapter rowsAdapter = new ArrayObjectAdapter(new ListRowPresenter());

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/ui/platform/PlatformGamesFragment.java

@@ -1,14 +1,17 @@
 package org.dolphinemu.dolphinemu.ui.platform;
 
 import android.os.Bundle;
+import android.util.TypedValue;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 import androidx.recyclerview.widget.GridLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 
 import org.dolphinemu.dolphinemu.R;
 import org.dolphinemu.dolphinemu.adapters.GameAdapter;
@@ -20,10 +23,13 @@ public final class PlatformGamesFragment extends Fragment implements PlatformGam
 
   private GameAdapter mAdapter;
   private RecyclerView mRecyclerView;
+  private SwipeRefreshLayout mSwipeRefresh;
+  private SwipeRefreshLayout.OnRefreshListener mOnRefreshListener;
 
-  public static PlatformGamesFragment newInstance(Platform platform)
+  public static PlatformGamesFragment newInstance(Platform platform,
+          SwipeRefreshLayout.OnRefreshListener onRefreshListener)
   {
-    PlatformGamesFragment fragment = new PlatformGamesFragment();
+    PlatformGamesFragment fragment = new PlatformGamesFragment(onRefreshListener);
 
     Bundle args = new Bundle();
     args.putSerializable(ARG_PLATFORM, platform);
@@ -32,6 +38,11 @@ public final class PlatformGamesFragment extends Fragment implements PlatformGam
     return fragment;
   }
 
+  public PlatformGamesFragment(SwipeRefreshLayout.OnRefreshListener onRefreshListener)
+  {
+    mOnRefreshListener = onRefreshListener;
+  }
+
   @Override
   public void onCreate(Bundle savedInstanceState)
   {
@@ -55,11 +66,19 @@ public final class PlatformGamesFragment extends Fragment implements PlatformGam
     RecyclerView.LayoutManager layoutManager = new GridLayoutManager(getActivity(), columns);
     mAdapter = new GameAdapter();
 
+    TypedValue typedValue = new TypedValue();
+    requireActivity().getTheme().resolveAttribute(R.attr.colorPrimary, typedValue, true);
+    mSwipeRefresh.setColorSchemeColors(typedValue.data);
+
+    mSwipeRefresh.setOnRefreshListener(mOnRefreshListener);
+
     mRecyclerView.setLayoutManager(layoutManager);
     mRecyclerView.setAdapter(mAdapter);
 
     mRecyclerView.addItemDecoration(new GameAdapter.SpacesItemDecoration(8));
 
+    setRefreshing(GameFileCacheService.isLoading());
+
     showGames();
   }
 
@@ -91,8 +110,14 @@ public final class PlatformGamesFragment extends Fragment implements PlatformGam
     mAdapter.refetchMetadata();
   }
 
+  public void setRefreshing(boolean refreshing)
+  {
+    mSwipeRefresh.setRefreshing(refreshing);
+  }
+
   private void findViews(View root)
   {
+    mSwipeRefresh = root.findViewById(R.id.swipe_refresh);
     mRecyclerView = root.findViewById(R.id.grid_games);
   }
 }

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/ui/platform/PlatformGamesView.java

@@ -1,5 +1,8 @@
 package org.dolphinemu.dolphinemu.ui.platform;
 
+import androidx.annotation.Nullable;
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
+
 /**
  * Abstraction for a screen representing a single platform's games.
  */
@@ -21,6 +24,11 @@ public interface PlatformGamesView
    */
   void onItemClick(String gameId);
 
+  /**
+   * Shows or hides the loading indicator.
+   */
+  void setRefreshing(boolean refreshing);
+
   /**
    * To be called when the game file cache is updated.
    */

Source/Android/app/src/main/res/layout/activity_tv_main.xml

@@ -1,7 +1,20 @@
 <?xml version="1.0" encoding="utf-8"?>
-<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+
+<!-- The SwipeRefreshLayout is used mainly for its ability to show a loading indicator, not for
+     its ability to detect swipes. But if someone is using this activity with a touchscreen
+     for whatever reason, we get the ability to refresh by swiping down more or less for free. -->
+
+<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/swipe_refresh"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <FrameLayout
          android:id="@+id/content"
          android:layout_width="match_parent"
          android:layout_height="match_parent">
 
-</FrameLayout>
+    </FrameLayout>
+
+</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>

Source/Android/app/src/main/res/layout/fragment_grid.xml

@@ -4,12 +4,19 @@
              android:layout_width="match_parent"
              android:layout_height="match_parent">
 
+    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+        android:id="@+id/swipe_refresh"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:layout_marginLeft="@dimen/activity_horizontal_margin"
+        android:layout_marginRight="@dimen/activity_horizontal_margin">
+
         <androidx.recyclerview.widget.RecyclerView
             android:id="@+id/grid_games"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
-        android:layout_marginLeft="@dimen/activity_horizontal_margin"
-        android:layout_marginRight="@dimen/activity_horizontal_margin"
             tools:listitem="@layout/card_game"/>
 
+    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
+
 </FrameLayout>