Android: Make GameFileCacheManager use LiveData, part 1

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/services/GameFileCacheManager.java

@@ -5,6 +5,8 @@ package org.dolphinemu.dolphinemu.services;
 import android.content.Context;
 import android.content.Intent;
 
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
 import androidx.localbroadcastmanager.content.LocalBroadcastManager;
 
 import org.dolphinemu.dolphinemu.DolphinApplication;
@@ -19,18 +21,12 @@ import java.util.List;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * Loads game list data on a separate thread.
  */
 public final class GameFileCacheManager
 {
-  /**
-   * This is broadcast when the contents of the cache change.
-   */
-  public static final String CACHE_UPDATED = "org.dolphinemu.dolphinemu.GAME_FILE_CACHE_UPDATED";
-
   /**
    * This is broadcast when the service is done with all requested work, regardless of whether
    * the contents of the cache actually changed. (Maybe the cache was already up to date.)
@@ -39,8 +35,8 @@ public final class GameFileCacheManager
           "org.dolphinemu.dolphinemu.GAME_FILE_CACHE_DONE_LOADING";
 
   private static GameFileCache gameFileCache = null;
-  private static final AtomicReference<GameFile[]> gameFiles =
+  private static final MutableLiveData<GameFile[]> gameFiles =
-          new AtomicReference<>(new GameFile[]{});
+          new MutableLiveData<>(new GameFile[]{});
 
   private static final ExecutorService executor = Executors.newFixedThreadPool(1);
   private static final AtomicBoolean loadInProgress = new AtomicBoolean(false);
@@ -50,9 +46,14 @@ public final class GameFileCacheManager
   {
   }
 
+  public static LiveData<GameFile[]> getGameFiles()
+  {
+    return gameFiles;
+  }
+
   public static List<GameFile> getGameFilesForPlatform(Platform platform)
   {
-    GameFile[] allGames = gameFiles.get();
+    GameFile[] allGames = gameFiles.getValue();
     ArrayList<GameFile> platformGames = new ArrayList<>();
     for (GameFile game : allGames)
     {
@@ -66,7 +67,7 @@ public final class GameFileCacheManager
 
   public static GameFile getGameFileByGameId(String gameId)
   {
-    GameFile[] allGames = gameFiles.get();
+    GameFile[] allGames = gameFiles.getValue();
     for (GameFile game : allGames)
     {
       if (game.getGameId().equals(gameId))
@@ -81,7 +82,7 @@ public final class GameFileCacheManager
   {
     GameFile matchWithoutRevision = null;
 
-    GameFile[] allGames = gameFiles.get();
+    GameFile[] allGames = gameFiles.getValue();
     for (GameFile otherGame : allGames)
     {
       if (game.getGameId().equals(otherGame.getGameId()) &&
@@ -155,7 +156,7 @@ public final class GameFileCacheManager
     // Common case: The game is in the cache, so just grab it from there.
     // (Actually, addOrGet already checks for this case, but we want to avoid calling it if possible
     // because onHandleIntent may hold a lock on gameFileCache for extended periods of time.)
-    GameFile[] allGames = gameFiles.get();
+    GameFile[] allGames = gameFiles.getValue();
     for (GameFile game : allGames)
     {
       if (game.getPath().equals(gamePath))
@@ -189,7 +190,6 @@ public final class GameFileCacheManager
         if (gameFileCache.getSize() != 0)
         {
           updateGameFileArray();
-          sendBroadcast(CACHE_UPDATED);
         }
       }
     }
@@ -218,14 +218,12 @@ public final class GameFileCacheManager
       if (changed)
       {
         updateGameFileArray();
-        sendBroadcast(CACHE_UPDATED);
       }
 
       boolean additionalMetadataChanged = gameFileCache.updateAdditionalMetadata();
       if (additionalMetadataChanged)
       {
         updateGameFileArray();
-        sendBroadcast(CACHE_UPDATED);
       }
 
       if (changed || additionalMetadataChanged)
@@ -243,7 +241,7 @@ public final class GameFileCacheManager
   {
     GameFile[] gameFilesTemp = gameFileCache.getAllGames();
     Arrays.sort(gameFilesTemp, (lhs, rhs) -> lhs.getTitle().compareToIgnoreCase(rhs.getTitle()));
-    gameFiles.set(gameFilesTemp);
+    gameFiles.postValue(gameFilesTemp);
   }
 
   private static void sendBroadcast(String action)

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

@@ -2,7 +2,6 @@
 
 package org.dolphinemu.dolphinemu.ui.main;
 
-import android.app.Activity;
 import android.content.BroadcastReceiver;
 import android.content.ContentResolver;
 import android.content.Context;
@@ -11,6 +10,7 @@ import android.content.IntentFilter;
 import android.net.Uri;
 
 import androidx.appcompat.app.AlertDialog;
+import androidx.core.app.ComponentActivity;
 import androidx.localbroadcastmanager.content.LocalBroadcastManager;
 
 import org.dolphinemu.dolphinemu.BuildConfig;
@@ -42,14 +42,14 @@ public final class MainPresenter
   private static boolean sShouldRescanLibrary = true;
 
   private final MainView mView;
-  private final Context mContext;
+  private final ComponentActivity mActivity;
   private BroadcastReceiver mBroadcastReceiver = null;
   private String mDirToAdd;
 
-  public MainPresenter(MainView view, Context context)
+  public MainPresenter(MainView view, ComponentActivity activity)
   {
     mView = view;
-    mContext = context;
+    mActivity = activity;
   }
 
   public void onCreate()
@@ -57,8 +57,9 @@ public final class MainPresenter
     String versionName = BuildConfig.VERSION_NAME;
     mView.setVersionString(versionName);
 
+    GameFileCacheManager.getGameFiles().observe(mActivity, (gameFiles) -> mView.showGames());
+
     IntentFilter filter = new IntentFilter();
-    filter.addAction(GameFileCacheManager.CACHE_UPDATED);
     filter.addAction(GameFileCacheManager.DONE_LOADING);
     mBroadcastReceiver = new BroadcastReceiver()
     {
@@ -67,23 +68,20 @@ public final class MainPresenter
       {
         switch (intent.getAction())
         {
-          case GameFileCacheManager.CACHE_UPDATED:
-            mView.showGames();
-            break;
           case GameFileCacheManager.DONE_LOADING:
             mView.setRefreshing(false);
             break;
         }
       }
     };
-    LocalBroadcastManager.getInstance(mContext).registerReceiver(mBroadcastReceiver, filter);
+    LocalBroadcastManager.getInstance(mActivity).registerReceiver(mBroadcastReceiver, filter);
   }
 
   public void onDestroy()
   {
     if (mBroadcastReceiver != null)
     {
-      LocalBroadcastManager.getInstance(mContext).unregisterReceiver(mBroadcastReceiver);
+      LocalBroadcastManager.getInstance(mActivity).unregisterReceiver(mBroadcastReceiver);
     }
   }
 
@@ -142,10 +140,10 @@ public final class MainPresenter
 
     if (sShouldRescanLibrary && !GameFileCacheManager.isRescanning())
     {
-      new AfterDirectoryInitializationRunner().run(mContext, false, () ->
+      new AfterDirectoryInitializationRunner().run(mActivity, false, () ->
       {
         mView.setRefreshing(true);
-        GameFileCacheManager.startRescan(mContext);
+        GameFileCacheManager.startRescan(mActivity);
       });
     }
 
@@ -172,20 +170,20 @@ public final class MainPresenter
     if (Arrays.stream(childNames).noneMatch((name) -> FileBrowserHelper.GAME_EXTENSIONS.contains(
             FileBrowserHelper.getExtension(name, false))))
     {
-      AlertDialog.Builder builder = new AlertDialog.Builder(mContext, R.style.DolphinDialogBase);
+      AlertDialog.Builder builder = new AlertDialog.Builder(mActivity, R.style.DolphinDialogBase);
-      builder.setMessage(mContext.getString(R.string.wrong_file_extension_in_directory,
+      builder.setMessage(mActivity.getString(R.string.wrong_file_extension_in_directory,
               FileBrowserHelper.setToSortedDelimitedString(FileBrowserHelper.GAME_EXTENSIONS)));
       builder.setPositiveButton(R.string.ok, null);
       builder.show();
     }
 
-    ContentResolver contentResolver = mContext.getContentResolver();
+    ContentResolver contentResolver = mActivity.getContentResolver();
     Uri canonicalizedUri = contentResolver.canonicalize(uri);
     if (canonicalizedUri != null)
       uri = canonicalizedUri;
 
     int takeFlags = result.getFlags() & Intent.FLAG_GRANT_READ_URI_PERMISSION;
-    mContext.getContentResolver().takePersistableUriPermission(uri, takeFlags);
+    mActivity.getContentResolver().takePersistableUriPermission(uri, takeFlags);
 
     mDirToAdd = uri.toString();
   }
@@ -196,24 +194,22 @@ public final class MainPresenter
     {
       boolean success = WiiUtils.installWAD(path);
       int message = success ? R.string.wad_install_success : R.string.wad_install_failure;
-      return mContext.getResources().getString(message);
+      return mActivity.getResources().getString(message);
     });
   }
 
   public void importWiiSave(String path)
   {
-    final Activity mainPresenterActivity = (Activity) mContext;
-
     CompletableFuture<Boolean> canOverwriteFuture = new CompletableFuture<>();
 
     runOnThreadAndShowResult(R.string.import_in_progress, 0, () ->
     {
       BooleanSupplier canOverwrite = () ->
       {
-        mainPresenterActivity.runOnUiThread(() ->
+        mActivity.runOnUiThread(() ->
         {
           AlertDialog.Builder builder =
-                  new AlertDialog.Builder(mContext, R.style.DolphinDialogBase);
+                  new AlertDialog.Builder(mActivity, R.style.DolphinDialogBase);
           builder.setMessage(R.string.wii_save_exists);
           builder.setCancelable(false);
           builder.setPositiveButton(R.string.yes, (dialog, i) -> canOverwriteFuture.complete(true));
@@ -252,14 +248,14 @@ public final class MainPresenter
           message = R.string.wii_save_import_error;
           break;
       }
-      return mContext.getResources().getString(message);
+      return mActivity.getResources().getString(message);
     });
   }
 
   public void importNANDBin(String path)
   {
     AlertDialog.Builder builder =
-            new AlertDialog.Builder(mContext, R.style.DolphinDialogBase);
+            new AlertDialog.Builder(mActivity, R.style.DolphinDialogBase);
 
     builder.setMessage(R.string.nand_import_warning);
     builder.setNegativeButton(R.string.no, (dialog, i) -> dialog.dismiss());
@@ -281,33 +277,31 @@ public final class MainPresenter
 
   private void runOnThreadAndShowResult(int progressTitle, int progressMessage, Supplier<String> f)
   {
-    final Activity mainPresenterActivity = (Activity) mContext;
+    AlertDialog progressDialog = new AlertDialog.Builder(mActivity, R.style.DolphinDialogBase)
-
-    AlertDialog progressDialog = new AlertDialog.Builder(mContext, R.style.DolphinDialogBase)
             .create();
     progressDialog.setTitle(progressTitle);
     if (progressMessage != 0)
-      progressDialog.setMessage(mContext.getResources().getString(progressMessage));
+      progressDialog.setMessage(mActivity.getResources().getString(progressMessage));
     progressDialog.setCancelable(false);
     progressDialog.show();
 
     new Thread(() ->
     {
       String result = f.get();
-      mainPresenterActivity.runOnUiThread(() ->
+      mActivity.runOnUiThread(() ->
       {
         progressDialog.dismiss();
 
         if (result != null)
         {
           AlertDialog.Builder builder =
-                  new AlertDialog.Builder(mContext, R.style.DolphinDialogBase);
+                  new AlertDialog.Builder(mActivity, R.style.DolphinDialogBase);
           builder.setMessage(result);
           builder.setPositiveButton(R.string.ok, (dialog, i) -> dialog.dismiss());
           builder.show();
         }
       });
-    }, mContext.getResources().getString(progressTitle)).start();
+    }, mActivity.getResources().getString(progressTitle)).start();
   }
 
   public static void skipRescanningLibrary()