Android: Use old folder picker on Android TV

See the comment I added to the code. This is a rather serious
issue for Android TV users from what I've heard.

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

@@ -162,10 +162,17 @@ public final class MainActivity extends AppCompatActivity implements MainView
 
   @Override
   public void launchFileListActivity()
+  {
+    if (DirectoryInitialization.preferOldFolderPicker(this))
+    {
+      FileBrowserHelper.openDirectoryPicker(this, FileBrowserHelper.GAME_EXTENSIONS);
+    }
+    else
     {
       Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
       startActivityForResult(intent, MainPresenter.REQUEST_DIRECTORY);
     }
+  }
 
   @Override
   public void launchOpenFileActivity()
@@ -202,7 +209,14 @@ public final class MainActivity extends AppCompatActivity implements MainView
       switch (requestCode)
       {
         case MainPresenter.REQUEST_DIRECTORY:
+          if (DirectoryInitialization.preferOldFolderPicker(this))
+          {
+            mPresenter.onDirectorySelected(FileBrowserHelper.getSelectedPath(result));
+          }
+          else
+          {
             mPresenter.onDirectorySelected(result);
+          }
           break;
 
         case MainPresenter.REQUEST_GAME_FILE:

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

@@ -112,6 +112,17 @@ public final class MainPresenter
     }
   }
 
+  /**
+   * Called when a selection is made using the legacy folder picker.
+   */
+  public void onDirectorySelected(String dir)
+  {
+    mDirToAdd = dir;
+  }
+
+  /**
+   * Called when a selection is made using the Storage Access Framework folder picker.
+   */
   public void onDirectorySelected(Intent result)
   {
     Uri uri = result.getData();

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

@@ -167,10 +167,17 @@ public final class TvMainActivity extends FragmentActivity implements MainView
 
   @Override
   public void launchFileListActivity()
+  {
+    if (DirectoryInitialization.preferOldFolderPicker(this))
+    {
+      FileBrowserHelper.openDirectoryPicker(this, FileBrowserHelper.GAME_EXTENSIONS);
+    }
+    else
     {
       Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
       startActivityForResult(intent, MainPresenter.REQUEST_DIRECTORY);
     }
+  }
 
   @Override
   public void launchOpenFileActivity()
@@ -226,7 +233,14 @@ public final class TvMainActivity extends FragmentActivity implements MainView
       switch (requestCode)
       {
         case MainPresenter.REQUEST_DIRECTORY:
+          if (DirectoryInitialization.preferOldFolderPicker(this))
+          {
+            mPresenter.onDirectorySelected(FileBrowserHelper.getSelectedPath(result));
+          }
+          else
+          {
             mPresenter.onDirectorySelected(result);
+          }
           break;
 
         case MainPresenter.REQUEST_GAME_FILE:

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/utils/DirectoryInitialization.java

@@ -9,6 +9,7 @@ package org.dolphinemu.dolphinemu.utils;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
+import android.os.Build;
 import android.os.Environment;
 import android.preference.PreferenceManager;
 
@@ -347,6 +348,30 @@ public final class DirectoryInitialization
     }
   }
 
+  public static boolean isExternalStorageLegacy()
+  {
+    return Build.VERSION.SDK_INT < Build.VERSION_CODES.Q || Environment.isExternalStorageLegacy();
+  }
+
+  public static boolean preferOldFolderPicker(Context context)
+  {
+    // As of January 2021, ACTION_OPEN_DOCUMENT_TREE seems to be broken on the Nvidia Shield TV
+    // (the activity can't be navigated correctly with a gamepad). We can use the old folder picker
+    // for the time being - Android 11 hasn't been released for this device. We have an explicit
+    // check for Android 11 below in hopes that Nvidia will fix this before releasing Android 11.
+    //
+    // No Android TV device other than the Nvidia Shield TV is known to have an implementation
+    // of ACTION_OPEN_DOCUMENT or ACTION_OPEN_DOCUMENT_TREE that even launches, but "fortunately"
+    // for us, the Nvidia Shield TV is the only Android TV device in existence so far that can
+    // run Dolphin at all (due to the 64-bit requirement), so we can ignore this problem.
+    //
+    // All phones which are running a compatible version of Android support ACTION_OPEN_DOCUMENT and
+    // ACTION_OPEN_DOCUMENT_TREE, as this is required by the Android CTS (unlike with Android TV).
+
+    return Build.VERSION.SDK_INT < Build.VERSION_CODES.R && isExternalStorageLegacy() &&
+            TvUtil.isLeanback(context);
+  }
+
   private static native void CreateUserDirectories();
 
   private static native void SetSysDirectory(String path);