Android: Fall back to native paths on <9

Apparently some of these devices have broken scoped storage?

android/app/src/main/java/com/github/stenzek/duckstation/FileHelper.java

@@ -1,15 +1,21 @@
 package com.github.stenzek.duckstation;
 
+import android.annotation.SuppressLint;
+import android.annotation.TargetApi;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.database.Cursor;
 import android.graphics.Bitmap;
 import android.graphics.ImageDecoder;
 import android.net.Uri;
+import android.os.Build;
 import android.os.ParcelFileDescriptor;
+import android.os.storage.StorageManager;
 import android.provider.DocumentsContract;
 import android.provider.MediaStore;
 
+import androidx.annotation.Nullable;
+
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileNotFoundException;
@@ -17,6 +23,8 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
+import java.lang.reflect.Array;
+import java.lang.reflect.Method;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
@@ -463,6 +471,127 @@ public class FileHelper {
         }
     }
 
+    private static final String PRIMARY_VOLUME_NAME = "primary";
+
+    @Nullable
+    public static String getFullPathFromTreeUri(@Nullable final Uri treeUri, Context con) {
+        if (treeUri == null) return null;
+        String volumePath = getVolumePath(getVolumeIdFromTreeUri(treeUri), con);
+        if (volumePath == null) return File.separator;
+        if (volumePath.endsWith(File.separator))
+            volumePath = volumePath.substring(0, volumePath.length() - 1);
+
+        String documentPath = getDocumentPathFromTreeUri(treeUri);
+        if (documentPath.endsWith(File.separator))
+            documentPath = documentPath.substring(0, documentPath.length() - 1);
+
+        if (documentPath.length() > 0) {
+            if (documentPath.startsWith(File.separator))
+                return volumePath + documentPath;
+            else
+                return volumePath + File.separator + documentPath;
+        } else return volumePath;
+    }
+
+    @SuppressLint("ObsoleteSdkInt")
+    private static String getVolumePath(final String volumeId, Context context) {
+        if (volumeId == null)
+            return null;
+
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) return null;
+        try {
+            StorageManager mStorageManager =
+                    (StorageManager) context.getSystemService(Context.STORAGE_SERVICE);
+            Class<?> storageVolumeClazz = Class.forName("android.os.storage.StorageVolume");
+            Method getVolumeList = mStorageManager.getClass().getMethod("getVolumeList");
+            Method getUuid = storageVolumeClazz.getMethod("getUuid");
+            Method getPath = storageVolumeClazz.getMethod("getPath");
+            Method isPrimary = storageVolumeClazz.getMethod("isPrimary");
+            Object result = getVolumeList.invoke(mStorageManager);
+
+            final int length = Array.getLength(result);
+            for (int i = 0; i < length; i++) {
+                Object storageVolumeElement = Array.get(result, i);
+                String uuid = (String) getUuid.invoke(storageVolumeElement);
+                Boolean primary = (Boolean) isPrimary.invoke(storageVolumeElement);
+
+                // primary volume?
+                if (primary && PRIMARY_VOLUME_NAME.equals(volumeId))
+                    return (String) getPath.invoke(storageVolumeElement);
+
+                // other volumes?
+                if (uuid != null && uuid.equals(volumeId))
+                    return (String) getPath.invoke(storageVolumeElement);
+            }
+            // not found.
+            return null;
+        } catch (Exception ex) {
+            return null;
+        }
+    }
+
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    private static String getVolumeIdFromTreeUri(final Uri treeUri) {
+        final String docId = DocumentsContract.getTreeDocumentId(treeUri);
+        final String[] split = docId.split(":");
+        if (split.length > 0) return split[0];
+        else return null;
+    }
+
+
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    private static String getDocumentPathFromTreeUri(final Uri treeUri) {
+        final String docId = DocumentsContract.getTreeDocumentId(treeUri);
+        final String[] split = docId.split(":");
+        if ((split.length >= 2) && (split[1] != null)) return split[1];
+        else return File.separator;
+    }
+
+    @Nullable
+    public static String getFullPathFromUri(@Nullable final Uri treeUri, Context con) {
+        if (treeUri == null) return null;
+        String volumePath = getVolumePath(getVolumeIdFromUri(treeUri), con);
+        if (volumePath == null) return File.separator;
+        if (volumePath.endsWith(File.separator))
+            volumePath = volumePath.substring(0, volumePath.length() - 1);
+
+        String documentPath = getDocumentPathFromUri(treeUri);
+        if (documentPath.endsWith(File.separator))
+            documentPath = documentPath.substring(0, documentPath.length() - 1);
+
+        if (documentPath.length() > 0) {
+            if (documentPath.startsWith(File.separator))
+                return volumePath + documentPath;
+            else
+                return volumePath + File.separator + documentPath;
+        } else return volumePath;
+    }
+
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    private static String getVolumeIdFromUri(final Uri treeUri) {
+        try {
+            final String docId = DocumentsContract.getDocumentId(treeUri);
+            final String[] split = docId.split(":");
+            if (split.length > 0) return split[0];
+            else return null;
+        } catch (Exception e) {
+            return null;
+        }
+    }
+
+
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    private static String getDocumentPathFromUri(final Uri treeUri) {
+        try {
+            final String docId = DocumentsContract.getDocumentId(treeUri);
+            final String[] split = docId.split(":");
+            if ((split.length >= 2) && (split[1] != null)) return split[1];
+            else return File.separator;
+        } catch (Exception e) {
+            return null;
+        }
+    }
+
     /**
      * Java class containing the data for a file in a find operation.
      */

android/app/src/main/java/com/github/stenzek/duckstation/GameDirectoriesActivity.java

@@ -7,6 +7,7 @@ import android.content.Intent;
 import android.content.SharedPreferences;
 import android.net.Uri;
 import android.os.Bundle;
+import android.os.FileUtils;
 import android.util.Log;
 import android.util.Property;
 import android.view.LayoutInflater;
@@ -291,6 +292,17 @@ public class GameDirectoriesActivity extends AppCompatActivity {
                 if (resultCode != RESULT_OK || data.getData() == null)
                     return;
 
+                // Use legacy storage on devices older than Android 9... apparently some of them
+                // have broken storage access framework....
+                if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.P) {
+                    final String path = FileHelper.getFullPathFromTreeUri(data.getData(), this);
+                    if (path != null) {
+                        addSearchDirectory(this, path, true);
+                        mDirectoryListAdapter.reload();
+                        return;
+                    }
+                }
+
                 try {
                     getContentResolver().takePersistableUriPermission(data.getData(),
                             Intent.FLAG_GRANT_READ_URI_PERMISSION);

android/app/src/main/java/com/github/stenzek/duckstation/MainActivity.java

@@ -272,6 +272,17 @@ public class MainActivity extends AppCompatActivity {
                 if (resultCode != RESULT_OK || data.getData() == null)
                     return;
 
+                // Use legacy storage on devices older than Android 9... apparently some of them
+                // have broken storage access framework....
+                if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.P) {
+                    final String path = FileHelper.getFullPathFromTreeUri(data.getData(), this);
+                    if (path != null) {
+                        GameDirectoriesActivity.addSearchDirectory(this, path, true);
+                        mGameList.refresh(false, false, this);
+                        return;
+                    }
+                }
+
                 try {
                     getContentResolver().takePersistableUriPermission(data.getData(),
                             Intent.FLAG_GRANT_READ_URI_PERMISSION);