feat: 외장 저장소 접근 기능 구현

app/src/main/java/be/gyu/android/file/explorer/MainActivity.java

@@ -1,12 +1,218 @@
 package be.gyu.android.file.explorer;
 
-import androidx.appcompat.app.AppCompatActivity;
+import android.Manifest;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.net.Uri;
+import android.os.Build;
 import android.os.Bundle;
+import android.os.Environment;
+import android.os.storage.StorageManager;
+import android.os.storage.StorageVolume;
+import android.provider.Settings;
+import android.view.Menu;
+import android.view.MenuItem;
+import android.webkit.MimeTypeMap;
+import android.widget.Toast;
+
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AlertDialog;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.appcompat.widget.Toolbar;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+import androidx.core.content.FileProvider;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+
+public class MainActivity extends AppCompatActivity implements FileAdapter.OnItemClickListener {
+
+    private static final int REQUEST_CODE_MANAGE_EXTERNAL_STORAGE = 1;
+    private RecyclerView recyclerView;
+    private FileAdapter fileAdapter;
+    private List<FileItem> fileList;
+    private File currentDirectory;
 
-public class MainActivity extends AppCompatActivity {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
+
+        Toolbar toolbar = findViewById(R.id.toolbar);
+        setSupportActionBar(toolbar);
+
+        recyclerView = findViewById(R.id.recyclerView);
+        recyclerView.setLayoutManager(new LinearLayoutManager(this));
+
+        fileList = new ArrayList<>();
+        fileAdapter = new FileAdapter(fileList);
+        fileAdapter.setOnItemClickListener(this);
+        recyclerView.setAdapter(fileAdapter);
+
+        if (checkStoragePermission()) {
+            loadFiles(Environment.getExternalStorageDirectory());
+        } else {
+            requestStoragePermission();
+        }
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        getMenuInflater().inflate(R.menu.main_menu, menu);
+        return true;
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
+        if (item.getItemId() == R.id.select_storage) {
+            showStorageSelectionDialog();
+            return true;
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
+    private void showStorageSelectionDialog() {
+        StorageManager storageManager = (StorageManager) getSystemService(STORAGE_SERVICE);
+        List<StorageVolume> storageVolumes = storageManager.getStorageVolumes();
+        List<String> volumeNames = new ArrayList<>();
+        List<File> volumePaths = new ArrayList<>();
+
+        for (StorageVolume volume : storageVolumes) {
+            if (volume.getState().equals(Environment.MEDIA_MOUNTED)) {
+                File path = volume.getDirectory();
+                if (path != null) {
+                    volumeNames.add(volume.getDescription(this));
+                    volumePaths.add(path);
+                }
+            }
+        }
+
+        AlertDialog.Builder builder = new AlertDialog.Builder(this);
+        builder.setTitle("Select Storage");
+        builder.setItems(volumeNames.toArray(new String[0]), (dialog, which) -> {
+            loadFiles(volumePaths.get(which));
+        });
+        builder.show();
+    }
+
+
+    private boolean checkStoragePermission() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+            return Environment.isExternalStorageManager();
+        } else {
+            return ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED;
+        }
+    }
+
+    private void requestStoragePermission() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+            try {
+                Intent intent = new Intent(Settings.ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION);
+                intent.addCategory("android.intent.category.DEFAULT");
+                intent.setData(Uri.parse(String.format("package:%s", getApplicationContext().getPackageName())));
+                startActivityForResult(intent, REQUEST_CODE_MANAGE_EXTERNAL_STORAGE);
+            } catch (Exception e) {
+                Intent intent = new Intent();
+                intent.setAction(Settings.ACTION_MANAGE_ALL_FILES_ACCESS_PERMISSION);
+                startActivityForResult(intent, REQUEST_CODE_MANAGE_EXTERNAL_STORAGE);
+            }
+        } else {
+            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, REQUEST_CODE_MANAGE_EXTERNAL_STORAGE);
+        }
+    }
+
+    private void loadFiles(File directory) {
+        this.currentDirectory = directory;
+        if (directory != null) {
+            setTitle(directory.getName());
+            fileList.clear();
+            File[] files = directory.listFiles();
+            if (files != null) {
+                for (File file : files) {
+                    fileList.add(new FileItem(file.getName(), file.getAbsolutePath(), file.isDirectory()));
+                }
+            } else {
+                Toast.makeText(this, "Cannot read this directory!", Toast.LENGTH_SHORT).show();
+            }
+        }
+        fileAdapter.notifyDataSetChanged();
+    }
+
+    @Override
+    public void onItemClick(FileItem item) {
+        File file = new File(item.getPath());
+        if (file.isDirectory()) {
+            if (file.canRead()) {
+                loadFiles(file);
+            } else {
+                Toast.makeText(this, "Permission Denied", Toast.LENGTH_SHORT).show();
+            }
+        } else {
+            openFile(file);
+        }
+    }
+
+    private void openFile(File file) {
+        Uri uri = FileProvider.getUriForFile(this, getApplicationContext().getPackageName() + ".provider", file);
+        Intent intent = new Intent(Intent.ACTION_VIEW);
+        String mime = MimeTypeMap.getSingleton().getMimeTypeFromExtension(MimeTypeMap.getFileExtensionFromUrl(uri.toString()));
+        intent.setDataAndType(uri, mime);
+        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
+        try {
+            startActivity(intent);
+        } catch (Exception e) {
+            Toast.makeText(this, "Cannot open file", Toast.LENGTH_SHORT).show();
+        }
+    }
+
+    @Override
+    public void onBackPressed() {
+        // Check against all storage volume roots
+        StorageManager storageManager = (StorageManager) getSystemService(STORAGE_SERVICE);
+        List<StorageVolume> storageVolumes = storageManager.getStorageVolumes();
+        boolean isAtRootOfAVolume = false;
+        for (StorageVolume volume : storageVolumes) {
+            File volumePath = volume.getDirectory();
+            if (volumePath != null && currentDirectory.equals(volumePath)) {
+                isAtRootOfAVolume = true;
+                break;
+            }
+        }
+
+        if (currentDirectory != null && !isAtRootOfAVolume) {
+            loadFiles(currentDirectory.getParentFile());
+        } else {
+            super.onBackPressed();
+        }
+    }
+
+    @Override
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+        if (requestCode == REQUEST_CODE_MANAGE_EXTERNAL_STORAGE) {
+            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+                loadFiles(Environment.getExternalStorageDirectory());
+            } else {
+                Toast.makeText(this, "Permission Denied", Toast.LENGTH_SHORT).show();
+            }
+        }
+    }
+
+    @Override
+    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+        super.onActivityResult(requestCode, resultCode, data);
+        if (requestCode == REQUEST_CODE_MANAGE_EXTERNAL_STORAGE) {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+                if (Environment.isExternalStorageManager()) {
+                    loadFiles(Environment.getExternalStorageDirectory());
+                } else {
+                    Toast.makeText(this, "Permission Denied", Toast.LENGTH_SHORT).show();
+                }
+            }
+        }
     }
 }

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

@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24.0"
+    android:viewportHeight="24.0"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M2,20h20v-4H2v4zm2,-3h2v2H4v-2zM2,4v4h20V4H2zm4,3H4V5h2v2zm-4,7h20v-4H2v4zm2,-3h2v2H4v-2z"/>
+</vector>

app/src/main/res/layout/activity_main.xml

@@ -6,9 +6,26 @@
     android:layout_height="match_parent"
     tools:context=".MainActivity">
 
+    <com.google.android.material.appbar.AppBarLayout
+        android:id="@+id/appBarLayout"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        app:layout_constraintTop_toTopOf="parent">
+
+        <androidx.appcompat.widget.Toolbar
+            android:id="@+id/toolbar"
+            android:layout_width="match_parent"
+            android:layout_height="?attr/actionBarSize" />
+
+    </com.google.android.material.appbar.AppBarLayout>
+
     <androidx.recyclerview.widget.RecyclerView
         android:id="@+id/recyclerView"
-        android:layout_width="match_parent"
+        android:layout_width="0dp"
-        android:layout_height="match_parent" />
+        android:layout_height="0dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@id/appBarLayout" />
 
 </androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/menu/main_menu.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+    <item
+        android:id="@+id/select_storage"
+        android:title="Select Storage"
+        android:icon="@drawable/ic_storage"
+        app:showAsAction="ifRoom" />
+</menu>