allow opening subdirs

app/src/main/java/com/simplemobiletools/filemanager/activities/MainActivity.java

@@ -5,6 +5,7 @@ import android.content.pm.PackageManager;
 import android.os.Bundle;
 import android.os.Environment;
 import android.support.v4.app.ActivityCompat;
+import android.support.v4.app.FragmentManager;
 import android.support.v7.app.AppCompatActivity;
 
 import com.simplemobiletools.filemanager.Constants;
@@ -14,7 +15,7 @@ import com.simplemobiletools.filemanager.fragments.ItemsFragment;
 
 import butterknife.ButterKnife;
 
-public class MainActivity extends AppCompatActivity {
+public class MainActivity extends AppCompatActivity implements ItemsFragment.ItemInteractionListener {
     private static final int STORAGE_PERMISSION = 1;
 
     @Override
@@ -32,20 +33,35 @@ public class MainActivity extends AppCompatActivity {
 
     private void tryInitFileManager() {
         if (Utils.hasStoragePermission(getApplicationContext())) {
-            initializeFileManager();
+            initRootFileManager();
         } else {
             ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, STORAGE_PERMISSION);
         }
     }
 
-    private void initializeFileManager() {
-        final Bundle bundle = new Bundle();
+    private void initRootFileManager() {
         final String path = Environment.getExternalStorageDirectory().toString();
+        openPath(path);
+    }
+
+    private void openPath(String path) {
+        final Bundle bundle = new Bundle();
         bundle.putString(Constants.PATH, path);
 
         final ItemsFragment fragment = new ItemsFragment();
         fragment.setArguments(bundle);
-        getSupportFragmentManager().beginTransaction().replace(R.id.fragment_holder, fragment).commit();
+        fragment.setListener(this);
+        getSupportFragmentManager().beginTransaction().replace(R.id.fragment_holder, fragment).addToBackStack("").commit();
+    }
+
+    @Override
+    public void onBackPressed() {
+        final FragmentManager manager = getSupportFragmentManager();
+        if (manager.getBackStackEntryCount() == 1)
+            finish();
+        else {
+            super.onBackPressed();
+        }
     }
 
     @Override
@@ -54,11 +70,16 @@ public class MainActivity extends AppCompatActivity {
 
         if (requestCode == STORAGE_PERMISSION) {
             if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
-                initializeFileManager();
+                initRootFileManager();
             } else {
                 Utils.showToast(getApplicationContext(), R.string.no_permissions);
                 finish();
             }
         }
     }
+
+    @Override
+    public void itemClicked(String path) {
+        openPath(path);
+    }
 }

app/src/main/java/com/simplemobiletools/filemanager/fragments/ItemsFragment.java

@@ -25,6 +25,9 @@ import butterknife.ButterKnife;
 public class ItemsFragment extends android.support.v4.app.Fragment implements AdapterView.OnItemClickListener {
     @BindView(R.id.items_list) ListView mListView;
 
+    private List<FileDirItem> mItems;
+    private ItemInteractionListener mListener;
+
     @Nullable
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
@@ -38,18 +41,22 @@ public class ItemsFragment extends android.support.v4.app.Fragment implements Ad
         super.onViewCreated(view, savedInstanceState);
 
         final String path = getArguments().getString(Constants.PATH);
-        List<FileDirItem> items = getItems(path);
-        Collections.sort(items);
+        mItems = getItems(path);
+        Collections.sort(mItems);
 
-        final ItemsAdapter adapter = new ItemsAdapter(getContext(), items);
+        final ItemsAdapter adapter = new ItemsAdapter(getContext(), mItems);
         mListView.setAdapter(adapter);
         mListView.setOnItemClickListener(this);
     }
 
+    public void setListener(ItemInteractionListener listener) {
+        mListener = listener;
+    }
+
     private List<FileDirItem> getItems(String path) {
         final List<FileDirItem> items = new ArrayList<>();
-        final File root = new File(path);
-        File[] files = root.listFiles();
+        final File base = new File(path);
+        File[] files = base.listFiles();
         for (File file : files) {
             final String curPath = file.getAbsolutePath();
             final String curName = Utils.getFilename(curPath);
@@ -60,6 +67,13 @@ public class ItemsFragment extends android.support.v4.app.Fragment implements Ad
 
     @Override
     public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
+        final FileDirItem item = mItems.get(position);
+        if (item.getIsDirectory()) {
+            mListener.itemClicked(item.getPath());
+        }
+    }
 
+    public interface ItemInteractionListener {
+        void itemClicked(String path);
     }
 }