Вот мой адаптер recyclerView, который показывает список из базы данных, кнопка просмотра предназначена для загрузки, а кнопка удаления удаляет файл из хранилища устройства, он работает отлично. Но как мне сделать видимость кнопки удаления невидимой / пропавшей, если файл не существует в хранилище устройства.
MainActivity mainActivity;
ArrayList<DownModel> downModels;
public MyAdapter(MainActivity mainActivity, ArrayList<DownModel> downModels) {
this.mainActivity =mainActivity;
this.downModels = downModels;
}
@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
LayoutInflater layoutInflater = LayoutInflater.from(mainActivity.getBaseContext());
View view = layoutInflater.inflate(R.layout.elements, viewGroup, false);
return new MyViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull final MyViewHolder myViewHolder, final int i) {
myViewHolder.mName.setText(downModels.get(i).getName());
myViewHolder.mDownload.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(myViewHolder.mDownload.getContext(), PdfView.class);
intent.putExtra("pdf_url", downModels.get(i).getLink());
intent.putExtra("pdf_name",downModels.get(i).getName());
myViewHolder.mDownload.getContext().startActivity(intent);
}
});
myViewHolder.mDelete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Context context = myViewHolder.itemView.getContext();
String pdfName = downModels.get(i).getName()+".pdf";
File file = new File(context.getFilesDir(), pdfName);
try {
if (file.exists())
file.delete();
Log.e("file","file"+file.getAbsolutePath());
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
@Override
public int getItemCount() {
return downModels.size();
}
}
RecyclerView
public class MainActivity extends AppCompatActivity {
FirebaseFirestore db;
RecyclerView mRecyclerView;
ArrayList<DownModel> downModelArrayList = new ArrayList<>();
MyAdapter myAdapter;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRecyclerView= findViewById(R.id.recycle);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
db=FirebaseFirestore.getInstance();
dataFromFirebase();
}
@Override
protected void onResume() {
super.onResume();
myAdapter.notifyDataSetChanged();
}
private void dataFromFirebase() {
if(downModelArrayList.size()>0)
downModelArrayList.clear();
db.collection("chapter1").orderBy("value")
.get()
.addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
@Override
public void onComplete(@NonNull Task<QuerySnapshot> task) {
for(DocumentSnapshot documentSnapshot: Objects.requireNonNull(task.getResult())) {
DownModel downModel= new DownModel(documentSnapshot.getString("name"),
documentSnapshot.getString("link"));
downModelArrayList.add(downModel);
}
myAdapter= new MyAdapter(MainActivity.this,downModelArrayList);
mRecyclerView.setAdapter(myAdapter);
}
})
.addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
Toast.makeText(MainActivity.this, "Error ;-.-;", Toast.LENGTH_SHORT).show();
}
})
;
}
} Макет
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_marginBottom="5dp"
android:layout_marginTop="5dp">
<TextView
android:id="@+id/name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="start"
android:text="Name"
android:textSize="20sp" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:layout_marginBottom="5dp"
android:orientation="horizontal"
android:weightSum="2"
>
<Button
android:id="@+id/down"
android:layout_width="0dp"
android:layout_height="30dp"
android:layout_marginEnd="10dp"
android:layout_weight="1"
android:background="#A00303"
android:elevation="7dp"
android:text="View"
android:textColor="#FFFFFF"
tools:visibility="visible" />
<Button
android:id="@+id/delete"
android:layout_width="0dp"
android:layout_height="30dp"
android:layout_marginStart="10dp"
android:layout_weight="1"
android:background="#A00303"
android:elevation="7dp"
android:text="Delete"
android:textColor="#FFFFFF"
tools:visibility="gone" />
</LinearLayout>
</LinearLayout>
</androidx.cardview.widget.CardView>
