I am having difficulty generating random items received by Firebase, I have read the documentation but I was confused.
I want to randomize items within FirebaseRecyclerAdapter according to the number of children entered.
Ex: if I have 3 items entered, it will randomize the 3's. But if I enter 10 items in Firebase, the random limit extends to 10. What is the best way to implement?
privatestaticContextmContext;DatabaseReferencereferencia;RecyclerViewlistaEmpresa;privatestaticStringempresa;//SearchViewsearchView;ImageViewbaner1;MainActivitymain=newMainActivity();DatabaseReferencedatabaseReferencia=FirebaseDatabase.getInstance().getReference();DatabaseReferenceemergenciaRef=databaseReferencia.child("Categorias").child("Emergencia"); //ok
DatabaseReference drogariaRef = databaseReferencia.child("Categorias").child("Drogaria");//ok
DatabaseReference hospitalRef = databaseReferencia.child("Categorias").child("Hospital");//ok
DatabaseReference alimentacaoRef = databaseReferencia.child("Categorias").child("Alimentacao");//ok
DatabaseReference supermercadoRef = databaseReferencia.child("Categorias").child("Supermercado"); //ok
DatabaseReference barRef = databaseReferencia.child("Categorias").child("Bar");//ok
DatabaseReference taxiRef = databaseReferencia.child("Categorias").child("Taxi"); //ok
DatabaseReference servicosRef = databaseReferencia.child("Categorias").child("Servicos");//ok
DatabaseReference postoDeGasolinaRef = databaseReferencia.child("Categorias").child("PostoDeGasolina");//ok
DatabaseReference saudeBelezaRef = databaseReferencia.child("Categorias").child("SaudeBeleza");//ok
DatabaseReference modaRef = databaseReferencia.child("Categorias").child("Moda");//ok
DatabaseReference comercioRef = databaseReferencia.child("Categorias").child("Comercio");//ok
DatabaseReference escolaRef = databaseReferencia.child("Categorias").child("Escola");//ok
DatabaseReference papelariaRef = databaseReferencia.child("Categorias").child("Papelaria");//ok
DatabaseReference prefeituraRef = databaseReferencia.child("Categorias").child("Prefeitura");
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_lista_estabelecimentos);
baner1 = (ImageView)findViewById(R.id.baner);
mContext = this;
listaEmpresa = (RecyclerView)findViewById(R.id.recyclerv_view);
listaEmpresa.setHasFixedSize(true);
listaEmpresa.setLayoutManager(new LinearLayoutManager(this));
//pega categoria do mainActivity
Bundle bundle = getIntent().getExtras();
if(bundle != null) {
int categoriaEscolhida = bundle.getInt("categoria");
switch (categoriaEscolhida){
case 0 :{
// Query randomData = emergenciaRef.orderByChild("id").startAt(gerarRandom()).limitToFirst();
referencia = emergenciaRef;
}
break;
case 1:{
referencia = drogariaRef;
}
break;
case 2:{
referencia = hospitalRef;
}
break;
case 3:{
referencia = alimentacaoRef;
}
break;
case 4:{
referencia = supermercadoRef;
}
break;
case 5:{
referencia = barRef;
}
break;
case 6:{
referencia = taxiRef;
}
break;
case 7:{
referencia = servicosRef;
}
break;
case 8:{
referencia = postoDeGasolinaRef;
}
break;
case 9:{
referencia = saudeBelezaRef;
}
break;
case 10:{
referencia = modaRef;
}
break;
case 11:{
referencia = comercioRef;
}
break;
case 12:{
referencia = escolaRef;
}
break;
case 13:{
referencia = papelariaRef;
}
break;
case 14:{
referencia = prefeituraRef;
}
break;
}
}
}
private int gerarRandom(int i) {
return 0;
}
@Override
protected void onStart() {
super.onStart();
FirebaseRecyclerAdapter<Empresas,FirebaseViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Empresas, FirebaseViewHolder>(
Empresas.class,
R.layout.layout_listaitem,
FirebaseViewHolder.class,
referencia){
@Override
protected void populateViewHolder(FirebaseViewHolder viewHolder, final Empresas emp, int position){
viewHolder.setImg(getApplicationContext(), emp.getFoto());
viewHolder.setNomeDaEmpresa(emp.getNomeDaEmpresa());
viewHolder.setEnd(emp.getEndereco());
viewHolder.setTel(emp.getTell());
viewHolder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(mContext,EmpresaDescricao.class);
intent.putExtra("foto" ,emp.getFoto());
intent.putExtra("nomeDaEmpresa",emp.getNomeDaEmpresa());
intent.putExtra("endereco",emp.getEndereco());
intent.putExtra("tell",emp.getTell());
intent.putExtra("localizacao",emp.getLocal());
intent.putExtra("site",emp.getSite());
intent.putExtra("descricao",emp.getDesc());
intent.putExtra("foto1",emp.getFoto1());
intent.putExtra("foto2",emp.getFoto2());
intent.putExtra("foto3",emp.getFoto3());
intent.putExtra("foto4",emp.getFoto4());
mContext.startActivity(intent);
}
});
}
};
listaEmpresa.setAdapter(firebaseRecyclerAdapter);
}
public static class FirebaseViewHolder extends RecyclerView.ViewHolder {
View mView;
public FirebaseViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
private void intent() {
Intent intent = new Intent(mContext, EmpresaDescricao.class);
mContext.startActivity(intent);
}
public void setNomeDaEmpresa(String nomeDaEmpresa) {
TextView nomDaEmpresa = (TextView) mView.findViewById(R.id.nomeDaEmpresa);
nomDaEmpresa.setText(nomeDaEmpresa);
}
public void setImg(Context ctx, String image) {
ImageView foto = (ImageView) mView.findViewById(R.id.image);
Picasso.with(ctx).load(image).into(foto);
}
public void setEnd(String endereco){
TextView end =(TextView)mView.findViewById(R.id.endereco);
end.setText(endereco);
}
public void setTel(String tell){
TextView tel =(TextView)mView.findViewById(R.id.telefone);
tel.setText(tell);
}}
public void banerClick(View view) {
Intent intent = null, chooser = null;
intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse(main.questionario));
chooser = Intent.createChooser(intent,"Launch browsers");
startActivity(chooser);
}}