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I’ve been researching this mistake for three days and I can’t fix it. I’m setting up a photo gallery for my app and need to popular an Array with the photos coming from Firebase to show them in the gallery. This error occurs when clicking on the gallery, so I already researched the error happens when I put items in the array and its size changes, I would have to notify the Adapter using notifyDataSetChanged(), but I could not find a way to do this or am notifying in the wrong place, I’ve used this method in several places and nothing... Can someone help me? Below the code
public class Galeria extends AppCompatActivity {
private GaleriaImagensAdapter adapter;
private List<String> valores;
private List<String> temporaria;
private ViewPager galeria;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_galeria);
getIntentAtual();
galeria = (ViewPager) findViewById(R.id.vp_galeria);
}
@Override
protected void onResume() {
super.onResume();
if(valores == null){
valores = new ArrayList<>();
}
valores = ConfiguracaoFirebase.galeriaFire();
if (adapter == null){
adapter = new GaleriaImagensAdapter(this, valores);
galeria.setAdapter(adapter);
}else {
adapter.notifyDataSetChanged();
}
}
private void getIntentAtual(){
if(getIntent().hasExtra("nome_sessao") && getIntent().hasExtra("sessao_bd")){
String tituloSessao = getIntent().getStringExtra("nome_sessao");
String nomeSessaoBD = getIntent().getStringExtra("sessao_bd");
}else{
Log.i("falha", "sem nada");
}
}
}
Here the gallery Adapter
public class GaleriaImagensAdapter extends PagerAdapter {
private Context context;
private List<String> valores;
private boolean doNotifyDataSetChangedOnce = false;
private int[] imagens = new int[] { R.drawable.cadastrar_usuario_branco_extraido, R.drawable.cadastrar_usuario_branco, R.drawable.cadastrar_usuario};
public GaleriaImagensAdapter(Context contextm, List<String> valor){
this.valores = valor;
this.context = context;
}
@Override
public int getCount() {
if (doNotifyDataSetChangedOnce){
doNotifyDataSetChangedOnce = false;
notifyDataSetChanged();
return valores.size();
}
@Override
public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
return view.equals(object);
}
@Override
public void destroyItem(ViewGroup pager, int position, Object object){
((ViewPager) pager).removeView((ImageView) object);
}
@Override
public Object instantiateItem(ViewGroup pager, int position){
ImageView imagem = new ImageView(context);
imagem.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
Glide.with(context).load(valores.get(position)).into(imagem);
((ViewPager) pager).addView(imagem, 0);
return imagem;
}
}
Here is the firebase code:
public static List galeriaFire(){
final List<String> imagensGaleria = new ArrayList<>();
firebase = ConfiguracaoFirebase.getFirebase().child("sessoes").child("galeria").child("2018").child("agosto");
post = new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot child : dataSnapshot.getChildren()){
imagensGaleria.add(child.getValue().toString());
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
};
firebase.addValueEventListener(post);
return imagensGaleria;
}
Down with the error:
09-14 12:36:06.651 3166-3166/doeamor.acaosocial.com.doeamor E/AndroidRuntime: FATAL EXCEPTION: main
Process: doeamor.acaosocial.com.doeamor, PID: 3166
java.lang.IllegalStateException: The application's PagerAdapter changed the adapter's contents without calling PagerAdapter#notifyDataSetChanged! Expected adapter item count: 0, found: 3 Pager id: doeamor.acaosocial.com.doeamor:id/vp_galeria Pager class: class android.support.v4.view.ViewPager Problematic adapter: class doeamor.acaosocial.com.doeamor.Adapter.GaleriaImagensAdapter
at android.support.v4.view.ViewPager.populate(ViewPager.java:1137)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1086)
at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1616)
at android.view.View.measure(View.java:17547)
at android.support.constraint.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:1212)
at android.support.constraint.ConstraintLayout.onMeasure(ConstraintLayout.java:1552)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:141)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2615)
at android.view.View.measure(View.java:17547)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2015)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1173)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1379)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1061)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5885)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
at android.view.Choreographer.doCallbacks(Choreographer.java:580)
at android.view.Choreographer.doFrame(Choreographer.java:550)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)