We Keep Coding

Like hitting counter in recyclerview

How to implement like button hitting count in RecyclerView. I have already created a like button and counter TextView with this code but when I hit the like button the application crashes. This is my code, what's wrong? I am using toggle button for like option and a TextView for counting like hitting.
This is my viewholder
public class WritingsViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public TextView MainTitle;
public ImageView Mainimage;
public ImageView Profimage;
public TextView ProfName;
public TextView txv;
public ToggleButton liketglbtn;
public TextView MainDesc, Idvkanme;
private ItemClickListner itemClickListner;
public void setItemClickListner(ItemClickListner itemClickListner) {
this.itemClickListner = itemClickListner;
}
public WritingsViewHolder(View itemView) {
super(itemView);
MainTitle = (TextView)itemView.findViewById(R.id.RTitle);
Mainimage = (ImageView)itemView.findViewById(R.id.rImageView);
Profimage = (ImageView)itemView.findViewById(R.id.Profile_Image);
ProfName = (TextView)itemView.findViewById(R.id.Prof_Name);
MainDesc = (TextView)itemView.findViewById(R.id.rDescriptionTv);
Idvkanme = (TextView)itemView.findViewById(R.id.Idavaka_Name);
txv = (TextView)itemView.findViewById(R.id.tx);
liketglbtn = (ToggleButton) itemView.findViewById(R.id.likeToggleBtn);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View v) {
itemClickListner.onClick(v,getAdapterPosition(),false);
}
}
This is my activity
public class WritingsActivity extends AppCompatActivity {
RecyclerView recyclerView;
FirebaseRecyclerOptions<IdavakaModel> options;
FirebaseRecyclerAdapter<IdavakaModel, WritingsViewHolder> adapter;
DatabaseReference MCC;
String categoryId = "";
RecyclerView.LayoutManager layoutManager;
TextView smsCountText;
int pendingSMSCount = 10;
static Button notifCount;
static int mNotifCount = 0;
Button FBcard, YoutubeCard;
private static final String APP_ID = "ca-app-pub-8867939169855032~9998384849";
Button mSaveBtn, mShareBtn;
private long backPressedTime;
private Toast backToast;
private int mCounter = 0;
ToggleButton btn;
TextView txv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_writings);
FBcard = (Button) findViewById(R.id.button1);
FBcard.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent toy = new Intent(WritingsActivity.this, IdavakaNewsUploadActivity.class);
startActivity(toy);
WritingsActivity.this.finish();
}
});
MobileAds.initialize(this,APP_ID);
AdView adView = (AdView) findViewById(R.id.adView);
AdRequest adRequest = new AdRequest.Builder().build();
adView.loadAd(adRequest);
//Bottom Navigation Bar
final BottomNavigationView bottomNavigationView = (BottomNavigationView)findViewById(R.id.botmnavigation);
bottomNavigationView.setSelectedItemId(R.id.action_privacy);
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem menuItem) {
switch (menuItem.getItemId()){
case R.id.myhome:
startActivity(new Intent(getApplicationContext(),MainActivity.class));
overridePendingTransition(0,0);
return true;
case R.id.action_notification:
startActivity(new Intent(getApplicationContext(),ChristianNewsMainActivity.class));
overridePendingTransition(0,0);
return true;
case R.id.action_privacy:
return true;
}
return false;
}
});
MCC= FirebaseDatabase.getInstance().getReference().child("Writings");
recyclerView = (RecyclerView) findViewById(R.id.readingroom_recyclerView);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
linearLayoutManager.setReverseLayout(true);
linearLayoutManager.setStackFromEnd(true);
recyclerView.setLayoutManager(linearLayoutManager);
LoadData(categoryId);
}
private void LoadData(String categoryId) {
options = new FirebaseRecyclerOptions.Builder<IdavakaModel>().setQuery(MCC,IdavakaModel.class).build();
adapter = new FirebaseRecyclerAdapter<IdavakaModel, WritingsViewHolder>(options) {
#Override
protected void onBindViewHolder(#NonNull WritingsViewHolder writingsViewHolder, int i, #NonNull IdavakaModel idavakaModel) {
writingsViewHolder.MainTitle.setText(idavakaModel.getTitle());
writingsViewHolder.MainDesc.setText(idavakaModel.getDesc());
writingsViewHolder.ProfName.setText(idavakaModel.getProfname());
writingsViewHolder.Idvkanme.setText(idavakaModel.getIdavakaname());
Picasso.get().load(idavakaModel.getPostimage())
.into(writingsViewHolder.Mainimage);
Picasso.get().load(idavakaModel.getProfimage())
.into(writingsViewHolder.Profimage);
writingsViewHolder.setItemClickListner(new ItemClickListner() {
#Override
public void onClick(View view, int position, boolean isLongClick) {
Intent detailsIntent = new Intent(WritingsActivity.this, IdavakaDetailActivity.class);
detailsIntent.putExtra("CategoryId", adapter.getRef(position).getKey());
startActivity(detailsIntent);
}
});
writingsViewHolder.liketglbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mCounter++;
txv.setText(Integer.toString(mCounter));
}
});
}
#NonNull
#Override
public WritingsViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.writngs_items, parent, false);
return new WritingsViewHolder(v);
}
};
adapter.startListening();
recyclerView.setAdapter(adapter);
}
#Override
public void onBackPressed() {
if (backPressedTime + 2000 > System.currentTimeMillis()) {
backToast.cancel();
super.onBackPressed();
WritingsActivity.this.finish();
return;
} else {
backToast = Toast.makeText(getBaseContext(), "See You Soon", Toast.LENGTH_SHORT);
backToast.show();
}
backPressedTime = System.currentTimeMillis();
WritingsActivity.this.finish();
}
public void onCustomToggleClick (View view) {
Toast.makeText(this, "Liked",Toast.LENGTH_SHORT).show();
}
}

You are getting NullPointerException because the TextView you are using is in Activity named txv where you are setting counter. But the problem is you have declared TextView in Activity but have not initialized anywhere in the Activity. You MUST initialize that variable via findViewbyId method before setting values.
Furthermore, you have initialized txv TextView and accessing on Activity that is why you are getting NLP. TextView is a part of Activity layout which you have not Initialized. On the hand you have initialized txv in Adapter which is of no use.

Open Bottom Sheet automatically without using a Button

I'm doing this project where I want to start an application ( Main activity ) with a bottom sheet as instruction to know how to use some functions, while the main activity is open at the background.
I've known how to transition between a bottom sheet to another but my main problem that the first bottom sheet needs a button it self to be activated, so my question is can it be done automatically when the application starts without the need of a button then dismissed after clicking on the button inside the bottom sheet ?
This is my Java Code:
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button buttonShow = findViewById(R.id.button_start);
buttonShow.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
final BottomSheetDialog bottomSheetDialog = new BottomSheetDialog(
MainActivity.this, R.style.BottomSheetDesign
);
View bottomSheetView = LayoutInflater.from(getApplicationContext())
.inflate(
R.layout.layout_bottom_sheet,
(LinearLayout)findViewById(R.id.BottomSheetContainer)
);
bottomSheetView.findViewById(R.id.ButtonNext).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
final BottomSheetDialog bottomSheetDialog1 = new BottomSheetDialog(
MainActivity.this, R.style.BottomSheetDesign
);
View bottomSheetView1 = LayoutInflater.from(getApplicationContext())
.inflate(
R.layout.layout_bottom_sheet1,
(LinearLayout)findViewById(R.id.BottomSheetContainer1)
);
bottomSheetView1.findViewById(R.id.ButtonDone).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
bottomSheetDialog1.dismiss();
}
});
bottomSheetDialog.dismiss();
bottomSheetDialog1.setContentView(bottomSheetView1);
bottomSheetDialog1.show();
}
});
bottomSheetDialog.setContentView(bottomSheetView);
bottomSheetDialog.show();
}
});

call bottomsheet directly in oncreate method
Try this code:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
openBottomSheet();
}
private void openBottomSheet() {
final BottomSheetDialog bottomSheetDialog = new BottomSheetDialog(
MainActivity.this, R.style.BottomSheetDesign
);
View bottomSheetView = LayoutInflater.from(getApplicationContext())
.inflate(
R.layout.layout_bottom_sheet,
(LinearLayout) findViewById(R.id.BottomSheetContainer)
);
bottomSheetView.findViewById(R.id.ButtonNext).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
final BottomSheetDialog bottomSheetDialog1 = new BottomSheetDialog(
MainActivity.this, R.style.BottomSheetDesign
);
View bottomSheetView1 = LayoutInflater.from(getApplicationContext())
.inflate(
R.layout.layout_bottom_sheet1,
(LinearLayout) findViewById(R.id.BottomSheetContainer1)
);
bottomSheetView1.findViewById(R.id.ButtonDone).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
bottomSheetDialog1.dismiss();
}
});
bottomSheetDialog.dismiss();
bottomSheetDialog1.setContentView(bottomSheetView1);
bottomSheetDialog1.show();
}
});
bottomSheetDialog.setContentView(bottomSheetView);
bottomSheetDialog.show();
}

Dynamically add Views in Dialog

I am trying to make Dialog that will consist 2x EditText and 1x Buttons. By clicking additional button you can add another 2x EditText and 1x Buttons. This 1x Button provide deleting this added pair. When i try to use button that should add another Views it's working properly. But button for deleting the View is working only for the first pairs. How can i do this with android:onClick, because i was trying buy it crashed.
Here is my code of Dialog class:
public class ExampleDialog extends AppCompatDialogFragment {
private EditText editTextUsername;
private EditText editTextPassword;
private ExampleDialogListener listener;
private LinearLayout parentLinearLayout;
private Context mContext;
Button dodaj,usun;
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
LayoutInflater inflater = getActivity().getLayoutInflater();
View view = inflater.inflate(R.layout.dialog_template, null);
builder.setView(view)
.setTitle("Login")
.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
}
})
.setPositiveButton("ok", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
String username = editTextUsername.getText().toString();
String password = editTextPassword.getText().toString();
listener.applyTexts(username, password);
}
});
editTextUsername = view.findViewById(R.id.edit_username);
editTextPassword = view.findViewById(R.id.edit_password);
parentLinearLayout = (LinearLayout) view.findViewById(R.id.parent_linear_layout);
dodaj = view.findViewById(R.id.add_field_button);
usun = view.findViewById(R.id.delete_button);
dodaj.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
final View rowView = inflater.inflate(R.layout.field, null);
// Add the new row before the add field button.
parentLinearLayout.addView(rowView, parentLinearLayout.getChildCount() - 1);
}
});
usun.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
parentLinearLayout.removeView((View) v.getParent());
usun = v.findViewById(R.id.delete_button);
}
});
return builder.create();
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
try {
listener = (ExampleDialogListener) context;
} catch (ClassCastException e) {
throw new ClassCastException(context.toString() +
"must implement ExampleDialogListener");
}
}
public void contexta(Context context)
{
this.mContext = context;
}
public interface ExampleDialogListener {
void applyTexts(String username, String password);
}
}
And there is the conception of Dialog box on the picture below:
Picture

This issue may be due to view reference. Check whether v.getParent() is the view you want to delete or not.
For testing you can use "removeViewAt(int index)" method. Pass an index and check whether view is deleted at index or not.

SetText from a Class to the main XML file

I'm trying to use the .setText within a java class to try to change the value of a TextView on the activity_main XML file, so far i'm getting the NullpointerExeption error and I've read that its due an error when declaring my variable. How can i achieve this? Do i need to declare it first at the mainActivity.java?
On my activity_main.xml i have a button -> it opens a custom listView -> if you press the 2 item on the list view -> it opens a custom alert dialog -> the custom alert dialog it contains 2 buttons -> if you press the second button -> it has to set the text of a TextView that is on activity_main.xml
Any help is appreciated!
MainActivity.java
final TextView KMLabel = (TextView)findViewById(R.id.KMlabel);
activity.main.xml
<TextView
android:id="#+id/KMlabel"
android:layout_alignBottom="#+id/TVKm"
android:layout_toRightOf="#+id/TVKm"
android:textSize="22sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#e6c009"
android:text="KM/H"
android:textStyle="italic"/>
custom.java
public class custom extends BaseAdapter{
Context context;
String Item[];
String SubItem[];
int flags[];
LayoutInflater inflter;
public custom(Context applicationContext, String[] Item, String[] SubItem , int[] flags) {
this.context = context;
this.Item = Item;
this.SubItem = SubItem;
this.flags = flags;
inflter = (LayoutInflater.from(applicationContext));
}
#Override
public int getCount() {
return Item.length;
}
#Override
public Object getItem(int i) {
return null;
}
#Override
public long getItemId(int i) {
return 0;
}
#Override
public View getView(int i, View view, ViewGroup viewGroup) {
view = inflter.inflate(R.layout.activity_items, null);
//TextView Prueba = (TextView)view.findViewById(R.id.KMlabel);
TextView item = (TextView) view.findViewById(R.id.item);
TextView subitem = (TextView) view.findViewById(R.id.subitem);
ImageView image = (ImageView) view.findViewById(R.id.image);
item.setText(Item[i]);
subitem.setText(SubItem[i]);
image.setImageResource(flags[i]);
return view;
}
viewdialog.java
public class ViewDialog {
public void showDialog(Activity activity, String msg){
final Dialog dialog = new Dialog(activity);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setCancelable(false);
dialog.setContentView(R.layout.custom_dialog);
//I'm declaring it like this
final TextView KMLabel = (TextView)activity.findViewById(R.id.KMlabel);
Button dialogButton = (Button) dialog.findViewById(R.id.btn_dialog);
dialogButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dialog.dismiss();
}
});
Button KmPerHr = (Button)dialog.findViewById(R.id.KmPerH);
KmPerHr.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//and calling it this way:
KMLabel.setText("MLL/H");
}
});
dialog.show();
}
}
LOGCAT:
FATAL EXCEPTION: main
Process: com.example.dell.getspeed, PID: 3925
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at com.example.dell.getspeed.ViewDialog$2.onClick(ViewDialog.java:38)
at android.view.View.performClick(View.java:5721)
at android.widget.TextView.performClick(TextView.java:10936)
at android.view.View$PerformClick.run(View.java:22620)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:7406)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)

You have to move your code
Button KmPerHr = (Button)dialog.findViewById(R.id.KmPerH);
KmPerHr.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//and calling it this way:
KMLabel.setText("MLL/H");
}
});
final TextView KMLabel = (TextView)dialog.findViewById(R.id.KMlabel);
Button dialogButton = (Button) dialog.findViewById(R.id.btn_dialog);
dialogButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dialog.dismiss();
}
});
below the dialog.show() code because code findViewById only work after you pop up dialog.

Create a Global class which extends to application class, then create a texview in Global
Textview t = null;
Then create two static methods to set and get this textview
Public static void setT(TextView p){
t = p;
}
And get it from
Public static TextView getT(){
return t;
}
Set TextView in your activity ,then access this textview from wherever you want until your activity is alive.

Try the code below:
MainActivity class:-------
public class MainActivity extends AppCompatActivity {
private TextView KMlabel;
private Button b;
private ViewDialog vd;
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.demo2);
vd = new ViewDialog();
KMlabel = (TextView) findViewById(R.id.KMlabel);
b = (Button) findViewById(R.id.b);
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
vd.showDialog(MainActivity.this , KMlabel , "Your Message" , "Your Text");
}
});
}
}
ViewDialog class:------
public class ViewDialog {
public void showDialog(Context context, final TextView v , String msg , final String text) {
createYesNoInfoDialog(context, msg, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
// do nothing
}
}, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
v.setText(text);
}
}).show();
}
private AlertDialog createYesNoInfoDialog(Context finalContext, String message,
DialogInterface.OnClickListener onNoListener, DialogInterface.OnClickListener onYesListener) {
AlertDialog a = new AlertDialog.Builder(finalContext).setTitle(
message)
.setNegativeButton("No", onNoListener)
.setPositiveButton("Yes", onYesListener).create();
return a;
}
}
demo2.xml:-----
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="xcxc"
android:id="#+id/KMlabel"/>
<Button
android:layout_width="match_parent"
android:text="Create Dialog"
android:layout_height="wrap_content"
android:id="#+id/b"/>
</LinearLayout>

R.id.KMlabel is on activity_main.xml so you have to initialize the TextView from MainActivity reference.
final TextView KMLabel = (TextView)activity.findViewById(R.id.KMlabel);
Edit:
You can use callback pattern for this:
ViewDialog:
public class ViewDialog {
// interface for callback
public interface OnSelectListener {
public void onOkSelect();
}
OnSelectListener mOnSelectListener;
public void showDialog(Activity activity, String msg, OnSelectListener mListener){
mOnSelectListener = mListener;
final Dialog dialog = new Dialog(activity);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setCancelable(false);
dialog.setContentView(R.layout.custom_dialog);
//I'm declaring it like this
final TextView KMLabel = (TextView)activity.findViewById(R.id.KMlabel);
Button dialogButton = (Button) dialog.findViewById(R.id.btn_dialog);
dialogButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dialog.dismiss();
}
});
Button KmPerHr = (Button)dialog.findViewById(R.id.KmPerH);
KmPerHr.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//pass to the implementation if not null
if( mOnSelectListener != null){
mOnSelectListener.onOkSelect();
}
}
});
dialog.show();
}
}
In MainActivity:
// initialize interface
ViewDialog.OnSelectListener mOnSelectListener = new ViewDialog.OnSelectListener(){
public void onOkSelect(){
KMLabel.setText("MLL/H");
}
};
ViewDialog viewDialog = new ViewDialog();
viewDialog.showDialog(this, "Message", mOnSelectListener);

This happens since you are trying to call the TextView within the custom alert dialog. TextView only belongs to the MainActivity. You can call or change that only within the MainActivity class. So please try this below.
MainActivity.class
public class MainActivity extends AppCompatActivity {
private TextView KMlabel;
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
KMlabel = (TextView) findViewById(R.id.KMlabel);
}
public void setTextKM(String string){
KMlabel.setText(string);
}
}
ViewDialog class
public class ViewDialog {
public void showDialog(Activity activity, String msg){
final Dialog dialog = new Dialog(activity);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setCancelable(false);
dialog.setContentView(R.layout.custom_dialog);
Button dialogButton = (Button) dialog.findViewById(R.id.btn_dialog);
dialogButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dialog.dismiss();
}
});
Button KmPerHr = (Button)dialog.findViewById(R.id.KmPerH);
KmPerHr.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
MainActivity mainActivity = new MainActivity();
mainActivity.setTextKM("MLL/H");
}
});
dialog.show();
}
}

Android Application crash on dialog Button click

Im trying to make a Dialog close when button is pressed.But Every time i press the button the application crashes.
public class CanvasPaint extends Activity implements OnClickListener {
final Button widthbtn = (Button) findViewById(R.id.widthbtn);
final Button widthpopBtn = (Button) findViewById(R.id.widthpopBtn);
final Context context = this;
final Dialog widthDialog = new Dialog(context);
widthbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
widthpopBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
widthDialog.dismiss();
}
});
widthDialog.show();
}
});
}

That's some inception code. Why are you setting a click listener inside a click listener? It should be more like
widthbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
widthDialog.show();
}
});
widthpopBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
widthDialog.dismiss();
}
});

Your dialog layout is not properly inflated, and therefore, your widthpopBtn will be null. Try inflating the layout like this:
LayoutInflater inflater = getLayoutInflater();
View dialogView = inflater.inflate(R.layout.your_dialog_layout, null);
Button widthpopBtn = (Button) dialogView.findViewById(R.id.widthpopBtn);