We Keep Coding

how is onActivityResult is different from registerForActivityResult?

actually previously i wanted to pick image fromthe gallery so i came
to know that onActivityResult was deprecated and we should use
registerForActivityResult(). so i used it by defining the mime type
as "image/*" but now i want to import pdf from gallery but there is
no such mime type for that i want to understand how these mime
things works and how can i achieve my task by
registerForActivityResult() method
i also want to understand the how we define the datatype of the someActivityResultLauncher as a string ?? i want to understand how this whole things work...can we define custom mime type by our own ?? please help me in this
'''
package com.parth.iitktimes;
import androidx.activity.result.ActivityResultCallback;
import androidx.activity.result.ActivityResultLauncher;
import androidx.activity.result.contract.ActivityResultContracts;
import androidx.appcompat.app.AppCompatActivity;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.material.card.MaterialCardView;
import java.io.IOException;
public class addBooks extends AppCompatActivity {
private MaterialCardView selectImage;
private TextView docName;
private Spinner semSpinner, branchSpinner;
private Button btnUpload;
private ActivityResultLauncher<String> someActivityResultLauncher; // why string
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_books);
selectImage = findViewById(R.id.select_image);
docName = findViewById(R.id.tvDocName);
semSpinner = findViewById(R.id.spinner_sem);
branchSpinner = findViewById(R.id.spinner_branch);
btnUpload = findViewById(R.id.btnUploadNotes);
btnUpload.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Toast.makeText(getApplicationContext(), "uploaded notes successfully", Toast.LENGTH_SHORT).show();
}
});
selectImage.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
someActivityResultLauncher.launch("");//what used i fill here??
}
});
String[] semesterItems = {"First", "Second", "Third", "Fourth", "Fifth", "Sixth", "Seventh", "Eighth"};
//attaching array adapter to the spinner
//since we not using custom spinner therefore we are using the default array adapter
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.support_simple_spinner_dropdown_item, semesterItems);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
semSpinner.setAdapter(adapter);
//on item selected listener to the spinner
semSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
imageCategory = eventSpinner.getSelectedItem().toString();
}
#Override
public void onNothingSelected(AdapterView<?> adapterView) {
//setting the default category as others
imageCategory = spinnerItems[0];
}
});
String[] branchItems = {"Mchanical", "Electrical", "CSE", "MTH"};
//attaching array adapter to the spinner
//since we not using custom spinner therefore we are using the default array adapter
ArrayAdapter<String> branchAdapter = new ArrayAdapter<String>(this, R.layout.support_simple_spinner_dropdown_item, branchItems);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
branchSpinner.setAdapter(adapter);
//on item selected listener to the spinner
branchSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
imageCategory = eventSpinner.getSelectedItem().toString();
}
#Override
public void onNothingSelected(AdapterView<?> adapterView) {
//setting the default category as others
imageCategory = spinnerItems[0];
}
});
//activity result launcher
someActivityResultLauncher = registerForActivityResult(
new ActivityResultContracts.GetContent(), new ActivityResultCallback<Uri>() {
#Override
public void onActivityResult(Uri result) {
try {
bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), result);
} catch (IOException e) {
e.printStackTrace();
}
preview_events_image.setImageBitmap(bitmap);
}
});
}
}

How to create dialog box when click on the item of recyclerview?

I'm trying to create a function that once a user clicks on the recycler view, a dialog box will pop out but I am stuck on the error as mentioned below. When I try to initialize AlertDialog.build and put this as the parameter, it shows an error. I had tried with a few other parameters like context, getActivity. But the error is still the same.
The code below is my full code
package com.example.tuitioncentre;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.database.Observable;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.firestore.DocumentSnapshot;
public class myadapter_tutorlist extends FirebaseRecyclerAdapter<User,myadapter_tutorlist.myviewholder> {
AlertDialog.Builder builder;
public myadapter_tutorlist(#NonNull FirebaseRecyclerOptions<User> options) {
super(options);
}
#Override
protected void onBindViewHolder(#NonNull final myviewholder holder, int position, #NonNull final User model) {
holder.name.setText("Tutor's Name:" + model.getUsername());
holder.phone.setText("Phone No:" + model.getPhone());
holder.email.setText("Email:" + model.getEmail());
holder.status.setText("Status: " + model.getActive().toString());
builder = new AlertDialog.Builder(this);
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(final View v) {
//Toast.makeText(v.getContext(),model.getUsername(),Toast.LENGTH_SHORT).show();
builder.setMessage(R.string.dialog_message) .setTitle(R.string.dialog_title);
builder.setMessage("Do you want to activate tutor account ?")
.setCancelable(false)
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
Toast.makeText(v.getContext(),"you choose yes action for alertbox", Toast.LENGTH_SHORT).show();
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// Action for 'NO' Button
dialog.cancel();
Toast.makeText(v.getContext(),"you choose no action for alertbox", Toast.LENGTH_SHORT).show();
}
});
//Creating dialog box
AlertDialog alert = builder.create();
//Setting the title manually
alert.setTitle("AlertDialogExample");
alert.show();
}
});
}
#NonNull
#Override
public myviewholder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
//put singlerow xml into view holder
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.singlerow,parent,false);
return new myviewholder(view);
}
class myviewholder extends RecyclerView.ViewHolder{
TextView name,phone,email,status;
public myviewholder(#NonNull View itemView) {
super(itemView);
name=(TextView)itemView.findViewById(R.id.nametext);
phone=(TextView)itemView.findViewById(R.id.phonetext);
email=(TextView)itemView.findViewById(R.id.emailtext);
status=(TextView)itemView.findViewById(R.id.statustext);
}
}
}

Passing "this" to AlertDialog.Builder(this); won't work as you're trying to pass a reference of your Adapter.
There are two correct ways to achieve this:
Add a variable to reference your Activity like Activity mActivity; in your Adapter class. Then, in your Activity class where you're initializing the Adapter, you can pass your activity context as "this". You can achieve it either with a constructor in the Adapter class or in your Activity class use your adapter instance once it is initialized to access the mActivity variable and set it.
Alternatively, you can use a view interface and implement it in your activity, override the method to show the AlertDialog in your activity. Then add a reference variable of that interface in your Adapter like SomeInterface mInfterface; and initialize it in your Activity class the same way mentioned above. Then you can just call that method to show the AlertDialog and pass the data to that method from the Adapter to show all information like -
mInterface.showAlertDialog(model);

first create this class:
class RecyclerItemClickListener extends RecyclerView.SimpleOnItemTouchListener {
interface OnRecyclerClickListener{
void onItemClick(View view, int position);
}
private final OnRecyclerClickListener mListener;
private final GestureDetectorCompat mGestureDetector;
public RecyclerItemClickListener(Context context, final RecyclerView recyclerView,
OnRecyclerClickListener listener) {
mListener = listener;
mGestureDetector = new GestureDetectorCompat(context, new GestureDetector.SimpleOnGestureListener(){
#Override
public boolean onSingleTapUp(MotionEvent e) {
View childView = recyclerView.findChildViewUnder(e.getX(), e.getY());
if (childView != null && mListener != null){
Log.d(TAG, "onSingleTapUp: calling listener.onItemClick");
mListener.onItemClick(childView, recyclerView.getChildAdapterPosition(childView));
}
return true;
}
});
}
#Override
public boolean onInterceptTouchEvent(#NonNull RecyclerView rv, #NonNull MotionEvent e) {
if (mGestureDetector != null){
boolean result = mGestureDetector.onTouchEvent(e);
return result;
} else {
return false;
}
}
}
and in MainActivity:
in onCreate method: first define recyclerView variable by findviewbyid() then:
recyclerView.addOnItemTouchListener(new RecyclerItemClickListener(this, recyclerView, this));
then implement onItemClick() method. you can define alert dialog here:
#Override
public void onItemClick(View view, int position) {
Toast.makeText(this, "normal tap on position " + position, Toast.LENGTH_SHORT).show();
}

First pass the context from the Activity or Fragment:
For activity:
myadapter_tutorlist(options, this);
For Fragment:
myadapter_tutorlist(options, getActivity());
Then create a Context variable in side the Adapter class:
public class myadapter_tutorlist extends FirebaseRecyclerAdapter<User,myadapter_tutorlist.myviewholder> {
AlertDialog.Builder builder;
Context context;
public myadapter_tutorlist(#NonNull FirebaseRecyclerOptions<User> options) {
super(options);
this.context = context;
}
Now you can pass this context to your AlertDialog
builder = new AlertDialog.Builder(context);

Android alert dialog not properly functioned

I used an alert dialog box for confirmation of delete, I make a recycler view in which two methods are applied 1.swipe for delete method, 2. menu bar delete method. In swipe method when I swipe the view it removed the list and show alert dialog when clicking no then it replaces not original space but another space that creates a space between them kindly guide me what issue it is?
package com.example.framelayout;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.ItemTouchHelper;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.StaggeredGridLayoutManager;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.res.Configuration;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.material.snackbar.BaseTransientBottomBar;
import com.google.android.material.snackbar.Snackbar;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class MainActivity extends AppCompatActivity implements RecyclerClickListener, RecyclerActionClick {
private RecyclerView recyclerView;
private detailAdapt adapt;
private List<detailModel> modelList = new ArrayList<>();
detailModel modelData, swipeData;
ItemTouchHelper.SimpleCallback simpleCallback = new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT) {
#Override
public boolean onMove(#NonNull RecyclerView recyclerView, #NonNull RecyclerView.ViewHolder viewHolder, #NonNull RecyclerView.ViewHolder target) {
return false;
}
#Override
public void onSwiped(#NonNull RecyclerView.ViewHolder viewHolder, int direction) {
final int position = viewHolder.getAdapterPosition();
if (direction == ItemTouchHelper.LEFT) {
swipeData = modelList.get(position);
showDialogBox(position, true);
}
}
};
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = findViewById(R.id.recycler_details);
populateList();
}
private void populateList() {
for (int i = 0; i < 10; i++) {
int img = R.drawable.ic_person;
String person = "Person " + i;
String name = "Person Name " + i;
String msg = "Person Last Message " + i;
detailModel model = new detailModel(person, name, msg, img);
modelList.add(model);
}
addRecycle(modelList);
}
private void addRecycle(List<detailModel> modelList) {
adapt = new detailAdapt(this, modelList, this, this);
LinearLayoutManager layout = new LinearLayoutManager(this);
layout.setSmoothScrollbarEnabled(true);
recyclerView.setAdapter(adapt);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(layout);
ItemTouchHelper helper = new ItemTouchHelper(simpleCallback);
helper.attachToRecyclerView(recyclerView);
}
#Override
public void onDeleteCLick(Object obj, int position) {
showDialogBox(position, false);
}
private void showDialogBox(final int position, final boolean isSwiped) {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Confirmation");
builder.setMessage("Are you sure to delete this Item");
builder.setCancelable(false);
builder.setPositiveButton("yes", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
deleteItem(position);
}
});
builder.setNegativeButton("no", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
if (isSwiped) {
modelList.add(position, swipeData);
adapt.notifyItemInserted(position);
}
}
});
AlertDialog dialog = builder.create();
dialog.show();
}
private void deleteItem(final int position) {
modelData = modelList.get(position);
modelList.remove(position);
adapt.notifyItemRemoved(position);
Snackbar snackbar = Snackbar.make(recyclerView, "item removed at position " + position, Snackbar.LENGTH_LONG);
snackbar.setAction("undo", new View.OnClickListener() {
#Override
public void onClick(View v) {
modelList.add(position, modelData);
adapt.notifyItemInserted(position);
}
});
snackbar.show();
}
#Override
public void onUndoCLick(Object obj, int position) {
}
#Override
public void onSingleClick(Object obj, int position) {
detailModel model = (detailModel) obj;
Toast.makeText(this, "click at " + position, Toast.LENGTH_SHORT).show();
}
}

Please remove below
modelList.add(position, swipeData);
adapt.notifyItemInserted(position);
from the cancel button of the alert dialog, as you already didn't remove the item yet, so no need to insert it again. instead replace them with notifyItemChanged(position); like below
builder.setNegativeButton("no", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
if (isSwiped) {
adapt.notifyItemChanged(position);
}
}
});

How to save the data a user inputs into the device's local internal storage?

I'm developing a Grade/GPA Calculator app on Android during my free time. What the app basically does until now is let the user add Semesters in the Main Activity and when the user clicks on a certain Semester the user is redirected to another Activity where the user can add new Courses for that specific semester. The problem I'm having is that when the user hits on the back button to go to to the Main Activity where the Semesters are located the courses that were added in that semester are erased. The same happens when I go to the phone's homepage and re-launch the app, everything that the user had created has been deleted.
I'm pretty sure my problem is that I'm not saving the data that the user creates to the phone's storage/app's storage, but I can't seem to figure out on how to do this. If anyone can point me in the right direction I would appreciate it. Thanks!
This is my MainActivity class's code: (My MainActivity is where Semesters are added)
package com.example.gradecalculator;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import java.util.ArrayList;
import java.util.Random;
public class MainActivity extends AppCompatActivity {
// Private Fields
private Dialog d;
private EditText semesterName;
private ListView semesterListView;
private ArrayList<String> semesterArray = new ArrayList<String>();
private SemesterAdapter customSemesterAdapter;
private ArrayList<Semester> mySemesters = new ArrayList<>();
private ArrayList<String> semesterBackgrounds = new ArrayList<String>();
private String getSemesterName;
private int randomBackground[] = new int[7];
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Initiating toolbar
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Making a new dialog
d = new Dialog(this);
// Initializing variables
semesterName = (EditText) d.findViewById(R.id.editTextSemesterName);
semesterListView = (ListView) findViewById(R.id.semesterList);
// Calling the removeSemesters() method
removeSemesters();
// Adding backgrounds to the backgrounds ArrayList
semesterBackgrounds.add("orange_background");
semesterBackgrounds.add("green_background");
semesterBackgrounds.add("aqua_background");
semesterBackgrounds.add("blue_background");
semesterBackgrounds.add("pink_background");
semesterBackgrounds.add("purple_background");
semesterBackgrounds.add("red_background");
semesterBackgrounds.add("yellow_background");
}
// Creating a custom Menu
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.top_menu, menu);
return true;
}
// Buttons in the custom Menu
#Override
public boolean onOptionsItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.editButton:
Toast.makeText(this, "Delete the desired Semesters by clicking on the trash button located to the right of each Semester", Toast.LENGTH_LONG).show();
return true;
}
return super.onOptionsItemSelected(item);
}
// When user clicks on "+New Semester" button open a popup where the user is prompted to
// type in the Semester Name and when "Done" is clicked the new semester appears in the Main
// Activity
public void newSemesterPopup(View v) {
TextView closePopup;
ImageButton doneButton;
d.setContentView(R.layout.new_semester_popup);
semesterName = (EditText) d.findViewById(R.id.editTextSemesterName);
semesterListView = (ListView) findViewById(R.id.semesterList);
doneButton = (ImageButton) d.findViewById(R.id.doneButton);
doneButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
addSemesters();
}
});
closePopup = (TextView) d.findViewById(R.id.exitButton);
closePopup.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
d.dismiss();
}
});
d.show();
}
// Adds semesters to Main Activity
public void addSemesters() {
getSemesterName = semesterName.getText().toString();
if (semesterArray.contains(getSemesterName)) {
Toast.makeText(getBaseContext(), "Semester Name Already Exists", Toast.LENGTH_SHORT).show();
} else if (getSemesterName == null || getSemesterName.trim().equals("")) {
Toast.makeText(getBaseContext(), "Cannot Add Empty Semester Name", Toast.LENGTH_SHORT).show();
} else {
semesterArray.add(getSemesterName);
mySemesters.add(new Semester(getSemesterName, semesterBackgrounds.get(new Random().nextInt(randomBackground.length))));
customSemesterAdapter = new SemesterAdapter(getApplicationContext(), R.layout.semester_row, mySemesters);
semesterListView.setAdapter(customSemesterAdapter);
d.dismiss();
}
}
// Removes unwanted semesters from Main Activity
public void removeSemesters() {
semesterListView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> parent, View view, final int position, long id) {
AlertDialog.Builder deleteAlert = new AlertDialog.Builder(MainActivity.this);
deleteAlert.setTitle("Semester Deletion Process");
deleteAlert.setMessage("Are you sure you want to delete the selected Semesters?");
deleteAlert.setNegativeButton("No! Cancel", null);
deleteAlert.setPositiveButton("Yes! Delete", new AlertDialog.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
customSemesterAdapter.remove(customSemesterAdapter.getItem(position));
semesterArray.remove(position);
customSemesterAdapter.notifyDataSetChanged();
Toast.makeText(MainActivity.this, "Semester Deleted Successfully.", Toast.LENGTH_SHORT).show();
}
});
deleteAlert.show();
return false;
}
});
openSemestersActivity();
}
// Open the SemesterActivity and uses .putExtra to pass data to the SemesterActivity to tell it what semester to render
// data accordingly
public void openSemestersActivity() {
final Intent semester = new Intent(this, SemesterActivity.class);
semesterListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
semester.putExtra("semester", semesterName.getText().toString());
startActivity(semester);
}
});
}
}
This is my SemesterActivity code: (My SemestersActivity is where Courses are added)
package com.example.gradecalculator;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import java.util.ArrayList;
import java.util.Random;
public class SemesterActivity extends AppCompatActivity {
// Private Fields
private Dialog d;
private EditText courseName;
private EditText courseCode;
private EditText courseCredits;
private ListView courseListView;
private ArrayList<String> courseArray = new ArrayList<String>();
private CourseAdapter customCourseAdapter;
private ArrayList<Course> myCourses = new ArrayList<>();
private ArrayList<String> coursesBackgrounds = new ArrayList<String>();
private String getCourseName;
private String getCourseCode;
private String getCourseCredits;
private int randomBackground[] = new int[7];
private TextView courseNameView;
private TextView courseCodeView;
private TextView courseCreditsView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_semester);
d = new Dialog(this);
courseNameView = (TextView) d.findViewById(R.id.editTextCourseName);
courseCodeView = (TextView) d.findViewById(R.id.editTextCourseCode);
courseCreditsView = (TextView) d.findViewById(R.id.editTextCourseCredits);
courseListView = (ListView) findViewById(R.id.coursesList);
// Retrieving the Extra and determining the semester we want to load
Intent myIntent = getIntent();
String semester = myIntent.getStringExtra("semester");
removeCourses();
// Initiating toolbar
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Adding backgrounds to the backgrounds ArrayList
coursesBackgrounds.add("orange_background_big");
coursesBackgrounds.add("green_background_big");
coursesBackgrounds.add("aqua_background_big");
coursesBackgrounds.add("blue_background_big");
coursesBackgrounds.add("pink_background_big");
coursesBackgrounds.add("purple_background_big");
coursesBackgrounds.add("red_background_big");
coursesBackgrounds.add("yellow_background_big");
}
// Creating a custom Menu
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.top_menu, menu);
return true;
}
// Buttons in the custom Menu
#Override
public boolean onOptionsItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.editButton:
Toast.makeText(this, "Delete the desired Courses by clicking on the trash button located to the right of each Semester", Toast.LENGTH_LONG).show();
return true;
}
return super.onOptionsItemSelected(item);
}
// New course popup
public void newCoursePopup(View v) {
TextView closePopup;
ImageButton doneButton;
d.setContentView(R.layout.new_course_popup);
courseName = (EditText) d.findViewById(R.id.editTextCourseName);
courseCode = (EditText) d.findViewById(R.id.editTextCourseCode);
courseCredits = (EditText) d.findViewById(R.id.editTextCourseCredits);
doneButton = (ImageButton) d.findViewById(R.id.doneButton);
doneButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
addCourses();
}
});
closePopup = (TextView) d.findViewById(R.id.exitButton);
closePopup.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
d.dismiss();
}
});
d.show();
}
// Adding courses to the Semester
public void addCourses() {
getCourseName = courseName.getText().toString();
getCourseCode = courseCode.getText().toString();
getCourseCredits = courseCredits.getText().toString();
if(courseArray.contains(getCourseName)) {
Toast.makeText(getBaseContext(), "Course Name Already Exists", Toast.LENGTH_SHORT).show();
}
else if(getCourseName == null || getCourseName.trim().equals("")) {
Toast.makeText(getBaseContext(), "Cannot Add Empty Course Name", Toast.LENGTH_SHORT).show();
}
else {
courseArray.add(getCourseName);
myCourses.add(new Course(getCourseName, getCourseCode, getCourseCredits, coursesBackgrounds.get(new Random().nextInt(randomBackground.length))));
customCourseAdapter = new CourseAdapter(getApplicationContext(), R.layout.course_row, myCourses);
courseListView.setAdapter(customCourseAdapter);
d.dismiss();
}
}
// Removing courses from the Semester
public void removeCourses() {
courseListView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> parent, View view, final int position, long id) {
AlertDialog.Builder deleteAlert = new AlertDialog.Builder(SemesterActivity.this);
deleteAlert.setTitle("Course Deletion Process");
deleteAlert.setMessage("Are you sure you want to delete the selected Courses?");
deleteAlert.setNegativeButton("No! Cancel", null);
deleteAlert.setPositiveButton("Yes! Delete", new AlertDialog.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
customCourseAdapter.remove(customCourseAdapter.getItem(position));
courseArray.remove(position);
customCourseAdapter.notifyDataSetInvalidated();
Toast.makeText(SemesterActivity.this, "Course Deleted Successfully", Toast.LENGTH_SHORT).show();
}
});
deleteAlert.show();
return false;
}
});
}
}

There are a couple of databases you can look into; You can use Room or Realm. You can also check out online DBs like Firestore by Firebase. The beauty about having an online db a user(Student) can access their data from a different phone if they lose or replace their current one. A recommended way to go is to have both to cover both scenarios.

How do I refresh TextView on activity calling after closing alert dialog in Android?

I have an alert dialog that allows user to edit a TextView. Currently, once the alert dialog closes, the user has to hit the back button and then re-enter the activity for the TextView to update. I've tried many solutions on SO but none seem to work. When the user clicks 'Save Changes', the TextView should update.
Calling activity:
package com.group1.workouttracker;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;
import java.util.List;
public class DayActivity extends Activity {
//does not extend ListActivity, so list functions must be called by myList object
private String buttonClicked;
private String thisSummary;
private Intent intent;
DatabaseHelper db;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_day);
db = DatabaseHelper.getInstance(getApplicationContext());
intent = getIntent();
buttonClicked = intent.getStringExtra("Day");
Button buttonCreateExercise = (Button) findViewById(R.id.buttonAddExercise);
buttonCreateExercise.setOnClickListener(new OnClickListenerCreateExercise(buttonClicked));
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void readSummary(String buttonClicked) {
TextView textViewSummary = (TextView) findViewById(R.id.textViewSummary);
textViewSummary.setOnLongClickListener(new OnLongClickListenerEditSummary(buttonClicked));
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onResume() {
super.onResume();
thisSummary = db.readSummary(buttonClicked).getSummary();
TextView summary = (TextView) findViewById(R.id.textViewSummary);
summary.setOnLongClickListener(new OnLongClickListenerEditSummary(buttonClicked));
summary.setText(thisSummary);
}
}
Alert Dialog that activates on a long press:
package com.group1.workouttracker;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnLongClickListener;
import android.widget.EditText;
import android.widget.NumberPicker;
import android.widget.Toast;
public class OnLongClickListenerEditSummary implements View.OnLongClickListener {
Context context;
String dayClicked = "";
#Override
public boolean onLongClick(View view) {
context = view.getContext();
final DatabaseHelper db = DatabaseHelper.getInstance(context);
ObjectDay objectDay = db.readSummary(dayClicked);
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
final View formElementsView = inflater.inflate(R.layout.edit_summary_form, null, false);
final long dayId = objectDay.getId();
final String dName = objectDay.getDayName();
final EditText editTextSummary = (EditText) formElementsView.findViewById(R.id.editTextSummary);
final CharSequence[] items = { "Edit", "Delete" };
new AlertDialog.Builder(context).setTitle("Exercise");
new AlertDialog.Builder(context)
.setView(formElementsView)
.setTitle("Edit Summary for " + dayClicked + ":")
.setPositiveButton("Save Changes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
ObjectDay objectDay = new ObjectDay();
objectDay.setId(dayId);
objectDay.setDayName(dName);
objectDay.setSummary(editTextSummary.getText().toString());
boolean updateSuccessful = DatabaseHelper.getInstance(context).updateSummary(objectDay);
if(updateSuccessful) {
Toast.makeText(context, "Summary was updated.", Toast.LENGTH_SHORT).show();
}
else {
Toast.makeText(context, "Unable to update summary.", Toast.LENGTH_SHORT).show();
}
//dialog.cancel();
dialog.dismiss();
}
}).show();
return false;
}
public void editRecord(final String dName) {
final DatabaseHelper db = DatabaseHelper.getInstance(context);
ObjectDay objectDay = db.readSummary(dName);
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
final View formElementsView = inflater.inflate(R.layout.edit_summary_form, null, false);
final EditText editTextDay = (EditText) formElementsView.findViewById(R.id.editTextSummary);
final EditText editTextSummary = (EditText) formElementsView.findViewById(R.id.editTextSummary);
editTextSummary.setText(objectDay.getSummary());
}
public OnLongClickListenerEditSummary(String dayClicked) {
this.dayClicked = dayClicked;
}
}
Edit: I was able to get this working correctly by adding the following code:
Activity:
public void passThrough(ObjectDay objDay) {
textViewSummary.setText(objDay.getSummary());
}
In .setpositive button:
((DayActivity) context).passThrough(objectDay);

Opening a dialog wont trigger the Activity's onPause/onResume (I'm not sure if that's true for dialog fragments). Instead you can apply an onDismissListener (which can be a member variable of the Activity or anonymous) to the dialog.
When the dialog is closed (by any means) you'll get some information and you can update your textfield. Alternatively you could do the same from the positive click listener.
Either
alert.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//UPDATE FROM HERE (call a method or manipulate an Activity member var)
}
});
OR
alert.setOnDismissListener(new OnDismissListener() {
public void onDismiss(DialogInterface dialog) {
//UPDATE FROM HERE (Check DialogInterface for positive if you want)
}
});
Edit, for your example:
class Whatever extends Activity {
private TextView mTextView;
private MyPassThroughListener mPassThroughListener = new MyPassThroughListener() {
#Override
public function passThrough(ObjectDay objDay) {
mTextView.setText(objDay.getSummary());
}
}
protected void onCreate(Bundle savedInstanceState) {
....
buttonCreateExercise.setOnClickListener(new OnClickListenerCreateExercise(mPassThroughListener ));
}
}
class OnLongClickListenerEditSummary {
MyPassThroughListener mPassThroughListener;
...
public OnLongClickListenerEditSummary (MyPassThroughListener passThroughListener) {
mPassThroughListener = passThroughListener;
}
#Override
public boolean onLongClick(View view) {
....
new AlertDialog.Builder(context)
.setPositiveButton("Save Changes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
ObjectDay objectDay = new ObjectDay();
objectDay.setId(dayId);
objectDay.setDayName(dName);
objectDay.setSummary(editTextSummary.getText().toString());
mPassThroughListener.passThrough(objectDay);
dialog.dismiss();
}
...
}
}
public interface MyPassThroughListener {
public function passThrough(ObjectDay objDay);
}