I have a MainAtivity which has some EditText and 2 button. Save button will save user input to ListView and List button to show ListView (which I display in second activity).
Is there anyway to collect data from multiple inputs then pass it to other activity. And after get that data how to combine it to a List item.
Please show me some code and explain cause I'm a beginner.
I have read some post and they suggest use startActivityForResult, intent, bundles but I still don't understand.
This is my Main class:
public class MainActivity extends AppCompatActivity {
String str, gender, vaccine, date;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button okay = (Button) findViewById(R.id.btnOk);
Button list = (Button) findViewById(R.id.btnList);
EditText name = (EditText) findViewById(R.id.inputName);
EditText address = (EditText) findViewById(R.id.inputAdd);
EditText phone = (EditText) findViewById(R.id.inputPhone);
RadioGroup radioGroup = (RadioGroup) findViewById(R.id.radioGroup);
RadioButton female = (RadioButton) findViewById(R.id.inputFemale);
RadioButton male = (RadioButton) findViewById(R.id.inputMale);
CheckBox first = (CheckBox)findViewById(R.id.inputFirst);
CheckBox second = (CheckBox)findViewById(R.id.inputSecond);
CheckBox third = (CheckBox)findViewById(R.id.inputThird);
EditText datefirst = (EditText) findViewById(R.id.dateFirst);
EditText datesecond = (EditText) findViewById(R.id.dateSecond);
EditText datethird = (EditText) findViewById(R.id.dateThird);
TextView result = (TextView)findViewById(R.id.textResult);
okay.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(female.isChecked()) gender = female.getText().toString();
if(male.isChecked()) gender = male.getText().toString();
if(first.isChecked()) {
vaccine = first.getText().toString();
date = datefirst.getText().toString();
}
if(second.isChecked()) {
vaccine = second.getText().toString();
date = datesecond.getText().toString();
}
if(third.isChecked()) {
vaccine = third.getText().toString();
date = datethird.getText().toString();
}
str = name.getText().toString() + "\n" + address.getText().toString() + "\n" + phone.getText().toString() + "\n" +
gender + "\n" + vaccine + "\n" + date;
result.setText(str);
Toast.makeText(getApplicationContext(),result.getText().toString(),Toast.LENGTH_SHORT).show();
Intent intent = new Intent(MainActivity.this, PersonView.class);
intent.putExtra("NAME",name.getText().toString());
startActivity(intent);
}
});
list.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(MainActivity.this, PersonView.class);
startActivity(intent);
}
});
}
}
This is my ListView class:
public class PersonView extends AppCompatActivity {
ArrayList<Person> listPerson;
PersonListViewAdapter personListViewAdapter;
ListView listViewPerson;
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
Intent intent = getIntent();
String message = intent.getStringExtra("NAME");
Button back = (Button) findViewById(R.id.btnBack);
back.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(PersonView.this, MainActivity.class);
//startActivityForResult(intent,2);
}
});
listPerson = new ArrayList<>();
listPerson.add(new Person("Lieu Mai","25 Mac Dinh Chi", "0786867073", "female","3 injection", "24/07/2000"));
personListViewAdapter = new PersonListViewAdapter(listPerson);
listViewPerson = findViewById(R.id.listPerson);
listViewPerson.setAdapter(personListViewAdapter);
}
class Person {
String name, address, phone, gender, vaccine, date;
public Person( String name, String address, String phone, String gender, String vaccine, String date) {
this.name = name;
this.address = address;
this.phone = phone;
this.gender = gender;
this.vaccine = vaccine;
this.date = date;
}
}
class PersonListViewAdapter extends BaseAdapter {
final ArrayList<Person> listPerson;
PersonListViewAdapter(ArrayList<Person> listPerson) {
this.listPerson = listPerson;
}
#Override
public int getCount() {
return listPerson.size();
}
#Override
public Object getItem(int position) {
return listPerson.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View viewPerson;
if (convertView == null) {
viewPerson = View.inflate(parent.getContext(), R.layout.person_view, null);
} else viewPerson = convertView;
Person person = (Person) getItem(position);
((TextView) viewPerson.findViewById(R.id.txtName)).setText(String.format("Name: %s", person.name));
((TextView) viewPerson.findViewById(R.id.txtAddress)).setText(String.format("Address : %s", person.address));
((TextView) viewPerson.findViewById(R.id.txtPhone)).setText(String.format("Phone number: %s", person.phone));
((TextView) viewPerson.findViewById(R.id.txtGender)).setText(String.format("Gender: %s", person.gender));
((TextView) viewPerson.findViewById(R.id.txtVaccine)).setText(String.format("Vaccine: %s", person.vaccine));
((TextView) viewPerson.findViewById(R.id.txtDate)).setText(String.format("Date: %s", person.date));
return viewPerson;
}
}
}
You should look into the Singleton pattern. It is very simple as there is no external DB. What it essentially is a class that manages the data and lets other classes and activities use the data while not allowing duplication.
You have a model Person
public class Person {
private String name;
public String address;
...
constructors and getters and setters
Create a class PersonsSingelton something like this.
public class PersonManagerSingleton {
private PersonManagerSingleton() {
loadPersonsDataSet();
}
private static PersonManagerSingleton instance = null;
public static PersonManagerSingleton getInstance() {
// if there is a instance already created use that instance of create new instance
// instance created in MainActivity and you try to create a new instance in Details
// should not happen as that will cause data duplication.
if (instance == null) {
instance = new PersonManagerSingleton();
}
return instance;
}
private ArrayList<Person> personList = new ArrayList<Person>();
private void loadPersonsDataSet() {
this.personList.add(new Person(...));
this.personList.add(new Person(...));
this.personList.add(new Person(...));
this.personList.add(new Person(...));
}
public ArrayList<Person> getpersonList() {
return personList;
}
public Person getPersonByID(int PersonNumber) {
for (int i = 0; i < this.personList.size(); i++) {
Person curPerson = this.personList.get(i);
if (curPerson.getNumber() == PersonNumber) {
return curPerson;
}
}
return null;
}
// methods for adding a new person used in Activity with the form.
// other methods ...
}
This would be like a state in React. of the State Manager.
Your person adapter constructor has to accept an ArrayList<Person> listPerson. So modify the activity passing the data to pass only the position of the ListView clicked. You need to modify your Adapter for that.
Use the Singleton created to access the data.
PersonManagerSingleton personSingelton = PersonManagerSingleton.getInstance();
ArrayList<Person> listPerson = personSingelton.getPersonList();
PersonAdapter Person = new PersonAdapter(listPerson);
So now only things left is to modify the Persons adapter to pass position using Intent and nothing else. and then you can use the instance of Singleton in other files to access the data using the listPerson.get(position) and using getters and setters.
Link to a project like this.
https://github.com/smitgabani/anroid_apps_using_java/tree/main/pokemon_app
Its an Activity with Tabs, I'm getting data from API using Volley library. There is only one Fragment. Whenever Tab is changed either by sliding or clicking the Tab, the function that calls the APIs is called with different data.
Problems:
1) It loads items every time on working internet, but it sometimes shows and sometimes not. When I press home button (i.e. activity is running and in background) and then select the app from opened apps list it shows data. I've to pause and resume app to view changes by pressing home button and reselecting from opened apps. If I lock screen and unlock screen then also it shows the content.
2) Similar to problem 1) there is an info button on top right corner it shows/hides a layout when clicked. But some time when problem 1) occurs it also behaves same.
3) Also looks similar to 1) and 2) there is TextView (Options) that shows/hides a layout when clicked But some time when problem 1) occurs it also behaves same.
Any help would be appreciated, I'm running out of time...
Here is screenshot: Screenshot
RestaurantDetailActivity.java
public class RestaurantDetailActivity extends AppCompatActivity {
LinearLayout contactLayout;
TabLayout tabLayout;
ViewPager viewPager;
TextView nameTv, descrTv, timingsTv, totalRatingsTv;
RatingBar ratingsRb;
ImageView restaurantIv;
String resId;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_restaurant_detail);
//get data from previews activity
Intent intent = getIntent();
//init views
nameTv = findViewById(R.id.nameTv);
ratingsRb = findViewById(R.id.ratingsRb);
descrTv = findViewById(R.id.descrTv);
timingsTv = findViewById(R.id.timingsTv);
totalRatingsTv = findViewById(R.id.totalRatingsTv);
contactLayout = findViewById(R.id.contactLayout);
tabLayout = findViewById(R.id.tabLayout);
viewPager = findViewById(R.id.viewPager);
timingsTv = findViewById(R.id.timingsTv);
restaurantIv = findViewById(R.id.restaurantIv);
resId = intent.getStringExtra("id");
//setup tabs
setupViewPager(viewPager);
tabLayout.setupWithViewPager(viewPager);
final String name = intent.getStringExtra("name");
final String ratings = intent.getStringExtra("ratings");
String description = intent.getStringExtra("description");
String status = intent.getStringExtra("status");
String resPaused = intent.getStringExtra("resPaused");
String open = intent.getStringExtra("openTime");
String close = intent.getStringExtra("closeTime");
//set data in header
nameTv.setText(name);
ratingsRb.setRating(Float.parseFloat(ratings));
descrTv.setText(description);
final String timings;
if (resPaused.equals("0")) {
timings = con24to12(open) + " - " + con24to12(close);timingsTv.setTextColor(getApplicationContext().getResources().getColor(R.color.colorWhite));
} else {
timings = "Closed Today";
timingsTv.setTextColor(getApplicationContext().getResources().getColor(R.color.colorRadish));
}
//set timings
if (Utils.compareOpenTime(open)) {
timingsTv.setTextColor(getApplicationContext().getResources().getColor(R.color.colorWhite));
timingsTv.setCompoundDrawablesWithIntrinsicBounds(R.drawable.ic_time_white, 0, 0, 0);
timingsTv.setText(con24to12(open));
} else {
timingsTv.setText(timings);
}
totalRatingsTv.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent1 = new Intent(getApplicationContext(), RestaurantReviewsActivity.class);
intent1.putExtra("restId", resId);
intent1.putExtra("restName", name);
intent1.putExtra("restRatings", ratings);
startActivity(intent1);
}
});
final Bitmap b = BitmapFactory.decodeFile(getExternalCacheDir() + "/TopServeImages" + "/" + intent.getStringExtra("image"));
restaurantIv.setImageBitmap(b);
}
ViewPagerAdapter adapter;
private void setupViewPager(ViewPager viewPager) {
adapter = new ViewPagerAdapter(getSupportFragmentManager());
final ProgressDialog progressDialog = new ProgressDialog(this);
progressDialog.setMessage("Getting Menu...");
progressDialog.show();
String token = "auth" + System.currentTimeMillis();
Map<String, String> params = new HashMap<>();
params.put("Token", token);
params.put("RestaurantID", resId);
Log.d("TheToken", Utils.getToken() + "" + Utils.getEmail());
String url = ApiManager.headerUrl + ApiManager.menuItemsUrl;
JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
url, new JSONObject(params),
new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
progressDialog.dismiss();
Log.d("TheResponse", response.toString());
try {
JSONObject jsonObject = response.getJSONObject("Response");
JSONArray jsonArray = jsonObject.getJSONArray("MenuCategories");
for (int i = 0; i < jsonArray.length(); i++) {
String menuItemCategoryID = jsonArray.getJSONObject(i).getString("MenuItemCategoryID");
String name = jsonArray.getJSONObject(i).getString("Name");
String restaurantID = jsonArray.getJSONObject(i).getString("RestaurantID");
adapter.addFragment(RestaurantFragment.newInstance((i + 1), "" + name, restaurantID, menuItemCategoryID), "" + name);
adapter.notifyDataSetChanged();
}
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "Exception: " + e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
progressDialog.dismiss();
try {
if (error.getMessage().toLowerCase().contains("no address associated with hostname")) {
Toast.makeText(getApplicationContext(), "Slow or no Internet connection...", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(), "Error: " + error.getMessage(), Toast.LENGTH_SHORT).show();
}
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "Error: " + e.getMessage(), Toast.LENGTH_SHORT).show();
}
}
});
Volley.newRequestQueue(this).add(jsonObjReq);
viewPager.setAdapter(adapter);
}
public class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> fragmentList = new ArrayList<>();
private final List<String> fragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return fragmentList.get(position);
}
#Override
public int getCount() {
return fragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
fragmentList.add(fragment);
fragmentTitleList.add(title);
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
return fragmentTitleList.get(position);
}
}
public void clicks(View view) {
if (view == findViewById(R.id.backTv)) {
onBackPressed();
} else if (view == findViewById(R.id.infoBtn)) {
if (contactLayout.getVisibility() == View.GONE) {
contactLayout.setVisibility(View.VISIBLE);
} else {
contactLayout.setVisibility(View.GONE);
}
}
}
public String con24to12(String from) {
DateFormat df = new SimpleDateFormat("HH:mm:ss");
DateFormat outputformat = new SimpleDateFormat("hh:mm aa");
Date date = null;
String output = null;
try {
date = df.parse(from);
output = outputformat.format(date);
from = output;
} catch (Exception pe) {
Toast.makeText(getApplicationContext(), "" + pe.getMessage(), Toast.LENGTH_SHORT).show();
}
return from;
}
}
RestaurantFragment.java
public class RestaurantFragment extends Fragment {
String title;
int page;
String restaurantId;
String menuItemCategoryID;
AdapterMenu mAdapter;
List<ModelMenu> menuList;
ImageView fabCartIv;
RecyclerView recyclerView;
public RestaurantFragment() {
}
public static RestaurantFragment newInstance(int page, String title, String restID, String menuItemCategoryID) {
RestaurantFragment fragmentFirst = new RestaurantFragment();
Bundle args = new Bundle();
args.putInt("someInt", page);
args.putString("someTitle", title);
args.putString("restId", restID);
args.putString("menuItemCategoryID", menuItemCategoryID);
fragmentFirst.setArguments(args);
return fragmentFirst;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
page = getArguments().getInt("someInt", 0);
title = getArguments().getString("someTitle");
restaurantId = getArguments().getString("restId");
menuItemCategoryID = getArguments().getString("menuItemCategoryID");
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_restaurant, container, false);
recyclerView = view.findViewById(R.id.menuRecyclerView);
fabCartIv = view.findViewById(R.id.fabCartIv);
loadMenuItems();
return view;
}
private void loadMenuItems() {
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity().getApplicationContext()));
menuList = new ArrayList<>();
String token = "auth" + System.currentTimeMillis();
Map<String, String> params = new HashMap<>();
params.put("Token", token);
params.put("RestaurantID", restaurantId);
String url = ApiManager.headerUrl + ApiManager.menuItemsUrl;
JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
url, new JSONObject(params),
new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
try {
JSONObject joResponse = response.getJSONObject("Response");
JSONArray jaMainMenu = joResponse.getJSONArray("MainMenu");
JSONArray jaMenuItemImages = joResponse.getJSONArray("MenuItemImages");
JSONArray jaLinkedMenuItems = joResponse.getJSONArray("LinkedMenuItems");
for (int i = 0; i < jaLinkedMenuItems.length(); i++) {
String menuItemCategoryID1 = jaLinkedMenuItems.getJSONObject(i).getString("MenuItemCategoryID");
if (menuItemCategoryID.equals(menuItemCategoryID1)) {
String menuItemID1 = jaLinkedMenuItems.getJSONObject(i).getString("MenuItemID");
for (int j = 0; j < jaMainMenu.length(); j++) {
String deleted = jaMainMenu.getJSONObject(j).getString("Deleted");
String description = jaMainMenu.getJSONObject(j).getString("Description");
String ingredients = jaMainMenu.getJSONObject(j).getString("Ingredients");
String inventory = jaMainMenu.getJSONObject(j).getString("Inventory");
String menuItemID = jaMainMenu.getJSONObject(j).getString("MenuItemID");
String name = jaMainMenu.getJSONObject(j).getString("Name");
String paused = jaMainMenu.getJSONObject(j).getString("Paused");
String price = jaMainMenu.getJSONObject(j).getString("Price");
String rating = jaMainMenu.getJSONObject(j).getString("Rating");
String restaurantID = jaMainMenu.getJSONObject(j).getString("RestaurantID");
String servedEnd = jaMainMenu.getJSONObject(j).getString("ServedEnd");
String servedStart = jaMainMenu.getJSONObject(j).getString("ServedStart");
String imageURL = jaMenuItemImages.getJSONObject(j).getString("ImageURL");
if (menuItemID1.equals(menuItemID)) {
ModelMenu cModels = new ModelMenu("" + deleted,
"" + description,
"" + ingredients,
"" + inventory,
"" + menuItemID,
"" + name,
"" + paused,
"$" + price,
"" + rating,
"" + restaurantID,
"" + servedEnd,
"" + servedStart,
"" + imageURL);
menuList.add(cModels);
}
}
mAdapter = new AdapterMenu(menuList, getActivity().getApplicationContext(), RestaurantFragment.this);
recyclerView.setAdapter(mAdapter);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
try {
if (error.getMessage().toLowerCase().contains("no address associated with hostname")) {
} else {
}
} catch (Exception e) {
e.printStackTrace();
}
}
});
Volley.newRequestQueue(getActivity()).add(jsonObjReq);
}
}
AdapterMenu.java
public class AdapterMenu extends RecyclerView.Adapter<AdapterMenu.MyHolder> {
List<ModelMenu> menuList;
Context context;
Fragment fragment;
public AdapterMenu(List<ModelMenu> menuList, Context context, Fragment fragment) {
this.menuList = menuList;
this.context = context;
this.fragment = fragment;
}
#NonNull
#Override
public MyHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(context).inflate(R.layout.row_menus, viewGroup, false);
return new MyHolder(view);
}
#Override
public void onBindViewHolder(#NonNull final MyHolder myHolder, int i) {
final String title = menuList.get(i).getName();
final String description = menuList.get(i).getDescription();
final String price = menuList.get(i).getPrice();
final String image = menuList.get(i).getImage();
final String ingredients = menuList.get(i).getIngredients();
final String restaurantID = menuList.get(i).getRestaurantID();
final String menuItemID = menuList.get(i).getMenuItemID();
String notServing;
if (menuList.get(i).getServedStart().equals("null") && menuList.get(i).getServedEnd().equals("null")) {
notServing = "";
myHolder.itemView.setBackgroundColor(context.getResources().getColor(R.color.colorWhite));
} else {
String startTime = Utils.timeTo12hr(menuList.get(i).getServedStart());
String endTime = Utils.timeTo12hr(menuList.get(i).getServedEnd());
notServing = "Only Serving between " + startTime + " - " + endTime;
myHolder.itemView.setBackgroundColor(context.getResources().getColor(R.color.colorGray1));
}
myHolder.titleTv.setText(title);
myHolder.descriptionTv.setText(description);
myHolder.priceTv.setText(price);
myHolder.notServingTv.setText(notServing);
myHolder.addHintTv.setText("Add " + title + " To Order");
myHolder.optionsTv.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (myHolder.addItemLayout.getVisibility() == View.VISIBLE) {
myHolder.addItemLayout.setVisibility(View.GONE);
myHolder.optionsTv.setCompoundDrawablesWithIntrinsicBounds(0, 0, R.drawable.ic_down_black, 0);
} else {
myHolder.addItemLayout.setVisibility(View.VISIBLE);
myHolder.optionsTv.setCompoundDrawablesWithIntrinsicBounds(0, 0, R.drawable.ic_up_black, 0);
}
}
});
myHolder.addItemBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
SharedPreferences sp = context.getSharedPreferences("OderSP", Context.MODE_PRIVATE);
int count = sp.getInt("itemCount", 0);
SharedPreferences.Editor editor = sp.edit();
editor.putInt("itemCount", count + 1);
editor.apply();
onAddField(context, myHolder, title, price);
}
});
myHolder.infoBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(context, MenuDetailActivity.class);
intent.putExtra("title", title);
intent.putExtra("description", description);
intent.putExtra("image", image);
intent.putExtra("ingredients", ingredients);
intent.putExtra("restaurantID", restaurantID);
intent.putExtra("menuItemID", menuItemID);
intent.putExtra("image", image);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent);
}
});
try {
final Bitmap b = BitmapFactory.decodeFile(context.getExternalCacheDir() + "/TopServeImages" + "/" + image);
if (b == null) {
ImageDownloader.execute(new Runnable() {
#Override
public void run() {
new ImageDownloader().awsImageDownload(myHolder, image);
}
});
} else {
myHolder.iconIv.setImageBitmap(b);
}
} catch (Exception e) {
ImageDownloader.execute(new Runnable() {
#Override
public void run() {
new ImageDownloader().awsImageDownload(myHolder, image);
}
});
}
}
private int itemsCount = 0;
private void onAddField(final Context context, MyHolder myHolder, final String title, String price) {
final LinearLayout parentLinearLayout = myHolder.itemView.findViewById(R.id.menu_roLl);
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
final View rowView = inflater.inflate(R.layout.row_additeminfo, null);
parentLinearLayout.addView(rowView, parentLinearLayout.getChildCount() - 1);
final TextView titleTv = rowView.findViewById(R.id.orderInfoTitleTv);
final TextView priceTv = rowView.findViewById(R.id.orderInfoPrice);
final ImageButton removeBtn = rowView.findViewById(R.id.orderInfoRemoveBtn);
itemsCount++;
EasyDB easyDB = EasyDB.init(context, "ITEMS_DB")
.setTableName("ITEMS_TABLE")
.addColumn(new Column("Item_Id", new String[]{"text", "unique"}))
.addColumn(new Column("Item_Name", new String[]{"text", "not null"}))
.addColumn(new Column("Item_Price", new String[]{"text", "not null"}))
.doneTableColumn();
easyDB.addData("Item_Id", title + (parentLinearLayout.getChildCount() - 1))
.addData("Item_Name", title)
.addData("Item_Price", price)
.doneDataAdding();
titleTv.setText("Order: " + itemsCount + " " + title);
priceTv.setText(price);
SharedPreferences sp = context.getSharedPreferences("OderSP", Context.MODE_PRIVATE);
itemsCount = sp.getInt("itemCount", 0);
SharedPreferences.Editor editor = sp.edit();
editor.putInt("itemCount", itemsCount);
editor.apply();
removeBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
onDelete(parentLinearLayout, view, title);
}
});
}
private void onDelete(final LinearLayout parentLinearLayout, final View v, final String title) {
AlertDialog.Builder builder = new AlertDialog.Builder(v.getRootView().getContext());
builder.setTitle("Remove this item?");
builder.setMessage(title);
builder.setPositiveButton("Remove", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
parentLinearLayout.removeView((View) v.getParent());
itemsCount--;
SharedPreferences sp = context.getSharedPreferences("OderSP", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sp.edit();
editor.putInt("itemCount", itemsCount);
editor.apply();
EasyDB easyDB = EasyDB.init(context, "ITEMS_DB")
.setTableName("ITEMS_TABLE")
.addColumn(new Column("Item_Id", new String[]{"text", "unique"}))
.addColumn(new Column("Item_Name", new String[]{"text", "not null"}))
.addColumn(new Column("Item_Price", new String[]{"text", "not null"}))
.doneTableColumn();
easyDB.deleteRow("Item_Id", "" + title + (parentLinearLayout.getChildCount()));
}
});
builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
}
});
builder.create().show();
}
#Override
public int getItemCount() {
return menuList.size();
}
class MyHolder extends RecyclerView.ViewHolder {
TextView titleTv, priceTv, descriptionTv, notServingTv, addHintTv, optionsTv, orderInfoTitleTv, orderInfoPrice;
ImageButton infoBtn, orderInfoRemoveBtn;
ImageView iconIv;
Button addItemBtn;
LinearLayout addItemLayout;
RelativeLayout orderInfoLayout;
MyHolder(#NonNull View itemView) {
super(itemView);
iconIv = itemView.findViewById(R.id.iconIv);
titleTv = itemView.findViewById(R.id.titleTv);
priceTv = itemView.findViewById(R.id.priceTv);
descriptionTv = itemView.findViewById(R.id.descriptionTv);
notServingTv = itemView.findViewById(R.id.notServingTv);
addHintTv = itemView.findViewById(R.id.addHintTv);
optionsTv = itemView.findViewById(R.id.optionsTv);
orderInfoTitleTv = itemView.findViewById(R.id.orderInfoTitleTv);
orderInfoPrice = itemView.findViewById(R.id.orderInfoPrice);
infoBtn = itemView.findViewById(R.id.infoBtn);
orderInfoRemoveBtn = itemView.findViewById(R.id.orderInfoRemoveBtn);
addItemBtn = itemView.findViewById(R.id.addItemBtn);
addItemLayout = itemView.findViewById(R.id.addItemLayout);
orderInfoLayout = itemView.findViewById(R.id.orderInfoLayout);
}
}
}
Here is how I fixed the issue:
First, understand the problem.
In the first activity where you fetch the restaurant list, that is fine.
When the restaurant is clicked, you pass the restaurant id to the RestaurantDetailActivity and do an API request.
In the API request you pass the restaurant id and get the response. The response contains a lost of all the categories of that restaurant and also the list of all the dishes provided by the restaurant in all the categories. This is very important.
At this stage you take only the list of categories in the response and start creating a fragment for each category. You pass the category id to each fragment.
Then each fragment does an API request to the the same API which was called at the activity level (point number 3 above). Each fragment does the same request independently and extracts only the list of menu items that belong to that category. That is a waste of resources.
When a fragment goes out of view , it is destroyed and then recreated when user swipes back to the tab. Every time user comes to a fragment, it loads data again. This repeated loading of data was causing the device to go unresponsive.
Now here is what I did. At step 3, when a string request is done for a particular restaurant and all the menu items are received in response. I create a separate List of menu items for each category at this stage and then pass the list to each fragment. Now each fragment has to just display the list it has received from the activity. Each fragment is not responsible for doing its own string request and parsing it to creating its own list of items. Rather it just received the list from activity and displays it. In this was only one API request is done at activity level. No matter how many time the user switches tabs, there is no extra API request.
public class ModelMenu implements Serializable {
private String deleted, description, ingredients, inventory, menuItemID, name, paused, price, rating, restaurantID, servedEnd, servedStart, image;
public ModelMenu() {
}
public ModelMenu(String name, String price) {
this.name = name;
this.price = price;
}
public ModelMenu(String deleted, String description, String ingredients, String inventory, String menuItemID, String name, String paused, String price, String rating, String restaurantID, String servedEnd, String servedStart, String image) {
this.deleted = deleted;
this.description = description;
this.ingredients = ingredients;
this.inventory = inventory;
this.menuItemID = menuItemID;
this.name = name;
this.paused = paused;
this.price = price;
this.rating = rating;
this.restaurantID = restaurantID;
this.servedEnd = servedEnd;
this.servedStart = servedStart;
this.image = image;
}
public String getDeleted() {
return deleted;
}
public void setDeleted(String deleted) {
this.deleted = deleted;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getIngredients() {
return ingredients;
}
public void setIngredients(String ingredients) {
this.ingredients = ingredients;
}
public String getInventory() {
return inventory;
}
public void setInventory(String inventory) {
this.inventory = inventory;
}
public String getMenuItemID() {
return menuItemID;
}
public void setMenuItemID(String menuItemID) {
this.menuItemID = menuItemID;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPaused() {
return paused;
}
public void setPaused(String paused) {
this.paused = paused;
}
public String getPrice() {
return price;
}
public void setPrice(String price) {
this.price = price;
}
public String getRating() {
return rating;
}
public void setRating(String rating) {
this.rating = rating;
}
public String getRestaurantID() {
return restaurantID;
}
public void setRestaurantID(String restaurantID) {
this.restaurantID = restaurantID;
}
public String getServedEnd() {
return servedEnd;
}
public void setServedEnd(String servedEnd) {
this.servedEnd = servedEnd;
}
public String getServedStart() {
return servedStart;
}
public void setServedStart(String servedStart) {
this.servedStart = servedStart;
}
public String getImage() {
return image;
}
public void setImage(String image) {
this.image = image;
}
}
public class RestaurantFragment extends Fragment {
private String title;
private int page;
private String restaurantId;
private String menuItemCategoryID;
private AdapterMenu mAdapter;
private List<ModelMenu> menuList;
TextView orderTimeTv, changeTimeTv, tenPercentTv, fifteenPercentTv, twentyPercentTv, customTipTv, totalTipTv, subTotalTv, taxTotalTv, totalTv, pickedTimeTv, pickedDateTv, todayTv, cancelTv, itemCountTv;
ImageView fabCartIv;
RecyclerView recyclerView;
public RestaurantFragment() {
// Required empty public constructor
}
// newInstance constructor for creating fragment with arguments
/*public static RestaurantFragment newInstance(int page, String title, String restID, String menuItemCategoryID) {
RestaurantFragment fragmentFirst = new RestaurantFragment();
Bundle args = new Bundle();
args.putInt("someInt", page);
args.putString("someTitle", title);
args.putString("restId", restID);
args.putString("menuItemCategoryID", menuItemCategoryID);
fragmentFirst.setArguments(args);
return fragmentFirst;
}*/
public static RestaurantFragment newInstance(int page, String title, String restID, String menuItemCategoryID, List<ModelMenu> menuList) {
RestaurantFragment fragmentFirst = new RestaurantFragment();
Bundle args = new Bundle();
args.putInt("someInt", page);
args.putString("someTitle", title);
args.putString("restId", restID);
args.putString("menuItemCategoryID", menuItemCategoryID);
args.putSerializable("menuList", (Serializable) menuList);
fragmentFirst.setArguments(args);
return fragmentFirst;
}
// Store instance variables based on arguments passed
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
page = getArguments().getInt("someInt", 0);
title = getArguments().getString("someTitle");
restaurantId = getArguments().getString("restId");
menuItemCategoryID = getArguments().getString("menuItemCategoryID");
menuList = (List<ModelMenu>) getArguments().getSerializable("menuList");
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_restaurant, container, false);
recyclerView = view.findViewById(R.id.menuRecyclerView);
itemCountTv = view.findViewById(R.id.itemCountTv);
fabCartIv = view.findViewById(R.id.fabCartIv);
/*if (title.equals("Appetizers")) {
loadDataAppetizers();
} else if (title.equals("Breakfast")) {
loadBreakfast();
} else if (title.equals("Noodle")) {
loadNoodle();
}*/
loadMenuItems();
fabCartIv.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
showCartDialog();
}
});
count();
return view;
}
private void loadMenuItems() {
//recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity().getApplicationContext()));
//Log.i("mytag", "list received with size: " + menuList.size() + ", in tab: " + title);
mAdapter = new AdapterMenu(menuList, getActivity().getApplicationContext(), RestaurantFragment.this);
recyclerView.setAdapter(mAdapter);
/*String token = "auth" + System.currentTimeMillis();
final ProgressDialog progressDialog = new ProgressDialog(getActivity());
//show progress dialog
progressDialog.setMessage("Getting Menu Items...");
progressDialog.show();*/
/*Map<String, String> params = new HashMap<>();
params.put("Token", token);
params.put("RestaurantID", restaurantId);
Log.d("TheToken", Utils.getToken() + "" + Utils.getEmail());
String url = ApiManager.headerUrl + ApiManager.menuItemsUrl;
JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
url, new JSONObject(params),
new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject response) {
//progressDialog.dismiss();
Log.d("TheResponse", response.toString());
try {
JSONObject joResponse = response.getJSONObject("Response");
JSONArray jaMainMenu = joResponse.getJSONArray("MainMenu");
JSONArray jaMenuItemImages = joResponse.getJSONArray("MenuItemImages");
JSONArray jaMenuCategories = joResponse.getJSONArray("MenuCategories");
JSONArray jaLinkedMenuItems = joResponse.getJSONArray("LinkedMenuItems");
JSONArray jaMenuSidesTitles = joResponse.getJSONArray("MenuSidesTitles");
JSONArray jaMenuSidesLinks = joResponse.getJSONArray("MenuSidesLinks");
JSONArray jaMenuSides = joResponse.getJSONArray("MenuSides");
*//*for (int j = 0; j < jaMenuCategories.length(); j++) {
String menuItemCategoryID = jaMainMenu.getJSONObject(j).getString("MenuItemCategoryID");
}*//*
for (int i = 0; i < jaLinkedMenuItems.length(); i++) {
String menuItemCategoryID1 = jaLinkedMenuItems.getJSONObject(i).getString("MenuItemCategoryID");
if (menuItemCategoryID.equals(menuItemCategoryID1)) {
String menuItemID1 = jaLinkedMenuItems.getJSONObject(i).getString("MenuItemID");
for (int j = 0; j < jaMainMenu.length(); j++) {
String deleted = jaMainMenu.getJSONObject(j).getString("Deleted");
String description = jaMainMenu.getJSONObject(j).getString("Description");
String ingredients = jaMainMenu.getJSONObject(j).getString("Ingredients");
String inventory = jaMainMenu.getJSONObject(j).getString("Inventory");
String menuItemID = jaMainMenu.getJSONObject(j).getString("MenuItemID");
String name = jaMainMenu.getJSONObject(j).getString("Name");
String paused = jaMainMenu.getJSONObject(j).getString("Paused");
String price = jaMainMenu.getJSONObject(j).getString("Price");
String rating = jaMainMenu.getJSONObject(j).getString("Rating");
String restaurantID = jaMainMenu.getJSONObject(j).getString("RestaurantID");
String servedEnd = jaMainMenu.getJSONObject(j).getString("ServedEnd");
String servedStart = jaMainMenu.getJSONObject(j).getString("ServedStart");
String imageURL = jaMenuItemImages.getJSONObject(j).getString("ImageURL");
if (menuItemID1.equals(menuItemID)) {
ModelMenu cModels = new ModelMenu("" + deleted,
"" + description,
"" + ingredients,
"" + inventory,
"" + menuItemID,
"" + name,
"" + paused,
"$" + price,
"" + rating,
"" + restaurantID,
"" + servedEnd,
"" + servedStart,
"" + imageURL);
menuList.add(cModels);
}
}
//adapter to be set to recyclerview
mAdapter = new AdapterMenu(menuList, getActivity().getApplicationContext(), RestaurantFragment.this);
recyclerView.setAdapter(mAdapter);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
//progressDialog.dismiss();
try {
if (error.getMessage().toLowerCase().contains("no address associated with hostname")) {
} else {
}
} catch (Exception e) {
e.printStackTrace();
}
}
});
Volley.newRequestQueue(getActivity()).add(jsonObjReq);*/
}
private int tipPercentage = 10;
private String date = "";
//used to pass lists in confirm order
private ArrayList idList = new ArrayList();
private ArrayList nameList = new ArrayList();
private ArrayList priceList = new ArrayList();
int ids = 0;
List<ModelMenu> menuList1;
MyAdapters myAdapters;
#SuppressLint("NewApi")
private void showCartDialog() {
View view = LayoutInflater.from(getActivity()).inflate(R.layout.dialog_cart, null);
RecyclerView recyclerView = view.findViewById(R.id.menusLayout);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
menuList1 = new ArrayList<>();
final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setView(view);
builder.setOnCancelListener(new DialogInterface.OnCancelListener() {
#Override
public void onCancel(DialogInterface dialogInterface) {
tipPercentage = 10;
totalPriceAddRemove = 0.0;
idList.clear();
nameList.clear();
priceList.clear();
ids = 0;
}
});
builder.create().show();
orderTimeTv = view.findViewById(R.id.orderTimeTv);
changeTimeTv = view.findViewById(R.id.changeTimeTv);
tenPercentTv = view.findViewById(R.id.tenPercentTv);
fifteenPercentTv = view.findViewById(R.id.fifteenPercentTv);
twentyPercentTv = view.findViewById(R.id.twentyPercentTv);
customTipTv = view.findViewById(R.id.customTipTv);
totalTipTv = view.findViewById(R.id.totalTipTv);
subTotalTv = view.findViewById(R.id.subTotalTv);
taxTotalTv = view.findViewById(R.id.taxTotalTv);
totalTv = view.findViewById(R.id.totalTv);
pickedTimeTv = view.findViewById(R.id.pickedTimeTv);
pickedDateTv = view.findViewById(R.id.pickedDateTv);
todayTv = view.findViewById(R.id.todayTv);
cancelTv = view.findViewById(R.id.cancelTv);
final Button checkoutBtn = view.findViewById(R.id.checkoutBtn);
Button doneDTBtn = view.findViewById(R.id.doneDTBtn);
final TimePicker timePicker = view.findViewById(R.id.timePicker);
HorizontalCalendar hcCalendar = view.findViewById(R.id.hcCalendar);
final LinearLayout dateTimePickLayout = view.findViewById(R.id.dateTimePickLayout);
final RelativeLayout pricesLayout = view.findViewById(R.id.pricesLayout);
dateTimePickLayout.setVisibility(View.GONE);
pricesLayout.setVisibility(View.VISIBLE);
EasyDB easyDB = EasyDB.init(getActivity(), "ITEMS_DB") // "TEST" is the name of the DATABASE
.setTableName("ITEMS_TABLE") // You can ignore this line if you want
.addColumn(new Column("Item_Id", "text", "unique"))
.addColumn(new Column("Item_Name", "text", "not null"))
.addColumn(new Column("Item_Price", "text", "not null"))
.doneTableColumn();
Cursor res = easyDB.getAllData();
while (res.moveToNext()) {
String id = res.getString(1);
String name = res.getString(2);
String price = res.getString(3);
ModelMenu modelMenu = new ModelMenu("" + name, "" + price);
menuList1.add(modelMenu);
idList.add(ids);
nameList.add(name);
priceList.add(price);
ids++;
}
onAddField(getActivity());
myAdapters = new MyAdapters(getActivity(), menuList1);
recyclerView.setAdapter(myAdapters);
timePicker.setIs24HourView(true);
Calendar calendar = Calendar.getInstance();
final int hours = calendar.get(Calendar.HOUR_OF_DAY);
final int minute = calendar.get(Calendar.MINUTE);
final int year = calendar.get(Calendar.YEAR);
final int month = calendar.get(Calendar.MONTH) + 1;
final int day = calendar.get(Calendar.DAY_OF_MONTH);
date = day + "/" + month + "/" + year;
pickedTimeTv.setText(hours + ":" + minute);
pickedDateTv.setText(day + "/" + month + "/" + year);
timePicker.setHour(hours);
timePicker.setMinute(minute);
timePicker.setOnTimeChangedListener(new TimePicker.OnTimeChangedListener() {
#Override
public void onTimeChanged(TimePicker timePicker, int hour, int minute) {
pickedTimeTv.setText(hour + ":" + minute);
}
});
}
Have you tried overriding onStop() in your Activities?
onStop() is called when your app is no longer visible to the user (i.e. pressing Home). You will next receive either onRestart(), onDestroy(), or nothing. This may explain your inconsistent behaviour.
You will likely need to take control and stop any updates to UI elements especially here, and then preserve the state of the UI as the user left it with onSaveInstanceState()
https://developer.android.com/topic/libraries/architecture/saving-states
I am new to app development and so far my app is working as intended but only when I launch it on my device from Android Studio. For example, I have once instance variable that I give a value of 1 in the onCreate() method. When I launch the app from android studio on to my device, it works fine and the variable has a value of 1. However, when I launch it from my device without using android studio, the variable is given a value of 0. I have also found that I will get a bunch of NullPointerExceptions on variables that I know should have a value, and once again it works when launched from Android Studio, but not when launched from the device.
Here is MainActivity
public class MainActivity extends AppCompatActivity
{
private ArrayList<String> arrayList;
private ArrayList<ListItem> itemList;
private ArrayAdapter<String> adapter;
private EditText txtInput;
private int payRoll;
private String value;
private Intent mainToPayroll;
private int hours;
private int earnings;
private ArrayList<Integer> rollList;
private ArrayList<Integer> hourList;
private ArrayList<Integer> wageList;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rollList = new ArrayList<>(0);
hourList = new ArrayList<>(0);
wageList = new ArrayList<>(0);
payRoll = 1;
Bundle bun = getIntent().getExtras();
if(bun != null)
{
rollList = bun.getIntegerArrayList("rolls");
hourList = bun.getIntegerArrayList("hours");
wageList = bun.getIntegerArrayList("wages");
payRoll = bun.getInt("roll");
}
ListView listView = (ListView) findViewById(R.id.listv);
String[] items = {};
arrayList = new ArrayList<>(Arrays.asList(items));
itemList = new ArrayList<>(0);
adapter = new ArrayAdapter<String>(this, R.layout.list_item, R.id.txtitem, arrayList);
listView.setAdapter(adapter);
Button btAdd = (Button) findViewById(R.id.btadd);
mainToPayroll = new Intent(this, PayrollActivity.class);
if(rollList != null)
{
for (int i = 0; i < rollList.size(); i++) {
ListItem newItem = new ListItem(rollList.get(i), hourList.get(i), wageList.get(i));
arrayList.add(newItem.toString());
itemList.add(newItem);
adapter.notifyDataSetChanged();
}
rollList.clear();
hourList.clear();
wageList.clear();
}
btAdd.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
ListItem newItem = new ListItem(payRoll, 0, 0);
arrayList.add(newItem.toString());
itemList.add(newItem);
adapter.notifyDataSetChanged();
payRoll++;
}
});
listView.setOnItemClickListener(new AdapterView.OnItemClickListener()
{
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
value = (String)adapter.getItem(position);
ListItem item = itemList.get(position);
Bundle info = new Bundle();
info.putString("val", value);
info.putInt("hours", item.getHours());
info.putInt("wage", item.getWages());
info.putInt("pos", position);
if(itemList.size() > 0)
{
for (ListItem items : itemList)
{
rollList.add(items.getPayroll());
hourList.add(items.getHours());
wageList.add(items.getWages());
}
}
info.putIntegerArrayList("rolls", rollList);
info.putIntegerArrayList("hours", hourList);
info.putIntegerArrayList("wages", wageList);
info.putInt("roll", payRoll);
info.putBoolean("rest", restore);
mainToPayroll.putExtras(info);
startActivity(mainToPayroll);
}
});
}
This Activity is started whenever an item on the listview is clicked
public class PayrollActivity extends AppCompatActivity
{
private static TextView text;
private String payrollNumber;
private int payrollHrs;
private int payrollWages;
private int position;
private Intent payrollToMain;
private Button returnButton;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_payroll);
final Bundle info = getIntent().getExtras();
System.out.print(getIntent().getType());
payrollNumber = info.getString("val");
payrollHrs = info.getInt("hours");
payrollWages = info.getInt("wage");
position = info.getInt("pos");
payrollToMain = new Intent(this, MainActivity.class);
returnButton = (Button) findViewById(R.id.btnRtrn);
returnButton.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
Bundle thing = new Bundle();
thing.putIntegerArrayList("rolls", info.getIntegerArrayList("rolls"));
thing.putIntegerArrayList("hours", info.getIntegerArrayList("hours"));
thing.putIntegerArrayList("wages", info.getIntegerArrayList("wages"));
thing.putInt("roll", info.getInt("roll"));
thing.putBoolean("rest", info.getBoolean("rest"));
payrollToMain.putExtras(thing);
startActivity(payrollToMain);
}
});
text = (TextView) findViewById(R.id.title);
text.setText(payrollNumber);
}
public static void setLabelText(String val)
{
text.setText(val);
}
This is a class I created for the items that go on the listview
public class ListItem
{
private int payroll;
private int hrs;
private int wages;
public ListItem(int roll, int hours, int wag)
{
payroll = roll;
hrs = hours;
wages = wag;
}
public int getPayroll()
{
return payroll;
}
public int getHours()
{
return hrs;
}
public int getWages()
{
return wages;
}
public void setPayroll(int roll)
{
payroll = roll;
}
public void setHrs(int hours)
{
hrs = hours;
}
public void setWages(int wage)
{
wages = wage;
}
public String toString()
{
return "Payroll " + payroll + "\n" + hrs + " hours\n$" + wages;
}
I think your problem is this piece of code in your MainActivity:
Bundle bun = getIntent().getExtras();
if(bun != null)
{
rollList = bun.getIntegerArrayList("rolls");
hourList = bun.getIntegerArrayList("hours");
wageList = bun.getIntegerArrayList("wages");
payRoll = bun.getInt("roll");
}
The getIntent().getExtras() may return a non-null Bundle object but the bundle may not have the keys you are trying to access, in which case all your instance variables will be set to null or zero for int.
You can get around this by simply checking if a particular key exists in the bundle and only setting your variable if it does.
bun.containsKey()
Or you can initialize your variables if they are null after loading them from the bundle.
Try uninstalling the app completely from the device and then try again. This solves the issue at times.
I have two errors in my code that I don't know how to solve it.
Please show them and tell me what to do.
Here are the codes of my app:
public class Food {
String price = null;
String name = null;
boolean selected = false;
public Food(String price, String name, boolean selected) {
super();
this.price = price;
this.name = name;
this.selected = selected;
}
public String getPrice() {
return price;
}
public void setPrice(String price) {
this.price = price;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public boolean isSelected() {
return selected;
}
public void setSelected(boolean selected) {
this.selected = selected;
}
}
public class MainActivity extends Activity {
MyCustomAdapter dataAdapter = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Generate list View from ArrayList
displayListView();
checkButtonClick();
}
private void displayListView() {
//Array list of foods
ArrayList<Food> foodList = new ArrayList<Food>();
Food food = new Food("15 SAR", "Chicken Meal", false);
foodList.add(food);
food = new Food("10 SAR", "Sliced Chicken", false);
foodList.add(food);
food = new Food("20 SAR", "Sandwich Chicken", false);
foodList.add(food);
food = new Food("10 SAR", "Hot Chicken", false);
foodList.add(food);
food = new Food("6 SAR", "Grilled potatoes", false);
foodList.add(food);
food = new Food("2 SAR", "Pepsi", false);
foodList.add(food);
food = new Food("17 SAR", "Fish Meal", false);
foodList.add(food);
//create an ArrayAdaptar from the String Array
dataAdapter = new MyCustomAdapter(this,
R.layout.food_info, foodList);
ListView listView = (ListView) findViewById(R.id.listView1);
// Assign adapter to ListView
listView.setAdapter(dataAdapter);
}
private class MyCustomAdapter extends ArrayAdapter<Food> {
private ArrayList<Food> foodList;
public MyCustomAdapter(Context context, int textViewResourceId,
ArrayList<Food> foodList) {
super(context, textViewResourceId, foodList);
this.foodList = new ArrayList<Food>();
this.foodList.addAll(foodList);
}
private class ViewHolder {
TextView price;
CheckBox name;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
Log.v("ConvertView", String.valueOf(position));
if (convertView == null) {
LayoutInflater vi = (LayoutInflater) getSystemService(
Context.LAYOUT_INFLATER_SERVICE);
convertView = vi.inflate(R.layout.food_info, null);
holder = new ViewHolder();
holder.price = (TextView) convertView.findViewById(R.id.price);
holder.name = (CheckBox) convertView.findViewById(R.id.checkBox);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
Food food = foodList.get(position);
holder.price.setText(" (" + food.getPrice() + ")");
holder.name.setText(food.getName());
holder.name.setChecked(food.isSelected());
holder.name.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
food.setSelected(b);
}
});
holder.name.setTag(food);
return convertView;
}
}
private void checkButtonClick() {
Button myButton = (Button) findViewById(R.id.findSelected);
myButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
setContentView(R.layout.invoic_page);
int totalPrice = 0;
for (Food f : foodList) {
if (f.isSelected) {
totalPrice += f.getPrice();
}
//totalPrice variable now has the total of all selected items
}
}
});
}
}
I tried to solve them as I can but other errors appear in different places of the code so I want the best solution.
The second issue of money as Strings. You can't simply add "1 SAR" and "2 SAR" and expect to get "3 SAR".
If this is a single currency system, don't append " SAR" everywhere and don't use strings to store the values, either ints or longs and store your currency's lowest division, e.g. halalas.
new Food("15 SAR", "Chicken Meal", false); becomes new Food(1500, "Chicken Meal", false);
Then to display to the user a price:
String forDisplay = String.format("%.2f SAR", totalHalas/100);
Alternatively, especially if this is a multicurrency system create a class for your currency:
Personally I would use a library for this: Joda Money.
But you can also roll your own:
public class Money {
private final String currency;
private final long value;
private final int dp;
public Money(long value, int dp, String currency){
this.value = value;
this.dp = dp;
this.currency = currency;
}
//optional helper factory method
public static Money sar(long halas){
return new Money(halas, 2, "SAR");
}
public Money add(Money other){
if(!other.currency.equals(currency))
throw new RuntimeException("Can't add different currencies");
if(!other.dp.equals(dp))
throw new RuntimeException("The decimal places do not match");
return new Money(value + other.value, dp, currency);
}
public String toString(){
return String.format("%."+dp+"f %s", value/Math.pow(10,dp), currency);
}
}
Example usage:
System.out.println(new Money(1500,2,"SAR").add(new Money(623,2,"SAR")));
//or:
System.out.println(Money.sar(1500).add(Money.sar(623)));
Outputs:
21.23 SAR
totalPrice is int and in Food model class price is String. So you need convet
for (Food f : foodList) {
if (f.isSelected) {
totalPrice += Integer.parseInt(f.getPrice());
}
//totalPrice variable now has the total of all selected items
}
and final Food food = foodList.get(position); need to define final
For the first error, you need need to make the food variable final:
// Make this final.
final Food food = foodList.get(position);
holder.name.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
food.setSelected(b);
}
});
For the second error, you need to convert the String value to interger:
for (Food f : foodList) {
if (f.isSelected) {
totalPrice += Integer.valueOf(f.getPrice());
}
}
But you better make the price variable as integer or BigInteger for price in Food class or BigDecimal.
UPDATE
Never save your currency in your price value. Instead, you can add a new variable like currency name. Do not save it for the sake of portability and future bug-free code.
I have a SQLite Database of Web site data (ftp address, username, password, port, homedir, url etc). I can add records to the table but can't seem to update them.
I created a SiteManager Activity that loads each row and creates a WebSite object from each row. The WebSite's properties are loaded into EditTexts. The person can edit the properties and than the Update button SHOULD update the table row but it doesn't. Logcat doesn't give any errors so I'm completely at a loss, not sure where to start.
public class SiteManager extends Activity {
private DBAdapter myDb;
private EditText siteManFTPAddress;
private EditText siteManFTPUsername;
private EditText siteManFTPPassword;
private EditText siteManFTPPort;
private EditText siteManURL;
private EditText siteManHome;
private ImageView favIcon;
public ListView site_list;
private Button openBtn;
private Button siteManUpdateBtn;
private int _rowId;
private String _name;
private String _remoteHomeDir;
private int _isLive;
private String _address;
private String _username;
private String _password;
private int _port;
private String _url;
private boolean _status = false;
private String siteFolder;
private List<WebSite> model = new ArrayList<WebSite>();
private ArrayAdapter<WebSite> adapter;
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.site_manager);
site_list = (ListView) findViewById(R.id.siteList);
adapter = new SiteAdapter(this, R.id.ftpsitename, R.layout.siterow,
model);
site_list.setAdapter(adapter);
addListeners();
openDb();
displayRecords();
}
public void addListeners() {
siteManFTPAddress = (EditText) findViewById(R.id.siteManFTPAdd);
siteManFTPUsername = (EditText) findViewById(R.id.siteManFTPUser);
siteManFTPPassword = (EditText) findViewById(R.id.siteManFTPPass);
siteManFTPPort = (EditText) findViewById(R.id.siteManFTPPort);
siteManURL = (EditText) findViewById(R.id.siteManURL);
siteManHome = (EditText) findViewById(R.id.siteManHome);
site_list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, final View view,
int position, long id) {
File rootDir = new File(Environment
.getExternalStorageDirectory() + "/My Webs");
final WebSite item = (WebSite) parent
.getItemAtPosition(position);
_name = item.getName();
siteFolder = rootDir.toString() + "/" + _name;
_remoteHomeDir = item.getHomeDir();
_isLive = item.isLive();
String tmpaddress = item.getAddress();
_address = tmpaddress;
siteManFTPAddress.setText(_address);
String tmpuser = item.getUsername();
_username = tmpuser;
siteManFTPUsername.setText(_username);
String tmppass = item.getPassword();
_password = tmppass;
siteManFTPPassword.setText(_password);
int tmpport = item.getPort();
_port = tmpport;
String portString = Integer.toString(tmpport);
siteManFTPPort.setText(portString);
String tmpURL = item.getUrl();
_url = tmpURL;
siteManURL.setText(_url);
String tmpHome = item.getHomeDir();
_remoteHomeDir = tmpHome;
siteManURL.setText(_remoteHomeDir);
}
});
openBtn = (Button) findViewById(R.id.openSiteBtn);
openBtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Intent returnResult = new Intent();
returnResult.putExtra("siteopen", "siteopen");
returnResult.putExtra("sitename", _name);
returnResult.putExtra("sitehome", siteFolder);
returnResult.putExtra("sitelive", _isLive);
returnResult.putExtra("siteremotehome", _remoteHomeDir);
returnResult.putExtra("siteaddress", _address);
returnResult.putExtra("siteusername", _username);
returnResult.putExtra("sitepassword", _password);
returnResult.putExtra("siteport", _port);
returnResult.putExtra("url", _url);
setResult(2, returnResult);
finish();
}
});
siteManUpdateBtn = (Button)findViewById(R.id.siteManFTPUpdate);
siteManUpdateBtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
_address = siteManFTPAddress.getText().toString();
_username = siteManFTPUsername.getText().toString();
_password = siteManFTPPassword.getText().toString();
String port = siteManFTPPort.getText().toString();
_port = Integer.parseInt(port);
Toast.makeText(SiteManager.this, "Update", Toast.LENGTH_LONG).show();
myDb.updateRow(_rowId, _name, _name, _isLive, _address, _username, _password, _port, _url);
model.clear();
adapter.notifyDataSetChanged();
displayRecords();
}
});
}
private void openDb() {
myDb = new DBAdapter(this);
myDb.open();
}
#Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
closeDb();
}
private void closeDb() {
myDb.close();
}
public void displayRecords() {
Cursor cursor = myDb.getAllRows();
displayRecordSet(cursor);
}
protected void displayRecordSet(Cursor c) {
if (c.moveToFirst()) {
do {
int rowId = c.getInt(c.getColumnIndex(DBAdapter.KEY_ROWID));
_rowId = c.getInt(rowId);
int keyNameIndex = c.getColumnIndex(DBAdapter.KEY_NAME);
_name = c.getString(keyNameIndex);
int keyHomeIndex = c.getColumnIndex(DBAdapter.KEY_HOME);
_remoteHomeDir = c.getString(keyHomeIndex);
int keyLiveIndex = c.getColumnIndex(DBAdapter.KEY_LIVE);
_isLive = c.getInt(keyLiveIndex);
int keyAddressIndex = c.getColumnIndex(DBAdapter.KEY_ADDRESS);
_address = c.getString(keyAddressIndex);
int keyUsernameIndex = c.getColumnIndex(DBAdapter.KEY_USERNAME);
_username = c.getString(keyUsernameIndex);
int keyPassIndex = c.getColumnIndex(DBAdapter.KEY_PASSWORD);
_password = c.getString(keyPassIndex);
int keyPortIndex = c.getColumnIndex(DBAdapter.KEY_PORT);
_port = c.getInt(keyPortIndex);
int keyUrlIndex = c.getColumnIndexOrThrow(DBAdapter.KEY_URL);
_url = c.getString(keyUrlIndex);
WebSite sitesFromDB = new WebSite(_rowId, _name, _remoteHomeDir,
_isLive, _address, _username, _password, _port, _url);
model.add(sitesFromDB);
adapter.notifyDataSetChanged();
if(adapter.isEmpty()){
}
} while (c.moveToNext());
}
c.close();
}
#Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
adapter.notifyDataSetChanged();
}
class SiteAdapter extends ArrayAdapter<WebSite> {
private final List<WebSite> objects;
private final Context context;
public SiteAdapter(Context context, int resource,
int textViewResourceId, List<WebSite> objects) {
super(context, R.id.sitename, R.layout.siterow, objects);
this.context = context;
this.objects = objects;
}
/** #return The number of items in the */
public int getCount() {
return objects.size();
}
public boolean areAllItemsSelectable() {
return false;
}
/** Use the array index as a unique id. */
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View rowView = inflater.inflate(R.layout.siterow, parent, false);
TextView textView = (TextView) rowView.findViewById(R.id.sitename);
textView.setText(objects.get(position).getName());
return (rowView);
}
}
DBAdapter.java
public boolean updateRow(long rowId, String name, String homedir,
int islive, String address, String username, String password,
int port, String url) {
String where = KEY_ROWID + "=" + rowId;
/*
* CHANGE 4:
*/
// TODO: Update data in the row with new fields.
// TODO: Also change the function's arguments to be what you need!
// Create row's data:
ContentValues newValues = new ContentValues();
newValues.put(KEY_NAME, name);
newValues.put(KEY_HOME, homedir);
newValues.put(KEY_LIVE, islive);
newValues.put(KEY_ADDRESS, address);
newValues.put(KEY_USERNAME, username);
newValues.put(KEY_PASSWORD, password);
newValues.put(KEY_PORT, port);
newValues.put(KEY_URL, url);
// newValues.put(KEY_PASSIVE, passive);
// Insert it into the database.
return db.update(DATABASE_TABLE, newValues, where, null) != 0;
}
The value _rowId is only ever set inside the displayRecordSet method where you iterate through the results from the database and set the _rowId:
int rowId = c.getInt(c.getColumnIndex(DBAdapter.KEY_ROWID));
_rowId = c.getInt(rowId);
This piece of code seems rather random to me. First you get the columnIndex for the rowId, next you get the index for this specific row and then you get the value of the column with index rowId and then set the _rowId field from this value.
I couldn't tell if the SQLite Database would be so nasty as to just return 0 if there isn't any value in the specified column, but that could definately be the problem.
So every time you get the _rowId set, it might just be set to 0 and when you try to update a row where rowId = 0 nothing happens, as no index in the database can be 0.
See the official documentation about getInt(columnIndex).
To diagnose issues like this, I usually add debug logs into the app. You can see these in your logcat. Log.d("tag", "there is something happening here: " + value);