Groceries DB

//--------------- Main Activity ------------------

import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.content.DialogInterface;
import android.graphics.Color;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;

import com.sdsmdg.tastytoast.TastyToast;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    ListView itemsList;
    EditText mask;
    Context context;
    DBHandler db;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setPointer();
    }

    private void setPointer() {
        this.context = this;
        db = new DBHandler(context);
        mask = findViewById(R.id.uInput);
        itemsList = findViewById(R.id.items_list);
        getData();
        findViewById(R.id.btnAddItem).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                addItem();
            }
        });
        itemsList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                TextView item = (TextView) view;
                String itemToDelete = item.getText().toString();
                itemToDelete = itemToDelete.substring(itemToDelete.indexOf(' ')).trim();
                askForDeletion(itemToDelete);
            }
        });
        findViewById(R.id.btnFindItem).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                cleanBackgrounds();
                EditText userInput = findViewById(R.id.uInput);
                String itemName = userInput.getText().toString();
                int index = getPositionFromAdapter(itemName);
                if(index != -1) {
                    itemsList.getChildAt(index).setBackgroundColor(Color.MAGENTA);
                } else {
                    TastyToast.makeText(context, "No such item", TastyToast.LENGTH_LONG, TastyToast.INFO).show();
                }
            }
        });
    }

    private void askForDeletion(final String itemName) {
        AlertDialog.Builder removeItemDialog = new AlertDialog.Builder(context);
        removeItemDialog.setTitle("Are you sure you want to delete " + itemName + "?");
        removeItemDialog.setPositiveButton("Remove", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                if(itemName.isEmpty() || itemName == null) {
                    return;
                }
                if(db.removeItem(itemName)) {
                    TastyToast.makeText(context, "Failed to remove item", TastyToast.LENGTH_LONG, TastyToast.INFO).show();
                }
                dialog.dismiss();
                getData();
            }
        });
        removeItemDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });
        removeItemDialog.show();
    }

    private void addItem() {
        AlertDialog.Builder addItemDialog = new AlertDialog.Builder(context);
        addItemDialog.setTitle("Add Item Dialog");
        final LinearLayout addItemDialogLayout = new LinearLayout(context);
        addItemDialogLayout.setOrientation(LinearLayout.VERTICAL);
        addItemDialogLayout.setPaddingRelative(20, 20, 20, 20);

        final EditText itemName = new EditText(context);
        itemName.setPaddingRelative(20, 20, 20, 20);
        final EditText amount = new EditText(context);
        amount.setPaddingRelative(60, 40, 60, 40);
        itemName.setHint("Enter the new item's name");
        amount.setHint("Enter the new item's amount");

        addItemDialogLayout.addView(itemName);
        addItemDialogLayout.addView(amount);

        addItemDialog.setView(addItemDialogLayout);
        addItemDialog.setPositiveButton("Add", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                if (itemName.getText().toString().isEmpty() ||
                        amount.getText().toString().isEmpty()) {
                    TastyToast.makeText(context, "Something is missing!", TastyToast.LENGTH_LONG, TastyToast.WARNING).show();
                    return;
                }
                try {
                    Integer.parseInt(amount.getText().toString());
                } catch(NumberFormatException nfe) {
                    TastyToast.makeText(context, "Amount should be a number!", TastyToast.LENGTH_LONG, TastyToast.ERROR).show();
                    return;
                }
                createItem(itemName.getText().toString(),
                           Integer.parseInt(amount.getText().toString()));
                dialog.dismiss();
            }
        });
        addItemDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });
        addItemDialog.show();
    }

    private void createItem(String itemName, int amount) {
        if(db.addItem(itemName, amount)) {
            Log.e("SQL", "createItem: OK");
            getData();
        } else {
            Log.e("SQL", "createItem: FAILURE");

        }
    }

    private void getData() {
        ItemAdapter adapter = new ItemAdapter(context, db.getItems());
        itemsList.setAdapter(adapter);
    }

    private int getPositionFromAdapter(String name) {
        for(int i = 0; i < itemsList.getAdapter().getCount(); i++) {
            String str = itemsList.getAdapter().getItem(i).toString();
            str = str.substring(str.indexOf(' ')).trim();
            if(str.matches(name)) {
                return i;
            }
        }
        return -1;
    }

    private void cleanBackgrounds() {
        for(int i = 0; i < itemsList.getCount(); i++) {
            itemsList.getChildAt(i).setBackgroundColor(Color.WHITE);
        }
    }
}

//------------- ItemAdapter ---------------------

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.List;

public class ItemAdapter extends BaseAdapter {

    Context context;
    List<String> items;

    public ItemAdapter(Context context, List<String> items) {
        this.context = context;
        this.items = items;
    }

    @Override
    public int getCount() {
        return items.size();
    }

    @Override
    public Object getItem(int position) {
        return items.get(position);
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        TextView iName = new TextView(context);
        iName.setPadding(100, 30, 100, 30);
        iName.setText(this.items.get(position));
        iName.setTextSize(18);
        return iName;
    }

    public Object getItemByName(String str) {
        for(int i = 0; i < items.size(); i++) {
            if(items.get(i).matches(str)) {
                return items.get(i);
            }
        }
        return null;
    }
}

//----------------- DBHandler -----------------------

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import android.widget.ListView;
import android.widget.Toast;

import androidx.annotation.Nullable;

import com.sdsmdg.tastytoast.TastyToast;

import java.util.ArrayList;
import java.util.List;

public class DBHandler extends SQLiteOpenHelper {

    //Database parameters
    private static final String DATABASE_NAME = "groceriesDB.db";
    private static final int DATABASE_VERSION = 1;

    //Table parameters
    private static final String GROCERIES_TABLE = "groceries";
    private static final String COLUMN_ITEM_ID = "item_id";
    private static final String COLUMN_ITEM_NAME = "item_name";
    private static final String COLUMN_ITEM_ANOUNT = "item_amount";

    private static SQLiteDatabase myDB;
    Context context;

    public DBHandler(@Nullable Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        this.context = context;
        myDB = getWritableDatabase();
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        String CREATE_ITEMS_TABLE = "CREATE TABLE IF NOT EXISTS " + GROCERIES_TABLE + "(" +
                                    COLUMN_ITEM_ID + " INTEGER PRIMARY KEY, " +
                                    COLUMN_ITEM_NAME + " TEXT UNIQUE, " +
                                    COLUMN_ITEM_ANOUNT + " INTEGER)";
        db.execSQL(CREATE_ITEMS_TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        //Do nothing
    }

    public boolean addItem(String itemName, int amount) {
        //Validate that the item is not in the database. If not, add the new item to the database
        if(exists(itemName)) {
            TastyToast.makeText(context, "Item with the same name already exists!", Toast.LENGTH_LONG, TastyToast.CONFUSING).show();
        } else {
            ContentValues values = new ContentValues();
            values.put("item_name", itemName);
            values.put("item_amount", amount);
            if(myDB.insert(GROCERIES_TABLE, null, values) != -1) {
                Log.e("addItem: ", "success!!!");
                return true;
            } else {
                Log.e("addItem: ", "failed!!!");
            }
        }
        return false;
    }

    protected boolean removeItem(String itemName) {
        //Validate that the item is not in the database. If not, add the new item to the database
        if(!exists(itemName)) {
            TastyToast.makeText(context, "Item with the same does not exists!", Toast.LENGTH_LONG, TastyToast.CONFUSING).show();
        } else {
            if(myDB.delete(GROCERIES_TABLE, COLUMN_ITEM_NAME + " = ?", new String[] {itemName}) == -1) {
                Log.e("removeItem: ", "success!!!");
                return true;
            } else {
                Log.e("removeItem: ", "failed!!!");
            }
        }
        return false;
    }

    private boolean exists(String itemName) {
        //check if an item with the same name exists in the database
        String query = String.format("SELECT * FROM %s WHERE %s = '%s'",
                                     GROCERIES_TABLE, COLUMN_ITEM_NAME, itemName);

        Cursor cursor = myDB.rawQuery(query, null);
        boolean b = cursor.moveToFirst();
        cursor.close();
        return b;
    }

    public List<String> getItems() {
        List<String> items = new ArrayList<>();
        Cursor cursor = myDB.rawQuery("SELECT * FROM " + GROCERIES_TABLE, null);
        if(cursor.moveToFirst()) {
            while(!cursor.isAfterLast()) {
                String str = cursor.getInt(cursor.getColumnIndex(COLUMN_ITEM_ANOUNT)) + " " +
                             cursor.getString(cursor.getColumnIndex(COLUMN_ITEM_NAME));
                items.add(str);
                cursor.moveToNext();
            }
        }
        cursor.close();
        return items;
    }
}

//------------------------- Activity_main.xml --------------------

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <LinearLayout
        android:id="@+id/linearLayout2"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:orientation="vertical"
        android:layout_marginStart="30dp"
        android:layout_marginEnd="30dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <TextView
            android:id="@+id/title"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="30dp"
            android:gravity="center"
            android:text="@string/title"
            android:textColor="@color/colorPrimary"
            android:textSize="32sp" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">

            <Button
                android:id="@+id/btnFindItem"
                style="@style/Widget.AppCompat.Button.Colored"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_margin="10dp"
                android:text="@string/find" />

            <EditText
                android:id="@+id/uInput"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_marginEnd="20dp"
                android:autofillHints=""
                android:hint="@string/item_name_here"
                android:inputType="text" />
        </LinearLayout>

        <ListView
            style="@style/Widget.AppCompat.ListView"
            android:id="@+id/items_list"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1" />

        <Button
            android:id="@+id/btnAddItem"
            style="@style/Widget.AppCompat.Button.ButtonBar.AlertDialog"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:text="@string/add_item"
            android:textSize="18sp" />
    </LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>