School, 09.10.2017, start of Grades systems

GradeItem.java
--------------
package com.example.mohamadpc.myapplication4;

/**
 * Created by MOHAMADPC on 03/10/2017.
 */

public class GradeItem {
    private String subjectName;
    private int grade;

    public GradeItem(String subjectName, int grade) {
        this.subjectName = subjectName;
        this.grade = grade;
    }

    public String getSubjectName() {
        return subjectName;
    }

    public void setSubjectName(String subjectName) {
        this.subjectName = subjectName;
    }

    public int getGrade() {
        return grade;
    }

    public void setGrade(int grade) {
        this.grade = grade;
    }

}

GradesAdapter.java
------------------
package com.example.mohamadpc.myapplication4;

import android.content.Context;
import android.content.SharedPreferences;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

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

import static android.icu.lang.UCharacter.GraphemeClusterBreak.T;

/**
 * Created by MOHAMADPC on 03/10/2017.
 */

public class GradesAdapter extends BaseAdapter {
    private Context context;
    private String userName;
    private List<GradeItem> gradesList;

    public GradesAdapter(String userName, Context context) {
        this.userName = userName;
        this.context = context;
        this.gradesList = LoadStudentGrades(userName, context);

    }


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

    @Override
    public Object getItem(int i) {
        return gradesList.get(i);
    }

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

    @Override
    public View getView(final int i, View view, ViewGroup viewGroup) {
        /*TextView tvSubject = new TextView(context);
        tvSubject.setTextSize(30);
        tvSubject.setText(gradesList.get(i).getSubjectName() + " : " + gradesList.get(i).getGrade());

        return tvSubject; */
        View rowView = LayoutInflater.from(context).inflate(R.layout.grade_item_layout, null);
        TextView tvSubjectName = (TextView) rowView.findViewById(R.id.tvItemSubject);
        final EditText etGrade = (EditText) rowView.findViewById(R.id.etItemGrade);
        tvSubjectName.setText(gradesList.get(i).getSubjectName());
        etGrade.setText(gradesList.get(i).getGrade() + "");

        rowView.findViewById(R.id.btnItemSave).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int mynewGrade = Integer.parseInt(etGrade.getText().toString());
                gradesList.get(i).setGrade(mynewGrade);

                SaveStudentGrades(userName, i, context);
                Toast.makeText(context, "Update OK!", Toast.LENGTH_SHORT).show();

            }
        });

        return rowView;
    }

    private List<GradeItem> LoadStudentGrades(String userName, Context context) {
        SharedPreferences gradePrefs = context.getSharedPreferences(userName, Context.MODE_PRIVATE);
        List<GradeItem> res = new ArrayList<>();

        // not soo good
        Object[] subjects = gradePrefs.getAll().keySet().toArray();

        for (int i = 0; i < subjects.length; i += 1) {
            String subjectName = (String) subjects[i];
            int grade = gradePrefs.getInt(subjectName, 0);
            res.add(new GradeItem(subjectName, grade));
        }
        return res;
    }

    private void SaveStudentGrades(String userName, int i, Context context) {
        SharedPreferences gradePrefs = context.getSharedPreferences(userName, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = gradePrefs.edit();

        editor.putInt(gradesList.get(i).getSubjectName(), gradesList.get(i).getGrade());
        editor.commit();
    }
}

MainActivity.java
-----------------
package com.example.mohamadpc.myapplication4;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    EditText etUserName, etPassword;

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

        connectToLayout();
    }

    private void connectToLayout() {
        etUserName = (EditText) findViewById(R.id.etUserName);
        etPassword = (EditText) findViewById(R.id.etPassword);

        findViewById(R.id.btnCancel).setOnClickListener(this);
        findViewById(R.id.btnLogin).setOnClickListener(this);
        findViewById(R.id.btnRegister).setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.btnLogin:
                String userName = etUserName.getText().toString();
                String password = etPassword.getText().toString();

                if (userName.length() == 0 || password.length() == 0) {
                    Toast.makeText(this, "Please fill user name and password!", Toast.LENGTH_LONG).show();
                    return;
                }

                if (isValid(userName, password)) {
                    Intent i = new Intent(this, WelcomeActivity.class);
                    i.putExtra("CurrentUser", userName);
                    startActivity(i);
                    //this.finish();
                } else {
                    Toast.makeText(this, "Invalid username or password!", Toast.LENGTH_LONG).show();
                }
                break;
            case R.id.btnCancel:
                this.finish();
                break;

            case R.id.btnRegister:
                userName = etUserName.getText().toString();
                password = etPassword.getText().toString();

                if (!isUserExist(userName)) {
                    if (addNewUser(userName, password)) {
                        Toast.makeText(this, "User was added!", Toast.LENGTH_LONG).show();
                        etUserName.setText("");
                        etPassword.setText("");
                    } else {
                        Toast.makeText(this, "Error adding a user " + userName, Toast.LENGTH_LONG).show();
                    }
                }

                break;
            default:
                Toast.makeText(this, "Error on click", Toast.LENGTH_LONG).show();
                break;
        }
    }


    private boolean addNewUser(String userName, String password) {
        SharedPreferences prefs = this.getSharedPreferences("myUsers", Context.MODE_PRIVATE);

        SharedPreferences.Editor editor = prefs.edit();
        editor.putString(userName, password);
        return editor.commit();
    }

    private boolean isUserExist(String userName) {
        SharedPreferences prefs = this.getSharedPreferences("myUsers", Context.MODE_PRIVATE);

        String savedPassword = prefs.getString(userName, "");

        return (!savedPassword.equals(""));
    }


    private boolean isValid(String userName, String password) {

        SharedPreferences prefs = this.getSharedPreferences("myUsers", Context.MODE_PRIVATE);

        String savedPassword = prefs.getString(userName, "");

        return (savedPassword.equals(password));
    }
}

WelcomeActivity.java
--------------------
package com.example.mohamadpc.myapplication4;

import android.database.DataSetObserver;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;

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

public class WelcomeActivity extends AppCompatActivity {
    private TextView tvWelcome;
    private String userName;
    private ListView lsvGrades;
    private List<GradeItem> myGrades;

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

        userName = getIntent().getStringExtra("CurrentUser");

        tvWelcome = (TextView) findViewById(R.id.tvWellcome);
        lsvGrades = (ListView) findViewById(R.id.lsvGrades);

        tvWelcome.setText(userName);
        myGrades = new ArrayList<GradeItem>();
        myGrades.add(new GradeItem("Arabic", 90));
        myGrades.add(new GradeItem("Hebrew", 99));
        myGrades.add(new GradeItem("Math", 83));
        myGrades.add(new GradeItem("History", 20));
        myGrades.add(new GradeItem("English", 98));
        myGrades.add(new GradeItem("Fatin", 30));
        myGrades.add(new GradeItem("Ayoub", 80));
        myGrades.add(new GradeItem("Lolo", 100));


        GradesAdapter gAdapter = new GradesAdapter(userName, this);
        lsvGrades.setAdapter(gAdapter);

    }
}

activity_layout.xml
-------------------
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dp"
        android:gravity="center"
        android:text="@string/login_title"
        android:textColor="#000ff0"
        android:textSize="32sp" />

    <EditText
        android:id="@+id/etUserName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dp"
        android:hint="@string/user_name_hint"
        android:textSize="24sp" />

    <EditText
        android:id="@+id/etPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Password"
        android:inputType="textPassword"
        android:textSize="24sp" />

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

        <Button
            android:id="@+id/btnLogin"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:text="Login"
            android:textSize="18sp" />


        <Button
            android:id="@+id/btnRegister"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:text="Register"
            android:textSize="18sp" />

        <Button
            android:id="@+id/btnCancel"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:text="Cancel"
            android:textSize="18sp" />
    </LinearLayout>
</LinearLayout>

activity_welcome.xml
--------------------
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:id="@+id/tvWellcome"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="20sp" />

    <ListView
        android:id="@+id/lsvGrades"
        android:layout_width="match_parent"
        android:layout_height="match_parent"></ListView>
</LinearLayout>

grade_item_layout.xml
---------------------
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#00fff0"
    android:orientation="horizontal">

    <TextView
        android:id="@+id/tvItemSubject"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="Subject Name"
        android:textSize="20sp" />

    <EditText
        android:id="@+id/etItemGrade"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:inputType="number"
        android:maxLength="3"
        android:text="Grade"
        android:textSize="20sp" />

    <Button
        android:id="@+id/btnItemSave"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="Save"
        android:textSize="20sp" />
</LinearLayout>