Initial stuff

i have recycle

app/src/androidTest/java/com/ireallydontcare/viet/posseidon/ExampleInstrumentedTest.java

+package com.ireallydontcare.viet.posseidon;
+
+import android.content.Context;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Test
+    public void useAppContext() {
+        // Context of the app under test.
+        Context appContext = InstrumentationRegistry.getTargetContext();
+
+        assertEquals("com.ireallydontcare.viet.posseidon", appContext.getPackageName());
+    }
+}

app/src/main/AndroidManifest.xml

+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.ireallydontcare.viet.posseidon">
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/AppTheme">
+        <activity
+            android:name=".SubjectActivity"
+            android:label="@string/app_name"
+            android:theme="@style/AppTheme.NoActionBar">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>
\ No newline at end of file

app/src/main/java/com/ireallydontcare/viet/posseidon/SubjectActivity.java

+package com.ireallydontcare.viet.posseidon;
+
+import android.os.AsyncTask;
+import android.os.Bundle;
+import android.support.design.widget.FloatingActionButton;
+import android.support.v7.app.AppCompatActivity;
+import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.RecyclerView;
+import android.support.v7.widget.Toolbar;
+import android.view.View;
+import android.view.Menu;
+import android.view.MenuItem;
+import android.widget.Toast;
+
+import com.ireallydontcare.viet.posseidon.adapter.SubjectAdapter;
+import com.ireallydontcare.viet.posseidon.fragments.NewDialogSubjectFragment;
+import com.ireallydontcare.viet.posseidon.model.Subject;
+
+import static java.security.AccessController.getContext;
+
+public class SubjectActivity extends AppCompatActivity
+        implements NewDialogSubjectFragment.NewSubjectDialogListener{
+
+    private RecyclerView subjectRecyclerView;
+    private SubjectAdapter subjectAdapter;
+    private RecyclerView.LayoutManager subjectLayoutManager;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_subject);
+        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
+        setSupportActionBar(toolbar);
+
+        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
+
+        fab.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                new NewDialogSubjectFragment().show(getSupportFragmentManager(), NewDialogSubjectFragment.TAG);
+            }
+        });
+
+        subjectRecyclerView = (RecyclerView) findViewById(R.id.SubjectRecyclerView);
+
+        // use this setting to improve performance if you know that changes
+        // in content do not change the layout size of the RecyclerView
+        subjectRecyclerView.setHasFixedSize(true);
+
+        // use a linear layout manager
+        subjectLayoutManager = new LinearLayoutManager(this);
+        subjectRecyclerView.setLayoutManager(subjectLayoutManager);
+
+        // specify an adapter (see also next example)
+        subjectAdapter = new SubjectAdapter();
+
+        subjectRecyclerView.setAdapter(subjectAdapter);
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        // Inflate the menu; this adds items to the action bar if it is present.
+        getMenuInflater().inflate(R.menu.menu_subject, menu);
+        return true;
+    }
+
+    @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();
+
+        //noinspection SimplifiableIfStatement
+        if (id == R.id.action_settings) {
+            return true;
+        }
+
+        return super.onOptionsItemSelected(item);
+    }
+
+    @Override
+    public void onShoppingItemCreated(final Subject newItem) {
+        new AsyncTask<Void, Void, Subject>() {
+
+            @Override
+            protected Subject doInBackground(Void... voids) {
+                return newItem;
+            }
+
+            @Override
+            protected void onPostExecute(Subject shoppingItem) {
+                subjectAdapter.addItem(shoppingItem);
+            }
+        }.execute();
+    }
+}

app/src/main/java/com/ireallydontcare/viet/posseidon/adapter/SubjectAdapter.java

+package com.ireallydontcare.viet.posseidon.adapter;
+
+import android.support.annotation.NonNull;
+import android.support.v7.widget.RecyclerView;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+
+import com.ireallydontcare.viet.posseidon.R;
+import com.ireallydontcare.viet.posseidon.model.Subject;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class SubjectAdapter extends RecyclerView.Adapter<SubjectAdapter.SubjectViewHolder> {
+    private final List<Subject> subjects;
+    // Provide a reference to the views for each data item
+    // Complex data items may need more than one view per item, and
+    // you provide access to all the views for a data item in a view holder
+
+
+
+    // Provide a suitable constructor (depends on the kind of dataset)
+    public SubjectAdapter() {
+        this.subjects = new ArrayList<>();
+    }
+
+    // Create new views (invoked by the layout manager)
+    @Override
+    public SubjectAdapter.SubjectViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+        // create a new view
+        View itemView = LayoutInflater
+                .from(parent.getContext())
+                .inflate(R.layout.item_subject, parent, false);
+
+        SubjectViewHolder vh = new SubjectViewHolder(itemView);
+        return vh;
+    }
+    // Replace the contents of a view (invoked by the layout manager)
+    @Override
+    public void onBindViewHolder(final SubjectViewHolder holder, int position) {
+        // - get element from your dataset at this position
+        // - replace the contents of the view with that element
+        final Subject subject = subjects.get(position);
+        holder.name.setText(subject.name);
+        holder.code.setText(subject.code);
+        holder.subject = subject;
+
+
+    }
+
+    @Override
+    public int getItemCount() {
+            return subjects.size();
+    }
+
+    public static class SubjectViewHolder extends RecyclerView.ViewHolder {
+        Subject subject;
+
+        TextView name;
+        TextView code;
+
+        public SubjectViewHolder(View itemView) {
+            super(itemView);
+            name = itemView.findViewById(R.id.subject_name);
+            code = itemView.findViewById(R.id.subject_code);
+        }
+    }
+
+    public void addItem(Subject subject){
+
+        subjects.add(subject);
+        notifyItemInserted(subjects.size() - 1);
+    }
+
+    public interface OnSubjectClickListener {
+        void onItemClick(Subject item);
+    }
+
+}
\ No newline at end of file

app/src/main/java/com/ireallydontcare/viet/posseidon/fragments/NewDialogSubjectFragment.java

+package com.ireallydontcare.viet.posseidon.fragments;
+
+import android.app.Dialog;
+import android.content.DialogInterface;
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v4.app.DialogFragment;
+import android.support.v4.app.FragmentActivity;
+import android.support.v7.app.AlertDialog;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.widget.EditText;
+
+import com.ireallydontcare.viet.posseidon.R;
+import com.ireallydontcare.viet.posseidon.model.Subject;
+
+public class NewDialogSubjectFragment extends DialogFragment {
+
+    public static final String TAG = "NewSubjectItemDialogFragment";
+
+    public interface NewSubjectDialogListener {
+        void onShoppingItemCreated(Subject newSubject);
+    }
+
+    private NewSubjectDialogListener listener;
+
+    @Override
+    public void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        FragmentActivity activity = getActivity();
+        if (activity instanceof NewSubjectDialogListener) {
+            listener = (NewSubjectDialogListener) activity;
+        } else {
+            throw new RuntimeException("Activity must implement the NewShoppingItemDialogListener interface!");
+        }
+    }
+
+    private EditText nameEditText;
+    private EditText codeEditText;
+    private EditText descriptionEditText;
+    private EditText creditEditText;
+
+    private View getContentView(){
+        View contentView = LayoutInflater.from(getContext()).inflate(R.layout.dialog_new_subject_item, null);
+        nameEditText = contentView.findViewById(R.id.SubjectName);
+        codeEditText = contentView.findViewById(R.id.SubjectCode);
+        descriptionEditText = contentView.findViewById(R.id.SubjectDescription);
+        creditEditText = contentView.findViewById(R.id.SubjectCredit);
+
+        return contentView;
+    }
+
+    @NonNull
+    @Override
+    public Dialog onCreateDialog(Bundle savedInstanceState) {
+        super.onCreateDialog(savedInstanceState);
+        return new AlertDialog.Builder(requireContext())
+                .setTitle(R.string.new_subject_item)
+                .setView(getContentView())
+                .setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
+                    @Override
+                    public void onClick(DialogInterface dialogInterface, int i) {
+                        listener.onShoppingItemCreated(getNewSubject());
+                    }
+                })
+                .create();
+    }
+
+
+    public Subject getNewSubject(){
+        Subject subject = new Subject();
+
+        subject.name = nameEditText.getText().toString();
+        subject.code = codeEditText.getText().toString();
+        subject.description = descriptionEditText.getText().toString();
+        subject.credit = Integer.parseInt(creditEditText.getText().toString());
+        return  subject;
+    }
+
+}

app/src/main/java/com/ireallydontcare/viet/posseidon/model/Event.java

+package com.ireallydontcare.viet.posseidon.model;
+
+public class Event {
+}

app/src/main/java/com/ireallydontcare/viet/posseidon/model/Subject.java

+package com.ireallydontcare.viet.posseidon.model;
+
+
+import android.arch.persistence.room.ColumnInfo;
+import android.arch.persistence.room.Entity;
+import android.arch.persistence.room.PrimaryKey;
+import android.arch.persistence.room.TypeConverter;
+
+@Entity(tableName = "subjectitem")
+public class Subject {
+
+    @ColumnInfo(name = "id")
+    @PrimaryKey(autoGenerate = true)
+    public Long id;
+
+    @ColumnInfo(name = "name")
+    public String name;
+
+    @ColumnInfo(name = "code")
+    public String code;
+
+    @ColumnInfo(name = "description")
+    public String description;
+
+
+    @ColumnInfo(name="credit")
+    public int credit;
+}

app/src/main/res/drawable-v24/ic_launcher_foreground.xml

+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path
+        android:fillType="evenOdd"
+        android:pathData="M32,64C32,64 38.39,52.99 44.13,50.95C51.37,48.37 70.14,49.57 70.14,49.57L108.26,87.69L108,109.01L75.97,107.97L32,64Z"
+        android:strokeWidth="1"
+        android:strokeColor="#00000000">
+        <aapt:attr name="android:fillColor">
+            <gradient
+                android:endX="78.5885"
+                android:endY="90.9159"
+                android:startX="48.7653"
+                android:startY="61.0927"
+                android:type="linear">
+                <item
+                    android:color="#44000000"
+                    android:offset="0.0" />
+                <item
+                    android:color="#00000000"
+                    android:offset="1.0" />
+            </gradient>
+        </aapt:attr>
+    </path>
+    <path
+        android:fillColor="#FFFFFF"
+        android:fillType="nonZero"
+        android:pathData="M66.94,46.02L66.94,46.02C72.44,50.07 76,56.61 76,64L32,64C32,56.61 35.56,50.11 40.98,46.06L36.18,41.19C35.45,40.45 35.45,39.3 36.18,38.56C36.91,37.81 38.05,37.81 38.78,38.56L44.25,44.05C47.18,42.57 50.48,41.71 54,41.71C57.48,41.71 60.78,42.57 63.68,44.05L69.11,38.56C69.84,37.81 70.98,37.81 71.71,38.56C72.44,39.3 72.44,40.45 71.71,41.19L66.94,46.02ZM62.94,56.92C64.08,56.92 65,56.01 65,54.88C65,53.76 64.08,52.85 62.94,52.85C61.8,52.85 60.88,53.76 60.88,54.88C60.88,56.01 61.8,56.92 62.94,56.92ZM45.06,56.92C46.2,56.92 47.13,56.01 47.13,54.88C47.13,53.76 46.2,52.85 45.06,52.85C43.92,52.85 43,53.76 43,54.88C43,56.01 43.92,56.92 45.06,56.92Z"
+        android:strokeWidth="1"
+        android:strokeColor="#00000000" />
+</vector>