Clipici Constantin-Mădălin - Curs 4 - Code Challenge 2

app/src/main/AndroidManifest.xml

@@ -11,10 +11,7 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.AndroidFundamentalsMai2021">
-        <activity android:name=".ConstraintLayoutSampleActivity"></activity>
-        <activity android:name=".MainActivity" />
-        <activity android:name=".EmailsActivity" />
-        <activity android:name=".StartActivity">
+        <activity android:name=".StudentActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 

app/src/main/java/com/magdamiu/androidfundamentalsmai2021/StartActivity.java

@@ -22,7 +22,7 @@ public void startMainActivityOnClick(View view) {
 
     public void startRecyclerViewActivityOnClick(View view) {
         // starts from the current activity, and moves the user to the EmailsActivity screen
-        Intent intentToStartEmailsActivity = new Intent(StartActivity.this, EmailsActivity.class);
+        Intent intentToStartEmailsActivity = new Intent(StartActivity.this, StudentActivity.class);
         startActivity(intentToStartEmailsActivity);
     }
 

app/src/main/java/com/magdamiu/androidfundamentalsmai2021/Student.java

@@ -0,0 +1,37 @@
+package com.magdamiu.androidfundamentalsmai2021;
+
+public class Student {
+    private int id;
+    private String firstName;
+    private String lastName;
+
+    public Student(int id, String firstName, String lastName) {
+        this.id = id;
+        this.firstName = firstName;
+        this.lastName = lastName;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+}

app/src/main/java/com/magdamiu/androidfundamentalsmai2021/StudentActivity.java

@@ -0,0 +1,66 @@
+package com.magdamiu.androidfundamentalsmai2021;
+
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+
+import android.content.Context;
+import android.os.Bundle;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class StudentActivity extends AppCompatActivity {
+
+    private List<Student> students;
+    private static Context context;
+    private RecyclerView recyclerView;
+    private RecyclerView.LayoutManager layoutManager;
+    private StudentAdapter studentAdapter;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        StudentActivity.context = getApplicationContext();
+        setContentView(R.layout.activity_students);
+
+        // data source for our RecyclerView
+        populateListOfStudents();
+
+        // init the UI elements
+        initView();
+
+        // set the linear layout manager to our recycler view
+        setLayoutManager();
+
+        // set the adapter to our recycler view
+        setAdapter();
+    }
+
+    private void initView() {
+        recyclerView = findViewById(R.id.recyclerViewStudents);
+    }
+
+    private void populateListOfStudents() {
+        students = new ArrayList<>();
+        int index;
+        for (int i = 0; i < 20; i++) {
+            index = i + 1;
+            students.add(new Student(index, "FirstName " + index, "LastName " + index));
+        }
+    }
+
+    private void setLayoutManager() {
+        layoutManager = new LinearLayoutManager(this);
+        recyclerView.setLayoutManager(layoutManager);
+    }
+
+    private void setAdapter() {
+        studentAdapter = new StudentAdapter(students);
+        recyclerView.setAdapter(studentAdapter);
+    }
+
+    public static Context getAppContext() {
+        return StudentActivity.context;
+    }
+}

app/src/main/java/com/magdamiu/androidfundamentalsmai2021/StudentAdapter.java

@@ -0,0 +1,44 @@
+package com.magdamiu.androidfundamentalsmai2021;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.annotation.NonNull;
+import androidx.core.content.ContextCompat;
+import androidx.core.content.res.ResourcesCompat;
+import androidx.recyclerview.widget.RecyclerView;
+
+import java.util.List;
+
+public class StudentAdapter extends RecyclerView.Adapter<StudentViewHolder> {
+    private final List<Student> students;
+
+    public StudentAdapter(List<Student> students) {
+        this.students = students;
+    }
+
+    @NonNull
+    @Override
+    public StudentViewHolder onCreateViewHolder(@NonNull  ViewGroup parent, int viewType) {
+        View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.student_item, parent, false);
+        return new StudentViewHolder(itemView);
+    }
+
+    // fills the item with the corresponding element from the list (data source)
+    @Override
+    public void onBindViewHolder(@NonNull StudentViewHolder holder, int position) {
+        Student currentStudent = students.get(position);
+        if (position % 2  == 1){
+            holder.getStudentView().setBackgroundColor(ContextCompat.getColor(StudentActivity.getAppContext(), R.color.grey));
+        }
+        holder.getTextFirstName().setText(currentStudent.getFirstName());
+        holder.getTextLastName().setText(currentStudent.getLastName());
+    }
+
+    // decides how many items(total number) to create in our recycler view
+    @Override
+    public int getItemCount() {
+        return students.size();
+    }
+}

app/src/main/java/com/magdamiu/androidfundamentalsmai2021/StudentViewHolder.java

@@ -0,0 +1,36 @@
+package com.magdamiu.androidfundamentalsmai2021;
+
+import android.view.View;
+import android.widget.LinearLayout;
+import android.widget.TextView;
+
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.RecyclerView;
+
+// the class associated to the item of the recycler view
+// each ui element from the item should have a dedicated field in this class
+public class StudentViewHolder extends RecyclerView.ViewHolder {
+    final private LinearLayout studentView;
+    final private TextView textFirstName;
+    final private TextView textLastName;
+
+    public StudentViewHolder(@NonNull View itemView) {
+        super(itemView);
+        studentView = itemView.findViewById(R.id.student);
+        textFirstName = itemView.findViewById(R.id.textFirstName);
+        textLastName = itemView.findViewById(R.id.textLastName);
+    }
+
+
+    public TextView getTextFirstName() {
+        return textFirstName;
+    }
+
+    public TextView getTextLastName() {
+        return textLastName;
+    }
+
+    public LinearLayout getStudentView() {
+        return studentView;
+    }
+}

app/src/main/res/layout/activity_emails.xml → app/src/main/res/layout/activity_students.xml

@@ -4,10 +4,10 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    tools:context=".EmailsActivity">
+    tools:context=".StudentActivity">
 
     <androidx.recyclerview.widget.RecyclerView
-        android:id="@+id/recyclerViewEmails"
+        android:id="@+id/recyclerViewStudents"
         android:layout_width="match_parent"
         android:layout_height="match_parent" />