Igor Lopatinskiy

app/build.gradle

@@ -22,6 +22,7 @@ dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation 'com.android.support:appcompat-v7:28.0.0'
     implementation 'com.android.support.constraint:constraint-layout:1.1.3'
+    implementation 'com.android.support:recyclerview-v7:28.0.0'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

app/src/main/java/ru/ok/technopolis/students/MainActivity.java

@@ -2,13 +2,145 @@
 
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
+import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.RecyclerView;
+import android.view.View;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.ImageView;
+import android.widget.RadioGroup;
+import android.widget.Toast;
+
+import java.util.Random;
 
 public class MainActivity extends AppCompatActivity {
 
+    private StudentAdapter adapter;
+    private ImageView photo;
+    private int photoId;
+    private EditText firstName;
+    private EditText lastName;
+    private RadioGroup radioGroup;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
+
+        RecyclerView recyclerView = findViewById(R.id.activity_main__list);
+        adapter = new StudentAdapter(this);
+        recyclerView.setLayoutManager(new LinearLayoutManager(this));
+        recyclerView.setAdapter(adapter);
+
+        photo = findViewById(R.id.activity_main__photo);
+        firstName = findViewById(R.id.activity_main__firstName);
+        lastName = findViewById(R.id.activity_main__lastName);
+        radioGroup = findViewById(R.id.activity_main__radio);
+
+        radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(RadioGroup group, int checkedId) {
+                randomizePhoto();
+            }
+        });
+
+        Button addButton = findViewById(R.id.activity_main__add);
+        addButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                clearFields();
+                adapter.setActiveStudent(adapter.NO_STUDENT);
+            }
+        });
+
+        Button saveButton = findViewById(R.id.activity_main__save);
+        saveButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                saveStudent();
+            }
+        });
+
+        Button deleteButton = findViewById(R.id.activity_main__delete);
+        deleteButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                deleteStudent();
+            }
+        });
+
+    }
+
+    private void deleteStudent() {
+        adapter.deleteStudent();
+    }
+
+    private void saveStudent() {
+
+        String firstNameStr = firstName.getText().toString();
+        String lastNameStr = lastName.getText().toString();
+        Boolean gender = null;
+        switch (radioGroup.getCheckedRadioButtonId()){
+            case R.id.activity_main__radio_male:
+                gender = true;
+                break;
+            case R.id.activity_main__radio_woman:
+                gender = false;
+                break;
+        }
+
+        if (firstNameStr.isEmpty() || lastNameStr.isEmpty() || gender == null){
+            Toast.makeText(this, "Заполните все поля", Toast.LENGTH_SHORT).show();
+            return;
+        }
+
+        Student student = new Student(
+                firstNameStr,
+                lastNameStr,
+                gender,
+                photoId
+        );
+        adapter.saveStudent(student);
+    }
+
+    private void randomizePhoto() {
+        int[] imgMale = {R.drawable.male_1, R.drawable.male_2, R.drawable.male_3};
+        int[] imgFemale = {R.drawable.female_1, R.drawable.female_2, R.drawable.female_3};
+
+        int i;
+        switch (radioGroup.getCheckedRadioButtonId()) {
+            case R.id.activity_main__radio_male:
+                i = new Random().nextInt(3);
+                photo.setImageDrawable(getResources().getDrawable(imgMale[i]));
+                photoId = imgMale[i];
+                break;
+            case R.id.activity_main__radio_woman:
+                i = new Random().nextInt(3);
+                photo.setImageDrawable(getResources().getDrawable(imgFemale[i]));
+                photoId = imgFemale[i];
+                break;
+            default:
+                photoId = imgMale[0];
+                break;
+        }
+    }
+
+    public void clearFields() {
+        photo.setImageDrawable(null);
+        firstName.setText("");
+        lastName.setText("");
+        radioGroup.clearCheck();
+    }
+
+    public void setActiveStudent(Student student) {
+        photo.setImageDrawable(getResources().getDrawable(student.getPhoto()));
+        firstName.setText(student.getFirstName());
+        lastName.setText(student.getSecondName());
+        if (student.isMale()){
+            radioGroup.check(R.id.activity_main__radio_male);
+        } else {
+            radioGroup.check(R.id.activity_main__radio_woman);
+        }
     }
 
 }

app/src/main/java/ru/ok/technopolis/students/Student.java

@@ -4,13 +4,13 @@ public class Student {
 
     private String firstName;
     private String secondName;
-    private boolean maleGender;
+    private boolean isMale;
     private int photo;
 
     public Student(String firstName, String secondName, boolean maleGender, int photo) {
         this.firstName = firstName;
         this.secondName = secondName;
-        this.maleGender = maleGender;
+        this.isMale = maleGender;
         this.photo = photo;
     }
 
@@ -30,12 +30,12 @@ public void setSecondName(String secondName) {
         this.secondName = secondName;
     }
 
-    public boolean isMaleGender() {
-        return maleGender;
+    public boolean isMale() {
+        return isMale;
     }
 
-    public void setMaleGender(boolean maleGender) {
-        this.maleGender = maleGender;
+    public void setMale(boolean male) {
+        this.isMale = male;
     }
 
     public int getPhoto() {
@@ -45,4 +45,11 @@ public int getPhoto() {
     public void setPhoto(int photo) {
         this.photo = photo;
     }
+
+    public void copy(Student student) {
+        this.firstName = student.firstName;
+        this.secondName = student.secondName;
+        this.isMale = student.isMale;
+        this.photo = student.photo;
+    }
 }

app/src/main/java/ru/ok/technopolis/students/StudentAdapter.java

@@ -0,0 +1,99 @@
+package ru.ok.technopolis.students;
+
+import android.content.Context;
+import android.support.annotation.NonNull;
+import android.support.v7.widget.RecyclerView;
+import android.text.Layout;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ImageView;
+import android.widget.TextView;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+
+public class StudentAdapter extends RecyclerView.Adapter<StudentAdapter.StudentViewHolder> {
+
+    public static final int NO_STUDENT = -1;
+    private MainActivity context;
+    private List<Student> students = new LinkedList<>();
+    private int activeStudent = NO_STUDENT;
+
+    public StudentAdapter(Context context) {
+        this.context = (MainActivity) context;
+    }
+
+    public void saveStudent(Student student) {
+        if (activeStudent == NO_STUDENT) {
+            students.add(student);
+            activeStudent = students.size() - 1;
+            notifyItemInserted(activeStudent);
+        } else {
+            Student oldStudent = students.get(activeStudent);
+            oldStudent.copy(student);
+            notifyItemChanged(activeStudent);
+        }
+    }
+
+    public void deleteStudent() {
+        if (activeStudent != NO_STUDENT) {
+            students.remove(activeStudent);
+            notifyItemRemoved(activeStudent);
+            activeStudent = NO_STUDENT;
+        }
+        context.clearFields();
+    }
+
+    public void setActiveStudent(int activeStudent) {
+        this.activeStudent = activeStudent;
+    }
+
+    @NonNull
+    @Override
+    public StudentViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
+        View view = LayoutInflater
+                .from(viewGroup.getContext())
+                .inflate(R.layout.recycler_item, viewGroup, false);
+        return new StudentViewHolder(view);
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull StudentViewHolder studentViewHolder, int i) {
+        studentViewHolder.bind(students.get(i));
+    }
+
+
+    @Override
+    public int getItemCount() {
+        return students.size();
+    }
+
+    public class StudentViewHolder extends RecyclerView.ViewHolder {
+
+        private ImageView face;
+        private TextView fullName;
+
+        public StudentViewHolder(@NonNull View itemView) {
+            super(itemView);
+            face = itemView.findViewById(R.id.recycler_item__image);
+            fullName = itemView.findViewById(R.id.recycler_item__text);
+
+            itemView.setOnClickListener(new View.OnClickListener() {
+                @Override
+                public void onClick(View v) {
+                    activeStudent = getAdapterPosition();
+
+                    Student student = students.get(getAdapterPosition());
+                    context.setActiveStudent(student);
+                }
+            });
+        }
+
+        private void bind(Student student) {
+            face.setImageDrawable(context.getResources().getDrawable(student.getPhoto()));
+            fullName.setText(student.getFirstName() + " " + student.getSecondName());
+        }
+    }
+}

app/src/main/java/ru/ok/technopolis/students/StudentHolder.java

@@ -0,0 +1,13 @@
+package ru.ok.technopolis.students;
+
+import android.support.annotation.NonNull;
+import android.support.v7.widget.RecyclerView;
+import android.view.View;
+
+public class StudentHolder extends RecyclerView.ViewHolder {
+
+    public StudentHolder(@NonNull View itemView) {
+        super(itemView);
+    }
+
+}