ListView Studenten FULL
menu.xml
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:id="@+id/menu_new_item"
        android:icon="@android:drawable/ic_menu_add"
        android:title="New"
        />

    <item android:id="@+id/menu_delete_modusan"
        android:icon="@android:drawable/ic_menu_delete"
        android:title="Löschmodus an" />

    <item android:id="@+id/menu_delete_modusaus"
        android:icon="@android:drawable/ic_menu_delete"

        android:title="Löschmodus beenden" />

    <item android:id="@+id/menu_delete_items"
        android:icon="@android:drawable/ic_menu_delete"
        android:title="Löschen" />

    <item android:id="@+id/menu_insert_new_items"
        android:icon="@android:drawable/ic_menu_edit"

        android:title="Einfügen neuer Einträge" />
</menu>

1)	anlegen eines Ordners „menu“
2)	file	new	XML	Layout-XML-File


String.xml
<resources>
    <string name="app_name">ListView_Studenten</string>
    <string name="hint">Status-Grafik</string>

    <string name="sem1">1. Semester</string>
    <string name="sem2">2. Semester</string>
    <string name="sem3">3. Semester</string>
    <string name="sem4">4. Semester</string>
    <string name="sem5">5. Semester</string>
    <string name="sem6">6. Semester</string>
    <string name="bachelor">Bachelorarbeit</string>
    <string name="new_student">Neuer Eintrag</string>
    <string name="edit_delete_student">Bearbeiten oder Löschen eines Eintrags</string>

    <string name="name_student">Name</string>
    <string name="matrnr_student">Matrnr</string>
    <string name="semester_student">Semester</string>
    <string name="note_student">Note</string>

    <string name="mn_delete">Löschen</string>
    <string name="mn_new">Neu</string>

    <string name="bn_delete">Löschen</string>
    <string name="bn_new">Neu</string>
    <string name="bn_savechanges">Speichern</string>
    <string name="bn_cancel">Abbrechen</string>

    <string-array name="semester_arrays">
        <item>1. Semester</item>
        <item>2. Semester</item>
        <item>3. Semester</item>
        <item>4. Semester</item>
        <item>5. Semester</item>
        <item>6. Semester</item>
        <item>Bachelorarbeit</item>
    </string-array>
</resources>




Color.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#3F51B5</color>
    <color name="colorPrimaryDark">#303F9F</color>
    <color name="colorAccent">#FF4081</color>
    <color name="colorCaption">#0000FF</color>
    <color name="colorError">#FF0000</color>
</resources>
activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ListView
        android:id="@+id/listview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"

        />

</RelativeLayout>



rowlayout.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/icon"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginRight="6dp"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"

        />
    <TextView
        android:id="@+id/tv_name"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:layout_marginTop="4dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="---"
        android:layout_toEndOf="@id/icon"
        />

    <TextView
        android:id="@+id/tv_matrnr"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="xxx"
        android:layout_below="@id/tv_name"
        android:layout_alignStart="@id/tv_name"
        />
    <TextView
        android:id="@+id/tv_note"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="1,0"
        android:layout_below="@id/tv_matrnr"
        android:layout_alignStart="@id/tv_name"
        />

    <TextView
        android:id="@+id/tv_select"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="xxx"
        android:layout_alignBaseline="@id/tv_matrnr"
        android:layout_alignParentRight="true"
        />
</RelativeLayout>



Activity_Edit_delete_new.xml

New	Activity	EmptyActivity

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/tv_caption"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/edit_delete_student"
        android:textSize="22dp"
        android:textColor="@color/colorCaption"
        />

    <TextView
        android:id="@+id/tv_stdname"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/name_student"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="50dp"
        android:layout_marginBottom="40dp"
        android:layout_below="@id/tv_caption"
        />

    <EditText
        android:id="@+id/ed_stdname"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:lines="1"
        android:text=""
        android:layout_marginRight="10dp"
        android:layout_toRightOf="@id/tv_stdname"
        android:layout_alignBaseline="@id/tv_stdname"
        />




    <TextView
        android:id="@+id/tv_stdmatrnr"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/matrnr_student"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="50dp"
        android:layout_marginBottom="40dp"
        android:layout_below="@id/tv_stdname"
        />
    <EditText
        android:id="@+id/ed_stdmatrnr"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:lines="1"
        android:text=""
        android:layout_marginRight="10dp"
        android:layout_toRightOf="@id/tv_stdmatrnr"
        android:layout_alignBaseline="@id/tv_stdmatrnr"
        android:layout_alignLeft="@id/ed_stdname"
        />


    <TextView
        android:id="@+id/tv_stdsem"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/semester_student"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="50dp"
        android:layout_marginBottom="40dp"
        android:layout_below="@id/tv_stdmatrnr"
        />

    <Spinner
        android:id="@+id/sp_semester"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:spinnerMode="dialog"
        android:prompt="@string/semester_student"
        android:entries="@array/semester_arrays"

        android:layout_marginRight="10dp"
        android:layout_toRightOf="@id/tv_stdsem"
        android:layout_alignBaseline="@id/tv_stdsem"
        android:layout_alignLeft="@id/ed_stdmatrnr"
        />



    <TextView
        android:id="@+id/tv_stdnote"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/note_student"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="50dp"
        android:layout_marginBottom="40dp"
        android:layout_below="@id/tv_stdsem"
        />
    <Spinner
        android:id="@+id/sp_noten"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:spinnerMode="dropdown"
        android:prompt="@string/note_student"
        android:layout_marginRight="10dp"
        android:layout_toRightOf="@id/tv_stdnote"
        android:layout_alignTop="@id/tv_stdnote"
        android:layout_alignLeft="@id/ed_stdmatrnr"
        />


    <TextView
        android:id="@+id/tv_stdselect"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Select"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="50dp"
        android:layout_marginBottom="40dp"
        android:layout_below="@id/tv_stdnote"
        />
    <EditText
        android:id="@+id/ed_stdselect"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:lines="1"
        android:text=""
        android:layout_marginRight="10dp"
        android:layout_toRightOf="@id/tv_stdselect"
        android:layout_alignBaseline="@id/tv_stdselect"
        android:layout_alignLeft="@id/ed_stdname"
        />

    <Button
        android:id="@+id/bnCancel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/bn_cancel"
        android:layout_below="@id/tv_stdselect"
        android:layout_marginTop="20dp"
        android:layout_marginRight="10dp"
        android:layout_alignParentRight="true"
        android:onClick="bnCancel_click"
        />

    <Button
        android:id="@+id/bnDelete"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/bn_delete"
        android:layout_toLeftOf="@id/bnCancel"
        android:layout_marginTop="20dp"
        android:layout_alignBaseline="@id/bnCancel"
        android:layout_marginRight="10dp"
        android:onClick="bnDelete_click"
        />

    <Button
        android:id="@+id/bnSaveChanges"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/bn_savechanges"
        android:layout_toLeftOf="@id/bnDelete"
        android:layout_marginTop="20dp"
        android:layout_alignBaseline="@id/bnCancel"
        android:layout_marginRight="10dp"
        android:onClick="bnSaveChanges_click"
        />
</RelativeLayout>


onclick



package com.example.kraft_300.testlistview_studenten;

import android.app.*;
import android.content.Intent;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.*;
import android.widget.*;

import java.text.DecimalFormat;


// oberer Balken mit  AppCompatActivity   !!!!!!!!!!
import android.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import java.util.*;

import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.*;
import android.util.Log;
import android.content.*;
import android.net.Uri;
import android.app.Activity;

// mit AppCompatActivity statt Activity
// hat man eine breitere Kopfzeile inkl. Menü 3 punkte !
public class MainActivity extends AppCompatActivity
        implements AdapterView.OnItemClickListener{
    // ,  AdapterView.OnItemLongClickListener

    private static final String TAG =  MainActivity.class.getSimpleName();

    private ListView listView = null;
    private StudentenAdapter adapter = null;

         // hier fehlt Code


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        listView = (ListView) findViewById(R.id.listview);

        Studentenliste.getInstance().loadInput(this,Const.FILENAME);

        adapter = new StudentenAdapter(this);
        listView.setAdapter(adapter);

        Studentenliste.getInstance().saveInput(this,Const.FILENAME);

        listView.setOnItemClickListener(this);
        Log.i(TAG, "*********************************  onCreate"); // import android.util.Log;
    }

    @Override
    protected void onStart() {
        super.onStart();
        ActionBar bar = getActionBar();
        if (bar!=null) {
            bar.setDisplayHomeAsUpEnabled(true);
        }
    }

    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        super.onPrepareOptionsMenu(menu);
         // hier fehlt Code
        return true;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.menu, menu);
        boolean res = super.onCreateOptionsMenu(menu);
         // hier fehlt Code
        return res;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        //noinspection SimplifiableIfStatement
        if (id == R.id.menu_new_item) {
            //Toast.makeText(this, "new angeklickt: "+item.getItemId(),  Toast.LENGTH_SHORT).show();
            Intent intent = new Intent(this,
                    activity_edit_delete_new.class);
            //viewIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            // startActivityForResult(viewIntent);
            intent.putExtra("ACTION",
                    activity_edit_delete_new.ACTION_NEW);  // Hash value
            startActivityForResult(intent,1);
            return true;
        }
         // hier fehlt Code
        return true;

    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        // hole aktuellen Student
        Student std = (Student) adapter.getItem(position);
        int i=3;
        switch (i) {
            case 1:
                Toast.makeText(MainActivity.this,
                        Integer.toString(position), Toast.LENGTH_LONG).show();
                break;
            case 2:
                showURL(std);
                break;
            case 3:
	         // hier fehlt Code

        }
        //return true;
    }

    private void showEditDeleteNew(Student std, int position) {
        //Anzeige des neuen View EditDeleteNew
        Intent viewintent = new Intent(this,activity_edit_delete_new.class);
        // die neuen Activity soll beim Ende zurückspringen
        // callBack-Methode
        viewintent.putExtra("ACTION",activity_edit_delete_new.ACTION_EDIT_DELETE);
        viewintent.putExtra(Student.STDNAME,std.name); // STDNAME ist hashkey
        viewintent.putExtra(Student.STDMATRNR,Integer.toString(std.matrnr));
        viewintent.putExtra(Student.STDSEMESTER,Integer.toString(std.semester));
        viewintent.putExtra(Student.STDNOTE,Double.toString(std.note));
        viewintent.putExtra(Student.STDINDEX,Integer.toString(position));
        if (std.select)
            viewintent.putExtra(Student.STDSELECT,"ja");
        else
            viewintent.putExtra(Student.STDSELECT,"nein");
        startActivityForResult(viewintent,1);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == 1) {
            // import android.app.Activity;
            if(resultCode == Activity.RESULT_OK){
                // neu laden
                Studentenliste.getInstance().saveInput(
                        this,Const.FILENAME);
                adapter.notifyDataSetChanged();
                Toast.makeText(this, "save gedrückt: ",Toast.LENGTH_LONG).show();
            }
            if (resultCode == Activity.RESULT_CANCELED) {
                //Write your code if there's no result
            }
        }
    }//onActivityResult

    private void showURL(Student std) {
        String url = "http://www.miwilhelm.de/"+std.semester+"/";
        // nun eine Webseite anzeigen
        Intent viewintent =
                new Intent("android.intent.action.VIEW", Uri.parse(url));
        startActivity(viewintent);
    }
}



public class Const {
    public static String FILENAME = "studenten.bin";
}





package com.example.vorllistview2;

import android.content.Context;
import android.util.Log;

import java.io.*;

public class Student {
    private static final String TAG =  MainActivity.class.getSimpleName();

    public static final String STDNAME = "STDNAME";
    public static final String STDMATRNR = "STDMATRNR";
    public static final String STDSEMESTER = "STDSEMESTER";
    public static final String STDNOTE = "STDNOTE";
    public static final String STDINDEX = "STDINDEX";
    public static final String STDSELECT = "STDSELECT";

    public String name="-";
    public int matrnr = 1;
    public int semester = 1;
    public double note=1.0;
    public boolean select=false;

    public Student() {

    }

    public Student(String name, int matrnr, int semester, double note) {
        this.name=name;
        this.matrnr = matrnr;
        this.semester=semester;
        this.note = note;
    }

    public void init(Student std) {
        this.name=std.name;
        this.matrnr = std.matrnr;
        this.semester=std.semester;
        this.note = std.note;
    }

    // localization
    public String getName(Context context) {
        switch (semester) {
            case 1:
                return context.getString(R.string.sem1);
            case 2:
                return context.getString(R.string.sem2);
            case 3:
                return context.getString(R.string.sem3);
            case 4:
                return context.getString(R.string.sem4);
            case 5:
                return context.getString(R.string.sem5);
            case 6:
                return context.getString(R.string.sem6);
            case 7:
                return context.getString(R.string.bachelor);
            default:
                return context.getString(R.string.sem1);
        }

    }

    public int getIdForDrawable() {
        switch (semester) {
            case 1:
                return R.drawable.sem1;
            case 2:
                return R.drawable.sem2;
            case 3:
                return R.drawable.sem3;
            case 4:
                return R.drawable.sem4;
            case 5:
                return R.drawable.sem5;
            case 6:
                return R.drawable.sem6;
            case 7:
                return R.drawable.bachelor;
            default:
                return R.drawable.sem1;
        }
    }  // getIdForDrawable


    public void write2File(DataOutputStream dout) {
        try {
            dout.writeUTF(name); // Erst die Anzahl, dann die Zeichen
            dout.writeInt(matrnr);
            dout.writeDouble(note);
            dout.writeInt(semester);
        }
        catch (IOException e) {
            Log.e(TAG,"************* write2File error",e);
            // oder ein Toast!
        }
    }

    public void loadfromFile(DataInputStream din) {
        try {
            name=din.readUTF(); // Erst die Anzahl, dann die Zeichen
            matrnr=din.readInt();
            note=din.readDouble();
            semester=din.readInt();
        }
        catch (IOException e) {
            Log.e(TAG,"************* loadFromFile error",e);
        }
    }

}



import android.content.Context;
import android.util.Log;

import java.io.*;
import java.util.*;

public class Studentenliste {
    private static final String TAG =  MainActivity.class.getSimpleName();



    public ArrayList<Student> liste = new ArrayList<Student>();

    // Design Pattern Singleton
    private static Studentenliste instance = new Studentenliste();

    public static Studentenliste getInstance() {
        return instance;
    }

    private Studentenliste() {
        boolean ok=false;
        if (ok) {
            insertStudenten();
        }
        else {

        }
    }

    private boolean FileExits(Context context, String filename) {
        try {
            FileInputStream fin = context.openFileInput(filename);
            fin.close();
            return true;
        }
        catch (IOException e){
            return false;
        }
    }

    public void loadInput(Context context, String filename) {
        try {
            if (FileExits(context, filename)) {
                FileInputStream fin = context.openFileInput(filename);
                DataInputStream din = new DataInputStream(fin);
                int n = din.readInt(); // Anzahl der Studenten in der Datei
                liste.clear();
                for (int i=0; i<n; i++) {
                    Student std = new Student();
                    std.loadfromFile(din);
                    liste.add(std);
                }
                din.close();
                fin.close();
            }
        }
        catch (IOException e){
        }
    }




    public void deleteSelectedStudent() {
        for (int i=liste.size()-1; i>=0; i--) {
            if (liste.get(i).select) {
                liste.remove(i);
            }
        }
    }
    public void createnewItems() {
        insertStudenten();
    }

    private void insertStudenten() {
        liste.clear();
        liste.add(new Student("Meier, Anton", 12345, 7, 1.3));
        liste.add(new Student("Schulze, Susanne", 12365, 6, 1.7));
        liste.add(new Student("Brandt, Hugo", 22345, 6, 2.7));
        liste.add(new Student("Binder, Gabi", 22365, 6, 4.0));
        liste.add(new Student("Märtens, Friedrich", 22845, 5, 3.0));
        liste.add(new Student("Müller, Andreas", 22349, 5, 1.0));
        liste.add(new Student("Baumann, Herbert", 20445, 4, 2.0));
        liste.add(new Student("Künneth, Thomas", 324455, 4, 3.7));
        liste.add(new Student("Unbereit, Peter", 324355, 4, 3.3));
        liste.add(new Student("Meyer, Hubert ", 324355, 3, 2.3));
        liste.add(new Student("Altmeier, Jutta", 324355, 3, 5.0));
        liste.add(new Student("Gisin, Nicoletta", 33445, 2, 2.7));
        liste.add(new Student("Telemann, Dieter", 34645, 2, 4.0));
        liste.add(new Student("Wagner, Hans", 38345, 2, 1.7));
        liste.add(new Student("Wolff, Bernd", 39345, 1, 3.7));
        liste.add(new Student("Prandtl, Daria", 40345, 1, 3.0));
        liste.add(new Student("Burton, Michael", 41445, 1, 2.3));
        liste.add(new Student("Fehr, Hauke", 42445, 1, 1.7));
        liste.add(new Student("Klenke, Mario", 44445, 1, 5.0));
    }



    public void saveInput(Context context, String filename) {
        try {
            FileOutputStream fout = context.openFileOutput(filename, Context.MODE_PRIVATE);
            DataOutputStream dout = new DataOutputStream(fout);
            dout.writeInt(liste.size());
            for (Student std : liste) {
                std.write2File(dout);
            }
            fout.close();
        }
        catch (IOException e){
        }
    }

    public void changeStudent(Student stdnew, int index) {
        if (index>=0 && index<liste.size()) {
            Student std = liste.get(index);
            std.init(stdnew);
        }
        else {

            Log.i(TAG, "Modul Studentenliste, changeStudent,"+
                    " falscher Index: "+index);
        }
    }

    public void newStudent(Student stdnew) {
        liste.add(stdnew);
    }

    public void deleteStudent(int index) {
        if (index>=0 && index<liste.size()) {
            liste.remove(index);
        }
        else {

            Log.i(TAG, "Modul Studentenliste, deleteStudent,"+
                    " falscher Index: "+index);
        }
    }


}


import android.content.Context;
import android.util.Log;
import android.widget.*;
import android.view.*;

import java.io.*;
import java.util.*;

public class StudentenAdapter extends BaseAdapter{
    private static final String TAG =  MainActivity.class.getSimpleName();

    private ArrayList<Student> liste = null;
    private final LayoutInflater inflator;

    public StudentenAdapter(Context context) {
        inflator = LayoutInflater.from(context);
        liste = Studentenliste.getInstance().liste;
        //Studentenliste.getInstance().saveInput(context,Const.FILENAME);
    }


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

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

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

    class ViewHolder {
        public ImageView icon;
        public TextView name;
        public TextView matrnr;
        public TextView note;
        public TextView select;
    }

    @Override



    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        // ist Zelle schon im Speicher
        if (convertView==null) {
            // Aufbau einen kleines Miniview für die zelle
            convertView = inflator.inflate(R.layout.rowlayout, parent, false);
            holder = new ViewHolder();
            holder.icon = (ImageView) convertView.findViewById(R.id.icon);
            holder.name = (TextView) convertView.findViewById(R.id.tv_name);
            holder.matrnr = (TextView) convertView.findViewById(R.id.tv_matrnr);
            holder.note = (TextView) convertView.findViewById(R.id.tv_note);
            holder.select = (TextView) convertView.findViewById(R.id.tv_select);
            convertView.setTag(holder);
        }
        else {
            holder = (ViewHolder) convertView.getTag();
        }
        // Füllen mit den aktuellen Werten
        Context context = parent.getContext();
        Student std = (Student) getItem(position);
        holder.icon.setImageResource(std.getIdForDrawable());
        holder.name.setText(std.name);
        holder.matrnr.setText(Integer.toString(std.matrnr));
        holder.note.setText(Double.toString(std.note)); // decimalformat
        if (std.select)
            holder.select.setText("x  ");
        else
            holder.select.setText("");
        //position = (++position) % getCount();
        return convertView;
    }
}


import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.content.*;
import android.widget.*;


import java.io.Console;
import java.text.DecimalFormat;
import java.util.*;
import java.util.regex.Pattern;
import android.text.*;  // onChangeEvent
import android.view.*;
import android.util.Log;
import android.app.Activity;



public class activity_edit_delete_new extends AppCompatActivity {
    private static final String TAG =  MainActivity.class.getSimpleName();


    public static final String ACTION_EDIT_DELETE="1";
    public static final String ACTION_EDIT="2";
    public static final String ACTION_DELETE="3";
    public static final String ACTION_NEW="4";

    public String action =  ACTION_EDIT_DELETE;

    private TextView tvCaption = null;
    private EditText edName=null;
    private EditText edMatrnr=null;
    private Spinner  spSemester = null;
    private Spinner  spNote = null;
    private EditText edSelect=null;

    private Button   bnSaveChanges = null;
    private Button   bnDelete = null;
    private Button   bnCancel = null;



    // onChangeEvent

    private Pattern namePattern =
   Pattern.compile("^([A-ZÜÄÖ][a-züäöß]{1,29})[,][ ]([A-ZÜÄÖ][a-züäöß]{1,29})$");
    private Pattern matrnrPattern =
      Pattern.compile("^[1-9][0-9]{4}$");

    private boolean isNameOk=false;
    private boolean isMatnrOk=false;

    private TextView tvValidStdname = null;
    private TextView validMatrnr = null;

    private int stdindex=0;

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

        tvCaption = (TextView) findViewById(R.id.tv_caption);
        edName = (EditText) findViewById(R.id.ed_stdname);
        edMatrnr = (EditText) findViewById(R.id.ed_stdmatrnr);
        spSemester = (Spinner) findViewById(R.id.sp_semester);
        spNote = (Spinner) findViewById(R.id.sp_noten);
        edSelect = (EditText) findViewById(R.id.ed_stdselect);

        bnSaveChanges = (Button) findViewById(R.id.bnSaveChanges);
        bnDelete = (Button) findViewById(R.id.bnDelete);
        bnCancel = (Button) findViewById(R.id.bnCancel);

        Intent intent = getIntent();

        List<String> list = new ArrayList<String>();
        list.add("1.0");
        list.add("1.3");
        list.add("1.7");
        list.add("2.0");
        list.add("2.3");
        list.add("2.7");
        list.add("3.0");
        list.add("3.3");
        list.add("3.7");
        list.add("4.0");
        list.add("5.0");
        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, list);

        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spNote.setAdapter(dataAdapter);

        // Abfrage auf Edit,Delete ODER New
        action = intent.getStringExtra("ACTION");
        if (action.equals(ACTION_EDIT_DELETE)) {
            tvCaption.setText( getString(R.string.edit_delete_student)  );
            edName.setText(intent.getStringExtra(Student.STDNAME));
            edMatrnr.setText(intent.getStringExtra(Student.STDMATRNR));

            edSelect.setText(intent.getStringExtra(Student.STDSELECT));

            // setzen des Semesters
            String dummy = intent.getStringExtra(Student.STDSEMESTER);
            int semesterIndex = 0;
            try {
                semesterIndex = Integer.parseInt(dummy) - 1;
            } catch (NumberFormatException e) {
                Toast.makeText(this,
                        "NumberFormatException: semesterIndex: "+dummy,
                        Toast.LENGTH_SHORT).show();
                semesterIndex = 0;
            }
            spSemester.setSelection(semesterIndex);

            // Note sendet

            dummy = intent.getStringExtra(Student.STDNOTE);  // 1.0  1.3  1.7
            int indexNote = 0;
            switch (dummy) {
                case "1.0":
                    indexNote = 0;
                    break;
                case "1.3":
                    indexNote = 1;
                    break;
                case "1.7":
                    indexNote = 2;
                    break;
                case "2.0":
                    indexNote = 3;
                    break;
                case "2.3":
                    indexNote = 4;
                    break;
                case "2.7":
                    indexNote = 5;
                    break;
                case "3.0":
                    indexNote = 6;
                    break;
                case "3.3":
                    indexNote = 7;
                    break;
                case "3.7":
                    indexNote = 8;
                    break;
                case "4.0":
                    indexNote = 9;
                    break;
                case "5.0":
                    indexNote = 10;
                    break;
            }
            spNote.setSelection(indexNote);
            this.isNameOk=true;
            this.isMatnrOk=true;

            dummy = intent.getStringExtra(Student.STDINDEX);
            stdindex = -1;
            try {
                stdindex = Integer.parseInt(dummy);
            } catch (NumberFormatException e) {
                Toast.makeText(this,
                        "NumberFormatException: stdindex: "+dummy,
                        Toast.LENGTH_SHORT).show();
                stdindex = -1;
            }

        }
        else {
            // new Student
            //stdindex = -1;
            tvCaption.setText( getString(R.string.new_student)  );
            // View.INVISIBLE   View.VISIBLE   View.GONE
            bnDelete.setVisibility(View.GONE);  // import android.view.*;
            bnSaveChanges.setText( getString(R.string.bn_new));
            spSemester.setSelection(0);
            spNote.setSelection(0);
            this.isNameOk=false;
            this.isMatnrOk=false;
        }  // if (action.equals(ACTION_EDIT_DELETE)) {
        setActionListeners();

    }  // create

    // onChangeEvent für Name´und Matrnr
    // wenn falsch, disabled saveButton
    private void setActionListeners() {
        edName.addTextChangedListener(new TextWatcher() {
            private boolean isValid(CharSequence s) {
                return namePattern.matcher(s).matches();
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            }

            @Override
            public void afterTextChanged(Editable s) {
                if (isValid(s))  {
                    //tvValidStdname.setText("");
                    isNameOk = true;
                }
                else {
                    //tvValidStdname.setText("*");
                    isNameOk=false;
                }

                Log.e("*********************isNameOk",
                        Boolean.toString(isNameOk));

                setEnabledbnOk();
            }
        });


        edMatrnr.addTextChangedListener(new TextWatcher() {

            private boolean isValid(CharSequence s) {
                return matrnrPattern.matcher(s).matches();
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            }

            @Override
            public void afterTextChanged(Editable s) {
                if (isValid(s))  {
                    //validMatrnr.setText("");
                    isMatnrOk = true;
                }
                else {
                    //validMatrnr.setText("*");
                    isMatnrOk = true;
                }
                setEnabledbnOk();
            }
        });
    }


    private void setEnabledbnOk() {
        bnSaveChanges.setEnabled(this.isNameOk && this.isMatnrOk);
    }

    private Student checkInputs() {
        String dummy;
        String name;
        int matrnr;
        int semester;
        double note=1.0;
        name = edName.getText().toString();
        try {
            matrnr = Integer.parseInt(edMatrnr.getText().toString());
        }
        catch (NumberFormatException e) {
            Toast.makeText(this, "wrong matrikelnumber",  Toast.LENGTH_SHORT).show();
            return null;
        }
        semester = ((int) spSemester.getSelectedItemPosition())+1;
        int indexNote = (int) spNote.getSelectedItemPosition();

        switch (indexNote) {
            case 0:
                note =1.0;
                break;
            case 1:
                note =1.3;
                break;
            case 2:
                note =1.7;
                break;
            case 3:
                note =2.0;
                break;
            case 4:
                note =2.3;
                break;
            case 5:
                note =2.7;
                break;
            case 6:
                note =3.0;
                break;
            case 7:
                note =3.3;
                break;
            case 8:
                note =3.7;
                break;
            case 9:
                note =4.0;
                break;
            case 10:
                note =5.0;
                break;
            default:
                note =5.0;
                break;
        }
        Student std = new Student();
        std.name=name;
        std.matrnr=matrnr;
        std.semester=semester;
        std.note=note;
        return std;
    }  // CheckInputs




    public void bnSaveChanges_click(View view) {
        if (action.equals(ACTION_EDIT_DELETE)) {
            Student std = checkInputs();
            if (std == null) {
                // es gab einen Fehler bei der Eingabe
                Toast.makeText(this,
                        "Fehler beim Check",
                        Toast.LENGTH_SHORT).show();
                return;
            }
            Toast.makeText(this,
              "stdindex: "+stdindex,Toast.LENGTH_SHORT).show();
            Studentenliste stdliste = Studentenliste.getInstance();
            stdliste.changeStudent(std, stdindex);
        }
        else {

            Student std = checkInputs();
            if (std == null) {
                Toast.makeText(this,
                        "Fehler beim Check",
                        Toast.LENGTH_SHORT).show();
                return;
            }
            Studentenliste stdliste = Studentenliste.getInstance();
            stdliste.newStudent(std);

        }
        Intent returnIntent = new Intent();
        returnIntent.putExtra("result", "1111");
        setResult(Activity.RESULT_OK, returnIntent);
        finish();
    }

    public void bnCancel_click(View view) {
        Intent returnIntent = new Intent();
        // import android.app.Activity;
        setResult(Activity.RESULT_CANCELED, returnIntent);
        finish();
    }

    public void bnDelete_click(View view) {
        Studentenliste stdliste = Studentenliste.getInstance();
        stdliste.deleteStudent(stdindex);

        Intent returnIntent = new Intent();
        returnIntent.putExtra("result", "2222");
        setResult(Activity.RESULT_OK, returnIntent);
        finish();
    }
}

23