snailmail/app/src/main/java/com/noahvogt/miniprojekt/MainActivity.java

package com.noahvogt.miniprojekt;

import android.os.Bundle;
import android.view.View;
import android.view.Menu;
import android.webkit.WebHistoryItem;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;
import com.google.android.material.navigation.NavigationView;

import androidx.appcompat.app.AlertDialog;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.AppBarConfiguration;
import androidx.navigation.ui.NavigationUI;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

public class MainActivity extends AppCompatActivity {

    private AppBarConfiguration mAppBarConfiguration;

    private AlertDialog.Builder dialogBuilder;
    private AlertDialog dialog;
    private EditText newemail_name, newemail_email, newemail_password;
    private Button newemail_save_button, newemail_cancel_button;

    public MainActivity() {
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        /*FloatingActionButton fab = findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });*/
        DrawerLayout drawer = findViewById(R.id.drawer_layout);
        NavigationView navigationView = findViewById(R.id.nav_view);
        // Passing each menu ID as a set of Ids because each
        // menu should be considered as top level destinations.
        mAppBarConfiguration = new AppBarConfiguration.Builder(
                R.id.nav_home, R.id.nav_gallery, R.id.nav_slideshow)
                .setDrawerLayout(drawer)
                .build();
        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
        NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
        NavigationUI.setupWithNavController(navigationView, navController);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onSupportNavigateUp() {
        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
        return NavigationUI.navigateUp(navController, mAppBarConfiguration)
                || super.onSupportNavigateUp();
    }

    public void onClick(View view) {
        // change inbox text (WARNING: throws error whenever drafts oder sent is active instead of inbox)
        //TextView text = (TextView) findViewById(R.id.text_home);
        //text.setText("Mail has been SuCceSsFuLlY aDdEd");

        // display snackbar message
        Snackbar.make(view, "Mail has been SuCceSsFuLlY aDdEd", Snackbar.LENGTH_LONG)
                .setAction("Action", null).show();
        createNewEmailDialog();
    }


    public void createNewEmailDialog(){
        dialogBuilder = new AlertDialog.Builder(this);
        final View emailPopupView = getLayoutInflater().inflate(R.layout.popup, null);
        newemail_name = (EditText) emailPopupView.findViewById(R.id.newemailpopup_name);
        newemail_email = (EditText) emailPopupView.findViewById(R.id.newemailpopup_email);
        newemail_password = (EditText) emailPopupView.findViewById(R.id.newemailpopup_password);

        newemail_save_button = (Button) emailPopupView.findViewById(R.id.saveButton);
        newemail_cancel_button = (Button) emailPopupView.findViewById(R.id.cancelButton);

        dialogBuilder.setView(emailPopupView);
        dialog = dialogBuilder.create();
        dialog.show();

        newemail_save_button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // define save button here
            }
        });

        newemail_cancel_button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // define save button here
                dialog.dismiss();
            }
        });

    }
}