Smarthome App #2: Login-Bildschirm

<?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:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="de.smarthome_blogger.smarthome.LoginActivity"
android:background="@color/layoutBackground"
android:id="@+id/frame">
 
	<android.support.v7.widget.CardView
	android:layout_width="match_parent"
	android:layout_height="wrap_content"
	android:layout_centerVertical="true"
	android:layout_margin="15dp"
	app:cardElevation="@dimen/cardViewElevation"
	app:cardCornerRadius="@dimen/cardViewCornerRadius"
	app:cardUseCompatPadding="true">
 
		<LinearLayout
		android:layout_width="match_parent"
		android:layout_height="wrap_content"
		android:orientation="vertical"
		android:padding="5dp">
		
			<ImageView
			android:layout_width="match_parent"
			android:layout_height="120dp"
			android:id="@+id/app_logo"
			android:layout_margin="10dp"
			android:src="@mipmap/ic_launcher"/>
			
			<EditText
			android:layout_width="match_parent"
			android:layout_height="wrap_content"
			android:inputType="textPersonName"
			android:hint="Nutzername"
			android:layout_marginBottom="5dp"
			android:id="@+id/username"/>
			
			<EditText
			android:layout_width="match_parent"
			android:layout_height="wrap_content"
			android:inputType="textPassword"
			android:hint="Passwort"
			android:layout_marginBottom="5dp"
			android:id="@+id/password"/>
			
			<EditText
			android:layout_width="match_parent"
			android:layout_height="wrap_content"
			android:inputType="textUri"
			android:hint="Server-IP"
			android:layout_marginBottom="5dp"
			android:id="@+id/server_ip"/>
			
			<CheckBox
			android:layout_width="match_parent"
			android:layout_height="wrap_content"
			android:text="Login-Daten speichern"
			android:id="@+id/save_login"
			android:gravity="center_horizontal|center_vertical"
			android:layout_marginBottom="5dp"
			android:checked="false"/>
			
			<RelativeLayout
			android:layout_width="match_parent"
			android:layout_height="wrap_content">
			
				<Button
				android:layout_width="wrap_content"
				android:layout_height="wrap_content"
				style="@style/Widget.AppCompat.Button.Colored"
				android:background="@color/colorPrimary"
				android:textColor="@color/textColorLight"
				android:text="Login"
				android:layout_alignParentRight="true"
				android:id="@+id/login_button"/>
			
				<ProgressBar
				android:layout_width="wrap_content"
				android:layout_height="wrap_content"
				android:indeterminate="true"
				android:layout_centerInParent="true"
				android:visibility="gone"
				android:id="@+id/loading_animation"/>
			
			</RelativeLayout>
		
		</LinearLayout>
	
	</android.support.v7.widget.CardView>
 
</RelativeLayout>

private EditText usernameField, passwordField, serverIpField;
private Button loginButton;
private CheckBox saveLogin;
private View loadingAnimation;

//Actionbar verstecken
getSupportActionBar().hide();
 
//Views deklarieren
usernameField = (EditText) findViewById(R.id.username);
passwordField = (EditText) findViewById(R.id.password);
serverIpField = (EditText) findViewById(R.id.server_ip);
 
loadingAnimation = findViewById(R.id.loading_animation);
 
loginButton = (Button) findViewById(R.id.login_button);
 
saveLogin = (CheckBox) findViewById(R.id.save_login);
 
//Dem Button eine Aktion zuweisen
loginButton.setOnClickListener(new View.OnClickListener() {
	@Override
	public void onClick(View v) {
		String username = usernameField.getText().toString();
		String password = passwordField.getText().toString();
		String serverIp = serverIpField.getText().toString();
 
		//Eingaben auf Vollständigkeit prüfen
		if(username.equals("")){
			fehlermeldung("Bitte gib deinen Nutzernamen ein");
		}
		else if(password.equals("")){
			fehlermeldung("Bitte gib dein Passwort ein");
		}
		else if(serverIp.equals("")){
			fehlermeldung("Bitte gib die Adresse des Servers ein");
		}
		else{
			SaveData.setSaveLoginData(getApplicationContext(), saveLogin.isChecked());
 
			login(username, password, serverIp);
		}
	}
});
 
//Haken je nach gespeicherten Daten setzen oder nicht
saveLogin.setChecked(SaveData.getSaveLoginData(getApplicationContext()));
 
//Bei jeder Änderung neu speichren, ob Login-Daten gespeichert werden sollen
saveLogin.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {	
	@Override
	public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
		SaveData.setSaveLoginData(getApplicationContext(), isChecked);
	}
});
 
//Wenn Nutzerdaten vorhanden: automatisch einloggen
if(SaveData.getSaveLoginData(getApplicationContext())){
	String username = SaveData.getUsername(getApplicationContext());
	String password = SaveData.getPassword(getApplicationContext());
	String serverIp = SaveData.getServerIp(getApplicationContext());
 
	if(username != null && password != null && serverIp != null){
		//Textfelder mit gespeicherten Daten füllen
		usernameField.setText(username);
		passwordField.setText(password);
		serverIpField.setText(serverIp);
 
		saveLogin.setChecked(true);
 
		login(username, password, serverIp);
	}
}

/**
* Versucht den Nutzer einzuloggen
* @param username
* @param password
* @param serverIp
*/
public void login(final String username, final String password, final String serverIp){
	loadingAnimation.setVisibility(View.VISIBLE);
	
	Map<String, String> requestData = new HashMap<>();
	requestData.put("action", "getrooms");
	requestData.put("username", username);
	requestData.put("password", password);
	
	HTTPRequest.sendRequest(getApplicationContext(), requestData, serverIp, new HTTPRequest.HTTPRequestCallback() {
		@Override
		public void onRequestResult(String result) {
			loadingAnimation.setVisibility(View.GONE);
			
			if(result.equals("wrongdata")){
				fehlermeldung("Anmeldung nicht möglich! Bitte überprüfe deine Eingaben");
			}
			else if(result.equals("unknownuser")){
				fehlermeldung("Dieser Nutzer existiert nicht");
			}
			else{
				//gegebenenfalls Login-Daten speichern
				if(saveLogin.isChecked()){
				SaveData.setLoginData(getApplicationContext(), username, password);
				SaveData.setServerIp(getApplicationContext(), serverIp);
			}
			
			Intent intent = new Intent(LoginActivity.this, MainActivity.class);
			intent.putExtra(MainActivity.EXTRA_ROOMS, result);
			startActivity(intent);
			}
		}
		
		@Override
		public void onError(String msg) {
			loadingAnimation.setVisibility(View.GONE);
			fehlermeldung(msg);
		}
	});
}
 
/**
* Zeigt die übergebene Nachricht an
* @param msg
*/
public void fehlermeldung(String msg){
	Snackbar.make(findViewById(R.id.frame), msg, Snackbar.LENGTH_SHORT).show();
}

public static String getUsername(Context context){
	return "Testnutzer";
}
 
public static String getPassword(Context context){
	return "password";
}
 
public static String getServerIp(Context context){
	return "192.168.178.xyz";
}
 
public static void setLoginData(Context context, String username, String password){}
 
public static void setServerIp(Context context, String serverIp){}
 
public static void setSaveLoginData(Context context, boolean saveLogin){}
 
public static boolean getSaveLoginData(Context context){
	return true;
}