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OpenCV app - Android camera keeps showing black screen

Background
I had started out this project on Android Studio with the intent of creating a OpenCV application that could process frames using the camera on my OnePlus android device. After running the application, I was gratified to see it finally launch on my device. However, the application shows up with a black screen where the camera preview should be. Here is my code for my MainActivity, activity_main, and AndroidManifest files:
EDIT: While the application launched on my device, I did give the application permission to use camera
MainActivity.java
package com.example.cv;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.SurfaceView;
import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.JavaCameraView;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgproc.Imgproc;
public class MainActivity extends AppCompatActivity implements CameraBridgeViewBase.CvCameraViewListener2
{
private static String TAG = "MainActivity";
JavaCameraView javaCameraView;
Mat mRGBA, mRGBAT;
BaseLoaderCallback baseLoaderCallback = new BaseLoaderCallback(MainActivity.this) {
#Override
public void onManagerConnected(int status)
{
if (status == BaseLoaderCallback.SUCCESS) {
javaCameraView.enableView();
} else {
super.onManagerConnected(status);
}
}
};
static
{
if (OpenCVLoader.initDebug())
{
Log.d(TAG, "OpenCV is Configured or Connected successfully.");
}
else
{
Log.d(TAG, "OpenCV not Working or Loaded.");
}
}
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
javaCameraView = (JavaCameraView) findViewById(R.id.my_camera_view);
javaCameraView.setVisibility(SurfaceView.VISIBLE);
javaCameraView.setCvCameraViewListener(MainActivity.this);
}
#Override
public void onCameraViewStarted(int width, int height)
{
mRGBA = new Mat(height, width, CvType.CV_8UC4);
}
#Override
public void onCameraViewStopped()
{
mRGBA.release();
}
#Override
public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame)
{
mRGBA = inputFrame.rgba();
mRGBAT = mRGBA.t();
Core.flip(mRGBA.t(), mRGBAT, 1);
Imgproc.resize(mRGBAT, mRGBAT, mRGBA.size());
return mRGBAT;
}
#Override
public void onPointerCaptureChanged(boolean hasCapture) {
}
#Override
protected void onDestroy() {
super.onDestroy();
if (javaCameraView != null)
{
javaCameraView.disableView();
}
}
#Override
protected void onPause() {
super.onPause();
if (javaCameraView != null)
{
javaCameraView.disableView();
}
}
#Override
protected void onResume() {
super.onResume();
if (OpenCVLoader.initDebug())
{
Log.d(TAG, "OpenCV is Configured or Connected successfully.");
baseLoaderCallback.onManagerConnected(BaseLoaderCallback.SUCCESS);
}
else
{
Log.d(TAG, "OpenCV not Working or Loaded.");
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION, this, baseLoaderCallback);
}
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<org.opencv.android.JavaCameraView
android:id="#+id/my_camera_view"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
</RelativeLayout>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.cv">
<uses-permission android:name="android.permission.CAMERA"/>
<uses-feature android:name="android.hardware.camera"/>
<uses-feature android:name="android.hardware.camera.autofocus"/>
<uses-feature android:name="android.hardware.camera.front"/>
<uses-feature android:name="android.hardware.camera.front.autofocus"/>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

The issue you are facing is actually with the camera permission check
Starting from Android Marshmallow, the CAMERA permission is considered a dangerous one and the user must explicitly agree on its usage at runtime, clicking on the system dialog
This wouldn't happen for "normal permissions" [e.g. INTERNET] that are granted by default. If you are interested in which ones are dangerous and which not you can check for the one of interest directly in the Android documentation
What's happening with your initial code is that you are mentioning you will require the camera permission in your manifest file and then you are enabling it from the Android Settings [toggling the Camera slider]. But then, when you start the app there is nothing in the code that goes and checks that toggle. Then you get a black screen because Android assumes that the user has not given explicit consent
This link from the Android documentation should help you understand more. Here the snippet that will make your code work. In a nutshell, with onCreate() you go and check if the user has already granted the permission and if not you will ask it. In onRequestPermissionResult() there is the check we were talking about before. If the user agreed the camera will start, otherwise it won't
private static final int MY_CAMERA_REQUEST_CODE = 100;
int activeCamera = CameraBridgeViewBase.CAMERA_ID_FRONT;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
javaCameraView = (JavaCameraView) findViewById(R.id.my_camera_view);
// checking if the permission has already been granted
if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
== PackageManager.PERMISSION_GRANTED) {
Log.d(TAG, "Permissions granted");
initializeCamera(javaCameraView, activeCamera);
} else {
// prompt system dialog
Log.d(TAG, "Permission prompt");
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA}, MY_CAMERA_REQUEST_CODE);
}
}
// callback to be executed after the user has givenapproval or rejection via system prompt
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == MY_CAMERA_REQUEST_CODE) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// camera can be turned on
Toast.makeText(this, "camera permission granted", Toast.LENGTH_LONG).show();
initializeCamera(javaCameraView, activeCamera);
} else {
// camera will stay off
Toast.makeText(this, "camera permission denied", Toast.LENGTH_LONG).show();
}
}
}
private void initializeCamera(JavaCameraView javaCameraView, int activeCamera){
javaCameraView.setCameraPermissionGranted();
javaCameraView.setCameraIndex(activeCamera);
javaCameraView.setVisibility(CameraBridgeViewBase.VISIBLE);
javaCameraView.setCvCameraViewListener(this);
}

Am I missing something to get google maps to open from android webview

Iam new to the android programming environment and am creating my first app. I am trying to get webview to open google maps when a google maps link is clicked within webview. Am I missing something as to why this is still opening the link in webview and not executing google maps instead? And when it is opening in webview it shows the destination fine but it does not show my location and states it is unable to determine my location on the bottom of the page being displayed
Here is the MainActivity
package com.example.micha.myapplication;
import android.content.Intent;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.webkit.CookieManager;
import android.webkit.DownloadListener;
import android.webkit.GeolocationPermissions;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class MainActivity extends AppCompatActivity {
/**
* WebViewClient subclass loads all hyperlinks in the existing WebView
*/
public class GeoWebViewClient extends WebViewClient {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
// When user clicks a hyperlink, load in the existing WebView
view.loadUrl(url);
return true;
}
}
/**
* WebChromeClient subclass handles UI-related calls
* Note: think chrome as in decoration, not the Chrome browser
*/
public class GeoWebChromeClient extends WebChromeClient {
#Override
public void onGeolocationPermissionsShowPrompt(String origin,
GeolocationPermissions.Callback callback) {
// Always grant permission since the app itself requires location
// permission and the user has therefore already granted it
callback.invoke(origin, true, false);
}
}
private WebView myWebView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myWebView = findViewById(R.id.webView);
WebView myWebView = findViewById(R.id.webView);
WebSettings webSettings = myWebView.getSettings();
myWebView.setWebViewClient(new GeoWebViewClient());
webSettings.setJavaScriptEnabled(true);
myWebView.getSettings().setGeolocationEnabled(true);
CookieManager.getInstance().setAcceptCookie(true);
//webSettings.setDomStorageEnabled(true);
myWebView.clearHistory();
myWebView.clearFormData();
myWebView.clearCache(true);
myWebView.setWebViewClient(new WebViewClient(){
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if( url.startsWith("http:") || url.startsWith("https:") ) {
return false;
}
if(url.contains("https://www.google.com/maps/"))
{
Uri gmmIntentUri = Uri.parse(url);
Intent mapIntent = new Intent(Intent.ACTION_VIEW, gmmIntentUri);
mapIntent.setPackage("com.google.android.apps.maps");
if (mapIntent.resolveActivity(getPackageManager()) != null) {
startActivity(mapIntent);
}
return true;
}
// Otherwise allow the OS to handle things like tel, mailto, etc.
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
startActivity( intent );
return true;
}
});
myWebView.loadUrl("http://www.example.com");
//THIS IS TO DOWNLOAD THE PDF FILES OR OTHER DOWNLOAD LINKS
myWebView.setDownloadListener(new DownloadListener() {
#Override
public void onDownloadStart(String url, String userAgent,
String contentDisposition, String mimetype,
long contentLength) {
startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
}
});
}
#Override
public void onBackPressed() {
if (myWebView.canGoBack()) {
myWebView.goBack();
return;
}
super.onBackPressed();
}
}
Here is the AndroidManifest.XML
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.micha.myapplication">
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACTION_DIAL"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_DOWNLOAD_MANAGER"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_GPS" />
<uses-permission android:name="android.permission.ACCESS_ASSISTED_GPS" />
<uses-permission android:name="android.permission.ACCESS_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_principal"
android:label="Admin Tools"
android:supportsRtl="true"
android:theme="#style/Theme.AppCompat.NoActionBar">
<activity android:name=".MainActivity"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

Found the problem.
if( url.startsWith("http:") || url.startsWith("https:") ) {
was preventing google maps from opening as it was forcing any url with https to stay within the webview. modified it to
if( url.startsWith("http:")) {
and all is good now.

Deep linking opens the app but does not open the exact url

I have made a WebView app and deep linking works on it. Whenever someone clicks a link to my website (on any other app) then my app opens but, the homepage loads up instead of the URL clicked. I want the exact URL of my website to open whenever the link is clicked instead of the homepage.
MainActivity.java
package com.yoalfaaz.yoalfaaz;
import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.ShareActionProvider;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.support.v4.view.MenuItemCompat;
public class MainActivity extends AppCompatActivity {
private WebView YoWeb;
private ShareActionProvider mShareActionProvider;
SwipeRefreshLayout swipe;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
YoWeb = (WebView)findViewById(R.id.webview); // Move your declaration up here
swipe = (SwipeRefreshLayout) findViewById(R.id.swiperefresh);
swipe.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
LoadWeb(YoWeb.getUrl()); // Pass in the current url to refresh
}
});
LoadWeb("https://www.yoalfaaz.com"); // load the home page only once
}
public void LoadWeb(String url) // Pass in URL you want to load
{
WebSettings webSettings = YoWeb.getSettings();
webSettings.setJavaScriptEnabled(true);
YoWeb.loadUrl(url); // Load the URL passed into the method
swipe.setRefreshing(true);
YoWeb.setWebViewClient(new WebViewClient() {
//onPageFinished Method
public void onPageFinished(WebView view, String url) {
//Hide the SwipeRefreshLayout
swipe.setRefreshing(false);
}
});
}
#Override
public void onBackPressed() {
if (YoWeb.canGoBack()) {
YoWeb.goBack();
} else {
super.onBackPressed();
}
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
switch (item.getItemId()) {
case R.id.action_settings:
return true;
default:
return super.onOptionsItemSelected(item);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate menu resource file.
getMenuInflater().inflate(R.menu.menu_main, menu);
// Locate MenuItem with ShareActionProvider
MenuItem item = menu.findItem(R.id.menu_item_share);
// Fetch and store ShareActionProvider
mShareActionProvider = (ShareActionProvider) MenuItemCompat.getActionProvider(item);
// Return true to display menu
return true;
}
// Call to update the share intent
private void setShareIntent(Intent shareIntent) {
if (mShareActionProvider != null) {
mShareActionProvider.setShareIntent(shareIntent);
}
}
//private Intent setShareIntent() {
// Intent shareIntent = new Intent();
// shareIntent.setAction(Intent.ACTION_SEND);
// shareIntent.putExtra(Intent.EXTRA_TEXT, "This is my text to send.");
// shareIntent.setType("text/plain");
// startActivity(shareIntent);
// return shareIntent;
//}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.yoalfaaz.yoalfaaz">
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name=".MainActivity"
android:configChanges="orientation|keyboardHidden"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
<intent-filter >
<action android:name="android.intent.action.VIEW"/>
<category android:name="android.intent.category.DEFAULT"/>
<category android:name="android.intent.category.BROWSABLE"/>
<data android:host="www.yoalfaaz.com" android:scheme="https"/>
</intent-filter>
</activity>
<activity android:name=".SplashScreen">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
How to make it work as it works with most other apps? Like if we click on a YouTube link in WhatsApp then that particular video opens in YouTube app instead of YouTube homepage.

LoadWeb("https://www.yoalfaaz.com"); // load the home page only once
Instead of hardcoding the URL, use getIntent().getData().toString() to get the URL(as a string) that is clicked from the other apps and use this URL to load web view.
Have a null check and load default URL if there is no URL received from getData().
Hope this helps.
========= EDITED to show the code as you have asked =====================
In your code, you are loading web view with this line.
LoadWeb("https://www.yoalfaaz.com"); // load the home page only once
Modify this line like below.
String url = "https://www.yoalfaaz.com";
if(null != getIntent().getData()){
url = getIntent().getData().toString();
}
LoadWeb(url);

Android - Hardcode Login not Working

Aim
To login to my Admin.xml via AdminLogin.xml
Flow of Classes
AdminLoginActivity ---> AdminActivity
AdminLoginActivityClass
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class AdminLoginActivity extends AppCompatActivity {
private Toolbar jAdminToolbar;
private EditText jAdminID;
private EditText jAdminPassword;
private Button jAdminLoginBtn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_admin_login);
jAdminToolbar = (Toolbar) findViewById(R.id.adminLoginToolbar);
setSupportActionBar(jAdminToolbar);
getSupportActionBar().setTitle("Admin Login");
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
jAdminID = (EditText) findViewById(R.id.adminLoginName);
jAdminPassword = (EditText) findViewById(R.id.adminLoginPassword);
jAdminLoginBtn = (Button) findViewById(R.id.adminLoginBtn);
jAdminLoginBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String adminLoginID = jAdminID.getText().toString();
String adminLoginPassword = jAdminPassword.getText().toString();
if(adminLoginID.equals("admin")&& adminLoginPassword.equals("admin")){
Intent intentAdmin = new Intent(AdminLoginActivity.this, AdminActivity.class);
intentAdmin.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intentAdmin);
finish();
}else{
Toast.makeText(AdminLoginActivity.this, "Failed Login", Toast.LENGTH_SHORT).show();
return;
}
}
});
}
}
AdminActivityClass
import android.content.Intent;
import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
public class AdminActivity extends AppCompatActivity {
private FirebaseAuth mAdminAuth;
private Toolbar jAdminToolbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_admin);
mAdminAuth = FirebaseAuth.getInstance();
jAdminToolbar = (Toolbar) findViewById(R.id.adminToolbar);
setSupportActionBar(jAdminToolbar);
getSupportActionBar().setTitle("Administrator");
}
#Override
public void onStart() {
super.onStart();
FirebaseUser currentUser = mAdminAuth.getCurrentUser();
if(currentUser == null){
sendUserToStartPage();
}
}
private void sendUserToStartPage(){
Intent intentStart = new Intent(AdminActivity.this, StartActivity.class);
startActivity(intentStart);
finish();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
getMenuInflater().inflate(R.menu.activity_admin_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
super.onOptionsItemSelected(item);
if(item.getItemId() == R.id.mainSignOutBtn){
FirebaseAuth.getInstance().signOut();
sendUserToStartPage();
}
if(item.getItemId() == R.id.mainViewContactsBtn){
Intent intentViewContacts = new Intent(AdminActivity.this, AllUsersActivity.class);
startActivity(intentViewContacts);
}
return true;
}
}
Manifest File
<?xml version="1.0" encoding="utf-8"?>
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<application
android:name=".SecurityApp"
android:allowBackup="true"
android:icon="#mipmap/appiconone"
android:label="#string/app_name"
android:roundIcon="#mipmap/appiconone"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".StartActivity" />
<activity
android:name=".ResidentRegistrationActivity"
android:parentActivityName=".StartActivity" />
<activity
android:name=".AdminLoginActivity"
android:parentActivityName=".LoginActivity">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.lenovo.securityapp.LoginActivity" />
</activity>
<activity
android:name=".LoginActivity"
android:parentActivityName=".StartActivity" />
<activity
android:name=".SettingsActivity"
android:parentActivityName=".MainActivity" />
<activity
android:name=".DetailsActivity"
android:parentActivityName=".SettingsActivity" />
<activity
android:name=".AllUsersActivity"
android:parentActivityName=".MainActivity" />
<activity android:name=".UserProfileActivity" />
<activity
android:name=".HelpInformationActivity"
android:parentActivityName=".StartActivity" />
<activity android:name=".AdminActivity" />
</application>
Problem
ToolBar on AdminLogin does not allow me to return to LoginActivity when I select the back Button
Admin Login does not work despite entering the hardcoded input for the Admin Name and Password. After clicking on the Login button, the app prompts out a White layout for a few seconds I am brought back to the StartActivity and the Toast message does not show "Failed Login".
SOLUTION
The problem was because the "AdminActivityClass" had
#Override
public void onStart() {
super.onStart();
FirebaseUser currentUser = mAdminAuth.getCurrentUser();
if(currentUser == null){
sendUserToStartPage();
}
}
private void sendUserToStartPage(){
Intent intentStart = new Intent(AdminActivity.this, StartActivity.class);
startActivity(intentStart);
finish();
}
Since the Admin login was hardcoded, the currentUser within the FirebaseUser currentUser = mAdminAuth.getCurrentUser(); was set to null. This caused the activity to be sent back to the start page (sendUserToStartPage();)

After posting your full set of code, you should be doing the following.
comment out the sendUserToStartPage(); inside of the currentuser == null and then try.
why? Because the user IS null. why? because you hard coded it into the code. The user admin with password admin does not exist in your Firebase (and if it does, you never checked it prior) so when you sign in, you do not create a session for admin, therefore the current user is null.
try doing this
if ("admin".equals(adminLoginID)) {
if ("admin".equals(adminLoginPassword)) {
//goto activity
}
} else {
//not admin
}
this might be better actually
if (("admin".equals(adminLoginID)) && ("admin".equals(adminLoginPassword))) {
//goto activity
} else {
//not admin
}
or even this....
if (("admin".equals(jAdminID.getText().toString().trim())) && ("admin".equals(jAdminPassword.getText().toString().trim()))) {
//goto activity
} else {
//not admin
}
Try this example in the manifest.
Youre manifest for the activities are missing a theme.
Also, its missed the meta-data.
<activity
android:name=".Leagues.CreateLeague"
android:label="Create League"
android:parentActivityName=".MainActivity"
android:screenOrientation="portrait"
android:theme="#style/AppTheme2">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.aaa.bbb.MainActivity" />
</activity>

Try like this smartly
take a String variable globally and declare and intialise them
in next step you need to add validations
String str_admin="admin";
if ((str_admin.equals(adminLoginID)) && (str_admin.equals(adminLoginPassword))) {
//pass reference of activity which you want to open it
} else {
//not admin
}
Happy to help yoh

Function Isolating Camera's LED Light and java.lang.NullPointerException: Attempt to invoke virtual method 'void android.hardware.Camera$Parameters

I am struggling to control the LED light next to my camera in the app I am trying to make for my own education purposes. I have tried to follow the methods in http://www.mkyong.com/android/how-to-turn-onoff-camera-ledflashlight-in-android/ , but I am trying to make the function more abstract and more general in order to increase reusable functionality and make the code more readable.
Upon creating my activity we first check, using PackageManager, that a LED camera does in fact exist. I then open the camera. The onClick function runs the functions changeScreen() and toggleLight(). Here you can see the clear advantages of using abstraction, ie toggleLight() works as a black box, using code set out elsewhere. The changeScreen function I know is correct, well before adding toggleLight() it was working correctly.
As the code should be correct, as it was taken from the example, I believe I have a problem with variable scope.
1) Where does the boolean isLighOn need to be declared, in the function or in the activity?
2) Same problem with the camera variable
How else should I go about creating an abstract function toggleLight()? I have checked around on this website, but a lot of posts send you to the link provided above. Moreover I believe an answer to this question would help many users and would provide reusable code.
Here is my code so far and I have posted the error I am getting below again.
package com.mycompany.myapplication;
import android.app.*;
import android.content.Context;
import android.content.pm.PackageManager;
import android.graphics.drawable.ColorDrawable;
import android.hardware.Camera;
import android.os.*;
import android.util.Log;
import android.view.*;
import android.widget.*;
public class MainActivity extends Activity {
public RelativeLayout container;
private boolean isLighOn = false;
private Camera camera;
#Override
protected void onStop() {
super.onStop();
if (camera != null) {
camera.release();
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Context context = this;
PackageManager pm = context.getPackageManager();
// if device support camera?
if (!pm.hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
Log.e("err", "Device has no camera!");
return;
}
camera = Camera.open();
container = (RelativeLayout) findViewById(R.id.MainActivity);
container.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
changeScreen(v);
toggleLight();
}
});
}
public void changeScreen(View v) {
ColorDrawable cd = (ColorDrawable) this.container.getBackground();
TextView ON = (TextView) findViewById(R.id.ON);
TextView OFF = (TextView) findViewById(R.id.OFF);
if (cd != null && cd.getColor() == getResources().getColor(R.color.BLACK)) {
container.setBackgroundColor(getResources().getColor(R.color.WHITE));
OFF.setVisibility(View.INVISIBLE);
ON.setVisibility(View.VISIBLE);
} else {
container.setBackgroundColor(getResources().getColor(R.color.BLACK));
OFF.setVisibility(View.VISIBLE);
ON.setVisibility(View.INVISIBLE);
}
}
public void toggleLight(){
final Camera.Parameters p = camera.getParameters();
if (isLighOn) {
Log.i("info", "torch is turn off!");
p.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
camera.setParameters(p);
camera.stopPreview();
isLighOn = false;
} else {
Log.i("info", "torch is turn on!");
p.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
camera.setParameters(p);
camera.startPreview();
isLighOn = true;
}
}
}
When I load the app on my Android Studio emulator, I get the screen "ON". However, when you click the screen the app crashes. This is only error message I can find in the IDE. I am not sure how to interpret this error message.
In response to a comment below I am now posting the code containing the permissions.
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.mycompany.myapplication">
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name=".MainActivity"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

Don't rely on an emulator to produce reliable camera behavior. Always verify camera-related code on real device!