Move getManager to FingerprintHelper

Partially fixes API level 19 compatibility

app/src/main/java/me/impy/aegis/AuthActivity.java

@@ -24,6 +24,7 @@ import me.impy.aegis.crypto.slots.FingerprintSlot;
 import me.impy.aegis.crypto.slots.PasswordSlot;
 import me.impy.aegis.crypto.slots.Slot;
 import me.impy.aegis.crypto.slots.SlotCollection;
+import me.impy.aegis.helpers.FingerprintHelper;
 import me.impy.aegis.helpers.FingerprintUiHelper;
 import me.impy.aegis.helpers.AuthHelper;
 
@@ -50,7 +51,7 @@ public class AuthActivity extends AegisActivity implements FingerprintUiHelper.C
         _slots = (SlotCollection) intent.getSerializableExtra("slots");
 
         // only show the fingerprint controls if the api version is new enough, permission is granted, a scanner is found and a fingerprint slot is found
-        FingerprintManager manager = FingerprintUiHelper.getManager(this);
+        FingerprintManager manager = FingerprintHelper.getManager(this);
         if (manager != null && _slots.has(FingerprintSlot.class)) {
             try {
                 KeyStoreHandle handle = new KeyStoreHandle();

app/src/main/java/me/impy/aegis/CustomAuthenticationSlide.java

@@ -14,7 +14,7 @@ import android.widget.TextView;
 
 import com.github.paolorotolo.appintro.ISlidePolicy;
 
-import me.impy.aegis.helpers.FingerprintUiHelper;
+import me.impy.aegis.helpers.FingerprintHelper;
 
 public class CustomAuthenticationSlide extends Fragment implements ISlidePolicy, RadioGroup.OnCheckedChangeListener {
     public static final int CRYPT_TYPE_INVALID = 0;
@@ -28,13 +28,12 @@ public class CustomAuthenticationSlide extends Fragment implements ISlidePolicy,
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         final View view = inflater.inflate(R.layout.fragment_authentication_slide, container, false);
-
         _buttonGroup = view.findViewById(R.id.rg_authenticationMethod);
         _buttonGroup.setOnCheckedChangeListener(this);
         onCheckedChanged(_buttonGroup, _buttonGroup.getCheckedRadioButtonId());
 
         // only show the fingerprint option if the api version is new enough, permission is granted and a scanner is found
-        FingerprintManager manager = FingerprintUiHelper.getManager(getContext());
+        FingerprintManager manager = FingerprintHelper.getManager(getContext());
         if (manager != null) {
             RadioButton button = view.findViewById(R.id.rb_fingerprint);
             TextView text = view.findViewById(R.id.text_rb_fingerprint);

app/src/main/java/me/impy/aegis/helpers/FingerprintHelper.java

@@ -0,0 +1,24 @@
+package me.impy.aegis.helpers;
+
+import android.Manifest;
+import android.content.Context;
+import android.hardware.fingerprint.FingerprintManager;
+import android.os.Build;
+
+public class FingerprintHelper {
+    private FingerprintHelper() {
+
+    }
+
+    public static FingerprintManager getManager(Context context) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            if (PermissionHelper.granted(context, Manifest.permission.USE_FINGERPRINT)) {
+                FingerprintManager manager = (FingerprintManager) context.getSystemService(Context.FINGERPRINT_SERVICE);
+                if (manager != null && manager.isHardwareDetected() && manager.hasEnrolledFingerprints()) {
+                    return manager;
+                }
+            }
+        }
+        return null;
+    }
+}

app/src/main/java/me/impy/aegis/helpers/FingerprintUiHelper.java

@@ -19,8 +19,6 @@
 
 package me.impy.aegis.helpers;
 
-import android.Manifest;
-import android.content.Context;
 import android.hardware.fingerprint.FingerprintManager;
 import android.os.Build;
 import android.os.CancellationSignal;
@@ -59,18 +57,6 @@ public class FingerprintUiHelper extends FingerprintManager.AuthenticationCallba
         mCallback = callback;
     }
 
-    public static FingerprintManager getManager(Context context) {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
-            if (PermissionHelper.granted(context, Manifest.permission.USE_FINGERPRINT)) {
-                FingerprintManager manager = (FingerprintManager) context.getSystemService(Context.FINGERPRINT_SERVICE);
-                if (manager != null && manager.isHardwareDetected() && manager.hasEnrolledFingerprints()) {
-                    return manager;
-                }
-            }
-        }
-        return null;
-    }
-
     public boolean isFingerprintAuthAvailable() {
         // The line below prevents the false positive inspection from Android Studio
         // noinspection ResourceType