Only add SwirlView to views on API 23 and above

Partially fixes API level 19 compatibility

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

@@ -3,9 +3,11 @@ package me.impy.aegis;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.hardware.fingerprint.FingerprintManager;
+import android.os.Build;
 import android.support.v7.app.AlertDialog;
 import android.os.Bundle;
 import android.view.View;
+import android.view.ViewGroup;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.LinearLayout;
@@ -44,9 +46,15 @@ public class AuthActivity extends AegisActivity implements FingerprintUiHelper.C
         setContentView(R.layout.activity_auth);
         _textPassword = findViewById(R.id.text_password);
         LinearLayout boxFingerprint = findViewById(R.id.box_fingerprint);
-        SwirlView imgFingerprint = findViewById(R.id.img_fingerprint);
         TextView textFingerprint = findViewById(R.id.text_fingerprint);
 
+        SwirlView imgFingerprint = null;
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            ViewGroup insertPoint = findViewById(R.id.img_fingerprint_insert);
+            imgFingerprint = new SwirlView(this);
+            insertPoint.addView(imgFingerprint, 0, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
+        }
+
         Intent intent = getIntent();
         _slots = (SlotCollection) intent.getSerializableExtra("slots");
 

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

@@ -3,6 +3,7 @@ package me.impy.aegis;
 import android.content.Context;
 import android.content.Intent;
 import android.hardware.fingerprint.FingerprintManager;
+import android.os.Build;
 import android.os.Bundle;
 import android.support.design.widget.Snackbar;
 import android.support.v4.app.Fragment;
@@ -47,7 +48,13 @@ public class CustomAuthenticatedSlide extends Fragment implements FingerprintUiH
         _textPassword = view.findViewById(R.id.text_password);
         _textPasswordConfirm = view.findViewById(R.id.text_password_confirm);
         _boxFingerprint = view.findViewById(R.id.box_fingerprint);
-        _imgFingerprint = view.findViewById(R.id.img_fingerprint);
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            ViewGroup insertPoint = view.findViewById(R.id.img_fingerprint_insert);
+            _imgFingerprint = new SwirlView(getContext());
+            insertPoint.addView(_imgFingerprint, 0, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
+        }
+
         _textFingerprint = view.findViewById(R.id.text_fingerprint);
         view.findViewById(R.id.main).setBackgroundColor(_bgColor);
         return view;

app/src/main/res/layout/activity_auth.xml

@@ -50,10 +50,11 @@
             android:layout_marginTop="12dp"
             android:visibility="invisible">
 
-            <com.mattprecious.swirl.SwirlView
-                android:id="@+id/img_fingerprint"
+            <LinearLayout
+                android:id="@+id/img_fingerprint_insert"
                 android:layout_width="60dp"
-                android:layout_height="60dp"/>
+                android:layout_height="60dp"
+                android:orientation="horizontal"/>
 
             <TextView
                 android:id="@+id/text_fingerprint"

app/src/main/res/layout/fragment_authenticated_slide.xml

@@ -82,10 +82,11 @@
             android:layout_height="match_parent"
             android:layout_marginTop="12dp">
 
-            <com.mattprecious.swirl.SwirlView
-                android:id="@+id/img_fingerprint"
+            <LinearLayout
+                android:id="@+id/img_fingerprint_insert"
                 android:layout_width="60dp"
-                android:layout_height="60dp"/>
+                android:layout_height="60dp"
+                android:orientation="horizontal"/>
 
             <TextView
                 android:id="@+id/text_fingerprint"