Fix fingerprint dialog behaviour after rotation

exxbrain · Oct 11, 2019 · a49d8b2 · a49d8b2
1 parent 95fe0a2
commit a49d8b2
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Showing 4 changed files with 76 additions and 52 deletions.
diff --git a/android-biometric-compat/src/main/java/com/exxbrain/android/biometric/BiometricPrompt.java b/android-biometric-compat/src/main/java/com/exxbrain/android/biometric/BiometricPrompt.java
@@ -18,7 +18,6 @@
 
 import android.annotation.SuppressLint;
 import android.app.Activity;
-import android.app.ActivityManager;
 import android.app.Fragment;
 import android.app.FragmentManager;
 import android.arch.lifecycle.Lifecycle;
@@ -35,12 +34,9 @@
 import android.support.annotation.Nullable;
 import android.support.v4.hardware.fingerprint.FingerprintManagerCompat;
 import android.util.Log;
-import android.widget.Toast;
 
 import java.lang.annotation.Retention;
 import java.security.Signature;
-import java.util.ArrayList;
-import java.util.List;
 import java.util.concurrent.Executor;
 
 import javax.crypto.Cipher;
@@ -184,7 +180,7 @@ Mac getMac() {
     /**
      * Callback structure provided to {@link BiometricPrompt}. Users of {@link
      * BiometricPrompt} must provide an implementation of this for listening to
-     * fingerprint events.
+     * fingerprint Events.
      */
     public abstract static class AuthenticationCallback {
         /**
@@ -401,6 +397,8 @@ public boolean isDeviceCredentialAllowed() {
         }
     }
 
+    public static LifecycleEvents Events;
+
     // Passed in from the client.
     private Activity mActivity;
     private Fragment mFragment;
@@ -454,7 +452,7 @@ public void run() {
      */
     private final LifecycleObserver mLifecycleObserver = new LifecycleObserver() {
         @OnLifecycleEvent(Lifecycle.Event.ON_PAUSE)
-        void onPause() {
+        void onPause(Fragment fragment) {
             if (!isChangingConfigurations() && !usingBiometricFragment()) {
                 // May be null if no authentication is occurring.
                 if (mFingerprintDialogFragment != null && mFingerprintHelperFragment != null) {
@@ -464,14 +462,22 @@ void onPause() {
             }
         }
         @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
-        void onResume() {
+        void onResume(Fragment fragment) {
             if (!usingBiometricFragment()) {
-                mFingerprintDialogFragment =
-                        (FingerprintDialogFragment) getFragmentManager().findFragmentByTag(
-                                DIALOG_FRAGMENT_TAG);
-                mFingerprintHelperFragment =
-                        (FingerprintHelperFragment) getFragmentManager().findFragmentByTag(
-                                FINGERPRINT_HELPER_FRAGMENT_TAG);
+                FingerprintDialogFragment dialogFragment = (FingerprintDialogFragment) getFragmentManager().findFragmentByTag(
+                        DIALOG_FRAGMENT_TAG);
+                if (dialogFragment == null && fragment instanceof FingerprintDialogFragment) {
+                    dialogFragment = (FingerprintDialogFragment) fragment;
+                }
+                FingerprintHelperFragment helperFragment = (FingerprintHelperFragment) getFragmentManager().findFragmentByTag(
+                        FINGERPRINT_HELPER_FRAGMENT_TAG);
+
+                if (dialogFragment == null || helperFragment == null) {
+                    return;
+                }
+
+                mFingerprintDialogFragment = dialogFragment;
+                mFingerprintHelperFragment = helperFragment;
 
                 if (DEBUG) Log.v(TAG, "FingerprintDialogFragment: " + mFingerprintDialogFragment);
                 if (DEBUG) Log.v(TAG, "FingerprintHelperFragment: " + mFingerprintHelperFragment);
@@ -501,8 +507,8 @@ void onResume() {
      * {@link AuthenticationCallback} after configuration changes.
      *
      * @param activity A reference to the client's activity.
-     * @param executor         An executor to handle callback events.
-     * @param callback         An object to receive authentication events.
+     * @param executor         An executor to handle callback Events.
+     * @param callback         An object to receive authentication Events.
      */
     @SuppressLint("LambdaLast")
     public BiometricPrompt(@NonNull Activity activity,
@@ -520,6 +526,8 @@ public BiometricPrompt(@NonNull Activity activity,
         mActivity = activity;
         mAuthenticationCallback = callback;
         mExecutor = executor;
+
+        Events = new LifecycleEvents(mLifecycleObserver);
     }
 
     /**
@@ -534,8 +542,8 @@ public BiometricPrompt(@NonNull Activity activity,
      * such as {@link Fragment#onCreate(Bundle)}.
      *
      * @param fragment A reference to the client's fragment.
-     * @param executor An executor to handle callback events.
-     * @param callback An object to receive authentication events.
+     * @param executor An executor to handle callback Events.
+     * @param callback An object to receive authentication Events.
      */
     @SuppressLint("LambdaLast")
     public BiometricPrompt(@NonNull Fragment fragment,
@@ -552,6 +560,8 @@ public BiometricPrompt(@NonNull Fragment fragment,
         mFragment = fragment;
         mAuthenticationCallback = callback;
         mExecutor = executor;
+
+        Events = new LifecycleEvents(mLifecycleObserver);
     }
 
     /**
@@ -640,7 +650,7 @@ public void onAuthenticationFailed() {
             if (fingerprintDialogFragment != null) {
                 mFingerprintDialogFragment = fingerprintDialogFragment;
             } else {
-                mFingerprintDialogFragment = FingerprintDialogFragment.newInstance(mLifecycleObserver);
+                mFingerprintDialogFragment = FingerprintDialogFragment.newInstance();
             }
 
             mFingerprintDialogFragment.setNegativeButtonListener(mNegativeButtonListener);

diff --git a/...metric-compat/src/main/java/com/exxbrain/android/biometric/FingerprintDialogFragment.java b/...metric-compat/src/main/java/com/exxbrain/android/biometric/FingerprintDialogFragment.java
@@ -21,8 +21,6 @@
 import android.app.Dialog;
 import android.app.DialogFragment;
 import android.arch.lifecycle.Lifecycle;
-import android.arch.lifecycle.LifecycleObserver;
-import android.arch.lifecycle.OnLifecycleEvent;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.res.Resources;
@@ -46,8 +44,6 @@
 import android.widget.ImageView;
 import android.widget.TextView;
 
-import java.lang.reflect.Method;
-
 /**
  * This class implements a custom AlertDialog that prompts the user for fingerprint authentication.
  * This class is not meant to be preserved across process death; for security reasons, the
@@ -58,31 +54,6 @@
 @SuppressLint("SyntheticAccessor")
 public class FingerprintDialogFragment extends DialogFragment {
 
-    private static class Events {
-        LifecycleObserver observer;
-        Events(LifecycleObserver observer) {
-            this.observer = observer;
-        }
-
-        void raise(Lifecycle.Event event) {
-            Method[] methods = observer.getClass().getDeclaredMethods();
-            for(Method mt : methods) {
-                if (mt.isAnnotationPresent(OnLifecycleEvent.class)) {
-                    OnLifecycleEvent annotation = mt.getAnnotation(OnLifecycleEvent.class);
-                    if (annotation.value() == event) {
-                        try {
-                            mt.invoke(observer);
-                        } catch (Exception e) {
-                            throw new RuntimeException(e);
-                        }
-                    }
-                }
-            }
-        }
-    }
-
-    private static Events events;
-
     private static final String TAG = "FingerprintDialogFrag";
     private static final String KEY_DIALOG_BUNDLE = "SavedBundle";
 
@@ -117,9 +88,8 @@ void raise(Lifecycle.Event event) {
     /**
      * Creates a dialog requesting for Fingerprint authentication.
      */
-    static FingerprintDialogFragment newInstance(LifecycleObserver observer) {
+    static FingerprintDialogFragment newInstance() {
         FingerprintDialogFragment fragment = new FingerprintDialogFragment();
-        events = new Events(observer);
         return fragment;
     }
 
@@ -239,7 +209,6 @@ public void onSaveInstanceState(@NonNull Bundle outState) {
     public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         mContext = getActivity();
-        events.raise(Lifecycle.Event.ON_CREATE);
 
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
             mErrorColor = getThemedColorFor(android.R.attr.colorError);
@@ -254,15 +223,15 @@ public void onResume() {
         super.onResume();
         mLastState = STATE_NONE;
         updateFingerprintIcon(STATE_FINGERPRINT);
-        events.raise(Lifecycle.Event.ON_RESUME);
+        BiometricPrompt.Events.raise(Lifecycle.Event.ON_RESUME, this);
     }
 
     @Override
     public void onPause() {
         super.onPause();
         // Remove everything since the fragment is going away.
         mHandler.removeCallbacksAndMessages(null);
-        events.raise(Lifecycle.Event.ON_PAUSE);
+        BiometricPrompt.Events.raise(Lifecycle.Event.ON_PAUSE, this);
     }
 
     @Override

diff --git a/...metric-compat/src/main/java/com/exxbrain/android/biometric/FingerprintHelperFragment.java b/...metric-compat/src/main/java/com/exxbrain/android/biometric/FingerprintHelperFragment.java
@@ -18,6 +18,8 @@
 
 import android.annotation.SuppressLint;
 import android.app.Fragment;
+import android.arch.lifecycle.Lifecycle;
+import android.arch.lifecycle.LifecycleObserver;
 import android.content.Context;
 import android.os.Bundle;
 import android.os.Handler;
@@ -259,6 +261,18 @@ public void onCreate(@Nullable Bundle savedInstanceState) {
         mContext = getActivity();
     }
 
+    @Override
+    public void onResume() {
+        super.onResume();
+        BiometricPrompt.Events.raise(Lifecycle.Event.ON_RESUME, this);
+    }
+
+    @Override
+    public void onPause() {
+        super.onPause();
+        BiometricPrompt.Events.raise(Lifecycle.Event.ON_PAUSE, this);
+    }
+
     @Override
     @SuppressWarnings("deprecation")
     @Nullable

diff --git a/android-biometric-compat/src/main/java/com/exxbrain/android/biometric/LifecycleEvents.java b/android-biometric-compat/src/main/java/com/exxbrain/android/biometric/LifecycleEvents.java
@@ -0,0 +1,31 @@
+package com.exxbrain.android.biometric;
+
+import android.app.Fragment;
+import android.arch.lifecycle.Lifecycle;
+import android.arch.lifecycle.LifecycleObserver;
+import android.arch.lifecycle.OnLifecycleEvent;
+
+import java.lang.reflect.Method;
+
+class LifecycleEvents {
+    LifecycleObserver observer;
+    LifecycleEvents(LifecycleObserver observer) {
+        this.observer = observer;
+    }
+
+    void raise(Lifecycle.Event event, Fragment fragment) {
+        Method[] methods = observer.getClass().getDeclaredMethods();
+        for(Method mt : methods) {
+            if (mt.isAnnotationPresent(OnLifecycleEvent.class)) {
+                OnLifecycleEvent annotation = mt.getAnnotation(OnLifecycleEvent.class);
+                if (annotation.value() == event) {
+                    try {
+                        mt.invoke(observer, fragment);
+                    } catch (Exception e) {
+                        throw new RuntimeException(e);
+                    }
+                }
+            }
+        }
+    }
+}