From e17f1110267145987fc7e6b0ae252364e0e2e4b7 Mon Sep 17 00:00:00 2001
From: Dasmer Singh <dasmer.singh@venmo.com>
Date: Sat, 10 Jan 2015 10:57:05 -0500
Subject: [PATCH 1/2] Add static BOOL isTouchIDPresented so LAContext is never
 invoked more than once at a time

---
 VENTouchLock/VENTouchLock.m | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/VENTouchLock/VENTouchLock.m b/VENTouchLock/VENTouchLock.m
index 99a5403..0348f25 100644
--- a/VENTouchLock/VENTouchLock.m
+++ b/VENTouchLock/VENTouchLock.m
@@ -127,12 +127,15 @@ - (void)requestTouchIDWithCompletion:(void (^)(VENTouchLockTouchIDResponse))comp
 
 - (void)requestTouchIDWithCompletion:(void (^)(VENTouchLockTouchIDResponse))completionBlock reason:(NSString *)reason
 {
-    if ([[self class] canUseTouchID]) {
+    static BOOL isTouchIDPresented = NO;
+    if ([[self class] canUseTouchID] && !isTouchIDPresented) {
+        isTouchIDPresented = YES;
         LAContext *context = [[LAContext alloc] init];
         context.localizedFallbackTitle = NSLocalizedString(@"Enter Passcode", nil);
         [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
                 localizedReason:reason
                           reply:^(BOOL success, NSError *error) {
+                              isTouchIDPresented = NO;
                               dispatch_async(dispatch_get_main_queue(), ^{
                                   if (success) {
                                       if (completionBlock) {

From f27ca6668f8059e931cd6f2da742441c03bdb6fd Mon Sep 17 00:00:00 2001
From: Dasmer Singh <dasmer.singh@venmo.com>
Date: Mon, 12 Jan 2015 10:16:39 -0500
Subject: [PATCH 2/2] Create VENTouchLockTouchIDResponsePromptAlreadyPresent

---
 VENTouchLock/VENTouchLock.h |  1 +
 VENTouchLock/VENTouchLock.m | 45 +++++++++++++++++++++----------------
 2 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/VENTouchLock/VENTouchLock.h b/VENTouchLock/VENTouchLock.h
index a9ef20d..1c13626 100644
--- a/VENTouchLock/VENTouchLock.h
+++ b/VENTouchLock/VENTouchLock.h
@@ -9,6 +9,7 @@ typedef NS_ENUM(NSUInteger, VENTouchLockTouchIDResponse) {
     VENTouchLockTouchIDResponseSuccess,
     VENTouchLockTouchIDResponseUsePasscode,
     VENTouchLockTouchIDResponseCanceled,
+    VENTouchLockTouchIDResponsePromptAlreadyPresent,
 };
 
 @interface VENTouchLock : NSObject
diff --git a/VENTouchLock/VENTouchLock.m b/VENTouchLock/VENTouchLock.m
index 0348f25..0280dae 100644
--- a/VENTouchLock/VENTouchLock.m
+++ b/VENTouchLock/VENTouchLock.m
@@ -128,22 +128,22 @@ - (void)requestTouchIDWithCompletion:(void (^)(VENTouchLockTouchIDResponse))comp
 - (void)requestTouchIDWithCompletion:(void (^)(VENTouchLockTouchIDResponse))completionBlock reason:(NSString *)reason
 {
     static BOOL isTouchIDPresented = NO;
-    if ([[self class] canUseTouchID] && !isTouchIDPresented) {
-        isTouchIDPresented = YES;
-        LAContext *context = [[LAContext alloc] init];
-        context.localizedFallbackTitle = NSLocalizedString(@"Enter Passcode", nil);
-        [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
-                localizedReason:reason
-                          reply:^(BOOL success, NSError *error) {
-                              isTouchIDPresented = NO;
-                              dispatch_async(dispatch_get_main_queue(), ^{
-                                  if (success) {
-                                      if (completionBlock) {
-                                          completionBlock(VENTouchLockTouchIDResponseSuccess);
+    if ([[self class] canUseTouchID]) {
+        if (!isTouchIDPresented) {
+            isTouchIDPresented = YES;
+            LAContext *context = [[LAContext alloc] init];
+            context.localizedFallbackTitle = NSLocalizedString(@"Enter Passcode", nil);
+            [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
+                    localizedReason:reason
+                              reply:^(BOOL success, NSError *error) {
+                                  isTouchIDPresented = NO;
+                                  dispatch_async(dispatch_get_main_queue(), ^{
+                                      if (success) {
+                                          if (completionBlock) {
+                                              completionBlock(VENTouchLockTouchIDResponseSuccess);
+                                          }
                                       }
-                                  }
-                                  else {
-                                      if (completionBlock) {
+                                      else {
                                           VENTouchLockTouchIDResponse response;
                                           switch (error.code) {
                                               case LAErrorUserFallback:
@@ -156,11 +156,18 @@ - (void)requestTouchIDWithCompletion:(void (^)(VENTouchLockTouchIDResponse))comp
                                                   response = VENTouchLockTouchIDResponseUndefined;
                                                   break;
                                           }
-                                          completionBlock(response);
+                                          if (completionBlock) {
+                                              completionBlock(response);
+                                          }
                                       }
-                                  }
-                              });
-                          }];
+                                  });
+                              }];
+        }
+        else {
+            if (completionBlock) {
+                completionBlock(VENTouchLockTouchIDResponsePromptAlreadyPresent);
+            }
+        }
     }
 }