Revert "Dev"

This reverts commit de40a7f.

build.gradle

@@ -5,7 +5,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.0.0-beta3'
+        classpath 'com.android.tools.build:gradle:3.0.0-beta2'
         classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
         classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.7.3'
     }
@@ -65,7 +65,7 @@ android {
 dependencies {
     api 'com.google.zxing:core:3.3.0'
     api 'com.google.zxing:android-core:3.3.0'
-    api 'com.android.support:support-annotations:26.0.2'
+    api 'com.android.support:support-annotations:26.0.1'
 }
 
 group = publishedGroupId

src/main/java/com/budiyev/android/codescanner/CodeScanner.java

@@ -66,6 +66,7 @@ public final class CodeScanner {
                     BarcodeFormat.PDF_417, BarcodeFormat.QR_CODE);
     private static final long AUTO_FOCUS_INTERVAL = 1000L;
     private static final int UNSPECIFIED = -1;
+    private static final int FOCUS_ATTEMPTS_THRESHOLD = 2;
     private final Lock mInitializeLock = new ReentrantLock();
     private final Context mContext;
     private final Handler mMainThreadHandler;
@@ -90,6 +91,7 @@ public final class CodeScanner {
     private volatile boolean mStoppingPreview;
     private boolean mPreviewActive;
     private boolean mFocusing;
+    private int mFocusAttemptsCount;
 
     /**
      * CodeScanner, associated with the first back-facing camera on the device
@@ -272,6 +274,7 @@ private void startPreviewInternal() {
             mStoppingPreview = false;
             mPreviewActive = true;
             mFocusing = false;
+            mFocusAttemptsCount = 0;
             scheduleAutoFocusTask();
         } catch (Exception ignored) {
         }
@@ -286,18 +289,21 @@ private void stopPreviewInternal() {
         mStoppingPreview = false;
         mPreviewActive = false;
         mFocusing = false;
+        mFocusAttemptsCount = 0;
     }
 
     private void autoFocusCamera() {
         if (!mInitialized || !mPreviewActive) {
             return;
         }
-        if (mFocusing) {
+        if (mFocusing && mFocusAttemptsCount < FOCUS_ATTEMPTS_THRESHOLD) {
+            mFocusAttemptsCount++;
             scheduleAutoFocusTask();
             return;
         }
         try {
             mCamera.autoFocus(mAutoFocusCallback);
+            mFocusAttemptsCount = 0;
             mFocusing = true;
         } catch (Exception e) {
             mFocusing = false;
@@ -417,6 +423,7 @@ private final class AutoFocusCallback implements Camera.AutoFocusCallback {
         @Override
         public void onAutoFocus(boolean success, Camera camera) {
             mFocusing = false;
+            scheduleAutoFocusTask();
         }
     }