Merge branch 'develop'

* develop:
  [*] updated readme with proper use-case code [+] added check for camera permission, autofocus and camera hardware detection
  [*] updated code to fix issue #8 , bumped up the version.

README.md

@@ -7,7 +7,7 @@ Android library using google's mobile vision api to read QR Code
 #Integration
 - QREader is available in the MavenCentral, so getting it as simple as adding it as a dependency
 ```gradle
-compile 'com.github.nisrulz:qreader:1.0.3'
+compile 'com.github.nisrulz:qreader:1.0.4'
 ```
 
 #Usage
@@ -78,6 +78,24 @@ QREader.getInstance().stop();
 QREader.getInstance().releaseAndCleanup();
 ```
 
+A typical use case would be , which works well with locking your device and when the app goes into background and then comes back in foreground
+```java
+  @Override protected void onStart() {
+    super.onStart();
+
+    // Call in onStart
+    QREader.getInstance().start();
+  }
+
+  @Override protected void onDestroy() {
+    super.onDestroy();
+
+    // Call in onDestroy
+    QREader.getInstance().stop();
+    QREader.getInstance().releaseAndCleanup();
+  }
+```
+
 
 > NOTE : 
 

app/build.gradle

@@ -38,6 +38,6 @@ android {
 dependencies {
     compile fileTree(dir: 'libs', include: ['*.jar'])
     testCompile 'junit:junit:4.12'
-    compile 'com.android.support:appcompat-v7:23.3.0'
+    compile 'com.android.support:appcompat-v7:23.4.0'
     compile project(':library')
 }

app/src/main/java/github/nisrulz/projectqreader/MainActivity.java

@@ -20,7 +20,6 @@
 import android.support.v7.app.AppCompatActivity;
 import android.util.Log;
 import android.view.SurfaceView;
-import android.widget.Button;
 import android.widget.TextView;
 import github.nisrulz.qreader.QRDataListener;
 import github.nisrulz.qreader.QREader;
@@ -29,8 +28,6 @@ public class MainActivity extends AppCompatActivity {
 
   private SurfaceView surfaceView;
   private TextView textView_qrcode_info;
-  private Button btn_toggle;
-  private boolean isRunning = false;
 
   @Override protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
@@ -53,24 +50,18 @@ public class MainActivity extends AppCompatActivity {
     QREader.getInstance().init(this, surfaceView);
   }
 
-  @Override protected void onResume() {
-    super.onResume();
+  @Override protected void onStart() {
+    super.onStart();
 
+    // Call in onStart
     QREader.getInstance().start();
-    isRunning = true;
-  }
-
-  @Override protected void onPause() {
-    super.onPause();
-
-    QREader.getInstance().stop();
-    isRunning = false;
   }
 
   @Override protected void onDestroy() {
     super.onDestroy();
 
+    // Call in onDestroy
+    QREader.getInstance().stop();
     QREader.getInstance().releaseAndCleanup();
-    isRunning = false;
   }
 }

gradle/wrapper/gradle-wrapper.properties

@@ -19,4 +19,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.12-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.13-all.zip

library/build.gradle

@@ -25,8 +25,8 @@ android {
     defaultConfig {
         minSdkVersion 9
         targetSdkVersion 23
-        versionCode 4
-        versionName "1.0.3"
+        versionCode 5
+        versionName "1.0.4"
         consumerProguardFiles 'consumer-proguard-rules.pro'
     }
     buildTypes {

library/src/main/java/github/nisrulz/qreader/QREader.java

@@ -34,8 +34,7 @@
  * QREader Singleton
  */
 public class QREader {
-
-  private static final String TAG = "QREader";
+  private static final String LOGTAG = "QREader";
   private CameraSource cameraSource = null;
   private BarcodeDetector barcodeDetector = null;
 
@@ -115,11 +114,42 @@ public void init(final Context context, final SurfaceView surfaceView) {
     this.context = context;
     this.surfaceView = surfaceView;
 
+    if (!hasAutofocus(context)) {
+      Log.e(LOGTAG, "Do not have autofocus feature, disabling autofocus feature in the library!");
+      autofocus_enabled = false;
+    }
+
+    if (!hasCameraHardware(context)) {
+      Log.e(LOGTAG, "Does not have camera hardware!");
+      return;
+    }
+    if (!checkCameraPermission(context)) {
+      Log.e(LOGTAG, "Do not have camera permission!");
+      return;
+    }
+
+    // Setup Barcodedetector
     if (barcodeDetector == null) {
       barcodeDetector =
           new BarcodeDetector.Builder(context).setBarcodeFormats(Barcode.QR_CODE).build();
+
+      if (barcodeDetector.isOperational()) {
+        barcodeDetector.setProcessor(new Detector.Processor<Barcode>() {
+          @Override public void release() {
+
+          }
+
+          @Override public void receiveDetections(Detector.Detections<Barcode> detections) {
+            final SparseArray<Barcode> barcodes = detections.getDetectedItems();
+            if (barcodes.size() != 0 && qrDataListener != null) {
+              qrDataListener.onDetected(barcodes.valueAt(0).displayValue);
+            }
+          }
+        });
+      }
     }
 
+    // Setup Camera
     if (cameraSource == null) {
       cameraSource =
           new CameraSource.Builder(context, barcodeDetector).setAutoFocusEnabled(autofocus_enabled)
@@ -144,24 +174,10 @@ public void start() {
     }
 
     @Override public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
-      if (barcodeDetector.isOperational()) {
-        barcodeDetector.setProcessor(new Detector.Processor<Barcode>() {
-          @Override public void release() {
-
-          }
-
-          @Override public void receiveDetections(Detector.Detections<Barcode> detections) {
-            final SparseArray<Barcode> barcodes = detections.getDetectedItems();
-            if (barcodes.size() != 0 && qrDataListener != null) {
-              qrDataListener.onDetected(barcodes.valueAt(0).displayValue);
-            }
-          }
-        });
-      }
     }
 
     @Override public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
-
+      stop();
     }
   };
 
@@ -171,14 +187,14 @@ private void startCameraView(Context context, CameraSource cameraSource,
 
       if (ActivityCompat.checkSelfPermission(context, Manifest.permission.CAMERA)
           != PackageManager.PERMISSION_GRANTED) {
-        Log.e(TAG, "Permission not granted!");
+        Log.e(LOGTAG, "Permission not granted!");
         return;
       } else if (!cameraRunning && cameraSource != null && surfaceView != null) {
         cameraSource.start(surfaceView.getHolder());
         cameraRunning = true;
       }
     } catch (IOException ie) {
-      Log.e(TAG, ie.getMessage());
+      Log.e(LOGTAG, ie.getMessage());
       ie.printStackTrace();
     }
   }
@@ -196,13 +212,13 @@ public void stop() {
         cameraRunning = false;
       }
     } catch (Exception ie) {
-      Log.e(TAG, ie.getMessage());
+      Log.e(LOGTAG, ie.getMessage());
       ie.printStackTrace();
     }
   }
 
   /**
-   * Release and cleanup qr eader.
+   * Release and cleanup qreader.
    */
   public void releaseAndCleanup() {
     stop();
@@ -211,5 +227,19 @@ public void releaseAndCleanup() {
       cameraSource = null;
     }
   }
+
+  private boolean checkCameraPermission(Context context) {
+    String permission = Manifest.permission.CAMERA;
+    int res = context.checkCallingOrSelfPermission(permission);
+    return (res == PackageManager.PERMISSION_GRANTED);
+  }
+
+  private boolean hasCameraHardware(Context context) {
+    return context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA);
+  }
+
+  private boolean hasAutofocus(Context context) {
+    return context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_AUTOFOCUS);
+  }
 }