fix/#13. Added a boolean to record when the camera is opening. This e…

…nables us to check and not start the camera again if it is currently opening. Added tests which check the new behavioural changes.

kbarcode/src/main/java/uk/co/brightec/kbarcode/BarcodeScanner.kt

@@ -95,6 +95,10 @@ class BarcodeScanner internal constructor(
             Timber.d("Attempted Camera2Source.start(), which has already been started")
             return
         }
+        if (cameraSource.isOpening()) {
+            Timber.d("Attempted Camera2Source.start(), which is currently opening")
+            return
+        }
 
         frameProcessor.barcodes.observeForever(barcodesObserver)
         startCameraSource()

kbarcode/src/main/java/uk/co/brightec/kbarcode/camera/Camera2Source.kt

@@ -21,6 +21,8 @@ internal class Camera2Source(
 
     @VisibleForTesting
     internal var cameraDevice: CameraDevice? = null
+    @VisibleForTesting
+    internal var cameraOpening = false
     var requestedFacing = CameraCharacteristics.LENS_FACING_BACK
 
     constructor(context: Context) : this(
@@ -29,17 +31,20 @@ internal class Camera2Source(
 
     fun isStarted() = cameraDevice != null
 
+    fun isOpening() = cameraOpening
+
     fun release() {
         cameraDevice?.close()
         cameraDevice = null
+        cameraOpening = false
     }
 
     @RequiresPermission(android.Manifest.permission.CAMERA)
     fun start(
         surfaces: List<Surface>,
         listener: OnCameraReadyListener?
     ) {
-        if (cameraDevice != null) return
+        if (cameraDevice != null || cameraOpening) return
 
         val cameraId = selectCamera()
         if (cameraId == null) {
@@ -48,8 +53,10 @@ internal class Camera2Source(
             listener?.onCameraFailure(exception)
             return
         }
+        cameraOpening = true
         cameraManager.openCamera(cameraId, object : CameraDevice.StateCallback() {
             override fun onOpened(camera: CameraDevice) {
+                cameraOpening = false
                 cameraDevice = camera
                 listener?.onCameraReady()
                 createCaptureSession(

kbarcode/src/test/java/uk/co/brightec/kbarcode/BarcodeScannerTest.kt

@@ -154,6 +154,38 @@ internal class BarcodeScannerTest {
         verify(barcodeScanner).startCameraSource()
     }
 
+    @Test
+    fun cameraIsStarted__start__resumeProcessing_doesntAddObserver_doesntStartCameraSource() {
+        doNothing().whenever(barcodeScanner).startCameraSource()
+
+        // GIVEN
+        whenever(cameraSource.isStarted()).thenReturn(true)
+
+        // WHEN
+        barcodeScanner.start()
+
+        // THEN
+        assertFalse(barcodeScanner.pauseProcessing)
+        verify(frameProcessor.barcodes, never()).observeForever(any())
+        verify(barcodeScanner, never()).startCameraSource()
+    }
+
+    @Test
+    fun cameraIsOpening__start__resumeProcessing_doesntAddObserver_doesntStartCameraSource() {
+        doNothing().whenever(barcodeScanner).startCameraSource()
+
+        // GIVEN
+        whenever(cameraSource.isOpening()).thenReturn(true)
+
+        // WHEN
+        barcodeScanner.start()
+
+        // THEN
+        assertFalse(barcodeScanner.pauseProcessing)
+        verify(frameProcessor.barcodes, never()).observeForever(any())
+        verify(barcodeScanner, never()).startCameraSource()
+    }
+
     @Test
     fun processingResumed__resume__resumeProcessing() {
         // GIVEN

kbarcode/src/test/java/uk/co/brightec/kbarcode/camera/Camera2SourceTest.kt

@@ -72,6 +72,30 @@ internal class Camera2SourceTest {
         assertTrue(result)
     }
 
+    @Test
+    fun nothing__isOpening__false() {
+        // GIVEN
+        // nothing
+
+        // WHEN
+        val result = cameraSource.isOpening()
+
+        // THEN
+        assertFalse(result)
+    }
+
+    @Test
+    fun cameraOpening__isOpening__true() {
+        // GIVEN
+        cameraSource.cameraOpening = true
+
+        // WHEN
+        val result = cameraSource.isOpening()
+
+        // THEN
+        assertTrue(result)
+    }
+
     @Test
     fun cameraDevice__release__closesCameraDevice() {
         // GIVEN
@@ -83,6 +107,7 @@ internal class Camera2SourceTest {
         // THEN
         verify(cameraDevice).close()
         assertNull(cameraSource.cameraDevice)
+        assertFalse(cameraSource.cameraOpening)
     }
 
     @Test
@@ -99,6 +124,20 @@ internal class Camera2SourceTest {
         )
     }
 
+    @Test
+    fun cameraOpening__start__doesNothing() {
+        // GIVEN
+        cameraSource.cameraOpening = true
+
+        // WHEN
+        cameraSource.start(mock(), mock())
+
+        // THEN
+        verify(cameraManager, never()).openCamera(
+            any(), any(), anyOrNull<Handler>()
+        )
+    }
+
     @Test
     fun noCameraId__start__error() {
         // GIVEN
@@ -115,7 +154,7 @@ internal class Camera2SourceTest {
     }
 
     @Test
-    fun cameraId__start__opensCamera() {
+    fun cameraId__start__setsOpening_opensCamera() {
         // GIVEN
         val cameraId = "some id"
         doReturn(cameraId).whenever(cameraSource).selectCamera()
@@ -124,13 +163,14 @@ internal class Camera2SourceTest {
         cameraSource.start(mock(), mock())
 
         // THEN
+        assertTrue(cameraSource.cameraOpening)
         verify(cameraManager).openCamera(
             eq(cameraId), any(), anyOrNull<Handler>()
         )
     }
 
     @Test
-    fun cameraId_cameraOpened__start__setCameraDevice_callListener_createSession() {
+    fun cameraId_cameraOpened__start__setsNotOpening_setCameraDevice_callListener_createSession() {
         doNothing().whenever(cameraSource).createCaptureSession(any(), any())
 
         // GIVEN
@@ -147,6 +187,7 @@ internal class Camera2SourceTest {
         cameraSource.start(surfaces, listener)
 
         // THEN
+        assertFalse(cameraSource.cameraOpening)
         verify(cameraSource).cameraDevice = cameraDevice
         verify(listener).onCameraReady()
         verify(cameraSource).createCaptureSession(surfaces, listener)