Merge pull request #135 from slepmog/master

Adding ability to select camera when integrating via intent

android-integration/src/main/java/com/google/zxing/integration/android/IntentIntegrator.java

@@ -249,25 +249,50 @@ public class IntentIntegrator {
   }
 
   /**
-   * Initiates a scan for all known barcode types.
+   * Initiates a scan for all known barcode types with the default camera.
    *
    * @return the {@link AlertDialog} that was shown to the user prompting them to download the app
-   *   if a prompt was needed, or null otherwiseo
+   *   if a prompt was needed, or null otherwise.
    */
   public final AlertDialog initiateScan() {
-    return initiateScan(ALL_CODE_TYPES);
+    return initiateScan(ALL_CODE_TYPES, -1);
   }
   
   /**
-   * Initiates a scan only for a certain set of barcode types, given as strings corresponding
+   * Initiates a scan for all known barcode types with the specified camera.
+   *
+   * @param cameraId camera ID of the camera to use. A negative value means "no preference".
+   * @return the {@link AlertDialog} that was shown to the user prompting them to download the app
+   *   if a prompt was needed, or null otherwise.
+   */
+  public final AlertDialog initiateScan(int cameraId) {
+    return initiateScan(ALL_CODE_TYPES, cameraId);
+  }
+
+  /**
+   * Initiates a scan, using the default camera, only for a certain set of barcode types, given as strings corresponding
    * to their names in ZXing's {@code BarcodeFormat} class like "UPC_A". You can supply constants
    * like {@link #PRODUCT_CODE_TYPES} for example.
    *
    * @param desiredBarcodeFormats names of {@code BarcodeFormat}s to scan for
    * @return the {@link AlertDialog} that was shown to the user prompting them to download the app
-   *   if a prompt was needed, or null otherwise
+   *   if a prompt was needed, or null otherwise.
    */
   public final AlertDialog initiateScan(Collection<String> desiredBarcodeFormats) {
+    return initiateScan(desiredBarcodeFormats, -1);
+  }
+  
+  /**
+   * Initiates a scan, using the specified camera, only for a certain set of barcode types, given as strings corresponding
+   * to their names in ZXing's {@code BarcodeFormat} class like "UPC_A". You can supply constants
+   * like {@link #PRODUCT_CODE_TYPES} for example.
+   *
+   * @param desiredBarcodeFormats names of {@code BarcodeFormat}s to scan for
+   * @param cameraId camera ID of the camera to use. A negative value means "no preference".
+   * @return the {@link AlertDialog} that was shown to the user prompting them to download the app
+   *   if a prompt was needed, or null otherwise
+   */
+  public final AlertDialog initiateScan(Collection<String> desiredBarcodeFormats, int cameraId) {
     Intent intentScan = new Intent(BS_PACKAGE + ".SCAN");
     intentScan.addCategory(Intent.CATEGORY_DEFAULT);
 
@@ -284,6 +309,11 @@ public class IntentIntegrator {
       intentScan.putExtra("SCAN_FORMATS", joinedByComma.toString());
     }
 	
+    // check requested camera ID
+    if (cameraId >= 0) {
+      intentScan.putExtra("SCAN_CAMERA_ID", cameraId);
+    }
+
     String targetAppPackage = findTargetAppPackage(intentScan);
     if (targetAppPackage == null) {
       return showDownloadDialog();

android/src/com/google/zxing/client/android/CaptureActivity.java

@@ -219,6 +219,13 @@ public final class CaptureActivity extends Activity implements SurfaceHolder.Cal
           }
         }
 		
+        if (intent.hasExtra(Intents.Scan.CAMERA_ID)) {
+          int cameraId = intent.getIntExtra(Intents.Scan.CAMERA_ID, -1);
+          if (cameraId >= 0) {
+            cameraManager.setManualCameraId(cameraId);
+          }
+        }
+        
         String customPromptMessage = intent.getStringExtra(Intents.Scan.PROMPT_MESSAGE);
         if (customPromptMessage != null) {
           statusView.setText(customPromptMessage);

android/src/com/google/zxing/client/android/Intents.java

@@ -81,6 +81,13 @@ public final class Intents {
      */
     public static final String FORMATS = "SCAN_FORMATS";
 	
+    /**
+     * Optional parameter to specify the id of the camera from which to recognize barcodes.
+     * Overrides the default camera that would otherwise would have been selected.
+     * If provided, should be an int.
+     */
+    public static final String CAMERA_ID = "SCAN_CAMERA_ID";
+
     /**
      * @see com.google.zxing.DecodeHintType#CHARACTER_SET
      */

android/src/com/google/zxing/client/android/camera/CameraManager.java

@@ -52,6 +52,7 @@ public final class CameraManager {
   private Rect framingRectInPreview;
   private boolean initialized;
   private boolean previewing;
+  private int requestedCameraId = -1;
   private int requestedFramingRectWidth;
   private int requestedFramingRectHeight;
   /**
@@ -75,7 +76,13 @@ public final class CameraManager {
   public synchronized void openDriver(SurfaceHolder holder) throws IOException {
     Camera theCamera = camera;
     if (theCamera == null) {
+	  
+      if (requestedCameraId >= 0) {
+        theCamera = OpenCameraInterface.open(requestedCameraId);
+      } else {
         theCamera = OpenCameraInterface.open();
+      }
+      
       if (theCamera == null) {
         throw new IOException();
       }
@@ -265,6 +272,21 @@ public final class CameraManager {
     return framingRectInPreview;
   }
 
+  
+  /**
+   * Allows third party apps to specify the camera ID, rather than determine
+   * it automatically based on available cameras and their orientation.
+   *
+   * @param cameraId camera ID of the camera to use. A negative value means "no preference".
+   */
+  public synchronized void setManualCameraId(int cameraId) {
+    if (initialized) {
+      throw new IllegalStateException();
+    } else {
+      requestedCameraId = cameraId;
+    }
+  }
+  
   /**
    * Allows third party apps to specify the scanning rectangle dimensions, rather than determine
    * them automatically based on screen resolution.

android/src/com/google/zxing/client/android/camera/open/OpenCameraInterface.java

@@ -26,12 +26,14 @@ public final class OpenCameraInterface {
   private OpenCameraInterface() {
   }
 
+  
   /**
-   * Opens a rear-facing camera with {@link Camera#open(int)}, if one exists, or opens camera 0.
+   * Opens the requested camera with {@link Camera#open(int)}, if one exists.
    *
+   * @param cameraId camera ID of the camera to use. A negative value means "no preference"
    * @return handle to {@link Camera} that was opened
    */
-  public static Camera open() {
+  public static Camera open(int cameraId) {
     
     int numCameras = Camera.getNumberOfCameras();
     if (numCameras == 0) {
@@ -39,6 +41,10 @@ public final class OpenCameraInterface {
       return null;
     }
 	  
+    boolean explicitRequest = cameraId >= 0;
+	  
+    if (!explicitRequest) {
+      // Select a camera if no explicit camera requested
       int index = 0;
       while (index < numCameras) {
         Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
@@ -49,16 +55,34 @@ public final class OpenCameraInterface {
         index++;
       }
       
+      cameraId = index;
+    }
+	  
     Camera camera;
-    if (index < numCameras) {
+    if (cameraId < numCameras) {
-      Log.i(TAG, "Opening camera #" + index);
+      Log.i(TAG, "Opening camera #" + cameraId);
-      camera = Camera.open(index);
+      camera = Camera.open(cameraId);
+    } else {
+      if (explicitRequest) {
+        Log.w(TAG, "Requested camera does not exist: " + cameraId);
+        camera = null;
       } else {
         Log.i(TAG, "No camera facing back; returning camera #0");
         camera = Camera.open(0);
       }
+    }
     
     return camera;
   }
   
+  
+  /**
+   * Opens a rear-facing camera with {@link Camera#open(int)}, if one exists, or opens camera 0.
+   *
+   * @return handle to {@link Camera} that was opened
+   */
+  public static Camera open() {
+    return open(-1);
+  }
+
 }