handle Camera.open() fail gracefully

app/src/main/java/com/simplemobiletools/camera/Preview.java

@@ -49,7 +49,15 @@ public class Preview extends ViewGroup implements SurfaceHolder.Callback, View.O
 
     public void setCamera(int cameraId) {
         currCameraId = cameraId;
-        final Camera newCamera = Camera.open(cameraId);
+        Camera newCamera;
+        try {
+            newCamera = Camera.open(cameraId);
+        } catch (Exception e) {
+            Utils.showToast(getContext(), R.string.camera_open_error);
+            Log.e(TAG, "setCamera open " + e.getMessage());
+            return;
+        }
+
         if (camera == newCamera) {
             return;
         }
@@ -73,7 +81,7 @@ public class Preview extends ViewGroup implements SurfaceHolder.Callback, View.O
                 try {
                     camera.setPreviewDisplay(surfaceHolder);
                 } catch (IOException e) {
-                    Log.e(TAG, "setCamera " + e.getMessage());
+                    Log.e(TAG, "setCamera setPreviewDisplay " + e.getMessage());
                 }
                 setupPreview();
             }

app/src/main/java/com/simplemobiletools/camera/Utils.java

@@ -1,6 +1,8 @@
 package com.simplemobiletools.camera;
 
+import android.content.Context;
 import android.hardware.Camera;
+import android.widget.Toast;
 
 public class Utils {
     public static Camera.CameraInfo getCameraInfo(int cameraId) {
@@ -8,4 +10,8 @@ public class Utils {
         Camera.getCameraInfo(cameraId, info);
         return info;
     }
+
+    public static void showToast(Context context, int resId) {
+        Toast.makeText(context, context.getResources().getString(resId), Toast.LENGTH_SHORT).show();
+    }
 }

app/src/main/res/values/strings.xml

@@ -1,3 +1,4 @@
 <resources>
     <string name="app_name">Simple Camera</string>
+    <string name="camera_open_error">An error occurred at obtaining the camera</string>
 </resources>