remember which camera was used last, open it by default

app/src/main/kotlin/com/simplemobiletools/camera/activities/MainActivity.kt

@@ -119,7 +119,7 @@ class MainActivity : SimpleActivity(), PhotoProcessor.MediaSavedListener {
         mCameraImpl = getMyCamera()
 
         if (config.alwaysOpenBackCamera) {
-            config.lastUsedCamera = mCameraImpl.getBackCameraId()
+            config.lastUsedCamera = mCameraImpl.getBackCameraId().toString()
         }
     }
 
@@ -196,7 +196,7 @@ class MainActivity : SimpleActivity(), PhotoProcessor.MediaSavedListener {
         mPreview = if (isLollipopPlus()) PreviewCameraTwo(this, camera_texture_view) else PreviewCameraOne(this, camera_surface_view)
         view_holder.addView(mPreview as ViewGroup)
 
-        val imageDrawable = if (config.lastUsedCamera == mCameraImpl.getBackCameraId()) R.drawable.ic_camera_front else R.drawable.ic_camera_rear
+        val imageDrawable = if (config.lastUsedCamera == mCameraImpl.getBackCameraId().toString()) R.drawable.ic_camera_front else R.drawable.ic_camera_rear
         toggle_camera.setImageResource(imageDrawable)
 
         mFocusCircleView = FocusCircleView(applicationContext)

app/src/main/kotlin/com/simplemobiletools/camera/helpers/Config.kt

@@ -46,9 +46,9 @@ class Config(context: Context) : BaseConfig(context) {
         get() = prefs.getBoolean(FLIP_PHOTOS, true)
         set(flipPhotos) = prefs.edit().putBoolean(FLIP_PHOTOS, flipPhotos).apply()
 
-    var lastUsedCamera: Int
+    var lastUsedCamera: String
-        get() = prefs.getInt(LAST_USED_CAMERA, context.getMyCamera().getBackCameraId())
+        get() = prefs.getString(LAST_USED_CAMERA, context.getMyCamera().getBackCameraId().toString())
-        set(cameraId) = prefs.edit().putInt(LAST_USED_CAMERA, cameraId).apply()
+        set(cameraId) = prefs.edit().putString(LAST_USED_CAMERA, cameraId).apply()
 
     var flashlightState: Int
         get() = prefs.getInt(FLASHLIGHT_STATE, FLASH_OFF)

app/src/main/kotlin/com/simplemobiletools/camera/helpers/Constants.kt

@@ -13,7 +13,7 @@ const val FOCUS_BEFORE_CAPTURE = "focus_before_capture"
 const val VOLUME_BUTTONS_AS_SHUTTER = "volume_buttons_as_shutter"
 const val TURN_FLASH_OFF_AT_STARTUP = "turn_flash_off_at_startup"
 const val FLIP_PHOTOS = "flip_photos"
-const val LAST_USED_CAMERA = "last_used_camera"
+const val LAST_USED_CAMERA = "last_used_camera_2"
 const val FLASHLIGHT_STATE = "flashlight_state"
 const val BACK_PHOTO_RESOLUTION_INDEX = "back_photo_resolution_index_2"
 const val BACK_VIDEO_RESOLUTION_INDEX = "back_video_resolution_index_2"

app/src/main/kotlin/com/simplemobiletools/camera/views/PreviewCameraOne.kt

@@ -202,7 +202,7 @@ class PreviewCameraOne : ViewGroup, SurfaceHolder.Callback, MyPreview {
             mCameraImpl!!.getBackCameraId()
         }
 
-        mConfig.lastUsedCamera = mCurrCameraId
+        mConfig.lastUsedCamera = mCurrCameraId.toString()
         releaseCamera()
         if (resumeCamera()) {
             setFlashlightState(FLASH_OFF)
@@ -243,7 +243,7 @@ class PreviewCameraOne : ViewGroup, SurfaceHolder.Callback, MyPreview {
     }
 
     private fun getResolutionIndex(): Int {
-        val isBackCamera = mConfig.lastUsedCamera == Camera.CameraInfo.CAMERA_FACING_BACK
+        val isBackCamera = mConfig.lastUsedCamera == Camera.CameraInfo.CAMERA_FACING_BACK.toString()
         return if (mIsInVideoMode) {
             if (isBackCamera) mConfig.backVideoResIndex else mConfig.frontVideoResIndex
         } else {

app/src/main/kotlin/com/simplemobiletools/camera/views/PreviewCameraTwo.kt

@@ -23,6 +23,7 @@ import android.view.ViewGroup
 import com.simplemobiletools.camera.activities.MainActivity
 import com.simplemobiletools.camera.dialogs.ChangeResolutionDialog
 import com.simplemobiletools.camera.extensions.config
+import com.simplemobiletools.camera.extensions.getMyCamera
 import com.simplemobiletools.camera.helpers.*
 import com.simplemobiletools.camera.interfaces.MyPreview
 import com.simplemobiletools.camera.models.FocusArea
@@ -81,6 +82,7 @@ class PreviewCameraTwo : ViewGroup, TextureView.SurfaceTextureListener, MyPrevie
     constructor(activity: MainActivity, textureView: AutoFitTextureView) : super(activity) {
         mActivity = activity
         mTextureView = textureView
+        mUseFrontCamera = activity.config.lastUsedCamera == activity.getMyCamera().getBackCameraId().toString()
 
         mTextureView.setOnTouchListener { view, event ->
             if (event.action == MotionEvent.ACTION_DOWN) {
@@ -241,6 +243,7 @@ class PreviewCameraTwo : ViewGroup, TextureView.SurfaceTextureListener, MyPrevie
                 }
 
                 mCameraId = cameraId
+                mActivity.config.lastUsedCamera = mCameraId
                 val configMap = getCameraCharacteristics().get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP)
                 val currentResolution = getCurrentResolution()