add a helper function for toggling timer visibility in the activity

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

@@ -411,11 +411,12 @@ class MainActivity : SimpleActivity(), PreviewListener, PhotoProcessor.MediaSave
         window.decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_LOW_PROFILE
     }
 
-    fun hideTimer() {
-        video_rec_curr_timer.text = 0.getFormattedDuration()
-        video_rec_curr_timer.beGone()
-        mCurrVideoRecTimer = 0
-        mTimerHandler.removeCallbacksAndMessages(null)
+    fun toggleTimer(show: Boolean) {
+        if (show) {
+            showTimer()
+        } else {
+            hideTimer()
+        }
     }
 
     private fun showTimer() {
@@ -423,6 +424,13 @@ class MainActivity : SimpleActivity(), PreviewListener, PhotoProcessor.MediaSave
         setupTimer()
     }
 
+    private fun hideTimer() {
+        video_rec_curr_timer.text = 0.getFormattedDuration()
+        video_rec_curr_timer.beGone()
+        mCurrVideoRecTimer = 0
+        mTimerHandler.removeCallbacksAndMessages(null)
+    }
+
     private fun setupTimer() {
         runOnUiThread(object : Runnable {
             override fun run() {

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

@@ -204,7 +204,7 @@ class PreviewCameraOne : ViewGroup, SurfaceHolder.Callback, MediaScannerConnecti
         if (setCamera(mCurrCameraId)) {
             setFlashlightState(FLASH_OFF)
             mActivity?.updateCameraIcon(mCurrCameraId == mCameraImpl!!.getFrontCameraId())
-            mActivity?.hideTimer()
+            mActivity?.toggleTimer(false)
         } else {
             mActivity?.toast(R.string.camera_switch_error)
         }