Aperture: Disable primary bar buttons on activity

Change-Id: I648f68d35c928b38afb60c5537d67fb687141e93
diff --git a/app/src/main/java/org/lineageos/aperture/MainActivity.kt b/app/src/main/java/org/lineageos/aperture/MainActivity.kt
index 7fadbf5..8737839 100644
--- a/app/src/main/java/org/lineageos/aperture/MainActivity.kt
+++ b/app/src/main/java/org/lineageos/aperture/MainActivity.kt
@@ -135,6 +135,7 @@
         set(value) {
             field = value
             updateSecondaryBarButtons(value)
+            updatePrimaryBarButtons(value)
         }
 
     private lateinit var camera: PhysicalCamera
@@ -862,6 +863,17 @@
         }
     }
 
+    /**
+     * Enable or disable primary bar buttons
+     */
+    private fun updatePrimaryBarButtons(cameraState: CameraState) {
+        runOnUiThread {
+            galleryButton.isEnabled = cameraState == CameraState.IDLE
+            // Shutter button must stay enabled
+            flipCameraButton.isEnabled = cameraState == CameraState.IDLE
+        }
+    }
+
     private fun cycleAspectRatio() {
         if (!canRestartCamera()) {
             return