Shoot from the volume keys, while the camera is up

android/app/src/main/java/com/locphamtran/recipescamera/MainActivity.kt

@@ -3,12 +3,15 @@ package com.locphamtran.recipescamera
 import android.content.Intent
 import android.os.Build
 import android.os.Bundle
+import android.view.KeyEvent
 
 import com.facebook.react.ReactActivity
 import com.facebook.react.ReactActivityDelegate
 import com.facebook.react.defaults.DefaultNewArchitectureEntryPoint.fabricEnabled
 import com.facebook.react.defaults.DefaultReactActivityDelegate
 
+import com.locphamtran.recipescamera.volume.VolumeShutterModule
+
 import expo.modules.ReactActivityDelegateWrapper
 
 class MainActivity : ReactActivity() {
@@ -31,6 +34,17 @@ class MainActivity : ReactActivity() {
     super.onNewIntent(intent)
   }
 
+  /**
+   * Volume keys double as a shutter release while the camera screen is up.
+   * This is the only place that runs before the window turns them into a
+   * stream-volume change, so the module gets first refusal and the keys it
+   * does not claim (everything, outside the camera) fall through to the
+   * default handling unchanged.
+   */
+  override fun dispatchKeyEvent(event: KeyEvent): Boolean {
+    return VolumeShutterModule.onKeyEvent(event) || super.dispatchKeyEvent(event)
+  }
+
   /**
    * Returns the name of the main component registered from JavaScript. This is used to schedule
    * rendering of the component.