fix #26, add automatic flash

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

@@ -34,9 +34,9 @@ class Config(context: Context) : BaseConfig(context) {
         get() = prefs.getInt(LAST_USED_CAMERA, Camera.CameraInfo.CAMERA_FACING_BACK)
         set(cameraId) = prefs.edit().putInt(LAST_USED_CAMERA, cameraId).apply()
 
-    var lastFlashlightState: Boolean
+    var flashlightState: Int
-        get() = prefs.getBoolean(LAST_FLASHLIGHT_STATE, false)
+        get() = prefs.getInt(FLASHLIGHT_STATE, FLASH_OFF)
-        set(enabled) = prefs.edit().putBoolean(LAST_FLASHLIGHT_STATE, enabled).apply()
+        set(state) = prefs.edit().putInt(FLASHLIGHT_STATE, state).apply()
 
     var backPhotoResIndex: Int
         get() = prefs.getInt(BACK_PHOTO_RESOLUTION_INDEX, -1)

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

@@ -9,8 +9,12 @@ val SAVE_PHOTOS = "save_photos"
 val SHOW_PREVIEW = "show_preview"
 val SOUND = "sound"
 val LAST_USED_CAMERA = "last_used_camera"
-val LAST_FLASHLIGHT_STATE = "last_flashlight_state"
+val FLASHLIGHT_STATE = "flashlight_state"
 val BACK_PHOTO_RESOLUTION_INDEX = "back_photo_resolution_index"
 val BACK_VIDEO_RESOLUTION_INDEX = "back_video_resolution_index"
 val FRONT_PHOTO_RESOLUTION_INDEX = "front_photo_resolution_index"
 val FRONT_VIDEO_RESOLUTION_INDEX = "front_video_resolution_index"
+
+val FLASH_OFF = 0
+val FLASH_ON = 1
+val FLASH_AUTO = 2

app/src/main/kotlin/com/simplemobiletools/camera/Preview.kt

@@ -6,6 +6,7 @@ import android.graphics.Rect
 import android.hardware.Camera
 import android.media.*
 import android.net.Uri
+import android.os.Build
 import android.os.Environment
 import android.os.Handler
 import android.util.Log
@@ -44,7 +45,6 @@ class Preview : ViewGroup, SurfaceHolder.Callback, MediaScannerConnection.OnScan
 
         private var mCurrVideoPath = ""
         private var mCanTakePicture = false
-        private var mIsFlashEnabled = false
         private var mIsRecording = false
         private var mIsVideoMode = false
         private var mIsSurfaceCreated = false
@@ -68,7 +68,6 @@ class Preview : ViewGroup, SurfaceHolder.Callback, MediaScannerConnection.OnScan
         mSurfaceHolder.addCallback(this)
         mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS)
         mCanTakePicture = false
-        mIsFlashEnabled = false
         mIsVideoMode = false
         mIsSurfaceCreated = false
         mSetupPreviewAfterMeasure = false
@@ -267,7 +266,7 @@ class Preview : ViewGroup, SurfaceHolder.Callback, MediaScannerConnection.OnScan
                 }
             }
 
-            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.JELLY_BEAN_MR1) {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
                 mCamera!!.enableShutterSound(false)
             }
 
@@ -465,15 +464,18 @@ class Preview : ViewGroup, SurfaceHolder.Callback, MediaScannerConnection.OnScan
     fun enableFlash() {
         mParameters!!.flashMode = Camera.Parameters.FLASH_MODE_TORCH
         mCamera!!.parameters = mParameters
-        mIsFlashEnabled = true
     }
 
     fun disableFlash() {
-        mIsFlashEnabled = false
         mParameters!!.flashMode = Camera.Parameters.FLASH_MODE_OFF
         mCamera!!.parameters = mParameters
     }
 
+    fun autoFlash() {
+        mParameters!!.flashMode = Camera.Parameters.FLASH_MODE_AUTO
+        mCamera!!.parameters = mParameters
+    }
+
     fun initPhotoMode() {
         stopRecording()
         cleanupRecorder()

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

@@ -44,7 +44,7 @@ class MainActivity : SimpleActivity(), SensorEventListener, PreviewListener, Pho
 
         private var mPreview: Preview? = null
         private var mPreviewUri: Uri? = null
-        private var mIsFlashEnabled = false
+        private var mFlashlightState = FLASH_OFF
         private var mIsInPhotoMode = false
         private var mIsAskingPermissions = false
         private var mIsCameraAvailable = false
@@ -140,7 +140,7 @@ class MainActivity : SimpleActivity(), SensorEventListener, PreviewListener, Pho
         mIsInPhotoMode = true
         mTimerHandler = Handler()
         mFadeHandler = Handler()
-        mIsFlashEnabled = config.lastFlashlightState
+        mFlashlightState = config.flashlightState
         setupPreviewImage(true)
     }
 
@@ -228,30 +228,37 @@ class MainActivity : SimpleActivity(), SensorEventListener, PreviewListener, Pho
             return
         }
 
-        mIsFlashEnabled = !mIsFlashEnabled
+        mFlashlightState = ++mFlashlightState % 3
         checkFlash()
     }
 
     private fun checkFlash() {
-        if (mIsFlashEnabled) {
+        when (mFlashlightState) {
-            enableFlash()
+            FLASH_ON -> enableFlash()
-        } else {
+            FLASH_AUTO -> autoFlash()
-            disableFlash()
+            else -> disableFlash()
         }
     }
 
     private fun disableFlash() {
         mPreview?.disableFlash()
         toggle_flash.setImageResource(R.drawable.ic_flash_off)
-        mIsFlashEnabled = false
+        mFlashlightState = FLASH_OFF
-        config.lastFlashlightState = mIsFlashEnabled
+        config.flashlightState = FLASH_OFF
     }
 
     private fun enableFlash() {
         mPreview?.enableFlash()
         toggle_flash.setImageResource(R.drawable.ic_flash_on)
-        mIsFlashEnabled = true
+        mFlashlightState = FLASH_ON
-        config.lastFlashlightState = mIsFlashEnabled
+        config.flashlightState = FLASH_ON
+    }
+
+    private fun autoFlash() {
+        mPreview?.autoFlash()
+        toggle_flash.setImageResource(R.drawable.ic_flash_auto)
+        mFlashlightState = FLASH_AUTO
+        config.flashlightState = FLASH_AUTO
     }
 
     private fun shutterPressed() {