fix preview and capture resolutions

- adjust the preview so the image captured is what the user sees
- add method MySize.isSupported; current support is for full, 16:9, 4:3 and 1:1 of the highest resolution
- cleanup ImageQualityManager, add method to get the full screen resolution which is just the resolution with the largest width
- change the UI to move settings to the top and remove the auto fading

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

@@ -10,7 +10,7 @@ import android.os.Handler
 import android.os.Looper
 import android.provider.MediaStore
 import android.view.*
-import android.widget.RelativeLayout
+import androidx.constraintlayout.widget.ConstraintLayout
 import com.bumptech.glide.Glide
 import com.bumptech.glide.load.engine.DiskCacheStrategy
 import com.bumptech.glide.load.resource.drawable.DrawableTransitionOptions
@@ -32,7 +32,6 @@ import kotlinx.android.synthetic.main.activity_main.*
 
 class MainActivity : SimpleActivity(), PhotoProcessor.MediaSavedListener, CameraXPreviewListener {
     companion object {
-        private const val FADE_DELAY = 5000L
         private const val CAPTURE_ANIMATION_DURATION = 100L
     }
 
@@ -84,7 +83,6 @@ class MainActivity : SimpleActivity(), PhotoProcessor.MediaSavedListener, Camera
         if (hasStorageAndCameraPermissions()) {
             resumeCameraItems()
             setupPreviewImage(mIsInPhotoMode)
-            scheduleFadeOut()
             mFocusCircleView.setStrokeColor(getProperPrimaryColor())
 
             if (isVideoCaptureIntent() && mIsInPhotoMode) {
@@ -216,11 +214,11 @@ class MainActivity : SimpleActivity(), PhotoProcessor.MediaSavedListener, Camera
         setContentView(R.layout.activity_main)
         initButtons()
 
-        (btn_holder.layoutParams as RelativeLayout.LayoutParams).setMargins(
+        (video_rec_curr_timer.layoutParams as ConstraintLayout.LayoutParams).setMargins(
             0,
             0,
             0,
-            (navigationBarHeight + resources.getDimension(R.dimen.activity_margin)).toInt()
+            (navigationBarHeight + resources.getDimension(R.dimen.big_margin)).toInt()
         )
 
         checkVideoCaptureIntent()
@@ -310,12 +308,8 @@ class MainActivity : SimpleActivity(), PhotoProcessor.MediaSavedListener, Camera
     }
 
     private fun launchSettings() {
-        if (settings.alpha == 1f) {
+        val intent = Intent(applicationContext, SettingsActivity::class.java)
-            val intent = Intent(applicationContext, SettingsActivity::class.java)
+        startActivity(intent)
-            startActivity(intent)
-        } else {
-            fadeInButtons()
-        }
     }
 
     private fun handleTogglePhotoVideo() {
@@ -415,34 +409,6 @@ class MainActivity : SimpleActivity(), PhotoProcessor.MediaSavedListener, Camera
         }
     }
 
-    private fun scheduleFadeOut() {
-        if (!config.keepSettingsVisible) {
-            mFadeHandler.postDelayed({
-                fadeOutButtons()
-            }, FADE_DELAY)
-        }
-    }
-
-    private fun fadeOutButtons() {
-        fadeAnim(settings, .5f)
-        fadeAnim(toggle_photo_video, .0f)
-        fadeAnim(change_resolution, .0f)
-        fadeAnim(last_photo_video_preview, .0f)
-    }
-
-    private fun fadeInButtons() {
-        fadeAnim(settings, 1f)
-        fadeAnim(toggle_photo_video, 1f)
-        fadeAnim(change_resolution, 1f)
-        fadeAnim(last_photo_video_preview, 1f)
-        scheduleFadeOut()
-    }
-
-    private fun fadeAnim(view: View, value: Float) {
-        view.animate().alpha(value).start()
-        view.isClickable = value != .0f
-    }
-
     private fun showTimer() {
         video_rec_curr_timer.beVisible()
         setupTimer()

app/src/main/kotlin/com/simplemobiletools/camera/dialogs/ChangeResolutionDialogX.kt

@@ -47,7 +47,12 @@ class ChangeResolutionDialogX(
         val items = photoResolutions.mapIndexed { index, resolution ->
             val megapixels = resolution.megaPixels
             val aspectRatio = resolution.getAspectRatio(activity)
-            RadioItem(index, "${resolution.width} x ${resolution.height}  ($megapixels MP,  $aspectRatio)")
+            if (resolution.isFullScreen) {
+                //TODO: Extract to string resource
+                RadioItem(index, "Full")
+            } else {
+                RadioItem(index, "${resolution.width} x ${resolution.height}  ($megapixels MP,  $aspectRatio)")
+            }
         }
         var selectionIndex = if (isFrontCamera) config.frontPhotoResIndex else config.backPhotoResIndex
         selectionIndex = selectionIndex.coerceAtLeast(0)

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

@@ -66,6 +66,7 @@ class Config(context: Context) : BaseConfig(context) {
         get() = prefs.getInt(FRONT_VIDEO_RESOLUTION_INDEX, 0)
         set(frontVideoResIndex) = prefs.edit().putInt(FRONT_VIDEO_RESOLUTION_INDEX, frontVideoResIndex).apply()
 
+    //TODO: Remove keepSettingsVisible since the view has moved to the top
     var keepSettingsVisible: Boolean
         get() = prefs.getBoolean(KEEP_SETTINGS_VISIBLE, false)
         set(keepSettingsVisible) = prefs.edit().putBoolean(KEEP_SETTINGS_VISIBLE, keepSettingsVisible).apply()

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

@@ -28,13 +28,12 @@ class ImageQualityManager(
             for (cameraId in cameraManager.cameraIdList) {
                 try {
                     val characteristics = cameraManager.getCameraCharacteristics(cameraId)
-                    for (lens in CAMERA_LENS) {
+                    val lensFacing = characteristics.get(CameraCharacteristics.LENS_FACING) ?: continue
-                        if (characteristics.get(CameraCharacteristics.LENS_FACING) == lens) {
+                    if (lensFacing in CAMERA_LENS) {
-                            val configMap = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP) ?: continue
+                        val configMap = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP) ?: continue
-                            val imageSizes = configMap.getOutputSizes(ImageFormat.JPEG).map { MySize(it.width, it.height) }
+                        val imageSizes = configMap.getOutputSizes(ImageFormat.JPEG).map { MySize(it.width, it.height) }
-                            val cameraSelector = lens.toCameraSelector()
+                        val cameraSelector = lensFacing.toCameraSelector()
-                            imageQualities.add(CameraSelectorImageQualities(cameraSelector, imageSizes))
+                        imageQualities.add(CameraSelectorImageQualities(cameraSelector, imageSizes))
-                        }
                     }
                 } catch (e: Exception) {
                     activity.showErrorToast(e)
@@ -52,19 +51,26 @@ class ImageQualityManager(
     }
 
     fun getUserSelectedResolution(cameraSelector: CameraSelector): MySize {
-        val index = if (cameraSelector == CameraSelector.DEFAULT_FRONT_CAMERA) config.frontPhotoResIndex else config.backPhotoResIndex
+        val resolutions = getSupportedResolutions(cameraSelector)
-        return imageQualities.filter { it.camSelector == cameraSelector }
+        var index = if (cameraSelector == CameraSelector.DEFAULT_FRONT_CAMERA) config.frontPhotoResIndex else config.backPhotoResIndex
-            .flatMap { it.qualities }
+        index = index.coerceAtMost(resolutions.lastIndex)
-            .sortedWith(compareByDescending<MySize> { it.ratio }.thenByDescending { it.pixels })
+        return resolutions[index]
-            .distinctBy { it.pixels }
-            .filter { it.megaPixels != "0.0" }[index]
     }
 
     fun getSupportedResolutions(cameraSelector: CameraSelector): List<MySize> {
+        val fullScreenSize = getFullScreenResolution(cameraSelector)
+        return listOf(fullScreenSize) + imageQualities.filter { it.camSelector == cameraSelector }
+            .flatMap { it.qualities }
+            .sortedByDescending { it.pixels }
+            .distinctBy { it.getAspectRatio(activity) }
+            .filter { it.isSupported() }
+    }
+
+    private fun getFullScreenResolution(cameraSelector: CameraSelector): MySize {
         return imageQualities.filter { it.camSelector == cameraSelector }
             .flatMap { it.qualities }
-            .sortedWith(compareByDescending<MySize> { it.ratio }.thenByDescending { it.pixels })
+            .sortedByDescending { it.width }
-            .distinctBy { it.pixels }
+            .first { it.isSupported() }
-            .filter { it.megaPixels != "0.0" }
+            .copy(isFullScreen = true)
     }
 }

app/src/main/kotlin/com/simplemobiletools/camera/implementations/CameraXPreview.kt

@@ -4,6 +4,7 @@ import android.annotation.SuppressLint
 import android.content.Context
 import android.hardware.SensorManager
 import android.hardware.display.DisplayManager
+import android.util.Rational
 import android.util.Size
 import android.view.*
 import android.view.GestureDetector.SimpleOnGestureListener
@@ -14,10 +15,12 @@ import androidx.camera.lifecycle.ProcessCameraProvider
 import androidx.camera.video.*
 import androidx.camera.video.VideoCapture
 import androidx.camera.view.PreviewView
+import androidx.camera.view.PreviewView.ScaleType
 import androidx.core.content.ContextCompat
 import androidx.core.view.doOnLayout
 import androidx.lifecycle.DefaultLifecycleObserver
 import androidx.lifecycle.LifecycleOwner
+import androidx.window.layout.WindowMetricsCalculator
 import com.bumptech.glide.load.ImageHeaderParser.UNKNOWN_ORIENTATION
 import com.simplemobiletools.camera.R
 import com.simplemobiletools.camera.dialogs.ChangeResolutionDialogX
@@ -49,6 +52,7 @@ class CameraXPreview(
     private val mainExecutor = ContextCompat.getMainExecutor(activity)
     private val displayManager = activity.getSystemService(Context.DISPLAY_SERVICE) as DisplayManager
     private val mediaSoundHelper = MediaSoundHelper()
+    private val windowMetricsCalculator = WindowMetricsCalculator.getOrCreate()
     private val videoQualityManager = VideoQualityManager(activity)
     private val imageQualityManager = ImageQualityManager(activity)
     private val exifRemover = ExifRemover(contentResolver)
@@ -120,7 +124,7 @@ class CameraXPreview(
 
     private fun bindCameraUseCases() {
         val cameraProvider = cameraProvider ?: throw IllegalStateException("Camera initialization failed.")
-        val rotation = previewView.display.rotation
+
         val resolution = if (isPhotoCapture) {
             imageQualityManager.getUserSelectedResolution(cameraSelector)
         } else {
@@ -128,22 +132,94 @@ class CameraXPreview(
             MySize(selectedQuality.width, selectedQuality.height)
         }
 
+        val isFullSize = resolution.isFullScreen
+        previewView.scaleType = if (isFullSize) ScaleType.FILL_CENTER else ScaleType.FIT_CENTER
+        val rotation = previewView.display.rotation
         val rotatedResolution = getRotatedResolution(resolution, rotation)
 
-        preview = buildPreview(rotatedResolution, rotation)
+        val previewUseCase = buildPreview(rotatedResolution, rotation)
         val captureUseCase = getCaptureUseCase(rotatedResolution, rotation)
-        cameraProvider.unbindAll()
-        camera = cameraProvider.bindToLifecycle(
-            activity,
-            cameraSelector,
-            preview,
-            captureUseCase,
-        )
 
-        preview?.setSurfaceProvider(previewView.surfaceProvider)
+        cameraProvider.unbindAll()
+        camera = if (isFullSize) {
+            val metrics = windowMetricsCalculator.computeCurrentWindowMetrics(activity).bounds
+            val screenWidth = metrics.width()
+            val screenHeight = metrics.height()
+            val viewPort = ViewPort.Builder(Rational(screenWidth, screenHeight), rotation).build()
+
+            val useCaseGroup = UseCaseGroup.Builder()
+                .addUseCase(previewUseCase)
+                .addUseCase(captureUseCase)
+                .setViewPort(viewPort)
+                .build()
+
+            cameraProvider.bindToLifecycle(
+                activity,
+                cameraSelector,
+                useCaseGroup,
+            )
+        } else {
+            cameraProvider.bindToLifecycle(
+                activity,
+                cameraSelector,
+                previewUseCase,
+                captureUseCase,
+            )
+        }
+
+        previewUseCase.setSurfaceProvider(previewView.surfaceProvider)
+        preview = previewUseCase
         setupZoomAndFocus()
     }
 
+    private fun getRotatedResolution(resolution: MySize, rotationDegrees: Int): Size {
+        return if (rotationDegrees == Surface.ROTATION_0 || rotationDegrees == Surface.ROTATION_180) {
+            Size(resolution.height, resolution.width)
+        } else {
+            Size(resolution.width, resolution.height)
+        }
+    }
+
+    private fun buildPreview(resolution: Size, rotation: Int): Preview {
+        return Preview.Builder()
+            .setTargetRotation(rotation)
+            .setTargetResolution(resolution)
+            .build()
+    }
+
+    private fun getCaptureUseCase(resolution: Size, rotation: Int): UseCase {
+        return if (isPhotoCapture) {
+            buildImageCapture(resolution, rotation).also {
+                imageCapture = it
+            }
+        } else {
+            buildVideoCapture().also {
+                videoCapture = it
+            }
+        }
+    }
+
+    private fun buildImageCapture(resolution: Size, rotation: Int): ImageCapture {
+        return Builder()
+            .setCaptureMode(CAPTURE_MODE_MAXIMIZE_QUALITY)
+            .setFlashMode(flashMode)
+            .setJpegQuality(config.photoQuality)
+            .setTargetRotation(rotation)
+            .setTargetResolution(resolution)
+            .build()
+    }
+
+    private fun buildVideoCapture(): VideoCapture<Recorder> {
+        val qualitySelector = QualitySelector.from(
+            videoQualityManager.getUserSelectedQuality(cameraSelector).toCameraXQuality(),
+            FallbackStrategy.higherQualityOrLowerThan(Quality.SD),
+        )
+        val recorder = Recorder.Builder()
+            .setQualitySelector(qualitySelector)
+            .build()
+        return VideoCapture.withOutput(recorder)
+    }
+
     private fun setupCameraObservers() {
         listener.setFlashAvailable(camera?.cameraInfo?.hasFlashUnit() ?: false)
         listener.onChangeCamera(isFrontCameraInUse())
@@ -166,56 +242,6 @@ class CameraXPreview(
         }
     }
 
-    private fun getCaptureUseCase(resolution: Size, rotation: Int): UseCase {
-        return if (isPhotoCapture) {
-            cameraProvider?.unbind(videoCapture)
-            buildImageCapture(resolution, rotation).also {
-                imageCapture = it
-            }
-        } else {
-            cameraProvider?.unbind(imageCapture)
-            buildVideoCapture().also {
-                videoCapture = it
-            }
-        }
-    }
-
-    private fun buildImageCapture(resolution: Size, rotation: Int): ImageCapture {
-        return Builder()
-            .setCaptureMode(CAPTURE_MODE_MAXIMIZE_QUALITY)
-            .setFlashMode(flashMode)
-            .setJpegQuality(config.photoQuality)
-            .setTargetRotation(rotation)
-            .setTargetResolution(resolution)
-            .build()
-    }
-
-    private fun getRotatedResolution(resolution: MySize, rotationDegrees: Int): Size {
-        return if (rotationDegrees == Surface.ROTATION_0 || rotationDegrees == Surface.ROTATION_180) {
-            Size(resolution.height, resolution.width)
-        } else {
-            Size(resolution.width, resolution.height)
-        }
-    }
-
-    private fun buildPreview(resolution: Size, rotation: Int): Preview {
-        return Preview.Builder()
-            .setTargetRotation(rotation)
-            .setTargetResolution(resolution)
-            .build()
-    }
-
-    private fun buildVideoCapture(): VideoCapture<Recorder> {
-        val qualitySelector = QualitySelector.from(
-            videoQualityManager.getUserSelectedQuality(cameraSelector).toCameraXQuality(),
-            FallbackStrategy.higherQualityOrLowerThan(Quality.SD),
-        )
-        val recorder = Recorder.Builder()
-            .setQualitySelector(qualitySelector)
-            .build()
-        return VideoCapture.withOutput(recorder)
-    }
-
     private fun hasBackCamera(): Boolean {
         return cameraProvider?.hasCamera(CameraSelector.DEFAULT_BACK_CAMERA) ?: false
     }

app/src/main/kotlin/com/simplemobiletools/camera/models/MySize.kt

@@ -4,18 +4,19 @@ import android.content.Context
 import android.util.Size
 import com.simplemobiletools.camera.R
 
-data class MySize(val width: Int, val height: Int) {
+data class MySize(val width: Int, val height: Int, val isFullScreen: Boolean = false) {
     companion object {
         private const val ONE_MEGA_PIXEL = 1000000
+        private const val ZERO_MEGA_PIXEL = "0.0"
     }
 
-    val ratio = width / height.toFloat()
+    private val ratio = width / height.toFloat()
 
     val pixels: Int = width * height
 
-    val megaPixels: String =  String.format("%.1f", (width * height.toFloat()) / ONE_MEGA_PIXEL)
+    val megaPixels: String = String.format("%.1f", (width * height.toFloat()) / ONE_MEGA_PIXEL)
 
-    fun isSixteenToNine() = ratio == 16 / 9f
+    private fun isSixteenToNine() = ratio == 16 / 9f
 
     private fun isFiveToThree() = ratio == 5 / 3f
 
@@ -37,6 +38,10 @@ data class MySize(val width: Int, val height: Int) {
 
     private fun isSquare() = width == height
 
+    fun isSupported(): Boolean {
+        return (isFourToThree() || isSixteenToNine() || isSquare()) && megaPixels != ZERO_MEGA_PIXEL
+    }
+
     fun getAspectRatio(context: Context) = when {
         isSixteenToNine() -> "16:9"
         isFiveToThree() -> "5:3"

app/src/main/res/drawable/gradient_background.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <gradient
+        android:angle="90"
+        android:endColor="@android:color/transparent"
+        android:startColor="@color/gradient_grey_start"/>
+</shape>

app/src/main/res/drawable/gradient_background_flipped.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <gradient
+        android:angle="270"
+        android:endColor="@android:color/transparent"
+        android:startColor="@color/gradient_grey_start"/>
+</shape>

app/src/main/res/layout/activity_main.xml

@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
-<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/view_holder"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:background="@android:color/black">
+    android:background="@android:color/black"
+    android:fitsSystemWindows="true">
 
     <androidx.camera.view.PreviewView
         android:id="@+id/preview_view"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
+        android:layout_height="match_parent" />
-        app:scaleType="fitStart" />
 
     <View
         android:id="@+id/capture_black_screen"
@@ -20,24 +20,28 @@
         android:alpha="0"
         android:background="@color/md_grey_black" />
 
+    <View
+        android:id="@+id/top_overlay"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:background="@drawable/gradient_background_flipped"
+        app:layout_constraintBottom_toBottomOf="@id/settings"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
     <ImageView
         android:id="@+id/settings"
         android:layout_width="@dimen/icon_size"
         android:layout_height="@dimen/icon_size"
-        android:layout_alignParentEnd="true"
         android:contentDescription="@string/settings"
         android:padding="@dimen/normal_margin"
-        android:src="@drawable/ic_settings_cog_vector" />
+        android:src="@drawable/ic_settings_cog_vector"
+        app:layout_constraintEnd_toStartOf="@id/change_resolution"
+        app:layout_constraintHorizontal_chainStyle="spread"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
 
-    <ImageView
-        android:id="@+id/toggle_photo_video"
-        android:layout_width="@dimen/icon_size"
-        android:layout_height="@dimen/icon_size"
-        android:layout_below="@+id/settings"
-        android:layout_alignParentEnd="true"
-        android:contentDescription="@string/toggle_photo_video"
-        android:padding="@dimen/normal_margin"
-        android:src="@drawable/ic_video_vector" />
 
     <ImageView
         android:id="@+id/change_resolution"
@@ -47,61 +51,106 @@
         android:layout_alignParentEnd="true"
         android:contentDescription="@string/resolution"
         android:padding="@dimen/normal_margin"
-        android:src="@drawable/ic_resolution_vector" />
+        android:src="@drawable/ic_resolution_vector"
+        app:layout_constraintEnd_toStartOf="@id/toggle_flash"
+        app:layout_constraintStart_toEndOf="@id/settings"
+        app:layout_constraintTop_toTopOf="@id/settings" />
+
+    <ImageView
+        android:id="@+id/toggle_flash"
+        android:layout_width="@dimen/icon_size"
+        android:layout_height="@dimen/icon_size"
+        android:layout_weight="1"
+        android:contentDescription="@string/toggle_flash"
+        android:padding="@dimen/normal_margin"
+        android:src="@drawable/ic_flash_off_vector"
+        app:layout_constraintEnd_toStartOf="@id/toggle_photo_video"
+        app:layout_constraintStart_toEndOf="@id/change_resolution"
+        app:layout_constraintTop_toTopOf="@id/settings" />
+
+    <ImageView
+        android:id="@+id/toggle_photo_video"
+        android:layout_width="@dimen/icon_size"
+        android:layout_height="@dimen/icon_size"
+        android:contentDescription="@string/toggle_photo_video"
+        android:padding="@dimen/normal_margin"
+        android:src="@drawable/ic_video_vector"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toEndOf="@id/toggle_flash"
+        app:layout_constraintTop_toTopOf="@id/settings" />
+
+
+    <androidx.constraintlayout.widget.Barrier
+        android:id="@+id/top_barrier"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        app:barrierDirection="bottom"
+        app:constraint_referenced_ids="settings,change_resolution,toggle_flash,toggle_photo_video" />
+
+
+    <View
+        android:id="@+id/bottom_overlay"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:background="@drawable/gradient_background"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="@id/shutter" />
+
+    <ImageView
+        android:id="@+id/toggle_camera"
+        android:layout_width="@dimen/icon_size"
+        android:layout_height="@dimen/icon_size"
+        android:contentDescription="@string/toggle_camera"
+        android:padding="@dimen/normal_margin"
+        android:src="@drawable/ic_camera_front_vector"
+        app:layout_constraintBottom_toBottomOf="@id/shutter"
+        app:layout_constraintEnd_toStartOf="@id/shutter"
+        app:layout_constraintHorizontal_chainStyle="spread"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="@id/shutter" />
+
+    <ImageView
+        android:id="@+id/shutter"
+        android:layout_width="@dimen/icon_size"
+        android:layout_height="@dimen/icon_size"
+        android:layout_marginBottom="@dimen/small_margin"
+        android:contentDescription="@string/shutter"
+        android:src="@drawable/ic_shutter_vector"
+        app:layout_constraintBottom_toTopOf="@id/video_rec_curr_timer"
+        app:layout_constraintEnd_toStartOf="@id/last_photo_video_preview"
+        app:layout_constraintStart_toEndOf="@id/toggle_camera"
+
+        app:layout_constraintVertical_bias="1"
+        app:layout_goneMarginBottom="@dimen/big_margin" />
 
     <ImageView
         android:id="@+id/last_photo_video_preview"
         android:layout_width="@dimen/icon_size"
         android:layout_height="@dimen/icon_size"
-        android:layout_below="@+id/change_resolution"
-        android:layout_alignParentEnd="true"
         android:contentDescription="@string/view_last_media"
-        android:padding="@dimen/medium_margin" />
+        android:padding="@dimen/medium_margin"
+        app:layout_constraintBottom_toBottomOf="@id/shutter"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toEndOf="@id/shutter"
+        app:layout_constraintTop_toTopOf="@id/shutter"
+        tools:src="@tools:sample/backgrounds/scenic" />
 
-    <LinearLayout
-        android:id="@+id/btn_holder"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-
-        android:layout_alignParentBottom="true"
-        android:gravity="center_horizontal|bottom">
-
-        <ImageView
-            android:id="@+id/toggle_camera"
-            android:layout_width="@dimen/icon_size"
-            android:layout_height="@dimen/icon_size"
-            android:layout_weight="1"
-            android:contentDescription="@string/toggle_camera"
-            android:padding="@dimen/normal_margin"
-            android:src="@drawable/ic_camera_front_vector" />
-
-        <ImageView
-            android:id="@+id/shutter"
-            android:layout_width="@dimen/icon_size"
-            android:layout_height="@dimen/icon_size"
-            android:layout_weight="1"
-            android:contentDescription="@string/shutter"
-            android:src="@drawable/ic_shutter_vector" />
-
-        <ImageView
-            android:id="@+id/toggle_flash"
-            android:layout_width="@dimen/icon_size"
-            android:layout_height="@dimen/icon_size"
-            android:layout_weight="1"
-            android:contentDescription="@string/toggle_flash"
-            android:padding="@dimen/normal_margin"
-            android:src="@drawable/ic_flash_off_vector" />
-
-    </LinearLayout>
 
     <TextView
         android:id="@+id/video_rec_curr_timer"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:layout_above="@+id/btn_holder"
         android:layout_centerHorizontal="true"
+        android:layout_marginTop="@dimen/small_margin"
+        android:layout_marginBottom="@dimen/big_margin"
         android:textColor="@android:color/white"
         android:visibility="gone"
-        tools:text="00:00" />
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        tools:text="00:00"
+        tools:visibility="gone" />
 
-</RelativeLayout>
+</androidx.constraintlayout.widget.ConstraintLayout>