Use camera-compose and restore double-tap to flip camera (#263)

* Move HDR color mode code out of CameraXViewfinder

* Replace CameraXViewfinder with camera-compose version

* Move double tap logic to same pointerInput as tapToFocus

feature/preview/build.gradle.kts

@@ -134,7 +134,7 @@ dependencies {
 
  // CameraX
  implementation(libs.camera.core)
- implementation(libs.camera.viewfinder.compose)
+ implementation(libs.camera.compose)
 
  // Hilt
  implementation(libs.dagger.hilt.android)

feature/preview/src/main/java/com/google/jetpackcamera/feature/preview/PreviewScreen.kt

@@ -38,6 +38,7 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberUpdatedState
 import androidx.compose.runtime.snapshotFlow
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -203,15 +204,11 @@ private fun ContentScreen(
  Scaffold(
  snackbarHost = { SnackbarHost(hostState = snackbarHostState) }
  ) {
- val lensFacing = remember(previewUiState) {
+ val lensFacing by rememberUpdatedState(
  previewUiState.currentCameraSettings.cameraLensFacing
- }
+ )
 
- val onFlipCamera = remember(lensFacing) {
- {
- onSetLensFacing(lensFacing.flip())
- }
- }
+ val onFlipCamera = { onSetLensFacing(lensFacing.flip()) }
 
  val isMuted = remember(previewUiState) {
  previewUiState.currentCameraSettings.audioMuted

feature/preview/src/main/java/com/google/jetpackcamera/feature/preview/ui/PreviewScreenComponents.kt

@@ -15,11 +15,15 @@
  */
 package com.google.jetpackcamera.feature.preview.ui
 
+import android.content.pm.ActivityInfo
 import android.content.res.Configuration
 import android.os.Build
 import android.util.Log
 import android.widget.Toast
+import androidx.camera.compose.CameraXViewfinder
+import androidx.camera.core.DynamicRange as CXDynamicRange
 import androidx.camera.core.SurfaceRequest
+import androidx.camera.viewfinder.compose.MutableCoordinateTransformer
 import androidx.camera.viewfinder.surface.ImplementationMode
 import androidx.compose.animation.core.EaseOutExpo
 import androidx.compose.animation.core.LinearEasing
@@ -51,7 +55,6 @@ import androidx.compose.material.icons.filled.CameraAlt
 import androidx.compose.material.icons.filled.FlipCameraAndroid
 import androidx.compose.material.icons.filled.Mic
 import androidx.compose.material.icons.filled.MicOff
-import androidx.compose.material.icons.filled.Nightlight
 import androidx.compose.material.icons.filled.Settings
 import androidx.compose.material.icons.filled.VideoStable
 import androidx.compose.material.icons.filled.Videocam
@@ -75,6 +78,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.rememberUpdatedState
 import androidx.compose.runtime.setValue
+import androidx.compose.runtime.snapshotFlow
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.alpha
@@ -98,6 +102,10 @@ import com.google.jetpackcamera.settings.model.AspectRatio
 import com.google.jetpackcamera.settings.model.LowLightBoost
 import com.google.jetpackcamera.settings.model.Stabilization
 import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.onCompletion
 import kotlinx.coroutines.launch
 
 private const val TAG = "PreviewScreen"
@@ -264,24 +272,12 @@ fun PreviewDisplay(
  }
  )
 
- val currentOnFlipCamera by rememberUpdatedState(onFlipCamera)
-
  surfaceRequest?.let {
  BoxWithConstraints(
  Modifier
  .testTag(PREVIEW_DISPLAY)
  .fillMaxSize()
- .background(Color.Black)
- .pointerInput(Unit) {
- detectTapGestures(
- onDoubleTap = { offset ->
- // double tap to flip camera
- Log.d(TAG, "onDoubleTap $offset")
- currentOnFlipCamera()
- }
- )
- },
-
+ .background(Color.Black),
  contentAlignment = Alignment.Center
  ) {
  val maxAspectRatio: Float = maxWidth / maxHeight
@@ -316,21 +312,94 @@ fun PreviewDisplay(
  .alpha(imageAlpha)
  .clip(RoundedCornerShape(16.dp))
  ) {
+ val implementationMode = when {
+ Build.VERSION.SDK_INT > 24 -> ImplementationMode.EXTERNAL
+ else -> ImplementationMode.EMBEDDED
+ }
+
+ DetectWindowColorModeChanges(
+ surfaceRequest = surfaceRequest,
+ implementationMode = implementationMode,
+ onRequestWindowColorMode = onRequestWindowColorMode
+ )
+
+ val coordinateTransformer = remember { MutableCoordinateTransformer() }
  CameraXViewfinder(
- modifier = Modifier.fillMaxSize(),
+ modifier = Modifier
+ .fillMaxSize()
+ .pointerInput(Unit) {
+ detectTapGestures(
+ onDoubleTap = { offset ->
+ // double tap to flip camera
+ Log.d(TAG, "onDoubleTap $offset")
+ onFlipCamera()
+ },
+ onTap = {
+ with(coordinateTransformer) {
+ val surfaceCoords = it.transform()
+ Log.d(
+ "TAG",
+ "onTapToFocus: " +
+ "input{$it} -> surface{$surfaceCoords}"
+ )
+ onTapToFocus(surfaceCoords.x, surfaceCoords.y)
+ }
+ }
+ )
+ },
  surfaceRequest = it,
- implementationMode = when {
- Build.VERSION.SDK_INT > 24 -> ImplementationMode.EXTERNAL
- else -> ImplementationMode.EMBEDDED
- },
- onRequestWindowColorMode = onRequestWindowColorMode,
- onTap = { x, y -> onTapToFocus(x, y) }
+ implementationMode = implementationMode,
+ coordinateTransformer = coordinateTransformer
  )
  }
  }
  }
 }
 
+@Composable
+fun DetectWindowColorModeChanges(
+ surfaceRequest: SurfaceRequest,
+ implementationMode: ImplementationMode,
+ onRequestWindowColorMode: (Int) -> Unit
+) {
+ if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+ val currentSurfaceRequest: SurfaceRequest by rememberUpdatedState(surfaceRequest)
+ val currentImplementationMode: ImplementationMode by rememberUpdatedState(
+ implementationMode
+ )
+ val currentOnRequestWindowColorMode: (Int) -> Unit by rememberUpdatedState(
+ onRequestWindowColorMode
+ )
+
+ LaunchedEffect(Unit) {
+ val colorModeSnapshotFlow =
+ snapshotFlow { Pair(currentSurfaceRequest.dynamicRange, currentImplementationMode) }
+ .map { (dynamicRange, implMode) ->
+ val isSourceHdr = dynamicRange.encoding != CXDynamicRange.ENCODING_SDR
+ val destSupportsHdr = implMode == ImplementationMode.EXTERNAL
+ if (isSourceHdr && destSupportsHdr) {
+ ActivityInfo.COLOR_MODE_HDR
+ } else {
+ ActivityInfo.COLOR_MODE_DEFAULT
+ }
+ }.distinctUntilChanged()
+
+ val callbackSnapshotFlow = snapshotFlow { currentOnRequestWindowColorMode }
+
+ // Combine both flows so that we call the callback every time it changes or the
+ // window color mode changes.
+ // We'll also reset to default when this LaunchedEffect is disposed
+ combine(colorModeSnapshotFlow, callbackSnapshotFlow) { colorMode, callback ->
+ Pair(colorMode, callback)
+ }.onCompletion {
+ currentOnRequestWindowColorMode(ActivityInfo.COLOR_MODE_DEFAULT)
+ }.collect { (colorMode, callback) ->
+ callback(colorMode)
+ }
+ }
+ }
+}
+
 @Composable
 fun StabilizationIcon(
  videoStabilization: Stabilization,