fix: Fix Android focus not using correct focus point (#958)

This commit fixes #758. I was having the same issue and looked into it a bit. I found
[this StackOverflow answer](https://stackoverflow.com/a/60585382) which described a
solution to the same problem. Rather than manually calculate the focus point, we can
get the PreviewView to do it for us. This fixes the issue because the PreviewView
factors in any scaling or resizing of the view on the screen, which we weren't doing
before. The only potential issue is that this needs to run on the UI thread
(which is what the `withContext` is doing), but I've tested it with frame processors
enabled and disabled, and have found no issues in either case.
This commit is contained in:
Menardi 2022-03-31 17:01:21 +01:00 committed by GitHub
parent a7e66ed47c
commit fe01295226
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2 changed files with 7 additions and 4 deletions

View File

@ -1,9 +1,9 @@
package com.mrousavy.camera
import androidx.camera.core.FocusMeteringAction
import androidx.camera.core.SurfaceOrientedMeteringPointFactory
import com.facebook.react.bridge.ReadableMap
import kotlinx.coroutines.guava.await
import kotlinx.coroutines.withContext
import java.util.concurrent.TimeUnit
suspend fun CameraView.focus(pointMap: ReadableMap) {
@ -16,8 +16,11 @@ suspend fun CameraView.focus(pointMap: ReadableMap) {
val x = pointMap.getDouble("x") * dpi
val y = pointMap.getDouble("y") * dpi
val factory = SurfaceOrientedMeteringPointFactory(this.width.toFloat(), this.height.toFloat())
val point = factory.createPoint(x.toFloat(), y.toFloat())
// Getting the point from the previewView needs to be run on the UI thread
val point = withContext(coroutineScope.coroutineContext) {
previewView.meteringPointFactory.createPoint(x.toFloat(), y.toFloat());
}
val action = FocusMeteringAction.Builder(point, FocusMeteringAction.FLAG_AF or FocusMeteringAction.FLAG_AE)
.setAutoCancelDuration(5, TimeUnit.SECONDS) // auto-reset after 5 seconds
.build()

View File

@ -121,7 +121,7 @@ class CameraView(context: Context, private val frameProcessorThread: ExecutorSer
private val cameraExecutor = Executors.newSingleThreadExecutor()
internal val takePhotoExecutor = Executors.newSingleThreadExecutor()
internal val recordVideoExecutor = Executors.newSingleThreadExecutor()
private var coroutineScope = CoroutineScope(Dispatchers.Main)
internal var coroutineScope = CoroutineScope(Dispatchers.Main)
internal var camera: Camera? = null
internal var imageCapture: ImageCapture? = null