Kotlin における findViewById
今日の朝の散歩です。
雪は初めてではないが、いつもの散歩コースでもやっぱり景色は新鮮に感じるなという顔している柴犬です。
鼻先の頭に雪を付けてあたりを見渡す柴犬です。
概要
次の画像のように、表示画面の一番下にTextView を配置してインフォメーションを表示しようとしました。
TextView を findViewById() で次のように捕えようとしましたがエラーとなりました。
TextView ob;
ob = (TextView)findViewById(R.ID.XXX);
ob.setText("hogehoge");
上でダメなので次を試しました。
val ob = findViewById(R.id.tvinfo)試した結果は次のようです。
このあと試行錯誤しましたので記録します。
目的の形
アプリ起動時は左の画像です。シャッター（Take Photo）をタップするとネットワークの情報がTextViewに表示されるようにしています。
右がシャッター（Take Photo）をタップした時の画像です。
撮影した画像
スマホのカメラ表示の範囲と撮影範囲が概ね合うようになりました。
activity_main.xml
TextView にスクロールを入れることにも結構手間取りました。
TextView のプロパティーの中でするものと思い込んでいろいろやってみました。ScrollView の中に入れ子にするとは思いませんでした。
<?xml version="1.0" encoding="utf-8"?>
<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:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<androidx.camera.view.PreviewView
android:id="@+id/viewFinder"
android:layout_width="match_parent"
android:layout_height="441dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
</androidx.camera.view.PreviewView>
<Button
android:id="@+id/image_capture_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_marginEnd="30dp"
android:elevation="2dp"
android:text="@string/take_photo"
app:layout_constraintEnd_toStartOf="@id/vertical_centerline"
app:layout_constraintTop_toBottomOf="@+id/viewFinder" />
<androidx.constraintlayout.widget.Guideline
android:id="@+id/vertical_centerline"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent=".50" />
<ScrollView
android:layout_width="match_parent"
android:layout_height="0px"
android:layout_marginTop="65dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/viewFinder" >
<TextView
android:id="@+id/tvinfo"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="TextView"/>
</ScrollView>
<Button
android:id="@+id/video_capture_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="30dp"
android:layout_marginTop="10dp"
android:elevation="2dp"
android:text="@string/start_capture"
app:layout_constraintStart_toStartOf="@+id/vertical_centerline"
app:layout_constraintTop_toBottomOf="@+id/viewFinder" />
</androidx.constraintlayout.widget.ConstraintLayout>
findViewById()の解決方法
build.gradle.kts （Module :App）で
android {
～
省略
～
buildFeatures {
viewBinding = true
}
}viewBinding = true を加えていたので
viewBinding.tvinfo.text = "hogehoge"とするだけでよかったです。
その後分かった記述方法
この記述でもいいようです。
var tvInfo = findViewById<View>(R.id.tvinfo) as TextView
tvInfo.SetText("hogehoge")MainActivity.kt
私の備忘録ですので、MainActivity.kt の全文も掲げています。
また、所有している Synology 製の NAS へのFTPを使ってアップロード途中のコードも入っています。
NAS へのアップロードはまだ成功していないのですが、成功したら記録しようと思っています。
package siba.inu.android.cameraapp
// apache FTPClient関係 commons-net-3.10.0.jar をインポート
import android.Manifest
import android.content.ContentValues
import android.content.pm.PackageManager
import android.net.ConnectivityManager
import android.os.AsyncTask
import android.os.Build
import android.os.Bundle
import android.provider.MediaStore
import android.util.Log
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.camera.core.CameraSelector
import androidx.camera.core.ImageAnalysis
import androidx.camera.core.ImageCapture
import androidx.camera.core.ImageCaptureException
import androidx.camera.core.ImageProxy
import androidx.camera.core.Preview
import androidx.camera.lifecycle.ProcessCameraProvider
import androidx.camera.video.FallbackStrategy
import androidx.camera.video.MediaStoreOutputOptions
import androidx.camera.video.Quality
import androidx.camera.video.QualitySelector
import androidx.camera.video.Recorder
import androidx.camera.video.Recording
import androidx.camera.video.VideoCapture
import androidx.camera.video.VideoRecordEvent
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import androidx.core.content.PermissionChecker
import android.text.method.ScrollingMovementMethod
import android.widget.TextView
import org.apache.commons.net.ftp.FTP
import org.apache.commons.net.ftp.FTPClient
import siba.inu.android.cameraapp.databinding.ActivityMainBinding
import java.io.File
import java.io.FileInputStream
import java.net.URL
import java.nio.ByteBuffer
import java.text.SimpleDateFormat
import java.util.Locale
import java.util.concurrent.ExecutorService
import java.util.concurrent.Executors
typealias LumaListener = (luma: Double) -> Unit
class MainActivity : AppCompatActivity() {
private lateinit var viewBinding: ActivityMainBinding
private var imageCapture: ImageCapture? = null
private var videoCapture: VideoCapture<Recorder>? = null
private var recording: Recording? = null
private lateinit var cameraExecutor: ExecutorService
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
viewBinding = ActivityMainBinding.inflate(layoutInflater)
setContentView(viewBinding.root)
// Request camera permissions
if (allPermissionsGranted()) {
startCamera()
} else {
ActivityCompat.requestPermissions(
this, REQUIRED_PERMISSIONS, REQUEST_CODE_PERMISSIONS)
}
// Set up the listeners for take photo and video capture buttons
viewBinding.imageCaptureButton.setOnClickListener { takePhoto() }
viewBinding.videoCaptureButton.setOnClickListener { captureVideo() }
cameraExecutor = Executors.newSingleThreadExecutor()
}
private fun takePhoto() {
// Get a stable reference of the modifiable image capture use case
val imageCapture = imageCapture ?: return
// Create time stamped name and MediaStore entry.
val name = SimpleDateFormat(FILENAME_FORMAT, Locale.US)
.format(System.currentTimeMillis())
val contentValues = ContentValues().apply {
put(MediaStore.MediaColumns.DISPLAY_NAME, name)
put(MediaStore.MediaColumns.MIME_TYPE, "image/jpeg")
if(Build.VERSION.SDK_INT > Build.VERSION_CODES.P) {
put(MediaStore.Images.Media.RELATIVE_PATH, "Pictures/CameraX-Image")
}
}
// Create output options object which contains file + metadata
val outputOptions = ImageCapture.OutputFileOptions
.Builder(contentResolver,
MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
contentValues)
.build()
// Set up image capture listener, which is triggered after photo has
// been taken
imageCapture.takePicture(
outputOptions,
ContextCompat.getMainExecutor(this),
object : ImageCapture.OnImageSavedCallback {
override fun onError(exc: ImageCaptureException) {
Log.e(TAG, "Photo capture failed: ${exc.message}", exc)
}
override fun
onImageSaved(output: ImageCapture.OutputFileResults){
val msg = "Photo capture succeeded: ${output.savedUri}"
Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT).show()
Log.d(TAG, msg)
//Fileオブジェクトの作成
val file = File("Pictures/CameraX-Image/${name}.jpg")
//アップロード
uploadFileToFtp(file,
"xxxxxxxxxx",
"xxxxxx",
"xxxxxxxxxxx",
"xxxxxxxxxxxxxxxxxxxxxxxxx")
}
}
)
}
// Implements VideoCapture use case, including start and stop capturing.
private fun captureVideo() {
val videoCapture = this.videoCapture ?: return
viewBinding.videoCaptureButton.isEnabled = false
val curRecording = recording
if (curRecording != null) {
// Stop the current recording session.
curRecording.stop()
recording = null
return
}
// create and start a new recording session
val name = SimpleDateFormat(FILENAME_FORMAT, Locale.US)
.format(System.currentTimeMillis())
val contentValues = ContentValues().apply {
put(MediaStore.MediaColumns.DISPLAY_NAME, name)
put(MediaStore.MediaColumns.MIME_TYPE, "video/mp4")
if (Build.VERSION.SDK_INT > Build.VERSION_CODES.P) {
put(MediaStore.Video.Media.RELATIVE_PATH, "Movies/CameraX-Video")
}
}
val mediaStoreOutputOptions = MediaStoreOutputOptions
.Builder(contentResolver, MediaStore.Video.Media.EXTERNAL_CONTENT_URI)
.setContentValues(contentValues)
.build()
recording = videoCapture.output
.prepareRecording(this, mediaStoreOutputOptions)
.apply {
if (PermissionChecker.checkSelfPermission(this@MainActivity,
Manifest.permission.RECORD_AUDIO) ==
PermissionChecker.PERMISSION_GRANTED)
{
withAudioEnabled()
}
}
.start(ContextCompat.getMainExecutor(this)) { recordEvent ->
when(recordEvent) {
is VideoRecordEvent.Start -> {
viewBinding.videoCaptureButton.apply {
text = getString(R.string.stop_capture)
isEnabled = true
}
}
is VideoRecordEvent.Finalize -> {
if (!recordEvent.hasError()) {
val msg = "Video capture succeeded: " +
"${recordEvent.outputResults.outputUri}"
Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT)
.show()
Log.d(TAG, msg)
} else {
recording?.close()
recording = null
Log.e(TAG, "Video capture ends with error: " +
"${recordEvent.error}")
}
viewBinding.videoCaptureButton.apply {
text = getString(R.string.start_capture)
isEnabled = true
}
}
}
}
}
private fun startCamera() {
val cameraProviderFuture = ProcessCameraProvider.getInstance(this)
cameraProviderFuture.addListener({
// Used to bind the lifecycle of cameras to the lifecycle owner
val cameraProvider: ProcessCameraProvider = cameraProviderFuture.get()
// Preview
val preview = Preview.Builder()
.build()
.also {
it.setSurfaceProvider(viewBinding.viewFinder.surfaceProvider)
}
val recorder = Recorder.Builder()
.setQualitySelector(QualitySelector.from(Quality.HIGHEST,
FallbackStrategy.higherQualityOrLowerThan(Quality.SD)))
.build()
videoCapture = VideoCapture.withOutput(recorder)
imageCapture = ImageCapture.Builder().build()
/*
val imageAnalyzer = ImageAnalysis.Builder().build()
.also {
setAnalyzer(
cameraExecutor,
LuminosityAnalyzer { luma ->
Log.d(TAG, "Average luminosity: $luma")
}
)
}
*/
// Select back camera as a default
val cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA
try {
// Unbind use cases before rebinding
cameraProvider.unbindAll()
// Bind use cases to camera
cameraProvider.bindToLifecycle(
this, cameraSelector, preview, imageCapture, videoCapture)
} catch(exc: Exception) {
Log.e(TAG, "Use case binding failed", exc)
}
}, ContextCompat.getMainExecutor(this))
}
private fun allPermissionsGranted() = REQUIRED_PERMISSIONS.all {
ContextCompat.checkSelfPermission(
baseContext, it) == PackageManager.PERMISSION_GRANTED
}
override fun onDestroy() {
super.onDestroy()
cameraExecutor.shutdown()
}
companion object {
private const val TAG = "CameraApp"
private const val FILENAME_FORMAT = "yyyy-MM-dd-HH-mm-ss-SSS"
private const val REQUEST_CODE_PERMISSIONS = 10
private val REQUIRED_PERMISSIONS =
mutableListOf (
Manifest.permission.CAMERA,
Manifest.permission.RECORD_AUDIO
).apply {
if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
add(Manifest.permission.WRITE_EXTERNAL_STORAGE)
}
}.toTypedArray()
}
override fun onRequestPermissionsResult(
requestCode: Int, permissions: Array<String>, grantResults:
IntArray) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults)
if (requestCode == REQUEST_CODE_PERMISSIONS) {
if (allPermissionsGranted()) {
startCamera()
} else {
Toast.makeText(this,
"Permissions not granted by the user.",
Toast.LENGTH_SHORT).show()
finish()
}
}
}
// NAS(FTPサーバー)にアップロード
fun uploadFileToFtp(file: File,
ftpServer: String,
ftpUsername: String,
ftpPassword: String,
ftpDirectory: String) {
try {
activenet()
val ftpClient = FTPClient()
ftpClient.connect(ftpServer)
ftpClient.login(ftpUsername, ftpPassword)
ftpClient.enterLocalPassiveMode()
ftpClient.setFileType(FTP.BINARY_FILE_TYPE)
ftpClient.changeWorkingDirectory(ftpDirectory)
val inputStream = FileInputStream(file)
val fileName = file.name
ftpClient.storeFile(fileName, inputStream)
inputStream.close()
ftpClient.logout()
ftpClient.disconnect()
} catch (e: Exception) {
e.printStackTrace()
//Toast.makeText(this, e.toString(), Toast.LENGTH_SHORT).show()
//viewBinding.tvinfo.text = e.toString()
}
}
fun activenet() {
val connectivityManager = getSystemService(ConnectivityManager::class.java)
val currentNetwork = connectivityManager.getActiveNetwork()
val caps = connectivityManager.getNetworkCapabilities(currentNetwork)
val linkProperties = connectivityManager.getLinkProperties(currentNetwork)
viewBinding.tvinfo.text = linkProperties.toString()
}
}
private class LuminosityAnalyzer(private val listener: LumaListener) : ImageAnalysis.Analyzer {
private fun ByteBuffer.toByteArray(): ByteArray {
rewind() // Rewind the buffer to zero
val data = ByteArray(remaining())
get(data) // Copy the buffer into a byte array
return data // Return the byte array
}
override fun analyze(image: ImageProxy) {
val buffer = image.planes[0].buffer
val data = buffer.toByteArray()
val pixels = data.map { it.toInt() and 0xFF }
val luma = pixels.average()
listener(luma)
image.close()
}
}
この件はここまでとします。