Android studio zoom surfaceview (camera2 API)

Question

我正在制作一个 android studio 应用程序，它必须在 Android 11（API30）上显示外部摄像头的视频图像。

我对 android studio 和 java 完全陌生。我设法用 chatgpt 从头开始写了一个预览 surfaceview，因为关于这个问题的教程不多。我现在正在研究缩放按钮，但我尝试的一切都不起作用。我做了一个 zoomthread 在后台运行但是当我在预览中按下缩放按钮时没有任何反应。

package com.example.concept3;

        import androidx.annotation.NonNull;
        import androidx.appcompat.app.AppCompatActivity;
        import androidx.core.app.ActivityCompat;

        import android.Manifest;
        import android.content.Context;
        import android.content.pm.PackageManager;
        import android.graphics.Rect;
        import android.hardware.camera2.CameraCaptureSession;
        import android.hardware.camera2.CameraCharacteristics;
        import android.hardware.camera2.CameraDevice;
        import android.hardware.camera2.CameraManager;
        import android.hardware.camera2.CameraAccessException;
        import android.hardware.camera2.CaptureRequest;
        import android.os.Bundle;
        import android.os.Handler;
        import android.os.Looper;
        import android.view.Surface;
        import android.view.SurfaceHolder;
        import android.view.SurfaceView;
        import android.view.View;
        import android.widget.Button;

        import java.util.ArrayList;
        import java.util.List;

public class MainActivity extends AppCompatActivity {
    private CameraCaptureSession captureSession;
    private Button zoomButton;
    private CaptureRequest.Builder builder;
    private CameraCharacteristics characteristics;
    String[] cameraIds;
    String cameraId;
    private int zoomLevel;
    private static final int REQUEST_CAMERA_PERMISSION = 44;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED){
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA}, REQUEST_CAMERA_PERMISSION);
        }

        CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);

        try{
            cameraIds = cameraManager.getCameraIdList();
            cameraId = cameraIds[0];

            cameraManager.openCamera(cameraId, new CameraDevice.StateCallback() {
                @Override
                public void onOpened(@NonNull CameraDevice cameraDevice) {
                    //camera configuratie
                    try {
                        builder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
                        SurfaceView surfaceView = findViewById(R.id.Beeld);
                        surfaceView.getHolder().addCallback(new SurfaceHolder.Callback() {
                            @Override
                            public void surfaceCreated(@NonNull SurfaceHolder holder) {
                                try {
                                    Surface surface = holder.getSurface();
                                    CaptureRequest.Builder builder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
                                    builder.addTarget(surface);

                                    List<Surface> outputSurface = new ArrayList<>(10000 );
                                    outputSurface.add(surface);

                                    cameraDevice.createCaptureSession(outputSurface, new CameraCaptureSession.StateCallback() {
                                        @Override
                                        public void onConfigured(@NonNull CameraCaptureSession session) {
                                            captureSession = session;
                                            try {
                                                builder.addTarget(surface);
                                                CaptureRequest request = builder.build();

                                                captureSession.setRepeatingRequest(request, null, null);

                                                zoomButton = findViewById(R.id.zoomButton);
                                                zoomButton.setOnClickListener(new View.OnClickListener() {
                                                    @Override
                                                    public void onClick(View v) {
                                                        if (cameraDevice != null){
                                                            Handler handler = new Handler(Looper.getMainLooper());
                                                            zoomThread thread = new zoomThread(cameraDevice, zoomLevel, cameraManager, builder, characteristics, surfaceView.getHolder().getSurface(), handler);
                                                            thread.start();
                                                        }
                                                    }
                                                });

                                            } catch (CameraAccessException e) {
                                                throw new RuntimeException(e);
                                            }
                                        }

                                        @Override
                                        public void onConfigureFailed(@NonNull CameraCaptureSession session) {
                                        }
                                    }, null);

                                } catch (CameraAccessException e) {
                                    throw new RuntimeException(e);
                                }
                            }

                            @Override
                            public void surfaceChanged(@NonNull SurfaceHolder holder, int format, int width, int height) {
                            }

                            @Override
                            public void surfaceDestroyed(@NonNull SurfaceHolder holder) {
                                captureSession.close();
                                captureSession = null;
                            }
                        });

                    } catch (CameraAccessException e) {
                        throw new RuntimeException(e);
                    }
                }

                @Override
                public void onDisconnected(@NonNull CameraDevice cameraDevice) {
                    cameraDevice.close();
                }

                @Override
                public void onError(@NonNull CameraDevice cameraDevice, int i) {
                    cameraDevice.close();
                }
            }, null);
        } catch (CameraAccessException e){
            e.printStackTrace();
        }
    }

    public class zoomThread extends Thread {
        private CameraDevice cameraDevice;
        private int zoomLevel;
        private CameraManager cameraManager;
        private CaptureRequest.Builder builder;
        private CameraCharacteristics characteristics;
        private Surface previewSurface;
        private Handler handler;
        float newZoom = 2.0f;

        public zoomThread(CameraDevice cameraDevice, int zoomLevel, CameraManager cameraManager, CaptureRequest.Builder builder, CameraCharacteristics characteristics, Surface previewSurface, Handler handler){
            this.zoomLevel = zoomLevel;
            this.cameraDevice = cameraDevice;
            this.cameraManager = cameraManager;
            this.builder = builder;
            this.characteristics = characteristics;
            this.previewSurface = previewSurface;
            this.handler = handler;
        }

        @Override
        public void run() {
            cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
            try {
                String cameraId = cameraManager.getCameraIdList()[0];
                characteristics = cameraManager.getCameraCharacteristics(cameraId);
            } catch (CameraAccessException e) {
                throw new RuntimeException(e);
            }
            float maxZoom = characteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM);
            if (zoomLevel <= maxZoom){
                Rect activeRect = characteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
                int centerX = activeRect.centerX();
                int centerY = activeRect.centerY();
                int deltaX = (int) ((0.5f * activeRect.width() / newZoom));
                int deltaY = (int) ((0.5f * activeRect.height() / newZoom));
                Rect newRect = new Rect(centerX - deltaX, centerY - deltaY, centerX + deltaX, centerY + deltaY);
                builder.set(CaptureRequest.SCALER_CROP_REGION, newRect);

                List<Surface> outputSurfaces = new ArrayList<Surface>();
                outputSurfaces.add(previewSurface);

                try {
                    cameraDevice.createCaptureSession(outputSurfaces, new CameraCaptureSession.StateCallback() {
                        @Override
                        public void onConfigured(@NonNull CameraCaptureSession session) {
                            CaptureRequest captureRequest = builder.build();
                            try {
                                session.setRepeatingRequest(captureRequest, null, null);
                            } catch (CameraAccessException e) {
                                throw new RuntimeException(e);
                            }
                        }

                        @Override
                        public void onConfigureFailed(@NonNull CameraCaptureSession session) {
                        }
                    },handler);
                } catch (CameraAccessException e) {
                    throw new RuntimeException(e);
                }
            }
        }
    }

}