MpPreview/app/src/main/java/com/xypower/mppreview/ui/CameraChannelActivity.java

package com.xypower.mppreview.ui;

import static java.lang.System.loadLibrary;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.camera.core.CameraInfo;
import androidx.camera.core.CameraSelector;
import androidx.camera.core.ImageAnalysis;
import androidx.camera.core.ImageCapture;
import androidx.camera.core.ImageCaptureException;
import androidx.camera.core.Preview;
import androidx.camera.lifecycle.ProcessCameraProvider;
import androidx.camera.view.PreviewView;
import androidx.core.content.ContextCompat;

import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

import com.google.common.util.concurrent.ListenableFuture;
import com.xypower.mppreview.MyAnalyzer;
import com.xypower.mppreview.R;
import com.xypower.mppreview.bean.Contants;
import com.xypower.mppreview.databinding.ActivityCameraChannelBinding;

import java.io.File;
import java.text.SimpleDateFormat;
import java.util.List;
import java.util.Locale;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class CameraChannelActivity extends AppCompatActivity implements View.OnClickListener {

    static {
        loadLibrary("mppreview");
    }

    private com.xypower.mppreview.databinding.ActivityCameraChannelBinding viewBinding;
    private int camerid;
    private ImageCapture imageCapture;
    private ExecutorService cameraExecutor;
    private File outputDirectory;

    private static native void setInt(int cmd, int val);

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        viewBinding = ActivityCameraChannelBinding.inflate(getLayoutInflater());
        setContentView(viewBinding.getRoot());
        camerid = getIntent().getIntExtra(Contants.CAMERAID, 0);
        initEvent();

        // 设置照片等保存的位置
        outputDirectory = getOutputDirectory();

        cameraExecutor = Executors.newSingleThreadExecutor();

        startCamera(camerid);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        cameraExecutor.shutdown();
    }

    private void initEvent() {
        viewBinding.imageCaptureButton.setOnClickListener(this);
        viewBinding.foward.setOnClickListener(this);
        viewBinding.back.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.image_capture_button:
                takePhoto();
                break;
            case R.id.foward:
                setInt(311, 101);
                break;
            case R.id.back:
                setInt(311, 201);
                break;
        }
    }

    private void startCamera(int cameraid) {
        // 将Camera的生命周期和Activity绑定在一起（设定生命周期所有者），这样就不用手动控制相机的启动和关闭。
        ListenableFuture<ProcessCameraProvider> cameraProviderFuture = ProcessCameraProvider.getInstance(this);

        cameraProviderFuture.addListener(() -> {
            try {
                // 将你的相机和当前生命周期的所有者绑定所需的对象
                ProcessCameraProvider processCameraProvider = cameraProviderFuture.get();

                // 创建一个Preview 实例，并设置该实例的 surface 提供者（provider）。
                PreviewView viewFinder = viewBinding.viewFinder;
                Preview preview = new Preview.Builder().build();
                preview.setSurfaceProvider(viewFinder.getSurfaceProvider());

                // 选择后置摄像头作为默认摄像头
//                CameraSelector cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA;

                List<CameraInfo> availableCameraInfos = processCameraProvider.getAvailableCameraInfos();
                CameraInfo cameraInfo = availableCameraInfos.get(cameraid);
                CameraSelector cameraSelector = cameraInfo.getCameraSelector();

                // 创建拍照所需的实例
                imageCapture = new ImageCapture.Builder().build();

                // 设置预览帧分析
                ImageAnalysis imageAnalysis = new ImageAnalysis.Builder().build();
                imageAnalysis.setAnalyzer(cameraExecutor, new MyAnalyzer());

                // 重新绑定用例前先解绑
                processCameraProvider.unbindAll();

                // 绑定用例至相机
                processCameraProvider.bindToLifecycle(CameraChannelActivity.this, cameraSelector, preview, imageCapture, imageAnalysis);

            } catch (Exception e) {
                Log.e(Contants.TAG, "用例绑定失败！" + e);
            }
        }, ContextCompat.getMainExecutor(this));

    }

    private void takePhoto() {
        // 确保imageCapture 已经被实例化, 否则程序将可能崩溃
        if (imageCapture != null) {
            // 创建带时间戳的输出文件以保存图片，带时间戳是为了保证文件名唯一
            File photoFile = new File(outputDirectory, new SimpleDateFormat(Contants.FILENAME_FORMAT, Locale.SIMPLIFIED_CHINESE).format(System.currentTimeMillis()) + ".jpg");

            // 创建 output option 对象，用以指定照片的输出方式
            ImageCapture.OutputFileOptions outputFileOptions = new ImageCapture.OutputFileOptions.Builder(photoFile).build();

            // 执行takePicture（拍照）方法
            imageCapture.takePicture(outputFileOptions, ContextCompat.getMainExecutor(this), new ImageCapture.OnImageSavedCallback() {// 保存照片时的回调
                @Override
                public void onImageSaved(@NonNull ImageCapture.OutputFileResults outputFileResults) {
                    Uri savedUri = Uri.fromFile(photoFile);
                    String msg = "照片捕获成功! " + savedUri;
                    Toast.makeText(getBaseContext(), msg, Toast.LENGTH_SHORT).show();
                    Log.d(Contants.TAG, msg);
                }

                @Override
                public void onError(@NonNull ImageCaptureException exception) {
                    Log.e(Contants.TAG, "Photo capture failed: " + exception.getMessage());
                }
            });
        }
    }

    private File getOutputDirectory() {
        File mediaDir = new File(getExternalMediaDirs()[0], getString(R.string.app_name));
        boolean isExist = mediaDir.exists() || mediaDir.mkdir();
        return isExist ? mediaDir : null;
    }


}