Dónde colocar el autofoco en la cámara de la clase android

Estoy tratando de usar autofoucs no tengo ni idea de dónde colocar autofoco nadie tiene una idea de cómo implementar autofocus?

———- clase de vista previa ———-

• Android: Transparente WebView sobre previsualización de cámara
• Android La función takePicture de la cámara no llama a la función de devolución de llamada
• Android Camera onPreviewFrame frame rate no es coherente
• Error de liberación de la cámara Android desde PreviewCallback
• Error en el método onPictureTaken en la cámara android

package com.marakana; import java.io.IOException; import android.content.Context; import android.hardware.Camera; import android.hardware.Camera.PreviewCallback; import android.util.Log; import android.view.SurfaceHolder; import android.view.SurfaceView; class Preview extends SurfaceView implements SurfaceHolder.Callback { // <1> private static final String TAG = "Preview"; SurfaceHolder mHolder; // <2> public Camera camera; // <3> Preview(Context context) { super(context); // Install a SurfaceHolder.Callback so we get notified when the // underlying surface is created and destroyed. mHolder = getHolder(); // <4> mHolder.addCallback(this); // <5> mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); // <6> } // Called once the holder is ready public void surfaceCreated(SurfaceHolder holder) { // <7> // The Surface has been created, acquire the camera and tell it where // to draw. camera = Camera.open(); // <8> try { camera.setPreviewDisplay(holder); // <9> camera.setPreviewCallback(new PreviewCallback() { // <10> // Called for each frame previewed public void onPreviewFrame(byte[] data, Camera camera) { // <11> Log.d(TAG, "onPreviewFrame called at: " + System.currentTimeMillis()); Preview.this.invalidate(); // <12> } }); } catch (IOException e) { // <13> e.printStackTrace(); } } // Called when the holder is destroyed public void surfaceDestroyed(SurfaceHolder holder) { // <14> camera.stopPreview(); camera = null; } // Called when holder has changed public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { // <15> camera.startPreview(); } } 

—————– actividad de la cámara ————————

 preview = new Preview(this); // <3> ((FrameLayout) findViewById(R.id.preview)).addView(preview); // <4> buttonClick = (Button) findViewById(R.id.buttonClick); buttonClick.setOnClickListener(new OnClickListener() { public void onClick(View v) { // <5> preview.camera.takePicture(shutterCallback, rawCallback, jpegCallback); } }); // Handles data for jpeg picture PictureCallback jpegCallback = new PictureCallback() { // <8> public void onPictureTaken(byte[] data, Camera camera) { FileOutputStream outStream = null; try { // Write to SD Card outStream = new FileOutputStream(imgPath); // <9> outStream.write(data); outStream.close(); intImg = new Intent(CameraActivity.this, DisplayImg.class); intImg.putExtra("imgPath",imgPath); startActivity(intImg); Log.d(TAG, "onPictureTaken - wrote bytes: " + data.length); } catch (FileNotFoundException e) { // <10> e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { } Log.d(TAG, "onPictureTaken - jpeg"); } }; 

 camera.autoFocus(new AutoFocusCallback() { @Override public void onAutoFocus(boolean success, Camera camera) { if(success){ camera.takePicture(shutterCallback, rawCallback, jpegCallback); } } }); 

  public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { // Set camera properties first Camera.Parameters parameters = camera.getParameters(); parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE); camera.setParameters(parameters); camera.startPreview(); camera.autoFocus(null); } 

 camera.autoFocus (new Camera.AutoFocusCallback {}); 

 preview.camera.autoFocus(null) // you can make optional callback once focus is achieved preview.camera.takePicture(shutterCallback, rawCallback, jpegCallback); 

 public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { // Set camera properties first Camera.Parameters parameters = camera.getParameters(); parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO); camera.setParameters(parameters); camera.startPreview(); camera.autoFocus(null); }