Android カメラに autofocus を実装する。

google先生にお尋ねしても、わかりやすいサイトが
なかったので、書きました。

カメラ部分は木南さんの本を参考にしています。
『Google-Androidアプリケーション開発入門』
ありがとうございます！！
買った方がいいですよ～。

シャッターボタンを押されたときに
Camera.autoFocus(Camera.AutoFocusCallback);
を呼んで,
Camera.AutoFocusCallback
で、autofocus を切って、takePicture すればOK

そうそう、カメラを使う場合には、manifest に

<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />

が必要です～。

public class MyPic extends Activity {

  private static final String TAG = "MyPic";
  private static final int IN_SAMPLE_SIZE = 1;
 
  private Camera mCamera;
  private ImageView mImage;
  private boolean mInProgress;
 
  private SurfaceHolder.Callback mSurfaceListener =
    new SurfaceHolder.Callback() {
   
    @Override
    public void surfaceCreated(SurfaceHolder holder) {
      mCamera = Camera.open();
      Log.i(TAG, "Camera opened");
      try {
        mCamera.setPreviewDisplay(holder);
      }
      catch (Exception e) {
        e.printStackTrace();
      }
    }
   
    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
      mCamera.release();
      mCamera = null;
      Log.i(TAG, "Camera released");
    }
   
    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
      Camera.Parameters parameters = mCamera.getParameters();
      parameters.setPreviewSize(width, height);
      mCamera.setParameters(parameters);
      mCamera.startPreview();
      Log.i(TAG, "Camera preview started");
      Log.i(TAG, "width  : " + width);
      Log.i(TAG, "height : " + height);
    }
  };

  private Camera.AutoFocusCallback mAutoFocusListener =
    new Camera.AutoFocusCallback() {  
    @Override
    public void onAutoFocus(boolean success, Camera camera) {
      Log.i(TAG,"AutoFocus : " + success);
      camera.autoFocus(null);
      camera.takePicture(mShutterListener, null, mPictureListener);
      mInProgress = true;
    }
  };
  
  private Camera.ShutterCallback mShutterListener = 
    new Camera.ShutterCallback() {
    @Override
    public void onShutter() {
      Log.i(TAG, "onShutter");
    }
  };
  
  private View.OnClickListener mButtonListener = 
    new View.OnClickListener() {   
    @Override
    public void onClick(View v) {
      if(mCamera != null && mInProgress == false){
        mCamera.autoFocus(mAutoFocusListener);
      }
    }
  };
  
  private Camera.PictureCallback mPictureListener = 
    new Camera.PictureCallback() {   
    @Override
    public void onPictureTaken(byte[] data, Camera camera) {
      Log.i(TAG, "Picture taken");
      if(data != null) {
        Log.i(TAG, "JPEG Picture Taken");
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inSampleSize = IN_SAMPLE_SIZE;
        Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length, options);
     
        mImage.setImageBitmap(bitmap);
        mImage.setVisibility(View.VISIBLE);
      }
    }
  };
  
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.camera2);
  
    mImage = (ImageView) findViewById(R.id.handpreview);
    SurfaceView surface = (SurfaceView) findViewById(R.id.surfaceview);
    SurfaceHolder holder = surface.getHolder();
  
    holder.addCallback(mSurfaceListener);
    holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
  
    ImageButton button = (ImageButton) findViewById(R.id.shutter);
    button.setOnClickListener(mButtonListener);
  } 
}