Android Open Source - MordazaCrush Camera Preview

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Back to project page MordazaCrush.
License

The source code is released under:
GNU General Public License
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Java Source Code

package org.confederacionpirata.mordazacrush;
//from w  ww .j av  a  2s .c o m
import java.io.IOException;
import java.util.List;

import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.hardware.Camera.Size;
import android.os.Build;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;

public class CameraPreview extends SurfaceView implements Callback {

  private Camera camera;
  private SurfaceHolder holder;
  private boolean started;

  @SuppressWarnings("deprecation")
  public CameraPreview(Context context) {

    super(context);
    camera = null;

    holder = getHolder();
    holder.addCallback(this);

    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB) {
      holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }
  }

  public Camera getCamera() {
    return camera;
  }

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

    if (holder.getSurface() != null) {

      if (started) {
        stopPreview();
        startPreview();
      }
    }

    selectCameraPreviewSize(width, height);
  }

  @Override
  public void surfaceCreated(SurfaceHolder holder) {

    startPreview();
  }

  @Override
  public void surfaceDestroyed(SurfaceHolder holder) {
  }

  private void initCamera() {

    try {

      // first back-facing camera
      camera = Camera.open();

      // camera features
      Parameters params = camera.getParameters();

      // auto focus
      if (params.getFocusMode() != null) {
        if (params.getSupportedFocusModes().contains(
            Camera.Parameters.FOCUS_MODE_AUTO)) {
          params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
        }
      }

      // auto white balance
      if (params.getWhiteBalance() != null) {
        if (params.getSupportedWhiteBalance().contains(
            Camera.Parameters.WHITE_BALANCE_AUTO)) {
          params.setWhiteBalance(Camera.Parameters.WHITE_BALANCE_AUTO);
        }
      }

      // disable flash
      if (params.getFlashMode() != null) {
        if (params.getSupportedFlashModes().contains(
            Camera.Parameters.FLASH_MODE_OFF)) {
          params.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
        }
      }

      camera.setParameters(params);

      started = false;

    } catch (Exception e) {

      Log.e(MCApp.LOGTAG, "Error opening the camera: " + e.getMessage());
      e.printStackTrace();
      camera = null;
    }
  }

  public void startPreview() {

    if (camera == null) {
      initCamera();
    }

    if (camera != null && !started) {

      try {

        camera.setPreviewDisplay(holder);
        camera.startPreview();
        started = true;

      } catch (IOException e) {
  
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
    }
  }

  public void stopPreview() {

    if (camera != null && started) {

      camera.stopPreview();
      camera.release();
      camera = null;
      started = false;
    }
  }

  private void selectCameraPreviewSize(int width, int height) {

    Parameters params = camera.getParameters();
    List<Size> camPreviewSizes = params.getSupportedPreviewSizes();

    // target
    Size selected = camPreviewSizes.get(0);
    double targetRatio = adaptedRatio(width, height);
    double minDelta = Double.MAX_VALUE;

    // explore possibilities
    for (Size size : camPreviewSizes) {
      
      // compare ratios
      double ratio = adaptedRatio(size.width, size.height);
      double delta = Math.abs(targetRatio - ratio);
      if (delta < minDelta) {

        // select the smallest difference
        selected = size;
        minDelta = delta;
      }
    }

    // set preview size
    params.setPreviewSize(selected.width, selected.height);
    camera.setParameters(params);
  }

  private double adaptedRatio(double width, double height) {

    return (width > height ? width / height : height / width);
  }

}
Java Source Code List
