Android Open Source - zbar-android-sdk Camera Support

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License

The source code is released under:

MIT License

Java Source Code

package net.sourceforge.zbar.android;
/*from  w w  w. j a va 2 s .c om*/
import java.io.IOException;

import android.hardware.Camera;
import android.hardware.Camera.AutoFocusCallback;
import android.hardware.Camera.Parameters;
import android.hardware.Camera.PreviewCallback;
import android.os.Build;
import android.os.Handler;
import android.os.Looper;
import android.view.SurfaceHolder;

public class CameraSupport {

  private static final long AUTO_FOCUS_DELAY = 1000;

  private Camera mCamera;
  private PreviewCallback mPreviewCallback;
  private AutoFocusCallback mAutoFocusCallback;
  private Handler mAutoFocusHandler = new Handler(Looper.getMainLooper());
  private boolean mContinuousAutoFocus = false;
  private boolean mPreviewing = false;

  public CameraSupport() {

  }

  public boolean open(PreviewCallback previewCallback,
      AutoFocusCallback autoFocusCallback) {
    if (!isOpen()) {
      try {
        mCamera = Camera.open();
        mCamera.getParameters().setFocusMode(
            Camera.Parameters.FOCUS_MODE_AUTO);
      } catch (Exception e) {

      }
      setAutoFocusCallback(autoFocusCallback);
      setPreviewCallback(previewCallback);
    }
    return isOpen();
  }

  public Camera getCamera() {
    return mCamera;
  }

  public boolean isOpen() {
    return mCamera != null;
  }

  public void setDisplayOrientation(int degrees) {
    if (isOpen()) {
      getCamera().setDisplayOrientation(degrees);
    }
  }

  public void release() {
    if (isOpen()) {
      stopPreview();
      Camera camera = mCamera;
      mCamera = null;
      camera.setPreviewCallback(null);
      camera.release();
    }
  }

  public void setContinuousAutoFocus(boolean enable) {
    mContinuousAutoFocus = enable;
    if (!isOpen()) {
      return;
    }
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
      Camera.Parameters parameters = getCamera().getParameters();
      for (String f : parameters.getSupportedFocusModes()) {
        if (f == Parameters.FOCUS_MODE_CONTINUOUS_PICTURE) {
          getCamera().getParameters().setFocusMode(
              Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
          return;
        }
      }
    }
    if (mContinuousAutoFocus) {
      autoFocus();
    }
  }

  public void setPreviewCallback(PreviewCallback previewCallback) {
    mPreviewCallback = previewCallback;
    if (isOpen()) {
      getCamera().setPreviewCallback(mPrivatePreviewCallback);
    }
  }

  public void setAutoFocusCallback(AutoFocusCallback callback) {
    mAutoFocusCallback = callback;
  }

  public void autoFocus() {
    if (isPreviewing()) {
      getCamera().autoFocus(mPrivateAutoFocusCallback);
    } else if (mContinuousAutoFocus && isOpen()) {
      mPrivateAutoFocusCallback.onAutoFocus(false, null);
    }
  }

  public void autofocus(AutoFocusCallback callback) {
    if (isPreviewing()) {
      getCamera().autoFocus(callback);
    }
  }

  public void setPreviewDisplay(SurfaceHolder holder) throws IOException {
    if (isOpen()) {
      getCamera().setPreviewDisplay(holder);
    }
  }

  public void startPreview() {
    if (!mPreviewing && isOpen()) {
      getCamera().startPreview();
      getCamera().setPreviewCallback(mPrivatePreviewCallback);
      mPreviewing = true;
    }
  }

  public void stopPreview() {
    if (isPreviewing()) {
      mPreviewing = false;
      try {
        getCamera().cancelAutoFocus();
        getCamera().setPreviewCallback(null);
        getCamera().stopPreview();
      } catch (Exception e) {

      }
    }
  }

  public boolean isPreviewing() {
    return isOpen() && mPreviewing;
  }

  private final PreviewCallback mPrivatePreviewCallback = new PreviewCallback() {

    @Override
    public void onPreviewFrame(byte[] data, Camera camera) {
      if (mPreviewCallback != null) {
        mPreviewCallback.onPreviewFrame(data, camera);
      }
    }
  };

  private final AutoFocusCallback mPrivateAutoFocusCallback = new AutoFocusCallback() {

    @Override
    public void onAutoFocus(boolean succeed, Camera camera) {
      if (mAutoFocusCallback != null && camera != null) {
        mAutoFocusCallback.onAutoFocus(succeed, camera);
      }
      if (mContinuousAutoFocus) {
        mAutoFocusHandler.postDelayed(mAutoFocusRunnable,
            AUTO_FOCUS_DELAY);
      }
    }
  };

  private Runnable mAutoFocusRunnable = new Runnable() {

    @Override
    public void run() {
      autoFocus();
    }
  };

}

Java Source Code List

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