Android Open Source - ZXingFragment Scanner View

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License

The source code is released under:

Apache License

Java Source Code

package de.klimek.zxingfragment;
/*from  ww  w . j  a v a2  s.c  o  m*/
import java.io.IOException;

import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.Size;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class ScannerView extends SurfaceView implements SurfaceHolder.Callback {
  public static final String TAG = ScannerView.class.getSimpleName();

  private SurfaceHolder mHolder;
  boolean mSurfaceCreated = false;

  private Camera mCamera;
  private Size mPreviewSize;

  private int mDisplayOrientation;

  public ScannerView(Context context, AttributeSet attrs) {
    super(context, attrs);
    mHolder = getHolder();
    mHolder.addCallback(this);
  }

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    final int width = resolveSize(getSuggestedMinimumWidth(),
        widthMeasureSpec);
    final int height = resolveSize(getSuggestedMinimumHeight(),
        heightMeasureSpec);

    // get camera previewsize
    if (mPreviewSize == null && mCamera != null) {
      mPreviewSize = mCamera.getParameters().getPreviewSize();
    }

    /*
     * Set height and width for the SurfaceView. Width and height depend on
     * the aspect ratio (no stretching).
     */
    if (mPreviewSize != null) {
      double aspectRatio = 0;
      if (mDisplayOrientation == 90 || mDisplayOrientation == 270) {
        aspectRatio = (double) mPreviewSize.height / mPreviewSize.width;
      } else {
        aspectRatio = (double) mPreviewSize.width / mPreviewSize.height;
      }
      
      int newWidth = (int) (height*aspectRatio);
      int newHeight = (int) (width/aspectRatio);
      
      if(newHeight < height) {
        setMeasuredDimension(newWidth, height);
      } else {
        setMeasuredDimension(width, newHeight);
      }
    } else {
      setMeasuredDimension(width, height);
    }
  }

  @Override
  public void surfaceCreated(SurfaceHolder holder) {
    mSurfaceCreated = true;
    startPreview(mCamera, mDisplayOrientation);
  }

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

  @Override
  public void surfaceDestroyed(SurfaceHolder holder) {
    mSurfaceCreated = false;
  }

  public void startPreview(Camera camera, int displayOrientation) {
    mCamera = camera;
    mDisplayOrientation = displayOrientation;
    if (mCamera != null && mSurfaceCreated) {
      try {
        mCamera.setPreviewDisplay(mHolder);
        mCamera.startPreview();
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }

  public void stopPreview() {
    if (mCamera != null) {
      mCamera.stopPreview();
    }
    mCamera = null;
    mPreviewSize = null;
  }
}

Java Source Code List

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