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I have added the proper native classes on Zxing in my Android project. The camera view of zxing scan is not showing in the right size. I have added the screenshot of the camera app. The scanner part of the camera should be displayed in the middle of the screen. Currently, it is displaying in at the top right corner, which is not correct. Please help me fix this issue.

**Complete View holder Java class code is added below.**

package com.scan;

import com.google.zxing.ResultPoint;
import com.scan.camera.CameraManager;
import com.ofss.digx.mobile.android.allied.R;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;

import java.util.ArrayList;
import java.util.List;


public final class ViewfinderView extends View {

  private static final int[] SCANNER_ALPHA = {0, 64, 128, 192, 255, 192, 128, 64};
  private static final long ANIMATION_DELAY = 80L;
  private static final int CURRENT_POINT_OPACITY = 0xA0;
  private static final int MAX_RESULT_POINTS = 20;
  private static final int POINT_SIZE = 6;

  private CameraManager cameraManager;
  private final Paint paint;
  private Bitmap resultBitmap;
  private final int maskColor;
  private final int resultColor;
  private final int laserColor;
  private final int resultPointColor;
  private int scannerAlpha;
  private List<ResultPoint> possibleResultPoints;
  private List<ResultPoint> lastPossibleResultPoints;

  // This constructor is used when the class is built from an XML resource.
  public ViewfinderView(Context context, AttributeSet attrs) {
    super(context, attrs);

    // Initialize these once for performance rather than calling them every time in onDraw().
    paint = new Paint(Paint.ANTI_ALIAS_FLAG);
    Resources resources = getResources();
    maskColor = resources.getColor(R.color.viewfinder_mask);
    resultColor = resources.getColor(R.color.result_view);
    laserColor = resources.getColor(R.color.viewfinder_laser);
    resultPointColor = resources.getColor(R.color.possible_result_points);
    scannerAlpha = 0;
    possibleResultPoints = new ArrayList<>(5);
    lastPossibleResultPoints = null;
  }

  public void setCameraManager(CameraManager cameraManager) {
    this.cameraManager = cameraManager;
  }

  @Override
  public void onDraw(Canvas canvas) {
    if (cameraManager == null) {
      return; // not ready yet, early draw before done configuring
    }
    Rect frame = cameraManager.getFramingRect();
    Rect previewFrame = cameraManager.getFramingRectInPreview();
    if (frame == null || previewFrame == null) {
      return;
    }
    int width = canvas.getWidth();
    int height = canvas.getHeight();

    // Draw the exterior (i.e. outside the framing rect) darkened
    paint.setColor(resultBitmap != null ? resultColor : maskColor);
    canvas.drawRect(0, 0, width, frame.top, paint);
    canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, paint);
    canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1, paint);
    canvas.drawRect(0, frame.bottom + 1, width, height, paint);

    if (resultBitmap != null) {
      // Draw the opaque result bitmap over the scanning rectangle
      paint.setAlpha(CURRENT_POINT_OPACITY);
      canvas.drawBitmap(resultBitmap, null, frame, paint);
    } else {

      // Draw a red "laser scanner" line through the middle to show decoding is active
      paint.setColor(laserColor);
      paint.setAlpha(SCANNER_ALPHA[scannerAlpha]);
      scannerAlpha = (scannerAlpha + 1) % SCANNER_ALPHA.length;
      int middle = frame.height() / 2 + frame.top;
      canvas.drawRect(frame.left + 2, middle - 1, frame.right - 1, middle + 2, paint);

      float scaleX = frame.width() / (float) previewFrame.width();
      float scaleY = frame.height() / (float) previewFrame.height();

      List<ResultPoint> currentPossible = possibleResultPoints;
      List<ResultPoint> currentLast = lastPossibleResultPoints;
      int frameLeft = frame.left;
      int frameTop = frame.top;
      if (currentPossible.isEmpty()) {
        lastPossibleResultPoints = null;
      } else {
        possibleResultPoints = new ArrayList<>(5);
        lastPossibleResultPoints = currentPossible;
        paint.setAlpha(CURRENT_POINT_OPACITY);
        paint.setColor(resultPointColor);
        synchronized (currentPossible) {
          for (ResultPoint point : currentPossible) {
            canvas.drawCircle(frameLeft + (int) (point.getX() * scaleX),
                    frameTop + (int) (point.getY() * scaleY),
                    POINT_SIZE, paint);
          }
        }
      }
      if (currentLast != null) {
        paint.setAlpha(CURRENT_POINT_OPACITY / 2);
        paint.setColor(resultPointColor);
        synchronized (currentLast) {
          float radius = POINT_SIZE / 2.0f;
          for (ResultPoint point : currentLast) {
            canvas.drawCircle(frameLeft + (int) (point.getX() * scaleX),
                    frameTop + (int) (point.getY() * scaleY),
                    radius, paint);
          }
        }
      }

      // Request another update at the animation interval, but only repaint the laser line,
      // not the entire viewfinder mask.
      postInvalidateDelayed(ANIMATION_DELAY,
              frame.left - POINT_SIZE,
              frame.top - POINT_SIZE,
              frame.right + POINT_SIZE,
              frame.bottom + POINT_SIZE);
    }
  }

  public void drawViewfinder() {
    Bitmap resultBitmap = this.resultBitmap;
    this.resultBitmap = null;
    if (resultBitmap != null) {
      resultBitmap.recycle();
    }
    invalidate();
  }

  /**
   * Draw a bitmap with the result points highlighted instead of the live scanning display.
   *
   * @param barcode An image of the decoded barcode.
   */
  public void drawResultBitmap(Bitmap barcode) {
    resultBitmap = barcode;
    invalidate();
  }

  public void addPossibleResultPoint(ResultPoint point) {
    List<ResultPoint> points = possibleResultPoints;
    synchronized (points) {
      points.add(point);
      int size = points.size();
      if (size > MAX_RESULT_POINTS) {
        // trim it
        points.subList(0, size - MAX_RESULT_POINTS / 2).clear();
      }
    }
  }

}


----------

**XML Code is added below**

<?xml version="1.0" encoding="UTF-8"?>

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <SurfaceView android:id="@+id/preview_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <com.scan.ViewfinderView
        android:id="@+id/viewfinder_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <TextView
        android:id="@+id/status_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|center_horizontal"
        android:background="@color/transparent"
        android:text="@string/msg_default_status"
        android:textColor="@color/status_text"
        android:textSize="14sp"/>

</FrameLayout>

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A P
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Robin Royal
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  • Why don't you use relative layout or constraint layout as root layout ? – M D Oct 10 '19 at 11:56
  • I have used relative layout but it didn't effect the scanner size. I think scanner size is managed by java class ViewfinderView. – Robin Royal Oct 10 '19 at 12:12
  • have you tried making viewFinderView wrap_content and setting gravity to center? – NotABot Oct 10 '19 at 12:43
  • tried but it is not working. – Robin Royal Oct 10 '19 at 12:53
  • I have tried this, Now Scanner size is correct but its area is showing at the top right. https://stackoverflow.com/questions/20398419/how-to-increase-scanning-area-size-in-zxing How to make it in the middle of the screen? – Robin Royal Oct 10 '19 at 13:08

0 Answers0