Android Open Source - bitfynd-wallet-android Scanner View

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License

The source code is released under:

GNU General Public License

Java Source Code

/*
 * Copyright 2012-2014 the original author or authors.
 *// w w  w. j av  a  2  s .  c om
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package de.schildbach.wallet.ui;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import javax.annotation.Nonnull;

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

import com.google.zxing.ResultPoint;

import de.schildbach.wallet.R;

/**
 * @author Andreas Schildbach
 */
public class ScannerView extends View
{
  private static final long LASER_ANIMATION_DELAY_MS = 100l;
  private static final int DOT_OPACITY = 0xa0;
  private static final int DOT_SIZE = 8;
  private static final int DOT_TTL_MS = 500;

  private final Paint maskPaint;
  private final Paint laserPaint;
  private final Paint dotPaint;
  private Bitmap resultBitmap;
  private final int maskColor;
  private final int resultColor;
  private final Map<ResultPoint, Long> dots = new HashMap<ResultPoint, Long>(16);
  private Rect frame, framePreview;

  public ScannerView(final Context context, final AttributeSet attrs)
  {
    super(context, attrs);

    final Resources res = getResources();
    maskColor = res.getColor(R.color.scan_mask);
    resultColor = res.getColor(R.color.scan_result_view);
    final int laserColor = res.getColor(R.color.scan_laser);
    final int dotColor = res.getColor(R.color.scan_dot);

    maskPaint = new Paint();
    maskPaint.setStyle(Style.FILL);

    laserPaint = new Paint();
    laserPaint.setColor(laserColor);
    laserPaint.setStrokeWidth(DOT_SIZE);
    laserPaint.setStyle(Style.STROKE);

    dotPaint = new Paint();
    dotPaint.setColor(dotColor);
    dotPaint.setAlpha(DOT_OPACITY);
    dotPaint.setStyle(Style.STROKE);
    dotPaint.setStrokeWidth(DOT_SIZE);
    dotPaint.setAntiAlias(true);
  }

  public void setFraming(@Nonnull final Rect frame, @Nonnull final Rect framePreview)
  {
    this.frame = frame;
    this.framePreview = framePreview;

    invalidate();
  }

  public void drawResultBitmap(@Nonnull final Bitmap bitmap)
  {
    resultBitmap = bitmap;

    invalidate();
  }

  public void addDot(@Nonnull final ResultPoint dot)
  {
    dots.put(dot, System.currentTimeMillis());

    invalidate();
  }

  @Override
  public void onDraw(final Canvas canvas)
  {
    if (frame == null)
      return;

    final long now = System.currentTimeMillis();

    final int width = canvas.getWidth();
    final int height = canvas.getHeight();

    // draw mask darkened
    maskPaint.setColor(resultBitmap != null ? resultColor : maskColor);
    canvas.drawRect(0, 0, width, frame.top, maskPaint);
    canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, maskPaint);
    canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1, maskPaint);
    canvas.drawRect(0, frame.bottom + 1, width, height, maskPaint);

    if (resultBitmap != null)
    {
      canvas.drawBitmap(resultBitmap, null, frame, maskPaint);
    }
    else
    {
      // draw red "laser scanner" to show decoding is active
      final boolean laserPhase = (now / 600) % 2 == 0;
      laserPaint.setAlpha(laserPhase ? 160 : 255);
      canvas.drawRect(frame, laserPaint);

      // draw points
      final int frameLeft = frame.left;
      final int frameTop = frame.top;
      final float scaleX = frame.width() / (float) framePreview.width();
      final float scaleY = frame.height() / (float) framePreview.height();

      for (final Iterator<Map.Entry<ResultPoint, Long>> i = dots.entrySet().iterator(); i.hasNext();)
      {
        final Map.Entry<ResultPoint, Long> entry = i.next();
        final long age = now - entry.getValue();
        if (age < DOT_TTL_MS)
        {
          dotPaint.setAlpha((int) ((DOT_TTL_MS - age) * 256 / DOT_TTL_MS));

          final ResultPoint point = entry.getKey();
          canvas.drawPoint(frameLeft + (int) (point.getX() * scaleX), frameTop + (int) (point.getY() * scaleY), dotPaint);
        }
        else
        {
          i.remove();
        }
      }

      // schedule redraw
      postInvalidateDelayed(LASER_ANIMATION_DELAY_MS);
    }
  }
}

Java Source Code List

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