/* * Copyright (C) 2008 ZXing authors * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.Zxing.Demo.view; 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 com.google.zxing.ResultPoint; import com.Zxing.Demo.R; import com.Zxing.Demo.camera.CameraManager; import java.util.Collection; import java.util.HashSet; /** * This view is overlaid on top of the camera preview. It adds the viewfinder rectangle and partial * transparency outside it, as well as the laser scanner animation and result points. * * @author dswitkin@google.com (Daniel Switkin) */ 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 = 100L; private static final int OPAQUE = 0xFF; private final Paint paint; private Bitmap resultBitmap; private final int maskColor; private final int resultColor; private final int frameColor; private final int laserColor; private final int resultPointColor; private int scannerAlpha; private Collection<ResultPoint> possibleResultPoints; private Collection<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(); Resources resources = getResources(); maskColor = resources.getColor(R.color.viewfinder_mask); resultColor = resources.getColor(R.color.result_view); frameColor = resources.getColor(R.color.viewfinder_frame); laserColor = resources.getColor(R.color.viewfinder_laser); resultPointColor = resources.getColor(R.color.possible_result_points); scannerAlpha = 0; possibleResultPoints = new HashSet<ResultPoint>(5); } @Override public void onDraw(Canvas canvas) { Rect frame = CameraManager.get().getFramingRect(); if (frame == 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(OPAQUE); canvas.drawBitmap(resultBitmap, frame.left, frame.top, paint); } else { // Draw a two pixel solid black border inside the framing rect paint.setColor(frameColor); canvas.drawRect(frame.left, frame.top, frame.right + 1, frame.top + 2, paint); canvas.drawRect(frame.left, frame.top + 2, frame.left + 2, frame.bottom - 1, paint); canvas.drawRect(frame.right - 1, frame.top, frame.right + 1, frame.bottom - 1, paint); canvas.drawRect(frame.left, frame.bottom - 1, frame.right + 1, frame.bottom + 1, paint); // 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); Collection<ResultPoint> currentPossible = possibleResultPoints; Collection<ResultPoint> currentLast = lastPossibleResultPoints; if (currentPossible.isEmpty()) { lastPossibleResultPoints = null; } else { possibleResultPoints = new HashSet<ResultPoint>(5); lastPossibleResultPoints = currentPossible; paint.setAlpha(OPAQUE); paint.setColor(resultPointColor); for (ResultPoint point : currentPossible) { canvas.drawCircle(frame.left + point.getX(), frame.top + point.getY(), 6.0f, paint); } } if (currentLast != null) { paint.setAlpha(OPAQUE / 2); paint.setColor(resultPointColor); for (ResultPoint point : currentLast) { canvas.drawCircle(frame.left + point.getX(), frame.top + point.getY(), 3.0f, paint); } } // Request another update at the animation interval, but only repaint the laser line, // not the entire viewfinder mask. postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top, frame.right, frame.bottom); } } public void drawViewfinder() { resultBitmap = null; 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) { possibleResultPoints.add(point); } }