Java tutorial
/* * 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.google.zxing.client.android; import android.annotation.SuppressLint; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Rect; import android.graphics.drawable.Drawable; import android.os.Build; import android.support.v4.content.ContextCompat; import android.util.AttributeSet; import android.view.View; import android.widget.RelativeLayout; import android.widget.TextView; import com.rainbow.demo.zxing.R; import com.google.zxing.ResultPoint; import com.google.zxing.client.android.camera.CameraManager; import java.util.ArrayList; import java.util.List; /** * 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 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; // private TextView statusText; private int i = 0;// private Rect mRect;// ?? private Drawable lineDrawable;// ?? // 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); maskColor = ContextCompat.getColor(context, R.color.viewfinder_mask); resultColor = ContextCompat.getColor(context, R.color.barcode_result_view); laserColor = ContextCompat.getColor(context, R.color.viewfinder_laser); resultPointColor = ContextCompat.getColor(context, R.color.possible_result_points); scannerAlpha = 0; possibleResultPoints = new ArrayList<>(5); lastPossibleResultPoints = null; // GradientDrawable?lineDrawable mRect = new Rect(); lineDrawable = getResources().getDrawable(R.drawable.zx_code_line); } public void setCameraManager(CameraManager cameraManager) { this.cameraManager = cameraManager; } public void setHintText(TextView textView) { this.statusText = textView; } @SuppressLint("DrawAllocation") @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, paint); canvas.drawRect(frame.right, frame.top, width, frame.bottom, paint); canvas.drawRect(0, frame.bottom, width, height, paint); /// // paint.setColor(getResources().getColor(R.color.encode_view)); int w = 16; int h = 2; int margin = 2; // canvas.drawRect(frame.left - margin - h, frame.top - margin - h, frame.left - margin + w - h, frame.top - margin + h - h, paint); canvas.drawRect(frame.left - margin - h, frame.top - margin - h, frame.left - margin + h - h, frame.top - margin + w - h, paint); // ? canvas.drawRect(frame.right + margin - w + h, frame.top - margin - h, frame.right + margin + h, frame.top - margin + h - h, paint); canvas.drawRect(frame.right + margin - h + h, frame.top - margin - h, frame.right + margin + h, frame.top - margin + w - h, paint); // canvas.drawRect(frame.left - margin - h, frame.bottom + margin - h + h, frame.left - margin + w - h, frame.bottom + margin + h, paint); canvas.drawRect(frame.left - margin - h, frame.bottom + margin - w + h, frame.left - margin + h - h, frame.bottom + margin + h, paint); // ? canvas.drawRect(frame.right + margin - w + h, frame.bottom + margin - h + h, frame.right + margin + h, frame.bottom + margin + h, paint); canvas.drawRect(frame.right + margin - h + h, frame.bottom + margin - w + h, frame.right + margin + h, frame.bottom + margin + h, paint); ///? drawLineRound(canvas, frame, paint); if (statusText != null) { RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) statusText.getLayoutParams(); lp.topMargin = frame.top - statusText.getMeasuredHeight() - 28; statusText.setLayoutParams(lp); statusText.setVisibility(View.VISIBLE); } if (resultBitmap != null) { // Draw the opaque result bitmap over the scanning rectangle if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { paint.setAlpha(CURRENT_POINT_OPACITY); } canvas.drawBitmap(resultBitmap, null, frame, paint); } else { // ?? if ((i += 5) < frame.bottom - frame.top) { /* ?? */ mRect.set(frame.left, frame.top + i - 1, frame.right, frame.top + i + 1); lineDrawable.setBounds(mRect); lineDrawable.draw(canvas); // invalidate(); } else { i = 0; } 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; if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { 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) { if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { 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); } } /** * ? * @param canvas * @param frame * @param paint2 */ private void drawLineRound(Canvas canvas, Rect frame, Paint paint2) { paint2.setColor(Color.parseColor("#38FFFFFF")); //left canvas.drawRect(frame.left, frame.top, frame.left + 1, frame.bottom, paint2); //right canvas.drawRect(frame.right - 1, frame.top, frame.right, frame.bottom, paint2); //top canvas.drawRect(frame.left, frame.top, frame.right, frame.top + 1, paint2); //bottom canvas.drawRect(frame.left, frame.bottom - 1, frame.right, frame.bottom, paint2); } 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(); } } } public void recycleLineDrawable() { if (lineDrawable != null) { lineDrawable.setCallback(null); } } }