/*
* 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.view;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Shader;
import android.graphics.Typeface;
import android.util.AttributeSet;
import android.view.View;
import com.google.zxing.ResultPoint;
import com.google.zxing.camera.CameraManager;
import java.util.ArrayList;
import java.util.List;
import cn.darkal.networkdiagnosis.R;
/**
* 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 = 30L;
private static final int CURRENT_POINT_OPACITY = 0xA0;
private static final int MAX_RESULT_POINTS = 20;
private static final int POINT_SIZE = 6;
/**
* 四个绿色边角对应的长度
*/
private int ScreenRate;
/**
* 四个绿色边角对应的宽度
*/
private static final int CORNER_WIDTH = 3;
/**
* 扫描框中的中间线的宽度
*/
private static final float MIDDLE_LINE_WIDTH = 3;
/**
* 扫描框中的中间线的与扫描框左右的间隙
*/
private static final float MIDDLE_LINE_PADDING = 5;
/**
* 中间那条线每次刷新移动的距离
*/
private static final float SPEEN_DISTANCE = 4;
/**
* 手机的屏幕密度
*/
private static float density;
/**
* 字体大小
*/
private static final int TEXT_SIZE = 13;
/**
* 字体距离扫描框下面的距离
*/
private static final int TEXT_PADDING_TOP = 24;
/**
* 画笔对象的引用
*/
private Paint paint;
/**
* 中间滑动线的最顶端位置
*/
private float slideTop;
/**
* 中间滑动线的最底端位置
*/
private int slideBottom;
boolean isFirst;
private CameraManager cameraManager;
private Bitmap resultBitmap;
private final int maskColor;
private final int resultColor;
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);
density = context.getResources().getDisplayMetrics().density;
//将像素转换成dp
ScreenRate = (int) (20 * density);
// 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);
resultPointColor = resources.getColor(R.color.possible_result_points);
scannerAlpha = 0;
possibleResultPoints = new ArrayList<ResultPoint>(5);
lastPossibleResultPoints = null;
}
public void setCameraManager(CameraManager cameraManager) {
this.cameraManager = cameraManager;
}
@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;
}
//初始化中间线滑动的最上边和最下边
if(!isFirst){
isFirst = true;
slideTop = frame.top;
slideBottom = frame.bottom;
}
//获取屏幕的宽和高
int width = canvas.getWidth();
int height = canvas.getHeight();
//画出扫描框外面的阴影部分，共四个部分，扫描框的上面到屏幕上面，扫描框的下面到屏幕下面
//扫描框的左边面到屏幕左边，扫描框的右边到屏幕右边
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 {
//画扫描框边上的角，总共8个部分
paint.setAlpha(0xFF);
paint.setColor(Color.GREEN);
canvas.drawRect(frame.left - 1, frame.top - 1, frame.left - 1 + ScreenRate, frame.top - 1 + CORNER_WIDTH, paint);
canvas.drawRect(frame.left - 1, frame.top - 1, frame.left - 1 + CORNER_WIDTH, frame.top - 1 + ScreenRate, paint);
canvas.drawRect(frame.right + 2 - ScreenRate, frame.top - 1, frame.right + 2, frame.top - 1 + CORNER_WIDTH, paint);
canvas.drawRect(frame.right+2 - CORNER_WIDTH, frame.top-1, frame.right+2, frame.top-1 + ScreenRate, paint);
canvas.drawRect(frame.left-1, frame.bottom+2 - CORNER_WIDTH, frame.left-1 + ScreenRate, frame.bottom+2, paint);
canvas.drawRect(frame.left-1, frame.bottom+2 - ScreenRate, frame.left-1 + CORNER_WIDTH, frame.bottom+2, paint);
canvas.drawRect(frame.right+2 - ScreenRate, frame.bottom+2 - CORNER_WIDTH, frame.right+2, frame.bottom+2, paint);
canvas.drawRect(frame.right+2 - CORNER_WIDTH, frame.bottom+2 - ScreenRate, frame.right+2, frame.bottom+2, paint);
paint.setColor(Color.WHITE);
canvas.drawLine(frame.left, frame.bottom, frame.left, frame.top, paint);
canvas.drawLine(frame.left, frame.top, frame.right, frame.top, paint);
canvas.drawLine(frame.right, frame.top, frame.right, frame.bottom, paint);
canvas.drawLine(frame.right, frame.bottom, frame.left, frame.bottom, paint);
//绘制中间的线,每次刷新界面，中间的线往下移动SPEEN_DISTANCE
slideTop += SPEEN_DISTANCE;
if(slideTop >= frame.bottom) {
slideTop = frame.top;
}
Shader shaderNew = new LinearGradient(frame.left + MIDDLE_LINE_PADDING, 0, frame.right - MIDDLE_LINE_PADDING, 0,
new int[] { 0x00FFFFFF, 0xFF00FF00, 0xFF00FF00, 0x00FFFFFF }, null, Shader.TileMode.MIRROR);
Shader shaderOld = paint.getShader();
paint.setShader(shaderNew);
canvas.drawRect(frame.left + MIDDLE_LINE_PADDING, slideTop - MIDDLE_LINE_WIDTH/2,
frame.right - MIDDLE_LINE_PADDING, slideTop + MIDDLE_LINE_WIDTH/2, paint);
paint.setShader(shaderOld);
//画扫描框下面的字
paint.setColor(Color.WHITE);
paint.setTextSize(TEXT_SIZE * density);
paint.setTextAlign(Paint.Align.CENTER);
paint.setTypeface(Typeface.create("system", Typeface.NORMAL));
//paint.setTypeface(Typeface.SANS_SERIF);
canvas.drawText(getResources().getString(R.string.scan_text), frame.centerX(), (float) (frame.bottom + (float)TEXT_PADDING_TOP * density), 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<ResultPoint>(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);
}
}
}
//只刷新扫描框的内容，其他地方不刷新
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();
}
}
}
}