/*
* 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.android.view;
import java.util.ArrayList;
import java.util.Collection;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;
import android.view.View;
import com.google.zxing.ResultPoint;
import com.martin.simpledevelop.R;
import com.zxing.android.camera.CameraManager;
/**
* 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 {
/**
* 刷新界面的时间
*/
private static final long ANIMATION_DELAY = 30L;
private static final int OPAQUE = 0xFF;
private static final int MAX_RESULT_POINTS = 5;
/**
* 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 = 10;
/**
* 扫描框中的中间线的宽度
*/
private static final int MIDDLE_LINE_WIDTH = 6;
/**
* 扫描框中的中间线的与扫描框左右的间隙
*/
private static final int MIDDLE_LINE_PADDING = 5;
/**
* 中间那条线每次刷新移动的距离
*/
private static final int SPEEN_DISTANCE = 5;
/**
* 手机的屏幕密度
*/
private static float density;
/**
* 字体大小
*/
private static final int TEXT_SIZE = 16;
/**
* 字体距离扫描框下面的距离
*/
private static final int TEXT_PADDING_TOP = 30;
/**
* 画笔对象的引用
*/
private Paint paint;
/**
* 中间滑动线的最顶端位置
*/
private int slideTop;
/**
* 中间滑动线的最底端位置
*/
private int slideBottom;
/**
* 将扫描的二维码拍下来，这里没有这个功能，暂时不考虑
*/
private Bitmap resultBitmap;
private final int maskColor;
private final int resultColor;
private final int resultPointColor;
private Collection<ResultPoint> possibleResultPoints;
private Collection<ResultPoint> lastPossibleResultPoints;
private CameraManager cameraManager;
boolean isFirst;
public ViewfinderView(Context context) {
this(context, null);
}
// 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 = 0x60000000;
resultColor = 0xb0000000;
resultPointColor = 0xc0ffff00;
possibleResultPoints = new ArrayList<ResultPoint>(5);
lastPossibleResultPoints = null;
density = context.getResources().getDisplayMetrics().density;
// 将像素转换成dp
ScreenRate = (int) (20 * density);
}
public void setCameraManager(CameraManager cameraManager) {
this.cameraManager = cameraManager;
}
@Override
public void onDraw(Canvas canvas) {
// 中间的扫描框，你要修改扫描框的大小，去CameraManager里面修改
Rect frame = cameraManager.getFramingRect();
if (frame == 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();
paint.setColor(resultBitmap != null ? resultColor : maskColor);
// 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
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(0xffffffff);
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);
// 这里画取景框四个角落的夹角
paint.setColor(0xff0ec3ff);
paint.setAntiAlias(true);
canvas.drawRect(frame.left - CORNER_WIDTH + 2, frame.top
- CORNER_WIDTH + 2, frame.left + ScreenRate - CORNER_WIDTH
+ 2, frame.top + 2, paint);
canvas.drawRect(frame.left - CORNER_WIDTH + 2, frame.top
- CORNER_WIDTH + 2, frame.left + 2, frame.top + ScreenRate
- CORNER_WIDTH + 2, paint);
canvas.drawRect(frame.right - ScreenRate + CORNER_WIDTH - 2,
frame.top - CORNER_WIDTH + 2, frame.right + CORNER_WIDTH
- 2, frame.top + 2, paint);
canvas.drawRect(frame.right - 2, frame.top - CORNER_WIDTH + 2,
frame.right + CORNER_WIDTH - 2, frame.top + ScreenRate
- CORNER_WIDTH + 2, paint);
canvas.drawRect(frame.left - CORNER_WIDTH + 2, frame.bottom - 2,
frame.left + ScreenRate - CORNER_WIDTH + 2, frame.bottom
+ CORNER_WIDTH - 2, paint);
canvas.drawRect(frame.left - CORNER_WIDTH + 2, frame.bottom
- ScreenRate + CORNER_WIDTH - 2, frame.left + 2,
frame.bottom + CORNER_WIDTH - 2, paint);
canvas.drawRect(frame.right - ScreenRate + CORNER_WIDTH - 2,
frame.bottom - 2, frame.right + CORNER_WIDTH - 2,
frame.bottom + CORNER_WIDTH - 2, paint);
canvas.drawRect(frame.right - 2, frame.bottom - ScreenRate
+ CORNER_WIDTH - 2, frame.right + CORNER_WIDTH - 2,
frame.bottom + CORNER_WIDTH - 2, 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;
}
Rect lineRect = new Rect();
lineRect.left = frame.left;
lineRect.right = frame.right;
lineRect.top = slideTop;
lineRect.bottom = slideTop + 18;
canvas.drawBitmap(((BitmapDrawable) (getResources()
.getDrawable(R.drawable.qr_scan_line))).getBitmap(), null,
lineRect, paint);
/**
* 不显示关键点 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); } }
*/
// 只刷新扫描框的内容，其他地方不刷新
postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top,
frame.right, frame.bottom);
}
}
@Override
protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
}
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) {
possibleResultPoints.add(point);
}
}