Android开源之行之走进zxing,轻松实现二维码扫描（二）

1 rect.left = rect.left * cameraResolution.y / screenResolution.x;
2             rect.right = rect.right * cameraResolution.y / screenResolution.x;
3             rect.top = rect.top * cameraResolution.x / screenResolution.y;
4             rect.bottom = rect.bottom * cameraResolution.x / screenResolution.y;

 1 void setDisplayOrientation(Camera camera, int angle) {
 2 
 3         Method method;
 4         try {
 5             method = camera.getClass().getMethod("setDisplayOrientation",
 6                     new Class[] { int.class });
 7             if (method != null)
 8                 method.invoke(camera, new Object[] { angle });
 9         } catch (Exception e1) {
10             e1.printStackTrace();
11         }
12     }

1 byte[] rotatedData = new byte[data.length];   
2          for (int y = 0; y < height; y++) {   
3          for (int x = 0; x < width; x++)   
4          rotatedData[x * height + height - y - 1] = data[x + y * width];   
5          }   
6          int tmp = width; // Here we are swapping, that‘s the difference to #11   
7          width = height;   
8          height = tmp;   
9          data = rotatedData;  

 1 void initFromCameraParameters(Camera camera) {
 2         Camera.Parameters parameters = camera.getParameters();
 3         WindowManager manager = (WindowManager) context
 4                 .getSystemService(Context.WINDOW_SERVICE);
 5         Display display = manager.getDefaultDisplay();
 6         Point theScreenResolution = new Point(display.getWidth(),
 7                 display.getHeight());
 8         screenResolution = theScreenResolution;
 9         Log.i(TAG, "Screen resolution: " + screenResolution);
10 
11         /************** 竖屏更改4 ******************/
12         Point screenResolutionForCamera = new Point();
13         screenResolutionForCamera.x = screenResolution.x;
14         screenResolutionForCamera.y = screenResolution.y;
15 
16         // preview size is always something like 480*320, other 320*480
17         if (screenResolution.x < screenResolution.y) {
18             screenResolutionForCamera.x = screenResolution.y;
19             screenResolutionForCamera.y = screenResolution.x;
20         }
21 
22         cameraResolution = CameraConfigurationUtils.findBestPreviewSizeValue(
23                 parameters, screenResolutionForCamera);
24         Log.i(TAG, "Camera resolution: " + cameraResolution);
25 
26     }

 1 private void drawStatusText(Canvas canvas, Rect frame, int width) {
 2 
 3         String statusText1 = getResources().getString(
 4                 R.string.viewfinderview_status_text1);
 5         String statusText2 = getResources().getString(
 6                 R.string.viewfinderview_status_text2);
 7         int statusTextSize = 45;
 8         int statusPaddingTop = 180;
 9 
10         paint.setColor(statusColor);
11         paint.setTextSize(statusTextSize);
12 
13         int textWidth1 = (int) paint.measureText(statusText1);
14         canvas.drawText(statusText1, (width - textWidth1) / 2, frame.top
15                 - statusPaddingTop, paint);
16 
17         int textWidth2 = (int) paint.measureText(statusText2);
18         canvas.drawText(statusText2, (width - textWidth2) / 2, frame.top
19                 - statusPaddingTop + 60, paint);
20     }

 1 private void drawFrameBounds(Canvas canvas, Rect frame) {
 2 
 3         paint.setColor(Color.WHITE);
 4         paint.setStrokeWidth(2);
 5         paint.setStyle(Paint.Style.STROKE);
 6 
 7         canvas.drawRect(frame, paint);
 8 
 9         paint.setColor(Color.BLUE);
10         paint.setStyle(Paint.Style.FILL);
11 
12         int corWidth = 15;
13         int corLength = 45;
14 
15         // 左上角
16         canvas.drawRect(frame.left - corWidth, frame.top, frame.left, frame.top
17                 + corLength, paint);
18         canvas.drawRect(frame.left - corWidth, frame.top - corWidth, frame.left
19                 + corLength, frame.top, paint);
20         // 右上角
21         canvas.drawRect(frame.right, frame.top, frame.right + corWidth,
22                 frame.top + corLength, paint);
23         canvas.drawRect(frame.right - corLength, frame.top - corWidth,
24                 frame.right + corWidth, frame.top, paint);
25         // 左下角
26         canvas.drawRect(frame.left - corWidth, frame.bottom - corLength,
27                 frame.left, frame.bottom, paint);
28         canvas.drawRect(frame.left - corWidth, frame.bottom, frame.left
29                 + corLength, frame.bottom + corWidth, paint);
30         // 右下角
31         canvas.drawRect(frame.right, frame.bottom - corLength, frame.right
32                 + corWidth, frame.bottom, paint);
33         canvas.drawRect(frame.right - corLength, frame.bottom, frame.right
34                 + corWidth, frame.bottom + corWidth, paint);
35     }

 1 private void drawScanLight(Canvas canvas, Rect frame) {
 2 
 3         if (scanLineTop == 0) {
 4             scanLineTop = frame.top;
 5         }
 6 
 7         if (scanLineTop >= frame.bottom) {
 8             scanLineTop = frame.top;
 9         } else {
10             scanLineTop += SCAN_VELOCITY;
11         }
12         Rect scanRect = new Rect(frame.left, scanLineTop, frame.right,
13                 scanLineTop + 30);
14         canvas.drawBitmap(scanLight, null, scanRect, paint);
15     }

  1 /**
  2  * This view is overlaid on top of the camera preview. It adds the viewfinder
  3  * rectangle and partial transparency outside it, as well as the laser scanner
  4  * animation and result points. 这是一个位于相机顶部的预览view,它增加了一个外部部分透明的取景框，以及激光扫描动画和结果组件
  5  * 
  6  * @author dswitkin@google.com (Daniel Switkin)
  7  */
  8 public final class ViewfinderView extends View {
  9 
 10     private static final int[] SCANNER_ALPHA = { 0, 64, 128, 192, 255, 192,
 11             128, 64 };
 12     private static final long ANIMATION_DELAY = 80L;
 13     private static final int CURRENT_POINT_OPACITY = 0xA0;
 14     private static final int MAX_RESULT_POINTS = 20;
 15     private static final int POINT_SIZE = 6;
 16 
 17     private CameraManager cameraManager;
 18     private final Paint paint;
 19     private Bitmap resultBitmap;
 20     private final int maskColor; // 取景框外的背景颜色
 21     private final int resultColor;// result Bitmap的颜色
 22     private final int laserColor; // 红色扫描线的颜色
 23     private final int resultPointColor; // 特征点的颜色
 24     private final int statusColor; // 提示文字颜色
 25     private int scannerAlpha;
 26     private List<ResultPoint> possibleResultPoints;
 27     private List<ResultPoint> lastPossibleResultPoints;
 28     // 扫描线移动的y
 29     private int scanLineTop;
 30     // 扫描线移动速度
 31     private final int SCAN_VELOCITY = 5;
 32     // 扫描线
 33     Bitmap scanLight;
 34 
 35     public ViewfinderView(Context context, AttributeSet attrs) {
 36         super(context, attrs);
 37 
 38         // Initialize these once for performance rather than calling them every
 39         // time in onDraw().
 40         paint = new Paint(Paint.ANTI_ALIAS_FLAG);
 41         Resources resources = getResources();
 42         maskColor = resources.getColor(R.color.viewfinder_mask);
 43         resultColor = resources.getColor(R.color.result_view);
 44         laserColor = resources.getColor(R.color.viewfinder_laser);
 45         resultPointColor = resources.getColor(R.color.possible_result_points);
 46         statusColor = resources.getColor(R.color.status_text);
 47         scannerAlpha = 0;
 48         possibleResultPoints = new ArrayList<ResultPoint>(5);
 49         lastPossibleResultPoints = null;
 50         scanLight = BitmapFactory.decodeResource(resources,
 51                 R.drawable.scan_light);
 52     }
 53 
 54     public void setCameraManager(CameraManager cameraManager) {
 55         this.cameraManager = cameraManager;
 56     }
 57 
 58     @SuppressLint("DrawAllocation")
 59     @Override
 60     public void onDraw(Canvas canvas) {
 61         if (cameraManager == null) {
 62             return; // not ready yet, early draw before done configuring
 63         }
 64 
 65         // frame为取景框
 66         Rect frame = cameraManager.getFramingRect();
 67         Rect previewFrame = cameraManager.getFramingRectInPreview();
 68         if (frame == null || previewFrame == null) {
 69             return;
 70         }
 71         int width = canvas.getWidth();
 72         int height = canvas.getHeight();
 73 
 74         // Draw the exterior (i.e. outside the framing rect) darkened
 75         // 绘制取景框外的暗灰色的表面，分四个矩形绘制
 76         paint.setColor(resultBitmap != null ? resultColor : maskColor);
 77         canvas.drawRect(0, 0, width, frame.top, paint);// Rect_1
 78         canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, paint); // Rect_2
 79         canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1,
 80                 paint); // Rect_3
 81         canvas.drawRect(0, frame.bottom + 1, width, height, paint); // Rect_4
 82 
 83         if (resultBitmap != null) {
 84             // Draw the opaque result bitmap over the scanning rectangle
 85             // 如果有二维码结果的Bitmap，在扫取景框内绘制不透明的result Bitmap
 86             paint.setAlpha(CURRENT_POINT_OPACITY);
 87             canvas.drawBitmap(resultBitmap, null, frame, paint);
 88         } else {
 89             // Draw a red "laser scanner" line through the middle to show
 90             // decoding is active
 91             drawFrameBounds(canvas, frame);
 92             drawStatusText(canvas, frame, width);
 93 
 94             // 绘制扫描线
 95             // paint.setColor(laserColor);
 96             // paint.setAlpha(SCANNER_ALPHA[scannerAlpha]);
 97             // scannerAlpha = (scannerAlpha + 1) % SCANNER_ALPHA.length;
 98             // int middle = frame.height() / 2 + frame.top;
 99             // canvas.drawRect(frame.left + 2, middle - 1, frame.right - 1,
100             // middle + 2, paint);
101 
102             drawScanLight(canvas, frame);
103 
104             float scaleX = frame.width() / (float) previewFrame.width();
105             float scaleY = frame.height() / (float) previewFrame.height();
106 
107             // 绘制扫描线周围的特征点
108             List<ResultPoint> currentPossible = possibleResultPoints;
109             List<ResultPoint> currentLast = lastPossibleResultPoints;
110             int frameLeft = frame.left;
111             int frameTop = frame.top;
112             if (currentPossible.isEmpty()) {
113                 lastPossibleResultPoints = null;
114             } else {
115                 possibleResultPoints = new ArrayList<ResultPoint>(5);
116                 lastPossibleResultPoints = currentPossible;
117                 paint.setAlpha(CURRENT_POINT_OPACITY);
118                 paint.setColor(resultPointColor);
119                 synchronized (currentPossible) {
120                     for (ResultPoint point : currentPossible) {
121                         canvas.drawCircle(frameLeft
122                                 + (int) (point.getX() * scaleX), frameTop
123                                 + (int) (point.getY() * scaleY), POINT_SIZE,
124                                 paint);
125                     }
126                 }
127             }
128             if (currentLast != null) {
129                 paint.setAlpha(CURRENT_POINT_OPACITY / 2);
130                 paint.setColor(resultPointColor);
131                 synchronized (currentLast) {
132                     float radius = POINT_SIZE / 2.0f;
133                     for (ResultPoint point : currentLast) {
134                         canvas.drawCircle(frameLeft
135                                 + (int) (point.getX() * scaleX), frameTop
136                                 + (int) (point.getY() * scaleY), radius, paint);
137                     }
138                 }
139             }
140 
141             // Request another update at the animation interval, but only
142             // repaint the laser line,
143             // not the entire viewfinder mask.
144             postInvalidateDelayed(ANIMATION_DELAY, frame.left - POINT_SIZE,
145                     frame.top - POINT_SIZE, frame.right + POINT_SIZE,
146                     frame.bottom + POINT_SIZE);
147         }
148     }
149 
150     /**
151      * 绘制取景框边框
152      * 
153      * @param canvas
154      * @param frame
155      */
156     private void drawFrameBounds(Canvas canvas, Rect frame) {
157 
158         paint.setColor(Color.WHITE);
159         paint.setStrokeWidth(2);
160         paint.setStyle(Paint.Style.STROKE);
161 
162         canvas.drawRect(frame, paint);
163 
164         paint.setColor(Color.BLUE);
165         paint.setStyle(Paint.Style.FILL);
166 
167         int corWidth = 15;
168         int corLength = 45;
169 
170         // 左上角
171         canvas.drawRect(frame.left - corWidth, frame.top, frame.left, frame.top
172                 + corLength, paint);
173         canvas.drawRect(frame.left - corWidth, frame.top - corWidth, frame.left
174                 + corLength, frame.top, paint);
175         // 右上角
176         canvas.drawRect(frame.right, frame.top, frame.right + corWidth,
177                 frame.top + corLength, paint);
178         canvas.drawRect(frame.right - corLength, frame.top - corWidth,
179                 frame.right + corWidth, frame.top, paint);
180         // 左下角
181         canvas.drawRect(frame.left - corWidth, frame.bottom - corLength,
182                 frame.left, frame.bottom, paint);
183         canvas.drawRect(frame.left - corWidth, frame.bottom, frame.left
184                 + corLength, frame.bottom + corWidth, paint);
185         // 右下角
186         canvas.drawRect(frame.right, frame.bottom - corLength, frame.right
187                 + corWidth, frame.bottom, paint);
188         canvas.drawRect(frame.right - corLength, frame.bottom, frame.right
189                 + corWidth, frame.bottom + corWidth, paint);
190     }
191 
192     /**
193      * 绘制提示文字
194      * 
195      * @param canvas
196      * @param frame
197      * @param width
198      */
199     private void drawStatusText(Canvas canvas, Rect frame, int width) {
200 
201         String statusText1 = getResources().getString(
202                 R.string.viewfinderview_status_text1);
203         String statusText2 = getResources().getString(
204                 R.string.viewfinderview_status_text2);
205         int statusTextSize = 45;
206         int statusPaddingTop = 180;
207 
208         paint.setColor(statusColor);
209         paint.setTextSize(statusTextSize);
210 
211         int textWidth1 = (int) paint.measureText(statusText1);
212         canvas.drawText(statusText1, (width - textWidth1) / 2, frame.top
213                 - statusPaddingTop, paint);
214 
215         int textWidth2 = (int) paint.measureText(statusText2);
216         canvas.drawText(statusText2, (width - textWidth2) / 2, frame.top
217                 - statusPaddingTop + 60, paint);
218     }
219 
220     /**
221      * 绘制移动扫描线
222      * 
223      * @param canvas
224      * @param frame
225      */
226     private void drawScanLight(Canvas canvas, Rect frame) {
227 
228         if (scanLineTop == 0) {
229             scanLineTop = frame.top;
230         }
231 
232         if (scanLineTop >= frame.bottom) {
233             scanLineTop = frame.top;
234         } else {
235             scanLineTop += SCAN_VELOCITY;
236         }
237         Rect scanRect = new Rect(frame.left, scanLineTop, frame.right,
238                 scanLineTop + 30);
239         canvas.drawBitmap(scanLight, null, scanRect, paint);
240     }
241 
242     public void drawViewfinder() {
243         Bitmap resultBitmap = this.resultBitmap;
244         this.resultBitmap = null;
245         if (resultBitmap != null) {
246             resultBitmap.recycle();
247         }
248         invalidate();
249     }
250 
251     /**
252      * Draw a bitmap with the result points highlighted instead of the live
253      * scanning display.
254      * 
255      * @param barcode
256      *            An image of the decoded barcode.
257      */
258     public void drawResultBitmap(Bitmap barcode) {
259         resultBitmap = barcode;
260         invalidate();
261     }
262 
263     public void addPossibleResultPoint(ResultPoint point) {
264         List<ResultPoint> points = possibleResultPoints;
265         synchronized (points) {
266             points.add(point);
267             int size = points.size();
268             if (size > MAX_RESULT_POINTS) {
269                 // trim it
270                 points.subList(0, size - MAX_RESULT_POINTS / 2).clear();
271             }
272         }
273     }
274 
275 }