add waitKeyEx method

Needed on windows (and maybe other systems?) to capture special buttons (like arrow keys).

Author: Garfonso

cc/io/io.cc

@@ -16,6 +16,7 @@ NAN_MODULE_INIT(Io::Init) {
   Nan::SetMethod(target, "imshowWait", ImshowWait);
   Nan::SetMethod(target, "imwrite", Imwrite);
   Nan::SetMethod(target, "waitKey", WaitKey);
+  Nan::SetMethod(target, "waitKeyEx", WaitKeyEx);
   Nan::SetMethod(target, "imencode", Imencode);
   Nan::SetMethod(target, "imdecode", Imdecode);
   Nan::SetMethod(target, "moveWindow", MoveWindow);
@@ -105,6 +106,16 @@ NAN_METHOD(Io::WaitKey) {
   info.GetReturnValue().Set(Nan::New(key));
 }
 
+NAN_METHOD(Io::WaitKeyEx) {
+  int key;
+  if (info[0]->IsNumber()) {
+    key = cv::waitKeyEx(info[0]->ToNumber(Nan::GetCurrentContext()).ToLocalChecked()->Value());
+  } else{
+    key = cv::waitKeyEx();
+  }
+  info.GetReturnValue().Set(Nan::New(key));
+}
+
 NAN_METHOD(Io::MoveWindow) {
 	FF::TryCatch tryCatch("Io::MoveWindow");
 	std::string winName;

cc/io/io.h

@@ -16,6 +16,7 @@ class Io {
 	static NAN_METHOD(Imshow);
 	static NAN_METHOD(ImshowWait);
 	static NAN_METHOD(WaitKey);
+	static NAN_METHOD(WaitKeyEx);
 	static NAN_METHOD(MoveWindow);
 	static NAN_METHOD(DestroyWindow);
 	static NAN_METHOD(DestroyAllWindows);
@@ -29,4 +30,4 @@ class Io {
 	static NAN_METHOD(ImdecodeAsync);
 };
 
-#endif
+#endif

lib/typings/cv.d.ts

@@ -205,6 +205,7 @@ export function transformAsync(mat: Mat, m: Mat): Promise<Mat>;
 export function undistortPoints(srcPoints: Point2[], cameraMatrix: Mat, distCoeffs: Mat): Point2[];
 export function undistortPointsAsync(srcPoints: Point2[], cameraMatrix: Mat, distCoeffs: Mat): Promise<Point2[]>;
 export function waitKey(delay?: number): number;
+export function waitKeyEx(delay?: number): number;
 
 export type DrawParams = {
   thickness?: number;