added window WaitKeyEx support (#1195)

highgui: added window WaitKeyEx support

highgui.cpp

@@ -29,6 +29,10 @@ int Window_WaitKey(int delay = 0) {
     return cv::waitKey(delay);
 }
 
+int Window_WaitKeyEx(int delay = 0) {
+    return cv::waitKeyEx(delay);
+}
+
 void Window_Move(const char* winname, int x, int y) {
     cv::moveWindow(winname, x, y);
 }

highgui.go

@@ -162,6 +162,16 @@ func (w *Window) WaitKey(delay int) int {
 	return int(C.Window_WaitKey(C.int(delay)))
 }
 
+// WaitKeyEx Similar to waitKey, but returns full key code.
+// Note
+// Key code is implementation specific and depends on used backend: QT/GTK/Win32/etc
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/d7/dfc/group__highgui.html#gafa15c0501e0ddd90918f17aa071d3dd0
+func (w *Window) WaitKeyEx(delay int) int {
+	return int(C.Window_WaitKey(C.int(delay)))
+}
+
 // MoveWindow moves window to the specified position.
 //
 // For further details, please see:

highgui_gocv.h

@@ -16,6 +16,7 @@ double Window_GetProperty(const char* winname, int flag);
 void Window_SetProperty(const char* winname, int flag, double value);
 void Window_SetTitle(const char* winname, const char* title);
 int Window_WaitKey(int);
+int Window_WaitKeyEx(int);
 void Window_Move(const char* winname, int x, int y);
 void Window_Resize(const char* winname, int width, int height);
 struct Rect Window_SelectROI(const char* winname, Mat img);

highgui_test.go

@@ -112,3 +112,13 @@ func TestTrackbarWithValue(t *testing.T) {
 		t.Error("Trackbar pos should have been 50")
 	}
 }
+
+func TestWaitKeyEx(t *testing.T) {
+
+	w := NewWindow("wait")
+	defer w.Close()
+
+	if w.WaitKeyEx(1) != -1 {
+		t.Error("WaitKeyEx failed!")
+	}
+}