Merge pull request #14872 from AhiyaHiya:feature/topmost_window

* Added mechanism to set/toggle NORMAL window to TOPMOST window.

* highgui: remove unnecessary/legacy code

modules/highgui/src/window.cpp

@@ -42,6 +42,7 @@
 #include "precomp.hpp"
 #include <map>
 #include "opencv2/core/opengl.hpp"
+#include "opencv2/core/utils/logger.hpp"
 
 // in later times, use this file as a dispatcher to implementations like cvcap.cpp
 
@@ -83,6 +84,16 @@ CV_IMPL void cvSetWindowProperty(const char* name, int prop_id, double prop_valu
         #endif
     break;
 
+    case cv::WND_PROP_TOPMOST:
+        #if defined(HAVE_WIN32UI)
+            cvSetPropTopmost_W32(name, (prop_value != 0 ? true : false));
+        #elif defined(HAVE_COCOA)
+            cvSetPropTopmost_COCOA(name, (prop_value != 0 ? true : false));
+        #else
+            CV_LOG_WARNING(NULL, "Property WND_PROP_TOPMOST is not supported on current GUI backend");
+        #endif
+    break;
+
     default:;
     }
 }
@@ -162,6 +173,18 @@ CV_IMPL double cvGetWindowProperty(const char* name, int prop_id)
             return -1;
         #endif
     break;
+
+    case cv::WND_PROP_TOPMOST:
+        #if defined(HAVE_WIN32UI)
+            return cvGetPropTopmost_W32(name);
+        #elif defined(HAVE_COCOA)
+            return cvGetPropTopmost_COCOA(name);
+        #else
+            CV_LOG_WARNING(NULL, "Property WND_PROP_TOPMOST is not supported on current GUI backend");
+            return -1;
+        #endif
+    break;
+
     default:
         return -1;
     }