Merge remote-tracking branch 'upstream/3.4' into merge-3.4

modules/highgui/src/precomp.hpp

@@ -107,6 +107,8 @@ double cvGetRatioWindow_GTK(const char* name);
 double cvGetOpenGlProp_W32(const char* name);
 double cvGetOpenGlProp_GTK(const char* name);
 
+double cvGetPropVisible_W32(const char* name);
+
 //for QT
 #if defined (HAVE_QT)
 CvRect cvGetWindowRect_QT(const char* name);

modules/highgui/src/window.cpp

@@ -152,6 +152,8 @@ CV_IMPL double cvGetWindowProperty(const char* name, int prop_id)
     case CV_WND_PROP_VISIBLE:
         #if defined (HAVE_QT)
             return cvGetPropVisible_QT(name);
+        #elif defined(HAVE_WIN32UI)
+            return cvGetPropVisible_W32(name);
         #else
             return -1;
         #endif

modules/highgui/src/window_w32.cpp

@@ -642,6 +642,24 @@ double cvGetOpenGlProp_W32(const char* name)
     return result;
 }
 
+double cvGetPropVisible_W32(const char* name)
+{
+    double result = -1;
+
+    CV_FUNCNAME( "cvGetPropVisible_W32" );
+
+    __BEGIN__;
+
+    if (!name)
+        CV_ERROR( CV_StsNullPtr, "NULL name string" );
+
+    result = (icvFindWindowByName( name ) != NULL);
+
+    __END__;
+
+    return result;
+}
+
 
 // OpenGL support