makes text module dependency optional

modules/datasets/CMakeLists.txt

 set(the_description "datasets framework")
-ocv_define_module(datasets opencv_core opencv_imgcodecs opencv_ml opencv_flann opencv_text WRAP python)
+ocv_define_module(datasets opencv_core opencv_imgcodecs opencv_ml opencv_flann OPTIONAL opencv_text WRAP python)
 
 ocv_warnings_disable(CMAKE_CXX_FLAGS /wd4267) # flann, Win64

modules/datasets/samples/tr_chars_benchmark.cpp

@@ -39,10 +39,13 @@
 //
 //M*/
 
-#include "opencv2/datasets/tr_chars.hpp"
+#include <iostream>
+#include <opencv2/opencv_modules.hpp>
 
-#include <opencv2/core.hpp>
+#ifdef HAVE_OPENCV_TEXT
 
+#include "opencv2/datasets/tr_chars.hpp"
+#include <opencv2/core.hpp>
 #include "opencv2/text.hpp"
 #include "opencv2/imgproc.hpp"
 #include "opencv2/imgcodecs.hpp"
@@ -127,3 +130,13 @@ int main(int argc, char *argv[])
 
     return 0;
 }
+
+#else
+
+int main()
+{
+    std::cerr << "OpenCV was built without text module" << std::endl;
+    return 0;
+}
+
+#endif // HAVE_OPENCV_TEXT

modules/datasets/samples/tr_icdar_benchmark.cpp

@@ -39,10 +39,13 @@
 //
 //M*/
 
-#include "opencv2/datasets/tr_icdar.hpp"
+#include <iostream>
+#include <opencv2/opencv_modules.hpp>
 
-#include <opencv2/core.hpp>
+#ifdef HAVE_OPENCV_TEXT
 
+#include "opencv2/datasets/tr_icdar.hpp"
+#include <opencv2/core.hpp>
 #include "opencv2/text.hpp"
 #include "opencv2/imgproc.hpp"
 #include "opencv2/imgcodecs.hpp"
@@ -50,8 +53,6 @@
 #include <cstdio>
 #include <cstdlib> // atoi
 
-#include <iostream>
-
 #include <string>
 #include <vector>
 
@@ -509,3 +510,13 @@ int main(int argc, char *argv[])
 
     return 0;
 }
+
+#else
+
+int main()
+{
+    std::cerr << "OpenCV was built without text module" << std::endl;
+    return 0;
+}
+
+#endif // HAVE_OPENCV_TEXT

modules/datasets/samples/tr_svt_benchmark.cpp

@@ -39,10 +39,13 @@
 //
 //M*/
 
-#include "opencv2/datasets/tr_svt.hpp"
+#include <iostream>
+#include <opencv2/opencv_modules.hpp>
 
-#include <opencv2/core.hpp>
+#ifdef HAVE_OPENCV_TEXT
 
+#include "opencv2/datasets/tr_svt.hpp"
+#include <opencv2/core.hpp>
 #include "opencv2/text.hpp"
 #include "opencv2/imgproc.hpp"
 #include "opencv2/imgcodecs.hpp"
@@ -50,8 +53,6 @@
 #include <cstdio>
 #include <cstdlib> // atoi
 
-#include <iostream>
-
 #include <string>
 #include <vector>
 
@@ -309,3 +310,13 @@ int main(int argc, char *argv[])
 
     return 0;
 }
+
+#else
+
+int main()
+{
+    std::cerr << "OpenCV was built without text module" << std::endl;
+    return 0;
+}
+
+#endif // HAVE_OPENCV_TEXT