Make gtk-2, X11, libjpeg and libpng private

doc/tutorial/unix/tutorial-install-fedora.dox

@@ -110,6 +110,15 @@ $ sudo dnf install libdmtx-devel
 \verbatim
 $ sudo dnf install gsl-devel
 \endverbatim
+- Gtk-2 for gui capabilities instead of X11
+\verbatim
+$ sudo dnf install gtk2-devel glib2-devel pango-devel atk-devel cairo-devel
+\endverbatim
+After installing the gtk packages, you need to explicitly enable gtk usage during ViSP cmake configuration step by:
+\verbatim
+$ cd $VISP_WS/visp-build
+$ cmake ../visp -DUSE_GTK=ON
+\endverbatim
 
 \subsection install_fedora_get_source Get ViSP source code
 

doc/tutorial/unix/tutorial-install-osx-homebrew.dox

@@ -250,6 +250,21 @@ dyld[33644]: Library not loaded: /System/Library/Frameworks/Python.framework/Ver
 To overcome this error, download and install the latest Python 2
 for macOS from [offical site](https://www.python.org/downloads/macos/).
 
+\subsubsection install_brew_3rdparty_other Other optional 3rd parties
+
+We give also the way to install other 3rd party libraries to enable specific capabilities.
+
+- Gtk-2 for gui capabilities instead of X11
+\verbatim
+$ brew install gtk
+\endverbatim
+After installing the gtk packages, you need to explicitly enable gtk usage during ViSP cmake configuration step by:
+\verbatim
+$ cd $VISP_WS/visp-build
+$ cmake ../visp -DUSE_GTK=ON
+\endverbatim
+
+
 \subsection install_brew_get_source Get ViSP source code
 
 There are different ways to get ViSP source code:

doc/tutorial/unix/tutorial-install-ubuntu.dox

@@ -31,7 +31,8 @@ $ mkdir -p $VISP_WS
 
 \section install_ubuntu_quick Quick ViSP installation
 
-In this section, we give minimal instructions to build ViSP from source just to try ViSP without entering in \ref install_ubuntu_advanced.
+In this section, we give minimal instructions to build ViSP from source just to try ViSP without entering in
+\ref install_ubuntu_advanced.
 
 - Install a small number of recommended 3rd parties
 
@@ -448,6 +449,15 @@ $ sudo apt-get install libgsl-dev
 \verbatim
 $ sudo apt-get install nlohmann-json3-dev
 \endverbatim
+- Gtk-2 for gui capabilities instead of X11
+\verbatim
+$ sudo apt-get install libgtk2.0-dev libglib2.0-dev libpango1.0-dev libatk1.0-dev libcairo2-dev
+\endverbatim
+After installing the gtk packages, you need to explicitly enable gtk usage during ViSP cmake configuration step by:
+\verbatim
+$ cd $VISP_WS/visp-build
+$ cmake ../visp -DUSE_GTK=ON
+\endverbatim
 
 \subsection install_ubuntu_visp_get_source Get ViSP source code
 

modules/gui/CMakeLists.txt

@@ -36,31 +36,33 @@
 # Add optional 3rd parties
 set(opt_incs "")
 set(opt_libs "")
+set(opt_libs_private "")
 
 # Display X11, GTK, GDI, D3D9. OpenCV already handled by core module
 if(USE_X11)
-  list(APPEND opt_incs ${X11_INCLUDE_DIR})
-  list(APPEND opt_libs ${X11_LIBRARIES})
+  # X11 is private
+  include_directories(${X11_INCLUDE_DIR})
+  list(APPEND opt_libs_private ${X11_LIBRARIES})
   mark_as_advanced(X11_xcb_icccm_INCLUDE_PATH)
   mark_as_advanced(X11_xcb_icccm_LIB)
   mark_as_advanced(X11_xcb_xkb_INCLUDE_PATH)
 endif()
+
 if(USE_GTK2)
-  list(APPEND opt_incs ${GTK2_INCLUDE_DIRS})
-  list(APPEND opt_libs ${GTK2_LIBRARIES})
-  # FS next lines removed until they proved to be useful
-#  if(UNIX)
-#    ## ignore gtk pedantic warnings by gcc specific -isystem :
-#    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -isystem ${GTK2_gtk_INCLUDE_PATH}")
-#  endif()
+  # gtk2 is private
+  include_directories(${GTK2_INCLUDE_DIRS})
+  list(APPEND opt_libs_private ${GTK2_LIBRARIES})
 endif()
+
 if(USE_GDI)
   list(APPEND opt_libs ${GDI_LIBRARIES})
 endif()
+
 if(USE_DIRECT3D)
   list(APPEND opt_incs ${DIRECT3D_INCLUDE_DIRS})
   list(APPEND opt_libs ${DIRECT3D_LIBRARIES})
 endif()
+
 if(USE_PCL)
   list(APPEND opt_incs ${PCL_INCLUDE_DIRS})
 
@@ -83,7 +85,7 @@ if(USE_PCL)
   list(APPEND opt_libs ${PCL_DEPS_LIBRARIES})
 endif()
 
-vp_add_module(gui visp_core)
+vp_add_module(gui visp_core PRIVATE_OPTIONAL ${opt_libs_private})
 vp_glob_module_sources()
 vp_module_include_directories(${opt_incs})
 vp_create_module(${opt_libs})

modules/gui/include/visp3/gui/vpDisplayGTK.h

@@ -1,5 +1,4 @@
-/****************************************************************************
- *
+/*
  * ViSP, open source Visual Servoing Platform software.
  * Copyright (C) 2005 - 2023 by Inria. All rights reserved.
  *
@@ -30,11 +29,7 @@
  *
  * Description:
  * Image display.
- *
- * Authors:
- * Christophe Collewet
- *
-*****************************************************************************/
+ */
 
 #ifndef vpDisplayGTK_h
 #define vpDisplayGTK_h
@@ -46,90 +41,89 @@
 #include <visp3/core/vpImage.h>
 
 /*!
-  \file vpDisplayGTK.h
-  \brief Define the GTK console to display images.
-*/
+ * \file vpDisplayGTK.h
+ * \brief Define the GTK console to display images.
+ */
 
 /*!
-
-  \class vpDisplayGTK
-
-  \ingroup group_gui_display
-
-  \brief The vpDisplayGTK allows to display image using the GTK 3rd party
-  library. Thus to enable this class GTK should be installed. Installation
-  instructions are provided here https://visp.inria.fr/3rd_gtk.
-
-  The example below shows how to display an image with this video device.
-  \code
-#include <visp3/core/vpImagePoint.h>
-#include <visp3/gui/vpDisplayGTK.h>
-#include <visp3/io/vpImageIo.h>
-
-int main()
-{
-#if defined(VISP_HAVE_GTK)
-  vpImage<unsigned char> I; // Grey level image
-
-  // Read an image in PGM P5 format
-#ifdef _WIN32
-  vpImageIo::read(I, "C:/Temp/visp-images/Klimt/Klimt.pgm");
-#else
-  vpImageIo::read(I, "/local/soft/ViSP/ViSP-images/Klimt/Klimt.pgm");
-#endif
-
-  vpDisplayGTK d;
-
-  // Initialize the display with the image I. Display and image are
-  // now link together.
-  d.init(I);
-
-  // Specify the window location
-  vpDisplay::setWindowPosition(I, 400, 100);
-
-  // Set the display window title
-  vpDisplay::setTitle(I, "My GTK display");
-
-  // Set the display background with image I content
-  vpDisplay::display(I);
-
-  // Draw a red rectangle in the display overlay (foreground)
-  vpDisplay::displayRectangle(I, 10, 10, 100, 20, vpColor::red, true);
-
-  // Draw a red rectangle in the display overlay (foreground)
-  vpImagePoint topLeftCorner;
-  topLeftCorner.set_i(50);
-  topLeftCorner.set_j(10);
-  vpDisplay::displayRectangle(I, topLeftCorner, 100, 20, vpColor::green, true);
-
-  // Flush the foreground and background display
-  vpDisplay::flush(I);
-
-  // Get non blocking keyboard events
-  std::cout << "Check keyboard events..." << std::endl;
-  char key[10];
-  bool ret;
-  for (int i=0; i< 200; i++) {
-    bool ret = vpDisplay::getKeyboardEvent(I, key, false);
-    if (ret)
-      std::cout << "keyboard event: key: " << "\"" << key << "\"" << std::endl;
-    vpTime::wait(40);
-  }
-
-  // Get a blocking keyboard event
-  std::cout << "Wait for a keyboard event..." << std::endl;
-  ret = vpDisplay::getKeyboardEvent(I, key, true);
-  std::cout << "keyboard event: " << ret << std::endl;
-  if (ret)
-    std::cout << "key: " << "\"" << key << "\"" << std::endl;
-
-  // Wait for a click in the display window
-  std::cout << "Wait for a button click..." << std::endl;
-  vpDisplay::getClick(I);
-#endif
-}
-  \endcode
-*/
+ * \class vpDisplayGTK
+ *
+ * \ingroup group_gui_display
+ *
+ * \brief The vpDisplayGTK allows to display image using the GTK 3rd party
+ * library. Thus to enable this class GTK should be installed. Installation
+ * instructions are provided here https://visp.inria.fr/3rd_gtk.
+ *
+ * The example below shows how to display an image with this video device.
+ * \code
+ * #include <visp3/core/vpImagePoint.h>
+ * #include <visp3/gui/vpDisplayGTK.h>
+ * #include <visp3/io/vpImageIo.h>
+ *
+ * int main()
+ * {
+ * #if defined(VISP_HAVE_GTK)
+ *   vpImage<unsigned char> I; // Grey level image
+ *
+ *   // Read an image in PGM P5 format
+ * #ifdef _WIN32
+ *   vpImageIo::read(I, "C:/Temp/visp-images/Klimt/Klimt.pgm");
+ * #else
+ *   vpImageIo::read(I, "/local/soft/ViSP/ViSP-images/Klimt/Klimt.pgm");
+ * #endif
+ *
+ *   vpDisplayGTK d;
+ *
+ *   // Initialize the display with the image I. Display and image are
+ *   // now link together.
+ *   d.init(I);
+ *
+ *   // Specify the window location
+ *   vpDisplay::setWindowPosition(I, 400, 100);
+ *
+ *   // Set the display window title
+ *   vpDisplay::setTitle(I, "My GTK display");
+ *
+ *   // Set the display background with image I content
+ *   vpDisplay::display(I);
+ *
+ *   // Draw a red rectangle in the display overlay (foreground)
+ *   vpDisplay::displayRectangle(I, 10, 10, 100, 20, vpColor::red, true);
+ *
+ *   // Draw a red rectangle in the display overlay (foreground)
+ *   vpImagePoint topLeftCorner;
+ *   topLeftCorner.set_i(50);
+ *   topLeftCorner.set_j(10);
+ *   vpDisplay::displayRectangle(I, topLeftCorner, 100, 20, vpColor::green, true);
+ *
+ *   // Flush the foreground and background display
+ *   vpDisplay::flush(I);
+ *
+ *   // Get non blocking keyboard events
+ *   std::cout << "Check keyboard events..." << std::endl;
+ *   char key[10];
+ *   bool ret;
+ *   for (int i=0; i< 200; i++) {
+ *     bool ret = vpDisplay::getKeyboardEvent(I, key, false);
+ *     if (ret)
+ *       std::cout << "keyboard event: key: " << "\"" << key << "\"" << std::endl;
+ *     vpTime::wait(40);
+ *   }
+ *
+ *   // Get a blocking keyboard event
+ *   std::cout << "Wait for a keyboard event..." << std::endl;
+ *   ret = vpDisplay::getKeyboardEvent(I, key, true);
+ *   std::cout << "keyboard event: " << ret << std::endl;
+ *   if (ret)
+ *     std::cout << "key: " << "\"" << key << "\"" << std::endl;
+ *
+ *   // Wait for a click in the display window
+ *   std::cout << "Wait for a button click..." << std::endl;
+ *   vpDisplay::getClick(I);
+ * #endif
+ * }
+ * \endcode
+ */
 class VISP_EXPORT vpDisplayGTK : public vpDisplay
 {
 private: