[gstreamermm] Examples: add few simple examples

[Marcin Kolny <mkolny src gnome org>]

commit 6dbbbb3cd6133392f64140627d2e3f2e5e36d60d
Author: Marcin Kolny <marcin kolny gmail com>
Date:   Sun Aug 28 20:47:24 2016 +0200

    Examples: add few simple examples

 .gitignore                          |    2 +
 examples/Makefile.am                |    8 +++-
 examples/basics/element_factory.cc  |   65 ++++++++++++++++++++++++++++
 examples/basics/init_gstreamermm.cc |   81 +++++++++++++++++++++++++++++++++++
 gstreamer/gstreamermm/init.h        |    5 ++
 gstreamer/src/elementfactory.hg     |    4 ++
 6 files changed, 164 insertions(+), 1 deletions(-)
---
diff --git a/.gitignore b/.gitignore
index dab89f3..7e79bd9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -39,6 +39,8 @@ stamp-h?
 
 #examples/
 /examples/*/example
+/examples/basics/element_factory
+/examples/basics/init_gstreamermm
 
 # gstreamer/
 gstreamer/gstreamermm/allocator.cc
diff --git a/examples/Makefile.am b/examples/Makefile.am
index b7d00bc..dd9b47a 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -55,12 +55,14 @@ noinst_PROGRAMS =                                           \
        ogg_rewriter/example                            \
        typefind/example                                        \
        optiongroup/example                                     \
+       basics/element_factory                          \
+       basics/init_gstreamermm                         \
        $(gl_examples)                                          \
        $(gui_examples)
 
 
 AM_CPPFLAGS = -I$(top_builddir) $(gstreamermm_includes) $(examples_cppflags)
-AM_CXXFLAGS = $(GSTREAMERMM_WXXFLAGS) -std=c++0x
+AM_CXXFLAGS = $(GSTREAMERMM_WXXFLAGS) -std=c++11
 LDADD = $(GSTREAMERMM_LIBS) $(local_libgstreamermm)
 
 all_media_player_example_SOURCES                       = all_media_player/main.cc
@@ -74,3 +76,7 @@ ogg_player_example_SOURCES                                    = ogg_player/main.cc
 opengl_filter_example_SOURCES                          = opengl_filter/main.cc 
 optiongroup_example_SOURCES                                    = optiongroup/main.cc
 typefind_example_SOURCES                                       = typefind/main.cc
+
+# basic examples
+basics_element_factory_SOURCES                         = basics/element_factory.cc
+basics_init_gstreamermm_SOURCES                                = basics/init_gstreamermm.cc
diff --git a/examples/basics/element_factory.cc b/examples/basics/element_factory.cc
new file mode 100644
index 0000000..5ba8418
--- /dev/null
+++ b/examples/basics/element_factory.cc
@@ -0,0 +1,65 @@
+/*
+ * This example presents how to use Gst::ElementFactory class, getting
+ * information and create specific element.
+ */
+#include <gstreamermm.h>
+
+#include <iostream>
+
+int main(int argc, char *argv[])
+{
+  Gst::init(argc, argv);
+
+  // Get list of all primary demuxers in the system
+  std::cout << "List of primary demuxers: " << std::endl;
+  for (Glib::RefPtr<Gst::ElementFactory> factory
+        : Gst::ElementFactory::get_elements(Gst::ELEMENT_FACTORY_TYPE_DEMUXER, Gst::RANK_PRIMARY))
+  {
+    std::cout << " * " << factory->get_name() << std::endl;
+  }
+  std::cout << std::endl;
+
+  Glib::RefPtr<Gst::ElementFactory> fakesrc_factory = Gst::ElementFactory::find("fakesrc");
+  if (!fakesrc_factory)
+  {
+    std::cerr << "Failed to find factory of type 'fakesrc'" << std::endl;
+    return -1;
+  }
+
+  // Read information about an author of the element
+  std::cout << "Author of the element '" << fakesrc_factory->get_name() << "' is "
+      << fakesrc_factory->get_metadata(GST_ELEMENT_METADATA_AUTHOR) << std::endl << std::endl;
+
+  // Read all available information about the element
+  std::cout << "All information about element '" << fakesrc_factory->get_name() << "':" << std::endl;
+  for (auto metadata_key : fakesrc_factory->get_metadata_keys())
+  {
+    std::cout << " * " << metadata_key << ": " << fakesrc_factory->get_metadata(metadata_key) << std::endl;
+  }
+
+
+  // Create element fakesrc
+
+  // Method 1
+  {
+    Glib::RefPtr<Gst::Element> fakesrc = fakesrc_factory->create("source");
+
+    if (!fakesrc)
+    {
+      std::cerr << "Failed to create element of type 'fakesrc'" << std::endl;
+      return -1;
+    }
+  }
+
+  // Method 2
+  {
+    Glib::RefPtr<Gst::Element> fakesrc = Gst::ElementFactory::create_element("fakesrc", "source");
+    if (!fakesrc)
+    {
+      std::cerr << "Failed to create element of type 'fakesrc'" << std::endl;
+      return -1;
+    }
+  }
+
+  return 0;
+}
diff --git a/examples/basics/init_gstreamermm.cc b/examples/basics/init_gstreamermm.cc
new file mode 100644
index 0000000..da54d0a
--- /dev/null
+++ b/examples/basics/init_gstreamermm.cc
@@ -0,0 +1,81 @@
+/*
+ * The example presents how to initialize gstreamermm, read
+ * version of GStreamer, and use GStreamer option group together
+ * with your application's option group.
+ */
+#include <gstreamermm.h>
+#include <glibmm.h>
+
+#include <iostream>
+
+class MainOptionGroup : public Glib::OptionGroup
+{
+public:
+  MainOptionGroup();
+
+  bool version;
+};
+
+MainOptionGroup::MainOptionGroup()
+: Glib::OptionGroup("main_group", "main group"),
+  version(false)
+{
+  Glib::OptionEntry entry1;
+  entry1.set_long_name("version");
+  entry1.set_short_name('v');
+  entry1.set_description("Show gstreamer version");
+  add_entry(entry1, version);
+}
+
+static void print_gstreamer_version()
+{
+  guint major, minor, micro, nano;
+
+  // Read GStreamer version
+  Gst::version(major, minor, micro, nano);
+
+  std::string nano_str;
+
+  switch (nano) {
+    case 1: nano_str = "(CSV)"; break;
+    case 2: nano_str = "(Prerelease)"; break;
+  }
+
+  std::cout << "This program is linked against GStreamer "
+      << major << "." << minor << "." << micro << "."
+      << nano << " " << nano_str << std::endl;
+}
+
+int main (int argc, char *argv[])
+{
+  // Initialize gstreamermm
+  Gst::init(argc, argv);
+
+  Glib::OptionContext context("- gstreamermm init example");
+
+  MainOptionGroup main_group;
+  context.set_main_group(main_group);
+
+  // Get GStreamer option group and add it to the context
+  Glib::OptionGroup gst_group = Gst::get_option_group();
+  context.add_group(gst_group);
+
+  try
+  {
+    context.parse(argc, argv);
+  }
+  catch (const Glib::Error& ex)
+  {
+    std::cerr << "Failed to initialize: " << ex.what() << std::endl;
+    return 1;
+  }
+
+  if (main_group.version)
+  {
+    print_gstreamer_version();
+  }
+
+  std::cout << "Run me with --help to see the Application options appended." << std::endl;
+
+  return 0;
+}
diff --git a/gstreamer/gstreamermm/init.h b/gstreamer/gstreamermm/init.h
index 4382068..87fcbff 100644
--- a/gstreamer/gstreamermm/init.h
+++ b/gstreamer/gstreamermm/init.h
@@ -250,6 +250,11 @@ void registry_fork_set_enabled(bool enabled);
  */
 bool update_registry();
 
+
+/*! A gstreamermm init example.
+ * @example basics/init_gstreamermm.cc
+ */
+
 }//end namespace Gst
 
 #endif //_GSTREAMERMM_INIT_H
diff --git a/gstreamer/src/elementfactory.hg b/gstreamer/src/elementfactory.hg
index d3cefb2..3169ab9 100644
--- a/gstreamer/src/elementfactory.hg
+++ b/gstreamer/src/elementfactory.hg
@@ -150,4 +150,8 @@ public:
   _WRAP_METHOD(bool is_type(ElementFactoryListType type) const, gst_element_factory_list_is_type)
 };
 
+/*! A gstreamermm Gst::ElementFactory example.
+ * @example basics/element_factory.cc
+ */
+
 } // namespace Gst