Config file loading options

include/ignition/gazebo/gui/Gui.hh

@@ -41,9 +41,24 @@ namespace gui
   /// ign-tools. Set to the name of the application if using ign-tools)
   /// \param[in] _guiConfig The GUI configuration file. If nullptr, the default
   /// configuration from IGN_HOMEDIR/.ignition/gazebo/gui.config will be used.
+  /// \return Zero if ran successfully.
   IGNITION_GAZEBO_GUI_VISIBLE int runGui(int &_argc, char **_argv,
                                      const char *_guiConfig);
 
+  /// \brief Run GUI application
+  /// \param[in] _argc Number of command line arguments (Used when running
+  /// without ign-tools. Set to 1 if using ign-tools). Note: The object
+  /// referenced by this variable must continue to exist for the lifetime of the
+  /// application.
+  /// \param[in] _argv Command line arguments (Used when running without
+  /// ign-tools. Set to the name of the application if using ign-tools)
+  /// \param[in] _guiConfig The GUI configuration file. If nullptr, the default
+  /// configuration from IGN_HOMEDIR/.ignition/gazebo/gui.config will be used.
+  /// \param[in] _guiConfigOption Options for loading GUI configuration.
+  /// \return Zero if ran successfully.
+  IGNITION_GAZEBO_GUI_VISIBLE int runGui(int &_argc, char **_argv,
+      const char *_guiConfig, const char *_guiConfigOption = nullptr);
+
   /// \brief Create a Gazebo GUI application
   /// \param[in] _argc Number of command line arguments (Used when running
   /// without ign-tools. Set to 1 if using ign-tools). Note: The object
@@ -60,11 +75,36 @@ namespace gui
   /// IGN_HOMEDIR/.ignition/gazebo/gui.config will be used.
   /// \param[in] _loadPluginsFromSdf If true, plugins specified in the world
   /// SDFormat file will get loaded.
+  /// \return The GUI application.
   IGNITION_GAZEBO_GUI_VISIBLE
   std::unique_ptr<ignition::gui::Application> createGui(
       int &_argc, char **_argv, const char *_guiConfig,
       const char *_defaultGuiConfig = nullptr, bool _loadPluginsFromSdf = true);
 
+  /// \brief Create a Gazebo GUI application
+  /// \param[in] _argc Number of command line arguments (Used when running
+  /// without ign-tools. Set to 1 if using ign-tools). Note: The object
+  /// referenced by this variable must continue to exist for the lifetime of the
+  /// application.
+  /// \param[in] _argv Command line arguments (Used when running without
+  /// ign-tools. Set to the name of the application if using ign-tools)
+  /// \param[in] _guiConfig The GUI configuration file. If nullptr, the default
+  /// configuration from IGN_HOMEDIR/.ignition/gazebo/gui.config will be used.
+  /// \param[in] _defaultGuiConfig The default GUI configuration file. If no
+  /// plugins were added from a world file or from _guiConfig, this
+  /// configuration file will be loaded. If this argument is a nullptr or if the
+  /// file does not exist, the default configuration from
+  /// IGN_HOMEDIR/.ignition/gazebo/gui.config will be used.
+  /// \param[in] _loadPluginsFromSdf If true, plugins specified in the world
+  /// SDFormat file will get loaded.
+  /// \param[in] _guiConfigOption Options for loading GUI configuration.
+  /// \return The GUI application.
+  IGNITION_GAZEBO_GUI_VISIBLE
+  std::unique_ptr<ignition::gui::Application> createGui(
+      int &_argc, char **_argv, const char *_guiConfig,
+      const char *_defaultGuiConfig, bool _loadPluginsFromSdf,
+      const char *_guiConfigOption);
+
 }  // namespace gui
 }  // namespace IGNITION_GAZEBO_VERSION_NAMESPACE
 }  // namespace gazebo

src/cmd/cmdgazebo.rb.in

@@ -122,6 +122,15 @@ COMMANDS = { 'gazebo' =>
   "                               provided, the default installed config is        \n"\
   "                               used.                                            \n"\
   "\n"\
+  "  --gui-config-option [arg]    Options for combining GUI configs with GUI       \n"\
+  "                               plugins defined on the world SDF file.           \n"\
+  "                               Available options:                               \n"\
+  "                               * prepend: Load all plugins from the GUI config  \n"\
+  "                                          first, then all plugins from the SDF  \n"\
+  "                                          file.                                 \n"\
+  "                               * merge: Same as prepend, but only the last      \n"\
+  "                                        instance of each plugin is loaded.      \n"\
+  "\n"\
   "  --physics-engine [arg]       Ignition Physics engine plugin to load.          \n"\
   "                               Gazebo will use DART by default.                 \n"\
   "                               (ignition-physics-dartsim-plugin)                \n"\
@@ -282,6 +291,9 @@ class Cmd
       opts.on('--gui-config [arg]', String) do |c|
         options['gui_config'] = c
       end
+      opts.on('--gui-config-option [arg]', String) do |c|
+        options['gui_config_option'] = c
+      end
       opts.on('--physics-engine [arg]', String) do |e|
         options['physics_engine'] = e
       end
@@ -465,7 +477,7 @@ See https://github.com/ignitionrobotics/ign-gazebo/issues/44 for more info."
           ENV['RMT_PORT'] = '1501'
           Process.setpgid(0, 0)
           Process.setproctitle('ign gazebo gui')
-          Importer.runGui(options['gui_config'])
+          Importer.runGui(options['gui_config'], options['gui_config_option'])
         end
 
         Signal.trap("INT") {
@@ -503,7 +515,7 @@ See https://github.com/ignitionrobotics/ign-gazebo/issues/44 for more info."
         end
 
         ENV['RMT_PORT'] = '1501'
-        Importer.runGui(options['gui_config'])
+        Importer.runGui(options['gui_config'], options['gui_config_option'])
       end
     rescue
       puts "Library error: Problem running [#{options['command']}]() "\

src/cmd/ign.cc

@@ -205,7 +205,7 @@ extern "C" int runServer(const char *_sdfString,
 }
 
 //////////////////////////////////////////////////
-extern "C" int runGui(const char *_guiConfig)
+extern "C" int runGui(const char *_guiConfig, const char *_guiConfigOption)
 {
   ignition::common::SignalHandler sigHandler;
   bool sigKilled = false;

src/gui/Gui.cc

@@ -44,6 +44,16 @@ namespace gui
 std::unique_ptr<ignition::gui::Application> createGui(
     int &_argc, char **_argv, const char *_guiConfig,
     const char *_defaultGuiConfig, bool _loadPluginsFromSdf)
+{
+  return createGui(_argc, _argv, _guiConfig, _defaultGuiConfig,
+      _loadPluginsFromSdf, nullptr);
+}
+
+//////////////////////////////////////////////////
+std::unique_ptr<ignition::gui::Application> createGui(
+    int &_argc, char **_argv, const char *_guiConfig,
+    const char *_defaultGuiConfig, bool _loadPluginsFromSdf,
+    const char *_guiConfigOption)
 {
   ignition::common::SignalHandler sigHandler;
   bool sigKilled = false;
@@ -162,6 +172,9 @@ std::unique_ptr<ignition::gui::Application> createGui(
   std::size_t runnerCount = 0;
 
   // Configuration file from command line
+
+  // TODO can't load config here because we may override it with SDF below
+
   if (_guiConfig != nullptr && std::strlen(_guiConfig) > 0 &&
       std::string(_guiConfig) != "_playback_")
   {
@@ -222,6 +235,19 @@ std::unique_ptr<ignition::gui::Application> createGui(
       runner->setParent(ignition::gui::App());
       ++runnerCount;
 
+      // Config options
+      if (_guiConfigOption != nullptr && std::strlen(_guiConfigOption) > 0)
+      {
+         auto option = std::string(_guiConfig);
+         if (option == "prepend")
+         {
+         }
+         else if (option == "merge")
+         {
+         }
+      }
+
+
       // Load plugins after creating GuiRunner, so they can access worldName
       if (_loadPluginsFromSdf)
       {
@@ -290,7 +316,15 @@ std::unique_ptr<ignition::gui::Application> createGui(
 //////////////////////////////////////////////////
 int runGui(int &_argc, char **_argv, const char *_guiConfig)
 {
-  auto app = gazebo::gui::createGui(_argc, _argv, _guiConfig);
+  return runGui(_argc, _argv, _guiConfig, nullptr);
+}
+
+//////////////////////////////////////////////////
+int runGui(int &_argc, char **_argv, const char *_guiConfig,
+    const char *_guiConfigOption)
+{
+  auto app = gazebo::gui::createGui(_argc, _argv, _guiConfig, nullptr, true,
+      _guiConfigOption);
   if (nullptr != app)
   {
     // Run main window.

src/ign.cc

@@ -355,7 +355,7 @@ extern "C" int runServer(const char *_sdfString,
 }
 
 //////////////////////////////////////////////////
-extern "C" int runGui(const char *_guiConfig)
+extern "C" int runGui(const char *_guiConfig, const char *_guiConfigOption)
 {
   // argc and argv are going to be passed to a QApplication. The Qt
   // documentation has a warning about these:
@@ -368,5 +368,6 @@ extern "C" int runGui(const char *_guiConfig)
   // be converted to a const char *. The const cast is here to prevent a warning
   // since we do need to pass a char* to runGui
   char *argv = const_cast<char *>("ign-gazebo-gui");
-  return ignition::gazebo::gui::runGui(argc, &argv, _guiConfig);
+  return ignition::gazebo::gui::runGui(argc, &argv, _guiConfig,
+      _guiConfigOption);
 }

src/ign.hh

@@ -66,8 +66,9 @@ extern "C" int runServer(const char *_sdfString,
 
 /// \brief External hook to run simulation GUI.
 /// \param[in] _guiConfig Path to Ignition GUI configuration file.
+/// \param[in] _guiConfigOption Option for loading GUI configs.
 /// \return 0 if successful, 1 if not.
-extern "C" int runGui(const char *_guiConfig);
+extern "C" int runGui(const char *_guiConfig, const char *_guiConfigOption);
 
 /// \brief External hook to find or download a fuel world provided a URL.
 /// \param[in] _pathToResource Path to the fuel world resource, ie,

tutorials/gui_config.md

@@ -15,12 +15,35 @@ There are a few places where the GUI configuration can come from:
 2. A `<gui>` element inside an SDF file
 3. The default configuration file at `$HOME/.ignition/gazebo/gui.config` \*
 
-Each of the items above takes precedence over the ones below it. For example,
-if a user chooses a `--gui-config`, the SDF's `<gui>` element is ignored. And
-the default configuration file is only loaded if no configuration is passed
-through the command line or the SDF file.
-
-> \* For log-playback, the default file is
+Each of the items above takes precedence over the ones below it by default.
+For example, if a user chooses a `--gui-config`, the SDF's `<gui>` element is
+ignored. The default configuration file is loaded if no configuration is
+passed through the command line or the SDF file.
+
+The default behaviour can be overridden using the `--gui-config-option`
+command line argument, which offers options:
+
+* `prepend`: Load plugins from both the config file and the SDF file. The config
+  file is loaded first.
+* `merge`: Like `prepend`, but only the last instance of each plugin is loaded,
+  which should usually come from the SDF file.
+
+The table below summarizes how all the options behave together.
+
+Not all
+combinations are useful, but we cover all corner cases (i.e. there's no point
+in providing a config and also opting to `ignore` it):
+
+--gui-config | SDF `<gui>`  | --gui-config-option     | Result
+------------ | ------------ | ----------------------- | ------
+empty        | no plugins   | empty / prepend / merge | Load plugins from `$HOME/.ignition/gazebo/gui.config`
+provided     | no plugins   | empty / prepend / merge | Load plugins from `--gui-config`
+empty        | has plugins  | empty                   | Load plugins from SDF
+empty        | has plugins  | prepend / merge         | Load plugins from `$HOME/.ignition/gazebo/gui.config` then SDF, merging as needed
+provided     | has plugins  | empty                   | Load plugins from `--gui-config`
+provided     | has plugins  | prepend / merge         | Load plugins from `--gui-config` then SDF, merging as needed
+
+> For log-playback, the default file is
 > `$HOME/.ignition/gazebo/playback_gui.config`
 
 ## Try it out
@@ -138,9 +161,9 @@ configuration files from the command line.
 Let's start by creating a custom configuration file, but instead of editing by
 hand, we'll create it from the UI.
 
-1. Let's start loading the SDF world we created above, with the `<gui>` element back:
+1. Start loading the SDF world we created above, with the `<gui>` element back:
 
-`ign gazebo <path to>/fuel_preview.sdf`
+    `ign gazebo <path to>/fuel_preview.sdf`
 
 2. Now from the top-right menu, choose to add the "View Angle" plugin. This
    plugin has convenient buttons to change the camera angle, try them out!
@@ -156,21 +179,33 @@ hand, we'll create it from the UI.
 
 7. Close Gazebo
 
-@image html files/gui_config/save_config.gif
+    @image html files/gui_config/save_config.gif
 
-1. Take a look at the saved file if you're curious, it will look a lot like
+8. Take a look at the saved file if you're curious, it will look a lot like
    the default file, but with more properties defined.
 
-2. Finally, let's load the previous world, with our custom configuration:
+9. Finally, let's load the previous world, with our custom configuration:
 
     `ign gazebo <path to>/fuel_preview.sdf --gui-config <path to>saved.config`
 
-3. Gazebo should open with your custom layout.
+10. Gazebo should open with your custom layout.
+
+    @image html files/gui_config/cmd_line.png
 
 **Tip**: From the top-left menu, you can choose "Save client configuration" to
 save directly to `$HOME/.ignition/gazebo/gui.config`.
 
-@image html files/gui_config/cmd_line.png
+**Tip**: In case you want to use the default GUI layout without editing the SDF file to
+remove `<gui>`, you can pass `--gui-config $HOME/.ignition/gazebo/gui.config`:
+
+#### Options
+
+The above gives you other plugins, but the 3D scene isn't nicely formatted to
+view the model (blue background, diagonal camera angle...). In order to get all
+the default plugins, but format the 3D scene as it is in the SDF, we can use the
+`merge` option:
 
+`ign gazebo --gui-config-option merge <path to>/fuel_preview.sdf`
 
+@image html files/gui_config/fuel_preview_merge.png