Fix launch substitutions for ign_args

ros_gz_sim/launch/gz_sim.launch.py.in

@@ -17,21 +17,53 @@
 from os import environ
 
 from launch import LaunchDescription
-from launch.actions import DeclareLaunchArgument
+from launch.actions import DeclareLaunchArgument, OpaqueFunction
 from launch.actions import ExecuteProcess
-from launch.substitutions import LaunchConfiguration, AndSubstitution, PythonExpression
-from launch.conditions import LaunchConfigurationEquals, LaunchConfigurationNotEquals, IfCondition
+from launch.substitutions import LaunchConfiguration
 
-
-def generate_launch_description():
+def launch_gz(context, *args, **kwargs):
     env = {'GZ_SIM_SYSTEM_PLUGIN_PATH':
            ':'.join([environ.get('GZ_SIM_SYSTEM_PLUGIN_PATH', default=''),
                      environ.get('LD_LIBRARY_PATH', default='')]),
            'IGN_GAZEBO_SYSTEM_PLUGIN_PATH':  # TODO(CH3): To support pre-garden. Deprecated.
                       ':'.join([environ.get('IGN_GAZEBO_SYSTEM_PLUGIN_PATH', default=''),
                                 environ.get('LD_LIBRARY_PATH', default='')])}
 
+    gz_args = LaunchConfiguration('gz_args').perform(context)
+    gz_version = LaunchConfiguration('gz_version').perform(context)
+    ign_args = LaunchConfiguration('ign_args').perform(context)
+    ign_version = LaunchConfiguration('ign_version').perform(context)
+    debugger = LaunchConfiguration('debugger').perform(context)
+
+    if not len(gz_args) and len(ign_args):
+        print("ign_args is deprecated, migrate to gz_args!")
+        exec_args = ign_args
+    else:
+        exec_args = gz_args
+
+    if len(ign_version) or (ign_version == '' and int(gz_version) < 7):
+        exec = 'ruby $(which ign) gazebo'
+
+        if len(ign_version):
+            gz_version = ign_version
+    else:
+        exec = 'ruby $(which gz) sim'
+
+    if debugger != 'false':
+        debug_prefix = 'x-terminal-emulator -e gdb -ex run --args'
+    else:
+        debug_prefix = None
+
+    return [ExecuteProcess(
+            cmd=[exec, exec_args, '--force-version', gz_version],
+            output='screen',
+            additional_env=env,
+            shell=True,
+            prefix=debug_prefix
+        )]
+
 
+def generate_launch_description():
     return LaunchDescription([
         DeclareLaunchArgument('gz_args', default_value='',
                               description='Arguments to be passed to Gazebo Sim'),
@@ -52,42 +84,5 @@ def generate_launch_description():
         DeclareLaunchArgument(
             'debugger', default_value='false',
             description='Run in Debugger'),
-
-        ExecuteProcess(
-            condition=IfCondition(
-                AndSubstitution(
-                    PythonExpression(["'", LaunchConfiguration('ign_version'), "' == ''"]),
-                    PythonExpression(["'", LaunchConfiguration('gz_version'), "' < '7'"])
-                )
-            ),
-            cmd=['ruby $(which ign) gazebo',
-                 LaunchConfiguration('gz_args'),
-                 '--force-version',
-                 LaunchConfiguration('gz_version'),
-                 ],
-            output='screen',
-            additional_env=env,
-            shell=True,
-            prefix=PythonExpression([
-                "'x-terminal-emulator -e gdb -ex run --args' if '", LaunchConfiguration('debugger'), "'=='true' else ''"])
-        ),
-
-        ExecuteProcess(
-            condition=IfCondition(
-                AndSubstitution(
-                    PythonExpression(["'", LaunchConfiguration('ign_version'), "' == ''"]),
-                    PythonExpression(["'", LaunchConfiguration('gz_version'), "' >= '7'"])
-                )
-            ),
-            cmd=['ruby $(which gz) sim',
-                 LaunchConfiguration('gz_args'),
-                 '--force-version',
-                 LaunchConfiguration('gz_version'),
-                 ],
-            output='screen',
-            additional_env=env,
-            shell=True,
-            prefix=PythonExpression([
-                "'x-terminal-emulator -e gdb -ex run --args' if '", LaunchConfiguration('debugger'), "'=='true' else ''"])
-        ),
+        OpaqueFunction(function = launch_gz),
     ])

ros_gz_sim/package.xml

@@ -13,6 +13,7 @@
   <buildtool_depend>ament_cmake</buildtool_depend>
   <buildtool_depend>pkg-config</buildtool_depend>
 
+  <depend>ament_index_python</depend>
   <depend>libgflags-dev</depend>
   <depend>rclcpp</depend>
   <depend>std_msgs</depend>

ros_ign_gazebo/CMakeLists.txt

@@ -46,18 +46,8 @@ else()
   message(STATUS "Compiling against Gazebo Fortress")
 endif()
 
-configure_file(
-  launch/ign_gazebo.launch.py.in
-  launch/ign_gazebo.launch.py.configured
-  @ONLY
-)
-file(GENERATE
-  OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/launch/ign_gazebo.launch.py"
-  INPUT "${CMAKE_CURRENT_BINARY_DIR}/launch/ign_gazebo.launch.py.configured"
-)
-
 install(FILES
-  "${CMAKE_CURRENT_BINARY_DIR}/launch/ign_gazebo.launch.py"
+  "${CMAKE_CURRENT_SOURCE_DIR}/launch/ign_gazebo.launch.py"
   DESTINATION share/${PROJECT_NAME}/launch
 )
 

ros_ign_gazebo/launch/ign_gazebo.launch.py

@@ -0,0 +1,33 @@
+# Copyright 2020 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Launch Gazebo Sim with command line arguments."""
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+
+from launch import LaunchDescription
+from launch.actions import IncludeLaunchDescription
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+
+def generate_launch_description():
+    ros_gz_sim_dir = get_package_share_directory('ros_gz_sim')
+    launch_dir = os.path.join(ros_gz_sim_dir, 'launch')
+
+    return LaunchDescription([
+        IncludeLaunchDescription(
+            PythonLaunchDescriptionSource(os.path.join(launch_dir, 'gz_sim.launch.py'))
+        )
+    ])