Merge pull request #292 from compas-dev/lazyload-vrep

Lazy-load V-REP remote API library

Author: gonzalocasas

CHANGELOG.rst

@@ -18,6 +18,7 @@ Unreleased
 **Changed**
 
 * The `Configuration` class has moved to `compas.robots`, but is still aliased within `compas_fab.robots`
+* Lazily load `V-REP remoteApi` library
 
 **Fixed**
 

src/compas_fab/backends/vrep/backend_features/vrep_add_attached_collision_mesh.py

@@ -2,16 +2,18 @@
 from __future__ import division
 from __future__ import print_function
 
-from compas_fab.backends.vrep.helpers import assert_robot
+from compas_fab.backends.interfaces import AddAttachedCollisionMesh
 from compas_fab.backends.vrep.helpers import DEFAULT_OP_MODE
 from compas_fab.backends.vrep.helpers import VrepError
-from compas_fab.backends.interfaces import AddAttachedCollisionMesh
-from compas_fab.backends.vrep.remote_api import vrep
+from compas_fab.backends.vrep.helpers import assert_robot
+from compas_fab.utilities import LazyLoader
 
 __all__ = [
     'VrepAddAttachedCollisionMesh',
 ]
 
+vrep = LazyLoader('vrep', globals(), 'compas_fab.backends.vrep.remote_api.vrep')
+
 
 class VrepAddAttachedCollisionMesh(AddAttachedCollisionMesh):
     """Callable to add a building member to the 3D scene and attach it to the robot.

src/compas_fab/backends/vrep/backend_features/vrep_remove_collision_mesh.py

@@ -2,15 +2,16 @@
 from __future__ import division
 from __future__ import print_function
 
-from compas_fab.backends.vrep.helpers import DEFAULT_OP_MODE
-from compas_fab.backends.vrep.remote_api import vrep
 from compas_fab.backends.interfaces import RemoveCollisionMesh
-
+from compas_fab.backends.vrep.helpers import DEFAULT_OP_MODE
+from compas_fab.utilities import LazyLoader
 
 __all__ = [
     'VrepRemoveCollisionMesh',
 ]
 
+vrep = LazyLoader('vrep', globals(), 'compas_fab.backends.vrep.remote_api.vrep')
+
 
 class VrepRemoveCollisionMesh(RemoveCollisionMesh):
     """Callable to remove collision meshes from the 3D scene.

src/compas_fab/backends/vrep/client.py

@@ -2,22 +2,24 @@
 
 import logging
 
-from compas_fab.backends.vrep.helpers import DEFAULT_OP_MODE
 from compas_fab.backends.interfaces.client import ClientInterface
 from compas_fab.backends.vrep import VrepError
+from compas_fab.backends.vrep.helpers import DEFAULT_OP_MODE
 from compas_fab.backends.vrep.helpers import assert_robot
 from compas_fab.backends.vrep.helpers import config_from_vrep
 from compas_fab.backends.vrep.helpers import config_to_vrep
 from compas_fab.backends.vrep.helpers import floats_from_vrep
 from compas_fab.backends.vrep.helpers import floats_to_vrep
 from compas_fab.backends.vrep.helpers import resolve_host
 from compas_fab.backends.vrep.planner import VrepPlanner
-from compas_fab.backends.vrep.remote_api import vrep
+from compas_fab.utilities import LazyLoader
 
 DEFAULT_SCALE = 1.
-CHILD_SCRIPT_TYPE = vrep.sim_scripttype_childscript
+CHILD_SCRIPT_TYPE = 1    # defined in vrepConst.sim_scripttype_childscript, but redefined here to prevent loading the remoteApi library
 LOG = logging.getLogger('compas_fab.backends.vrep.client')
 
+vrep = LazyLoader('vrep', globals(), 'compas_fab.backends.vrep.remote_api.vrep')
+
 __all__ = [
     'VrepClient',
 ]

src/compas_fab/backends/vrep/helpers.py

@@ -5,14 +5,13 @@
 from compas.robots import Configuration
 
 from compas_fab.backends.exceptions import BackendError
-from compas_fab.backends.vrep.remote_api import vrep
 
 
 __all__ = [
     'VrepError',
 ]
 
-DEFAULT_OP_MODE = vrep.simx_opmode_blocking
+DEFAULT_OP_MODE = 0x010000  # defined in vrepConst.simx_opmode_blocking, but redefined here to prevent loading the remoteApi library
 
 # --------------------------------------------------------------------------
 # MAPPINGS