Fix issue #9

ik_ros/src/ik_ros/ik_solver_interfaces.py

@@ -1,10 +1,35 @@
-from .trac_ik.setup_node import TracIKSetupNode
-from .exotica.setup_node import EXOTicaSetupNode
-from .pybullet.setup_node import PybulletSetupNode
 
-from .trac_ik.interface import TracIKInterface
-from .exotica.interface import EXOTicaInterface
-# NOTE: pybullet does not have an interface (see README.md in ik_ros/src/ik_ros/pybullet)
+###########
+## TracIK
+trac_ik_available = True
+try:
+    from .trac_ik.setup_node import TracIKSetupNode
+    from .trac_ik.interface import TracIKInterface
+except ModuleNotFoundError:
+    TracIKSetupNode = None
+    TracIKInterface = None
+    trac_ik_available = False
+
+###########
+## EXOTica
+exotica_available = True
+try:
+    from .exotica.setup_node import EXOTicaSetupNode
+    from .exotica.interface import EXOTicaInterface
+except ModuleNotFoundError:
+    EXOTicaSetupNode = None
+    EXOTicaInterface = None
+    exotica_available = False
+
+###########
+## Pybullet
+## NOTE: pybullet does not have an interface (see README.md in ik_ros/src/ik_ros/pybullet)
+pybullet_available = True
+try:
+    from .pybullet.setup_node import PybulletSetupNode
+except ModuleNotFoundError:
+    PybulletSetupNode = None
+    pybullet_available = True
 
 """
 
@@ -18,12 +43,17 @@
 
 class SolverInterface:
 
-    def __init__(self, setup_node, interface):
+    def __init__(self, setup_node, interface, is_available):
         self.setup_node = setup_node
         self.interface = interface
+        self.is_available = is_available
 
 solver_interfaces = {
-    'trac_ik': SolverInterface(TracIKSetupNode, TracIKInterface),
-    'exotica': SolverInterface(EXOTicaSetupNode, EXOTicaInterface),
-    'pybullet': SolverInterface(PybulletSetupNode, None),
+    'trac_ik': SolverInterface(TracIKSetupNode, TracIKInterface, trac_ik_available),
+    'exotica': SolverInterface(EXOTicaSetupNode, EXOTicaInterface, exotica_available),
+    'pybullet': SolverInterface(PybulletSetupNode, None, pybullet_available),
 }
+
+for name, interface in solver_interfaces.items():
+    if not interface.is_available:
+        print(f">>>>>>>{name} interface is not available<<<<<<<<")