showbase: make input device binding explicit, not automatic

direct/src/showbase/ShowBase.py

@@ -307,12 +307,7 @@ class ShowBase(DirectObject.DirectObject):
         ## This is the global input device manager, which keeps track of
         ## connected input devices.
         self.devices = InputDeviceManager.getGlobalPtr()
-        # add existing devices to the data graph
-        for device in self.devices.devices:
-            self.connectDevice(device)
-        # Checks for device connection and disconnection
-        self.accept('connect-device', self.connectDevice)
-        self.accept('disconnect-device', self.disconnectDevice)
+        self.__inputDeviceNodes = {}
 
         self.createStats()
 
@@ -1681,76 +1676,56 @@ class ShowBase(DirectObject.DirectObject):
         return self.mouseWatcherNode.getModifierButtons().isDown(
             KeyboardButton.meta())
 
-    def connectDevice(self, device):
+    def attachInputDevice(self, device, prefix=None):
         """
-        This function will get called each time a new device got
-        connected and will add that new device to the data graph.
+        This function attaches an input device to the data graph, which will
+        cause the device to be polled and generate events.  If a prefix is
+        given and not None, it is used to prefix events generated by this
+        device, separated by a hyphen.
 
-        Each device class will get a specific prefix for thrown events. Those
-        are currently as follow
-
-        gamepad
-        flight_stick
-        steering_wheel
-        dance_pad
-        mouse
-        keyboard
-        unclassified_device
-
-        In addition, the index of that device will appended to the prefix,
-        so for example if you hit the A button of the first connected gamepad
-        you will get an event like "gamepad0-action_a" the second gamepad will
-        then be catchable via "gamepad1-button_event" and so on.
-        Note, each device class will have a separate 0 based index, this way
-        you can have a gamepad0 as well as a steering_wheel0 and flight_stick0.
-
-        All newly created button throwers will be stored in
-        the deviceButtonThrowers lsit
+        If you call this, you should consider calling detachInputDevice when
+        you are done with the device or when it is disconnected.
         """
-        idn = self.dataRoot.attachNewNode(InputDeviceNode(device, device.getName()))
-        prefix = "unclassified_device"
-        if device.getDeviceClass() == InputDevice.DC_gamepad:
-            prefix = "gamepad"
-        elif device.getDeviceClass() == InputDevice.DC_flight_stick:
-            prefix = "flight_stick"
-        elif device.getDeviceClass() == InputDevice.DC_steering_wheel:
-            prefix = "steering_wheel"
-        elif device.getDeviceClass() == InputDevice.DC_dance_pad:
-            prefix = "dance_pad"
-        elif device.getDeviceClass() == InputDevice.DC_mouse:
-            prefix = "mouse"
-        elif device.getDeviceClass() == InputDevice.DC_keyboard:
-            prefix = "keyboard"
 
-        currentPrefixes = []
-        for np in self.dataRoot.findAllMatches("**/{}".format(prefix)):
-            bt = np.node()
-            currentPrefixes.append(bt.getPrefix())
+        # Protect against the same device being attached multiple times.
+        assert device not in self.__inputDeviceNodes
 
-        id = 0
-        # Find the next free ID for the newly connected device
-        while "{}{}-".format(prefix, id) in currentPrefixes:
-            id+=1
-        # Setup the button thrower for that device and register it's event prefix
-        bt = idn.attachNewNode(ButtonThrower(prefix))
-        assert self.notify.debug("Registered event prefix {}{}-".format(prefix, id))
-        bt.node().setPrefix("{}{}-".format(prefix, id))
-        # append the new button thrower to the list of device button throwers
+        idn = self.dataRoot.attachNewNode(InputDeviceNode(device, device.name))
+
+        # Setup the button thrower to generate events for the device.
+        bt = idn.attachNewNode(ButtonThrower(device.name))
+        if prefix is not None:
+            bt.node().setPrefix(prefix + '-')
+
+        assert self.notify.debug("Attached input device {0} with prefix {1}".format(device, prefix))
+        self.__inputDeviceNodes[device] = idn
         self.deviceButtonThrowers.append(bt)
 
-    def disconnectDevice(self, device):
+    def detachInputDevice(self, device):
         """
-        This function will get called each time a new device got
-        connected. It is then used to clean up the given device from the
-        data graph.
+        This should be called after attaching an input device using
+        attachInputDevice and the device is disconnected or you no longer wish
+        to keep polling this device for events.
+
+        You do not strictly need to call this if you expect the device to be
+        reconnected (but be careful that you don't reattach it).
         """
-        self.notify.debug("Disconnect device {}".format(device.getName()))
-        idn = self.dataRoot.find("**/{}".format(device.getName()))
-        for bt in list(self.deviceButtonThrowers):
-            if bt.getName() == idn.getName():
+
+        if device not in self.__inputDeviceNodes:
+            assert device in self.__inputDeviceNodes
+            return
+
+        assert self.notify.debug("Detached device {0}".format(device.name))
+
+        # Remove the ButtonThrower from the deviceButtonThrowers list.
+        idn = self.__inputDeviceNodes[device]
+        for bt in self.deviceButtonThrowers:
+            if idn.isAncestorOf(bt):
                 self.deviceButtonThrowers.remove(bt)
                 break
+
         idn.removeNode()
+        del self.__inputDeviceNodes[device]
 
     def addAngularIntegrator(self):
         if not self.physicsMgrAngular:
@@ -1944,10 +1919,6 @@ class ShowBase(DirectObject.DirectObject):
         # Check if there were newly connected devices.
         self.devices.update()
 
-        # Poll all connected devices.
-        for device in self.devices.devices:
-            device.poll()
-
         # traverse the data graph.  This reads all the control
         # inputs (from the mouse and keyboard, for instance) and also
         # directly acts upon them (for instance, to move the avatar).
@@ -3163,6 +3134,8 @@ class ShowBase(DirectObject.DirectObject):
     setup_mouse = setupMouse
     setup_mouse_cb = setupMouseCB
     enable_software_mouse_pointer = enableSoftwareMousePointer
+    detach_input_device = detachInputDevice
+    attach_input_device = attachInputDevice
     add_angular_integrator = addAngularIntegrator
     enable_particles = enableParticles
     disable_particles = disableParticles