protocol: add the message for getting the point size

The dimensions of the tablet are in device units, the point size tells us how
big the actual tablet is.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

test/test_messages.py

@@ -250,6 +250,12 @@ class TestProtocolAny(unittest.TestCase):
         msg = p.execute(Interactions.GET_HEIGHT)
         self.assertEqual(msg.height, 14800)
 
+    def test_get_point_size(self, cb=None):
+        # this is hardcoded for the spark
+        p = Protocol(self.protocol_version, callback=None)
+        msg = p.execute(Interactions.GET_POINT_SIZE)
+        self.assertEqual(msg.point_size, 10)
+
     def test_unknown_e3(self, cb=None):
         def _cb(request, requires_reply=True, userdata=None, timeout=5):
             self.assertEqual(request.opcode, 0xe3)
@@ -546,6 +552,20 @@ class TestProtocolIntuosPro(TestProtocolSlate):
 
         super().test_register_wait_for_button(cb or _cb)
 
+    def test_get_point_size(self, cb=None, pointsize=12):
+        def _cb(request, requires_reply=True, userdata=None, timeout=5):
+            self.assertEqual(request.opcode, 0xea)
+            self.assertEqual(request.length, 2)
+            self.assertEqual(request[0], 0x14)
+            ps = little_u32(pointsize)
+            return NordicData([0xeb, 6, 0x14, 0x00] + list(ps))
+
+        cb = cb or _cb
+
+        p = Protocol(self.protocol_version, callback=cb)
+        msg = p.execute(Interactions.GET_POINT_SIZE)
+        self.assertEqual(msg.point_size, pointsize - 1)
+
 
 if __name__ == "__main__":
     unittest.main(sys.argv[1:])

tuhi/protocol.py

@@ -104,6 +104,7 @@ class Interactions(enum.Enum):
     REGISTER_WAIT_FOR_BUTTON = enum.auto()
     REGISTER_COMPLETE = enum.auto()
     SET_FILE_TRANSFER_REPORTING_TYPE = enum.auto()
+    GET_POINT_SIZE = enum.auto()
 
     UNKNOWN_E3 = enum.auto()
 
@@ -799,7 +800,7 @@ class MsgGetWidthSpark(Msg):
 
     .. attribute:: width
 
-        The width of the tablet in points (mm/100)
+        The width of the tablet in points (see :class:`MsgGetPointSize`)
     '''
     interaction = Interactions.GET_WIDTH
     opcode = Msg.OPCODE_NOOP
@@ -814,7 +815,7 @@ class MsgGetWidthSlate(Msg):
     '''
     .. attribute:: width
 
-        The width of the tablet in points (mm/100)
+        The width of the tablet in points (see :class:`MsgGetPointSize`)
     '''
     interaction = Interactions.GET_WIDTH
     opcode = 0xea
@@ -841,7 +842,7 @@ class MsgGetHeightSpark(Msg):
 
     .. attribute:: height
 
-        The height of the tablet in points (mm/100)
+        The height of the tablet in points (see :class:`MsgGetPointSize`)
     '''
     interaction = Interactions.GET_HEIGHT
     opcode = Msg.OPCODE_NOOP
@@ -856,7 +857,7 @@ class MsgGetHeightSlate(Msg):
     '''
     .. attribute:: height
 
-        The height of the tablet in points (mm/100)
+        The height of the tablet in points (see :class:`MsgGetPointSize`)
     '''
     interaction = Interactions.GET_HEIGHT
     opcode = 0xea
@@ -876,6 +877,52 @@ class MsgGetHeightSlate(Msg):
         self.height = little_u32(reply[2:6])
 
 
+class MsgGetPointSizeSpark(Msg):
+    '''
+    This is a fake message. The Spark and Slate doesn't seem to have a
+    getter for this one, it just times out. We just hardcode the value here.
+
+    .. attribute:: point_size
+
+        The point_size of the tablet in µm
+    '''
+    interaction = Interactions.GET_POINT_SIZE
+    opcode = Msg.OPCODE_NOOP
+    protocol = ProtocolVersion.ANY
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.point_size = 10
+
+
+class MsgGetPointSize(Msg):
+    '''
+    .. attribute:: point_size
+
+        The point size in micrometers
+    '''
+    interaction = Interactions.GET_POINT_SIZE
+    opcode = 0xea
+    protocol = ProtocolVersion.INTUOS_PRO
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.args = little_u16(0x14)
+
+    def _handle_reply(self, reply):
+        if reply.opcode != 0xeb:
+            raise UnexpectedReply(self)
+
+        if little_u16(reply[0:2]) != 0x14:
+            raise UnexpectedDataError(reply)
+
+        # This is strange. The return value is supposed to be the point size
+        # but it's off by one. The IntuosPro returns 6 but a point size of 5
+        # matches the physical dimensions. So let's assume there's a bug in
+        # the firmware or the specs are wrong or something.
+        self.point_size = little_u32(reply[2:6]) - 1
+
+
 class MsgUnknownE3Command(Msg):
     interaction = Interactions.UNKNOWN_E3
     opcode = 0xe3