proto: replace pointer/keyboard/touchscreen with a generic "interface" event

Since these events are merely notifications of a single object, we can make
this more generic. This allows us to introduce future capabilities without
having to bump the seat.

doc/protocol/doc/initial-handshake.md

@@ -67,14 +67,14 @@ sequenceDiagram
     EIS-->>client: ei_device.name(some name)
     EIS-->>client: ei_device.device_type()
     EIS-->>client: ei_device.capabilities(some name)
-    EIS-->>client: ei_device.pointer(new_id, version)
-    EIS-->>client: ei_device.keyboard(new_id, version)
+    EIS-->>client: ei_device.interface(new_id, "ei_pointer", version)
+    EIS-->>client: ei_device.interface(new_id, "ei_keyboard", version)
     EIS-->>client: ei_seat.device(new_id, version)
     EIS-->>client: ei_device.name(some name)
     EIS-->>client: ei_device.device_type()
     EIS-->>client: ei_device.capabilities(some name)
     EIS-->>client: ei_device.region()
-    EIS-->>client: ei_device.touchscreen(new_id, version)
+    EIS-->>client: ei_device.interface(new_id, "ei_touchscreen", version)
 
     EIS-->>client: ei_device.resume()
     EIS-->>client: ei_device.resume()

doc/protocol/doc/specification.md

@@ -13,6 +13,8 @@ In that protocol specification:
 - an argument with an XML attribute `enum` carries a value of the corresponding enum
 - an argument with an XML attribute `interface` attribute indicates that an object in the same message is
   of that interface type
+- an argument with an XML attribute `interface_arg` attribute indicates that an object in the same message is
+  of the interface given in the named argument.
 - an enum with an XML attribute `bitfield` indicates a single-bit value.
 - each request, event or enum has an XML attribute `since` to indicate the
   interface version this request, event or enum was introduced in

proto/protocol.dtd

@@ -28,6 +28,7 @@
   <!ATTLIST arg type CDATA #REQUIRED>
   <!ATTLIST arg summary CDATA #IMPLIED>
   <!ATTLIST arg interface CDATA #IMPLIED>
+  <!ATTLIST arg interface_arg CDATA #IMPLIED>
   <!ATTLIST arg allow-null CDATA #IMPLIED>
   <!ATTLIST arg enum CDATA #IMPLIED>
 <!ELEMENT description (#PCDATA)>

proto/protocol.xml

@@ -784,64 +784,28 @@
       <arg name="scale" type="float" summary="the physical scale for this region"/>
     </event>
 
-    <event name="pointer" since="1">
-      <description summary="device pointer interface notification">
-        Notification that a new device has a pointer interface.
+    <event name="interface" since="1">
+      <description summary="device capability notification">
+        Notification that a new device has a sub-interface.
 
-        This event is only sent if the device has the
-        ei_device.capabilities.pointer or
-        ei_device.capabilities.pointer_absolute capability.
+        This event may be sent for the
+        - "ei_pointer" interface if the device has the
+          ei_device.capabilities.pointer or
+          ei_device.capabilities.pointer_absolute capability.
+        - "ei_keyboard" interface if the device has the
+          ei_device.capabilities.keyboard capability
+        - "ei_touchscreen" interface if the device has the
+          ei_device.capabilities.touchscreen capability
 
-        This event is only sent if the client announced support for the
-        "ei_pointer" interface in ei_handshake.interface_version.
         The interface version is equal or less to the client-supported
-        version in ei_handshake.interface_version for the "ei_pointer"
-        interface.
+        version in ei_handshake.interface_version for the respective interface.
 
-        This event is optional and sent immediately after object creation.
+        This event is optional and sent immediately after object creation
+        and at most once per interface.
         It is a protocol violation to send this event after the ei_device.done event.
       </description>
-      <arg name="pointer" type="new_id" interface="ei_pointer"/>
-      <arg name="version" type="uint32" summary="the interface version"/>
-    </event>
-
-    <event name="keyboard" since="1">
-      <description summary="device pointer interface notification">
-        Notification that a new device has a keyboard interface.
-
-        This event is only sent if the device has the
-        ei_device.capabilities.keyboard.
-
-        This event is only sent if the client announced support for the
-        "ei_keyboard" interface in ei_handshake.interface_version.
-        The interface version is equal or less to the client-supported
-        version in ei_handshake.interface_version for the "ei_keyboard"
-        interface.
-
-        This event is optional and sent immediately after object creation.
-        It is a protocol violation to send this event after the ei_device.done event.
-      </description>
-      <arg name="keyboard" type="new_id" interface="ei_keyboard"/>
-      <arg name="version" type="uint32" summary="the interface version"/>
-    </event>
-
-    <event name="touchscreen" since="1">
-      <description summary="device touchscreen interface notification">
-        Notification that a new device has a touchscreen interface.
-
-        This event is only sent if the device has the
-        ei_device.capabilities.touchscreen.
-
-        This event is only sent if the client announced support for the
-        "ei_touchscreen" interface in ei_handshake.interface_version.
-        The interface version is equal or less to the client-supported
-        version in ei_handshake.interface_version for the "ei_touchscreen"
-        interface.
-
-        This event is optional and sent immediately after object creation.
-        It is a protocol violation to send this event after the ei_device.done event.
-      </description>
-      <arg name="touchscreen" type="new_id" interface="ei_touchscreen"/>
+      <arg name="object" type="new_id" interface_arg="interface_name" />
+      <arg name="interface_name" type="string" summary="the interface name" />
       <arg name="version" type="uint32" summary="the interface version"/>
     </event>
 

src/libei-device.c

@@ -388,44 +388,32 @@ handle_msg_frame(struct ei_device *device, uint32_t serial, uint64_t time)
 }
 
 static struct brei_result *
-handle_msg_pointer(struct ei_device *device, object_id_t id, uint32_t version)
+handle_msg_interface(struct ei_device *device, object_id_t id, const char *name,
+		     uint32_t version)
 {
 	DISCONNECT_IF_INVALID_ID(device, id);
 
-	if (device->pointer)
+	if (streq(name, "ei_pointer")) {
+		if (device->pointer)
+			return brei_result_new(EI_CONNECTION_DISCONNECT_REASON_PROTOCOL,
+					       "Duplicate ei_pointer interface object on device");
+		device->pointer = ei_pointer_new(device, id, version);
+	} else if (streq(name, "ei_keyboard")) {
+		if (device->keyboard)
+			return brei_result_new(EI_CONNECTION_DISCONNECT_REASON_PROTOCOL,
+					       "Duplicate ei_keyboard interface object on device");
+
+		device->keyboard = ei_keyboard_new(device, id, version);
+	} else if (streq(name, "ei_touchscreen")) {
+		if (device->touchscreen)
+			return brei_result_new(EI_CONNECTION_DISCONNECT_REASON_PROTOCOL,
+					       "Duplicate ei_touchscreen interface object on device");
+
+		device->touchscreen = ei_touchscreen_new(device, id, version);
+	} else {
 		return brei_result_new(EI_CONNECTION_DISCONNECT_REASON_PROTOCOL,
-				       "Duplicate ei_pointer interface object on device");
-
-	device->pointer = ei_pointer_new(device, id, version);
-
-	return NULL;
-}
-
-static struct brei_result *
-handle_msg_keyboard(struct ei_device *device, object_id_t id, uint32_t version)
-{
-	DISCONNECT_IF_INVALID_ID(device, id);
-
-	if (device->keyboard)
-		return brei_result_new(EI_CONNECTION_DISCONNECT_REASON_PROTOCOL,
-				       "Duplicate ei_keyboard interface object on device");
-
-	device->keyboard = ei_keyboard_new(device, id, version);
-
-	return NULL;
-}
-
-static struct brei_result *
-handle_msg_touchscreen(struct ei_device *device, object_id_t id, uint32_t version)
-{
-	DISCONNECT_IF_INVALID_ID(device, id);
-
-	if (device->touchscreen)
-		return brei_result_new(EI_CONNECTION_DISCONNECT_REASON_PROTOCOL,
-				       "Duplicate ei_touchscreen interface object on device");
-
-	device->touchscreen = ei_touchscreen_new(device, id, version);
-
+				       "Unsupported interface '%s' on device", name);
+	}
 	return NULL;
 }
 
@@ -442,9 +430,7 @@ static const struct ei_device_interface interface = {
 	.start_emulating = handle_msg_start_emulating,
 	.stop_emulating = handle_msg_stop_emulating,
 	.frame = handle_msg_frame,
-	.pointer = handle_msg_pointer,
-	.keyboard = handle_msg_keyboard,
-	.touchscreen = handle_msg_touchscreen,
+	.interface = handle_msg_interface,
 };
 
 const struct ei_device_interface *

src/libeis-device.c

@@ -765,15 +765,15 @@ eis_device_add(struct eis_device *device)
 	if (eis_device_has_capability(device, EIS_DEVICE_CAP_POINTER) ||
 	    eis_device_has_capability(device, EIS_DEVICE_CAP_POINTER_ABSOLUTE)) {
 		device->pointer = eis_pointer_new(device);
-		rc = eis_device_event_pointer(device, eis_pointer_get_id(device->pointer),
-					      eis_pointer_get_version(device->pointer));
+		rc = eis_device_event_interface(device, eis_pointer_get_id(device->pointer),
+						"ei_pointer", eis_pointer_get_version(device->pointer));
 		if (rc < 0)
 			goto out;
 	}
 	if (eis_device_has_capability(device, EIS_DEVICE_CAP_KEYBOARD)) {
 		device->keyboard = eis_keyboard_new(device);
-		rc = eis_device_event_keyboard(device, eis_keyboard_get_id(device->keyboard),
-					       eis_keyboard_get_version(device->keyboard));
+		rc = eis_device_event_interface(device, eis_keyboard_get_id(device->keyboard),
+						 "ei_keyboard", eis_keyboard_get_version(device->keyboard));
 		if (rc < 0)
 			goto out;
 
@@ -785,8 +785,8 @@ eis_device_add(struct eis_device *device)
 	}
 	if (eis_device_has_capability(device, EIS_DEVICE_CAP_TOUCH)) {
 		device->touchscreen = eis_touchscreen_new(device);
-		rc = eis_device_event_touchscreen(device, eis_touchscreen_get_id(device->touchscreen),
-						  eis_touchscreen_get_version(device->touchscreen));
+		rc = eis_device_event_interface(device, eis_touchscreen_get_id(device->touchscreen),
+						"ei_touchscreen", eis_touchscreen_get_version(device->touchscreen));
 		if (rc < 0)
 			goto out;
 	}

test/eiproto.py.tmpl

@@ -232,6 +232,14 @@ class Interface:
     def connect(self, event: str, callback: Callable):
         self.callbacks[event] = callback
 
+    @classmethod
+    def lookup(cls, name: str) -> "Interface":
+        return {
+{% for interface in interfaces %}
+            "{{interface.name}}": {{interface.camel_name}},
+{% endfor %}
+        }[name]
+
 
 {% for interface in interfaces %}
 @attr.s
@@ -256,8 +264,13 @@ class {{interface.camel_name}}(Interface):
         new_objects = {
         {% for arg in incoming.arguments %}
         {% if arg.signature == "n" %}
-        {# Note: this only works while the version argument is always called version #}
+            {% if arg.interface %}
+            {# Note: this only works while the version argument is always called version #}
             "{{arg.name}}": {{arg.interface.camel_name}}.create({{arg.name}}, version),
+            {% else %}
+            {# Note: this only works while the argument is called interface_name #}
+            "{{arg.name}}": Interface.lookup(interface_name).create({{arg.name}}, version),
+            {% endif %}
         {% endif %}
         {% endfor %}
         }