Message improvements (#35)

Allow messages to be sent with a reply callback.
Demo application.

demo/!MsgDemo/!Run,feb

@@ -0,0 +1,5 @@
+If "<Python3$Dir>" = "" Then Error "!Python3 has not been seen."
+Set MsgDemo$Dir <Obey$Dir>
+WimpSlot -min 3M
+Run <Python3$Dir>.bin.python38 <MsgDemo$Dir>.!RunImage
+| > RAM:Log 2>&1

demo/!MsgDemo/!RunImage,a73

@@ -0,0 +1,103 @@
+import swi
+import sys
+import os
+import ctypes
+
+import riscos_toolbox as toolbox
+from riscos_toolbox import Point, BBox, Wimp
+
+from riscos_toolbox.objects.iconbar import Iconbar, IconbarClickedEvent
+from riscos_toolbox.events import toolbox_handler, message_handler, reply_handler, UserMessage
+from riscos_toolbox.application import Application
+
+Message_Hello      = 0xabcd
+Message_AddRequest = 0xadd0
+Message_AddResult  = 0xadd1
+Message_NoMessage  = 0xdead
+
+class HelloMessage(UserMessage):
+    event_id = Message_Hello
+    _fields_ = [
+        ("name", ctypes.c_char*10),
+    ]
+
+class AddRequestMessage(UserMessage):
+    event_id = Message_AddRequest
+    _fields_ = [
+        ("a", ctypes.c_uint32),
+        ("b", ctypes.c_uint32),
+    ]
+
+class AddResultMessage(UserMessage):
+    event_id = Message_AddResult
+    _fields_ = [
+        ("q", ctypes.c_uint32),
+    ]
+
+class NoMessage(UserMessage):
+    event_id = Message_NoMessage
+
+class MsgDemo(Application):
+    def __init__(self):
+        super().__init__('<MsgDemo$Dir>')
+
+    @message_handler(HelloMessage)
+    def reset_request(self, code, id_block, message):
+        if code is not None:
+            if code.recorded:
+                message.acknowledge()
+
+    @message_handler(AddRequestMessage)
+    def add_request(self, code, id_block, message):
+        arr = AddResultMessage()
+        arr.q = message.a + message.b
+        message.reply(arr)
+
+    @toolbox_handler(0xd1e)
+    def quit(self, event, id_block, poll_block):
+        toolbox.quit()
+
+    @toolbox_handler(IconbarClickedEvent)
+    def iconbar_clicked(self, event, id_block, poll_block):
+        arq = AddRequestMessage()
+        arq.a = 1
+        arq.b = 2
+        arq.broadcast(recorded=False,
+                      reply_callback=lambda m:self._add_reply(m, arq.a, arq.b))
+
+        none = NoMessage()
+        none.broadcast(recorded=False,
+                      reply_callback=lambda m:self._no_reply(m, False))
+
+        none = NoMessage()
+        none.broadcast(recorded=True,
+                      reply_callback=lambda m:self._no_reply(m, True))
+
+        hello = HelloMessage()
+        hello.name = b"World"
+        hello.broadcast(recorded=True,
+                      reply_callback=lambda m:self._hello_reply(m))
+
+    @reply_handler(AddResultMessage)
+    def _add_reply(self, code, message, a, b):
+        if message:
+            if message.q != a + b:
+                swi.swi("Wimp_ReportError","sI","FFFFWrong reply.", 1)
+        else:
+            swi.swi("Wimp_ReportError","sI","FFFFDidn't get a reply?", 1)
+
+    @reply_handler(NoMessage)
+    def _no_reply(self, code, message, recorded):
+        if recorded and message is None:
+            swi.swi("Wimp_ReportError","sI","FFFFNo bounce.", 1)
+        if not recorded and message is not None:
+            swi.swi("Wimp_ReportError","sI","FFFFGot a reply?", 1)
+
+    @reply_handler(HelloMessage)
+    def _hello_reply(self, code, message):
+        if code is not None:
+            swi.swi("Wimp_ReportError","sI","FFFFMessage bounced", 1)
+
+if __name__ == "__main__":
+    app = MsgDemo()
+    app.run()

demo/!MsgDemo/Messages

@@ -0,0 +1,2 @@
+#
+_TaskName:Message Demo

riscos_toolbox/__init__.py

@@ -4,22 +4,11 @@
 import ctypes
 import traceback
 import struct
-import sys
 
 from ._types import *
+from ._consts import *
 from .base import Object, _objects, get_object, create_object, find_objects, _application
 from .events import *
-from ._consts import Wimp
-
-
-class Toolbox:
-    Error             = 0x44ec0
-    ObjectAutoCreated = 0x44ec1
-    ObjectDeleted     = 0x44ec2
-
-
-class Messages:
-    Quit = 0
 
 
 _quit = False
@@ -84,10 +73,10 @@ def _handler_block(handlers, add=[]):
             block[index] = id
         return block
 
-    wimp_messages  = _handler_block(events._message_handlers)
-    toolbox_events = _handler_block(
-        events._toolbox_handlers,
-        [Toolbox.ObjectAutoCreated, Toolbox.ObjectDeleted])
+    wimp_messages  = _handler_block(events._message_handlers,
+                         list(events._reply_messages))
+    toolbox_events = _handler_block(events._toolbox_handlers,
+                         [Toolbox.ObjectAutoCreated, Toolbox.ObjectDeleted])
 
     wimp_ver, task_handle, sprite_area = \
         swi.swi('Toolbox_Initialise', '0IbbsbI;III',
@@ -108,9 +97,11 @@ def run(application):
     global _quit
 
     while not _quit:
+        flags = application.poll_flags
+        if events.null_polls():
+            flags = flags & ~Wimp.Poll.NullMask
         reason, sender = swi.swi(
-            'Wimp_Poll', 'II;I.I',
-            application.poll_flags,
+            'Wimp_Poll', 'II;I.I', flags,
             ctypes.addressof(poll_buffer))
 
         try:
@@ -134,13 +125,22 @@ def run(application):
 
                 toolbox_dispatch(event_code, application, _id_block, poll_block)
 
-            elif reason in (Wimp.UserMessage, Wimp.UserMessageRecorded):
-                message = struct.unpack("I", poll_block[16:20])[0]
+            elif reason in [
+                Wimp.UserMessage,
+                Wimp.UserMessageRecorded,
+                Wimp.UserMessageAcknowledge
+            ]:
+                message = MessageInfo.create(
+                    reason, *struct.unpack("IIIII", poll_block[0:20]))
+
                 if message == Messages.Quit:
                     _quit = True
                     continue
+
                 message_dispatch(message, application, _id_block, poll_block)
             else:
+                if reason == Wimp.Null:
+                    events.null_poll()
                 wimp_dispatch(reason, application, _id_block, poll_block)
 
         except Exception as e:

riscos_toolbox/_consts.py

@@ -1,3 +1,5 @@
+"""RISC OS Toolbox library: constants"""
+
 
 class Wimp:
     Null = 0
@@ -35,3 +37,13 @@ class Poll:
         PollWord                   = (1 << 22)
         PollWordHighPriority       = (1 << 23)
         SaveFPRegs                 = (1 << 24)
+
+
+class Toolbox:
+    Error             = 0x44ec0
+    ObjectAutoCreated = 0x44ec1
+    ObjectDeleted     = 0x44ec2
+
+
+class Messages:
+    Quit = 0