feat(io): Emit property change signals for byteorder and signedness

Added `PropertiesChanged` signals for `byteorder` and `signed` property
updates. Updated D-Bus interface annotations to specify change signal
behavior for properties. Simplified `emit_io_change` implementation.

Signed-off-by: Sven Sager <s.sager@kunbus.com>

src/revpi_middleware/ios1/interface_ios.py

@@ -24,15 +24,33 @@ class InterfaceInput:
             <method name="SetSigned">
                 <arg name="signed" type="b" direction="in"/>
             </method>
-            <property name="address" type="n" access="read"/>
+            <property name="address" type="n" access="read">
-            <property name="bmk" type="s" access="read"/>
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
-            <property name="bitaddress" type="n" access="readwrite"/>
+            </property>
-            <property name="byteorder" type="s" access="readwrite"/>
+            <property name="bmk" type="s" access="read">
-            <property name="defaultvalue" type="v" access="read"/>
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
-            <property name="length" type="q" access="read"/>
+            </property>
-            <property name="name" type="s" access="read"/>
+            <property name="bitaddress" type="n" access="readwrite">
-            <property name="signed" type="b" access="readwrite"/>
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
-            <property name="value" type="v" access="read"/>
+            </property>
+            <property name="byteorder" type="s" access="readwrite">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="invalidates"/>
+            </property>
+            <property name="defaultvalue" type="v" access="read">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
+            </property>
+            <property name="length" type="q" access="read">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
+            </property>
+            <property name="name" type="s" access="read">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
+            </property>
+            <property name="signed" type="b" access="readwrite">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="invalidates"/>
+            </property>
+            <property name="value" type="v" access="read">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="true"/>
+            </property>
         </interface>
     </node>
     """
@@ -53,7 +71,6 @@ class InterfaceInput:
             self.variant_type = "ay"
 
     def emit_io_change(self):
-        if self.interface_name:
         self.PropertiesChanged(
             self.interface_name,
             {
@@ -93,6 +110,15 @@ class InterfaceInput:
             self.io._set_byteorder(value)
             self.variant_type = get_variant_type(self.io)
 
+            # Changing the byteorder can change the value, but we do NOT send a signal for that
+            # because the real value of the process image was not changed. But we inform the client
+            # about the changed byteorder property.
+            self.PropertiesChanged(
+                self.interface_name,
+                {},
+                ["byteorder"],
+            )
+
     @property
     def defaultvalue(self) -> Variant:
         return Variant(
@@ -121,6 +147,15 @@ class InterfaceInput:
             self.io._set_signed(value)
             self.variant_type = get_variant_type(self.io)
 
+            # Changing the signedness can change the value, but we do NOT send a signal for that
+            # because the real value of the process image was not changed. But we inform the client
+            # about the changed signedness property.
+            self.PropertiesChanged(
+                self.interface_name,
+                {},
+                ["signed"],
+            )
+
     @property
     def value(self) -> Variant:
         if not self.io._parentdevice._selfupdate:
@@ -145,15 +180,33 @@ class InterfaceOutput(InterfaceInput):
             <method name="SetValue">
                 <arg name="value" type="v" direction="in"/>
             </method>
-            <property name="address" type="n" access="read"/>
+            <property name="address" type="n" access="read">
-            <property name="bmk" type="s" access="read"/>
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
-            <property name="bitaddress" type="n" access="readwrite"/>
+            </property>
-            <property name="byteorder" type="s" access="readwrite"/>
+            <property name="bmk" type="s" access="read">
-            <property name="defaultvalue" type="v" access="read"/>
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
-            <property name="length" type="q" access="read"/>
+            </property>
-            <property name="name" type="s" access="read"/>
+            <property name="bitaddress" type="n" access="readwrite">
-            <property name="signed" type="b" access="readwrite"/>
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
-            <property name="value" type="v" access="readwrite"/>
+            </property>
+            <property name="byteorder" type="s" access="readwrite">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="invalidates"/>
+            </property>
+            <property name="defaultvalue" type="v" access="read">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
+            </property>
+            <property name="length" type="q" access="read">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
+            </property>
+            <property name="name" type="s" access="read">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="const"/>
+            </property>
+            <property name="signed" type="b" access="readwrite">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="invalidates"/>
+            </property>
+            <property name="value" type="v" access="readwrite">
+                <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal" value="true"/>
+            </property>
         </interface>
     </node>
     """