Refactor port connection logic and UI integration for improved usability

src/bonsai/bonsai/bim/module/system/operator.py

@@ -265,37 +265,31 @@ class ConnectPort(bpy.types.Operator, tool.Ifc.Operator):
 class AddRelatedPortConnection(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.add_related_port_connection"
     bl_label = "Connect Port"
-    bl_description = "Click to select a port to connect to"
     bl_options = {"REGISTER", "UNDO"}
-
-    element_id: bpy.props.IntProperty(default=0, options={"SKIP_SAVE"})
-
+    
+    relating_port_id: bpy.props.IntProperty()
+    
     def invoke(self, context, event):
-        if self.element_id == 0:
-            self.report({'ERROR'}, "No port specified")
-            return {'CANCELLED'}
-        context.window_manager.modal_handler_add(self)
-        return {'RUNNING_MODAL'}
-
-    def modal(self, context, event):
-        if event.type == 'LEFTMOUSE' and event.value == 'PRESS':
-            if context.active_object:
-                target_element = tool.Ifc.get_entity(context.active_object)
-                if target_element and target_element.is_a("IfcDistributionPort"):
-                    source_element = tool.Ifc.get().by_id(self.element_id)
-                    core.connect_port(tool.Ifc, port1=source_element, port2=target_element)
-                    self.report({'INFO'}, "Ports connected")
-                    return {'FINISHED'}
-                else:
-                    self.report({'WARNING'}, "Selected object is not a port")
-            return {'RUNNING_MODAL'}
-        elif event.type in {'RIGHTMOUSE', 'ESC'}:
-            self.report({'INFO'}, "Cancelled")
-            return {'CANCELLED'}
-        return {'RUNNING_MODAL'}
-
+        return context.window_manager.invoke_props_dialog(self)
+    
+    def draw(self, context):
+        props = tool.System.get_system_props()
+        self.layout.prop(props, "related_port", text="Select Port")
+    
     def _execute(self, context):
-        return {'CANCELLED'}
+        props = tool.System.get_system_props()
+        
+        if not props.related_port or props.related_port == "NONE":
+            return {"CANCELLED"}
+        
+        port_obj = bpy.data.objects.get(props.related_port)
+        related_port = tool.Ifc.get_entity(port_obj)
+        relating_port = tool.Ifc.get().by_id(self.relating_port_id)
+        
+        core.connect_port(tool.Ifc, port1=relating_port, port2=related_port)
+        PortData.is_loaded = False
+        
+        return {"FINISHED"}
 
 
 class DisconnectPort(bpy.types.Operator, tool.Ifc.Operator):
@@ -454,19 +448,19 @@ class CycleFlowDirection(bpy.types.Operator, tool.Ifc.Operator):
             return {"CANCELLED"}
 
         current_direction = port.FlowDirection or "NOTDEFINED"
-        flow_cycle = ["SOURCE", "SINK", "SOURCEANDSINK", "NOTDEFINED"]
         
-        try:
-            current_index = flow_cycle.index(current_direction)
-            next_direction = flow_cycle[(current_index + 1) % len(flow_cycle)]
-        except ValueError:
-            next_direction = "SOURCE"
+        flow_cycle_map = {
+            "SOURCE": "SINK",
+            "SINK": "SOURCEANDSINK",
+            "SOURCEANDSINK": "NOTDEFINED",
+            "NOTDEFINED": "SOURCE"
+        }
+        next_direction = flow_cycle_map.get(current_direction, "SOURCE")
 
         tool.Ifc.run("attribute.edit_attributes", product=port, attributes={"FlowDirection": next_direction})
         
         connected_port = tool.System.get_connected_port(port)
         if connected_port:
-            # Map flow direction to connected port's complementary direction
             connected_direction_map = {
                 "SOURCE": "SINK",
                 "SINK": "SOURCE",

src/bonsai/bonsai/bim/module/system/prop.py

@@ -34,7 +34,7 @@ from bpy.props import (
     FloatVectorProperty,
     CollectionProperty,
 )
-from typing import TYPE_CHECKING, Union
+from typing import TYPE_CHECKING, Union, Optional
 
 
 def get_system_class(self: "BIMSystemProperties", context: bpy.types.Context) -> list[tuple[str, str, str]]:
@@ -93,51 +93,24 @@ def toggle_decorations(self: "BIMSystemProperties", context: bpy.types.Context)
         decorator.SystemDecorator.uninstall()
 
 
-def is_port_available_for_connection(self: "BIMSystemProperties", obj: bpy.types.Object) -> bool:
-    element = tool.Ifc.get_entity(obj)
-    if not element or not element.is_a("IfcDistributionPort"):
-        return False
-    connected_port = tool.System.get_connected_port(element)
-    if connected_port is not None:
-        return False
+def get_available_ports_for_connection(self: "BIMSystemProperties", context: bpy.types.Context) -> list[tuple[str, str, str]]:
+    items = []
+    active_object_ports = set(tool.System.get_ports(tool.Ifc.get_entity(context.active_object)))
     
-    if bpy.context.active_object:
-        active_element = tool.Ifc.get_entity(bpy.context.active_object)
-        if active_element:
-            active_ports = tool.System.get_ports(active_element)
-            if element in active_ports:
-                return False
+    ifc_file = tool.Ifc.get()
+    for ifc_port in ifc_file.by_type("IfcDistributionPort"):
+        port = tool.Ifc.get_object(ifc_port)
+        if not port:
+            continue
+        
+        if tool.System.get_connected_port(ifc_port) is not None or ifc_port in active_object_ports:
+            continue
+        
+        port_object = tool.Ifc.get_object(tool.System.get_port_relating_element(ifc_port))
+        suggestion = f"{port_object.name} > {port.name}"
+        items.append((port.name, suggestion, ""))
     
-    return True
-
-
-def update_related_port_object(self: "BIMSystemProperties", context: bpy.types.Context) -> None:
-    if self.related_port_object is None:
-        return
-    if not context.active_object:
-        return
-    
-    source_element = tool.Ifc.get_entity(context.active_object)
-    target_element = tool.Ifc.get_entity(self.related_port_object)
-    
-    if not source_element or not target_element:
-        return
-    
-    if not target_element.is_a("IfcDistributionPort"):
-        return
-    
-    source_port = None
-    for port in tool.System.get_ports(source_element):
-        if not tool.System.get_connected_port(port):
-            source_port = port
-            break
-    
-    if not source_port:
-        return
-    
-    core.connect_port(tool.Ifc, port1=source_port, port2=target_element)
-    PortData.is_loaded = False
-    self.related_port_object = None
+    return items if items else [("NONE", "Ports are hidden or not available", "")]
 
 
 class BIMSystemProperties(PropertyGroup):
@@ -155,12 +128,10 @@ class BIMSystemProperties(PropertyGroup):
     should_draw_decorations: BoolProperty(
         name="Should Draw Decorations", description="Toggle system decorations", update=toggle_decorations
     )
-    related_port_object: PointerProperty(
-        type=bpy.types.Object,
+    related_port: EnumProperty(
         name="Connect To Port",
-        description="Select a port to connect to. Use eyedropper to pick a port object",
-        poll=is_port_available_for_connection,
-        update=update_related_port_object,
+        description="Select a port to connect to",
+        items=get_available_ports_for_connection,
     )
 
     if TYPE_CHECKING:
@@ -174,7 +145,7 @@ class BIMSystemProperties(PropertyGroup):
         edited_system_id: int
         system_class: str
         should_draw_decorations: bool
-        related_port_object: Union[bpy.types.Object, None]
+        related_port: str
 
     @property
     def active_system_ui_item(self) -> Union[System, None]:

src/bonsai/bonsai/bim/module/system/ui.py

@@ -181,9 +181,8 @@ class BIM_PT_ports(Panel):
                 op = cols[1].operator("bim.cycle_flow_direction", text="", icon=flow_direction_icon, emboss=True)
                 op.port_id = port_data["id"]
             else:
-                blank0 = cols[0].column(align=True)
-                blank0.scale_x = 0.1
-                blank0.label(text="", icon="BLANK1")
+                op = cols[0].operator("bim.add_related_port_connection", text="", icon='PLUGIN')
+                op.relating_port_id = port_data["id"]
                 op = cols[1].operator("bim.cycle_flow_direction", text="", icon=flow_direction_icon, emboss=True)
                 op.port_id = port_data["id"]
             
@@ -236,15 +235,14 @@ class BIM_PT_ports(Panel):
                 blank5.scale_x = 0.1
                 blank5.label(text="", icon="BLANK1")
                 
-                col6_row = cols[6].row(align=True)
-                col6_row.alignment = 'LEFT'
-                col6_row.prop(props, "related_port_object", text="", icon='OBJECT_DATA')
-                col6_row.scale_x = 0.35
+                cols[6].label(text="Port is disconnected")
                 
                 blank7 = cols[7].column(align=True)
                 blank7.scale_x = 0.1
                 blank7.label(text="", icon="BLANK1")
-                cols[8].label(text="Port is disconnected")
+                blank8 = cols[8].column(align=True)
+                blank8.scale_x = 0.1
+                blank8.label(text="", icon="BLANK1")
 
 
 class BIM_PT_port(Panel):

src/bonsai/bonsai/tool/system.py

@@ -117,14 +117,8 @@ class System(bonsai.core.tool.System):
         port.PredefinedType = "USERDEFINED"
         
         systems = ifcopenshell.util.system.get_element_systems(element)
-        if systems:
-            system = systems[0]
-            if hasattr(system, "PredefinedType") and system.PredefinedType:
-                port.SystemType = system.PredefinedType
-            else:
-                port.SystemType = "USERDEFINED"
-        else:
-            port.SystemType = "USERDEFINED"
+        system = systems[0] if systems else None
+        port.SystemType = getattr(system, "PredefinedType", None) or "USERDEFINED"
         
         matrix = element_obj.matrix_world.copy()
         matrix.translation = bpy.context.scene.cursor.matrix.translation