Bonsai: position drawings on sheets without leaving Blender

Sheet items could only be placed by the automatic row-packing layout in
SheetBuilder.add_drawing/add_document. Any correction meant opening the
layout SVG in Inkscape via bim.open_layout, which is the round trip that
D&D Phase 1 Item 07 asks to remove.

Adds bim.edit_sheet_item_position, which reads the current position of
the selected drawing, schedule or reference from the sheet layout SVG,
offers it as X/Y in millimetres, and writes the whole group back so the
view title keeps its offset from the content.

Scale is deliberately not exposed. build_drawings/build_documents inline
the referenced SVG under a plain translate(), so the image width/height
only drives the clip rect and cannot scale the view.

Generated with the assistance of an AI coding tool.

src/bonsai/bonsai/bim/module/drawing/__init__.py

@@ -63,6 +63,7 @@ classes = (
     operator.EditAssignedProduct,
     operator.EditElementFilter,
     operator.EditSheet,
+    operator.EditSheetItemPosition,
     operator.EditText,
     operator.EditTextPopup,
     operator.EnableAddAnnotationType,

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

@@ -2165,6 +2165,54 @@ class RemoveDrawingFromSheet(bpy.types.Operator, tool.Ifc.Operator):
         tool.Drawing.remove_drawing_from_sheet(ifc_file.by_id(self.reference))
 
 
+class EditSheetItemPosition(bpy.types.Operator, tool.Ifc.Operator):
+    bl_idname = "bim.edit_sheet_item_position"
+    bl_label = "Edit Position On Sheet"
+    bl_description = "Set the position of the selected drawing, schedule or reference on its sheet layout"
+    bl_options = {"REGISTER", "UNDO"}
+
+    x: bpy.props.FloatProperty(name="X", description="Distance in mm from the left edge of the sheet", unit="NONE")
+    y: bpy.props.FloatProperty(name="Y", description="Distance in mm from the top edge of the sheet", unit="NONE")
+
+    @classmethod
+    def poll(cls, context):
+        active_item = tool.Drawing.get_active_sheet_item()
+        if active_item is None or active_item.is_sheet:
+            cls.poll_message_set("No sheet item selected.")
+            return False
+        if active_item.reference_type not in ("DRAWING", "SCHEDULE", "REFERENCE"):
+            cls.poll_message_set("Only drawings, schedules and references can be positioned.")
+            return False
+        return True
+
+    def invoke(self, context, event):
+        assert context.window_manager
+        position = self.get_position()
+        if position is None:
+            self.report({"ERROR"}, "Item was not found in the sheet layout.")
+            return {"CANCELLED"}
+        self.x, self.y = position
+        return context.window_manager.invoke_props_dialog(self)
+
+    def get_position(self):
+        sheet_item = tool.Drawing.get_active_sheet_item()
+        assert sheet_item
+        reference = tool.Ifc.get().by_id(sheet_item.ifc_definition_id)
+        sheet = tool.Drawing.get_reference_document(reference)
+        if sheet is None:
+            return None
+        return sheeter.SheetBuilder().get_sheet_item_position(reference, sheet)
+
+    def _execute(self, context):
+        sheet_item = tool.Drawing.get_active_sheet_item()
+        assert sheet_item
+        reference = tool.Ifc.get().by_id(sheet_item.ifc_definition_id)
+        sheet = tool.Drawing.get_reference_document(reference)
+        if sheet is None or not sheeter.SheetBuilder().set_sheet_item_position(reference, sheet, self.x, self.y):
+            self.report({"ERROR"}, "Item was not found in the sheet layout.")
+            return {"CANCELLED"}
+
+
 class CreateSheets(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.create_sheets"
     bl_label = "Create Sheets"

src/bonsai/bonsai/bim/module/drawing/sheeter.py

@@ -24,6 +24,7 @@ import urllib.parse
 import uuid
 import xml.etree.ElementTree as ET
 from pathlib import Path
+from typing import Union
 from xml.dom import minidom
 
 import ifcopenshell.util.geolocation
@@ -211,6 +212,71 @@ class SheetBuilder:
 
         layout_tree.write(layout_path)
 
+    def find_sheet_item(
+        self, layout_root: ET.Element, reference: ifcopenshell.entity_instance
+    ) -> Union[ET.Element, None]:
+        for g in layout_root.findall(f"{SVG}g"):
+            if g.attrib.get("data-id") == str(reference.id()):
+                return g
+        return None
+
+    def get_sheet_item_position(
+        self, reference: ifcopenshell.entity_instance, sheet: ifcopenshell.entity_instance
+    ) -> Union[Vector, None]:
+        """Position in mm of a drawing/schedule/reference placed on a sheet layout."""
+        layout_path = tool.Drawing.get_document_uri(sheet, "LAYOUT")
+        assert layout_path
+        if not os.path.exists(layout_path):
+            return None
+
+        layout_root = ET.parse(layout_path).getroot()
+        view = self.find_sheet_item(layout_root, reference)
+        if view is None:
+            return None
+
+        content = self.get_sheet_item_content(view)
+        if content is None:
+            return None
+        return Vector((self.convert_to_mm(content.attrib["x"]), self.convert_to_mm(content.attrib["y"])))
+
+    def set_sheet_item_position(
+        self, reference: ifcopenshell.entity_instance, sheet: ifcopenshell.entity_instance, x: float, y: float
+    ) -> bool:
+        """Move a sheet item and its view title to an absolute position in mm."""
+        ET.register_namespace("", "http://www.w3.org/2000/svg")
+        ET.register_namespace("xlink", "http://www.w3.org/1999/xlink")
+
+        layout_path = tool.Drawing.get_document_uri(sheet, "LAYOUT")
+        assert layout_path
+        if not os.path.exists(layout_path):
+            return False
+
+        layout_tree = ET.parse(layout_path)
+        view = self.find_sheet_item(layout_tree.getroot(), reference)
+        if view is None:
+            return False
+
+        content = self.get_sheet_item_content(view)
+        if content is None:
+            return False
+
+        offset = Vector((x, y)) - Vector(
+            (self.convert_to_mm(content.attrib["x"]), self.convert_to_mm(content.attrib["y"]))
+        )
+
+        for image in view.findall(f"{SVG}image"):
+            image.attrib["x"] = str(round(self.convert_to_mm(image.attrib["x"]) + offset.x, 4))
+            image.attrib["y"] = str(round(self.convert_to_mm(image.attrib["y"]) + offset.y, 4))
+
+        layout_tree.write(layout_path)
+        return True
+
+    def get_sheet_item_content(self, view: ET.Element) -> Union[ET.Element, None]:
+        for image in view.findall(f"{SVG}image"):
+            if image.attrib.get("data-type") in ("foreground", "content"):
+                return image
+        return None
+
     def remove_drawing(self, reference: ifcopenshell.entity_instance, sheet: ifcopenshell.entity_instance) -> None:
         ET.register_namespace("", "http://www.w3.org/2000/svg")
 

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

@@ -516,6 +516,7 @@ class BIM_PT_sheets(Panel):
             row3.separator(factor=0.5, type="SPACE")
 
             row3.operator("bim.edit_sheet", icon="GREASEPENCIL", text="")
+            row3.operator("bim.edit_sheet_item_position", icon="ORIENTATION_VIEW", text="")
             row3.operator("bim.add_drawing_to_sheet", icon="IMAGE_PLANE", text="")
             row3.operator("bim.add_schedule_to_sheet", icon="PRESET_NEW", text="")
             row3.operator("bim.add_reference_to_sheet", icon="IMAGE_REFERENCE", text="")