Simplify giving bg entity coordinates in generate_graph

spinetoolbox/spine_db_editor/generate_graph.py

@@ -29,7 +29,7 @@ def generate_graph(
     color_parameter="",
     arc_width_parameter="",
     bg_img_path=None,
-    bg_img_coordinate_map=None,
+    bg_img_entity_coordinates=None,
 ):
     """Launches Spine Db Editor and generates a graph."""
     if not pyside6_version_check():
@@ -53,9 +53,8 @@ def generate_graph(
     graph_view.arc_width_parameter = arc_width_parameter
     if bg_img_path:
         graph_view.set_bg_image(bg_img_path)
-    if bg_img_coordinate_map:
-        (bg1, graph1), (bg2, graph2), *_ignored = bg_img_coordinate_map.items()
-        graph_view.fit_bg(bg1, bg2, graph1, graph2)
+    if bg_img_entity_coordinates:
+        graph_view.set_bg_entity_coordinates(bg_img_entity_coordinates)
     tree_view = editor.ui.treeView_entity
     model = tree_view.model()
     selection_model = tree_view.selectionModel()

spinetoolbox/spine_db_editor/graphics_items.py

@@ -947,10 +947,10 @@ def _do_resize(self, rect, strong):
     def fit_rect(self, rect):
         self._do_resize(rect, True)
 
-    def fit_coordinates(self, bg1, bg2, scen1, scen2):
+    def fit_coordinates(self, p1, p2, scen1, scen2):
         size = self._renderer.defaultSize()
-        x1, y1 = bg1
-        x2, y2 = bg2
+        x1, y1 = p1
+        x2, y2 = p2
         scene_x1, scene_y1 = scen1
         scene_x2, scene_y2 = scen2
         y1 += size.height()

spinetoolbox/spine_db_editor/widgets/custom_qgraphicsviews.py

@@ -47,6 +47,7 @@ def __init__(self, parent):
         self.color_parameter = ""
         self.arc_width_parameter = ""
         self._bg_item = None
+        self._bg_entity_coordinates = None
         self.selected_items = []
         self.removed_items = set()
         self.hidden_items = {}
@@ -516,9 +517,19 @@ def set_bg_image(self, file_path, transform=None):
         self._bg_item = BgItem(file_path)
         self.scene().addItem(self._bg_item)
 
-    def fit_bg(self, bg1, bg2, scen1, scen2):
-        bg1, bg2, scen1, scen2 = [self._spine_db_editor.convert_position(*p) for p in (bg1, bg2, scen1, scen2)]
-        self._bg_item.fit_coordinates(bg1, bg2, scen1, scen2)
+    def set_bg_entity_coordinates(self, entity_coordinates):
+        self._bg_entity_coordinates = {
+            ent: self._spine_db_editor.convert_position(*p) for ent, p in entity_coordinates.items()
+        }
+        self.fit_bg_coordinates()
+
+    def fit_bg_coordinates(self):
+        (ent1, p1), (ent2, p2), *_ignored = self._bg_entity_coordinates.items()
+        pos_by_name = {item.display_data: item.pos() for item in self.entity_items}
+        scen1, scen2 = pos_by_name.get(ent1), pos_by_name.get(ent2)
+        if None in (scen1, scen2):
+            return
+        self._bg_item.fit_coordinates(p1, p2, (scen1.x(), scen1.y()), (scen2.x(), scen2.y()))
 
     def clear_scene(self):
         for item in self.scene().items():

spinetoolbox/spine_db_editor/widgets/graph_view_mixin.py

@@ -388,6 +388,7 @@ def _complete_graph(self, layout_gen_id, x, y):
             self.ui.graphicsView.reset_zoom()
         else:
             self.ui.graphicsView.apply_zoom()
+        self.ui.graphicsView.fit_bg_coordinates()
 
     def _get_selected_db_map_entity_ids(self):
         """Returns a set of ids corresponding to selected entities in the trees.