Now newly added edges also snap to all underlying vertices!

zxlive/commands.py

@@ -286,7 +286,23 @@ def undo(self) -> None:
         self.update_graph_view()
 
     def redo(self) -> None:
-        self.g.add_edge(((self.u, self.v)), self.ety)
+        self.g.add_edge((self.u, self.v), self.ety)
+        self.update_graph_view()
+
+@dataclass
+class AddEdges(BaseCommand):
+    """Adds multiple edges of the same type to a graph."""
+    pairs: list[tuple[VT,VT]]
+    ety: EdgeType
+
+    def undo(self) -> None:
+        for u, v in self.pairs:
+            self.g.remove_edge((u, v, self.ety))
+        self.update_graph_view()
+
+    def redo(self) -> None:
+        for u, v in self.pairs:
+            self.g.add_edge((u, v), self.ety)
         self.update_graph_view()
 
 

zxlive/editor_base_panel.py

@@ -17,15 +17,16 @@
 from zxlive.sfx import SFXEnum
 
 from .base_panel import BasePanel, ToolbarSection
-from .commands import (AddEdge, AddNode, AddNodeSnapped, AddWNode, ChangeEdgeColor,
+from .commands import (AddEdge, AddEdges, AddNode, AddNodeSnapped, AddWNode, ChangeEdgeColor,
                        ChangeNodeType, ChangePhase, MoveNode, SetGraph,
                        UpdateGraph)
 from .common import VT, GraphT, ToolType, get_data
 from .dialogs import show_error_msg
 from .eitem import EItem, HAD_EDGE_BLUE, EItemAnimation
+from .vitem import VItem, BLACK
 from .graphscene import EditGraphScene
 from .settings import display_setting
-from .vitem import BLACK
+
 from . import animations
 
 
@@ -179,15 +180,33 @@ def add_vert(self, x: float, y: float, edges: list[EItem]) -> None:
         self.play_sound_signal.emit(SFXEnum.THATS_A_SPIDER)
         self.undo_stack.push(cmd)
 
-    def add_edge(self, u: VT, v: VT) -> None:
+    def add_edge(self, u: VT, v: VT, verts: list[VItem]) -> None:
+        """Add an edge between vertices u and v. `verts` is a list of VItems that collide with the edge.
+        """
         graph = self.graph_view.graph_scene.g
         if vertex_is_w(graph.type(u)) and get_w_partner(graph, u) == v:
             return None
         if graph.type(u) == VertexType.W_INPUT and len(graph.neighbors(u)) >= 2 or \
             graph.type(v) == VertexType.W_INPUT and len(graph.neighbors(v)) >= 2:
             return None
-        cmd = AddEdge(self.graph_view, u, v, self._curr_ety)
+        if not self.snap_vertex_edge or not verts:
+            cmd = AddEdge(self.graph_view, u, v, self._curr_ety)
+            self.undo_stack.push(cmd)
+            return
+
+        ux, uy = graph.row(u), graph.qubit(u)
+        # Line was drawn from u to v, we want to order vs with the earlier items first.
+        def dist(vitem: VItem) -> float:
+            return (graph.row(vitem.v) - ux)**2 + (graph.row(vitem.v) - uy)**2
+        verts.sort(key=dist)
+        vs = [vitem.v for vitem in verts]
+        pairs = [(u, vs[0])]
+        for i in range(1, len(vs)):
+            pairs.append((vs[i-1],vs[i]))
+        pairs.append((vs[-1],v))
+        cmd = AddEdges(self.graph_view, pairs, self._curr_ety)
         self.undo_stack.push(cmd)
+
 
     def vert_moved(self, vs: list[tuple[VT, float, float]]) -> None:
         self.undo_stack.push(MoveNode(self.graph_view, vs))

zxlive/graphscene.py

@@ -18,7 +18,7 @@
 from typing import Optional, Iterator, Iterable
 
 from PySide6.QtCore import Qt, Signal, QRectF
-from PySide6.QtGui import QBrush, QColor, QTransform
+from PySide6.QtGui import QBrush, QColor, QTransform, QPainterPath
 from PySide6.QtWidgets import QGraphicsScene, QGraphicsSceneMouseEvent, QGraphicsItem
 
 from pyzx.graph.base import EdgeType
@@ -235,7 +235,7 @@ class EditGraphScene(GraphScene):
     # Note that we have to set the argument types to `object`,
     # otherwise it doesn't work for some reason...
     vertex_added = Signal(object, object, object)  # Actual types: float, float, list[EItem]
-    edge_added = Signal(object, object)  # Actual types: VT, VT
+    edge_added = Signal(object, object, object)  # Actual types: VT, VT, list[VItem]
 
     # Currently selected edge type for preview when dragging
     # to add a new edge
@@ -304,7 +304,18 @@ def add_vertex(self, e: QGraphicsSceneMouseEvent) -> None:
     def add_edge(self, e: QGraphicsSceneMouseEvent) -> None:
         assert self._drag is not None
         self.removeItem(self._drag)
+        v1 = self._drag.start
+        self._drag = None
         for it in self.items(e.scenePos(), deviceTransform=QTransform()):
             if isinstance(it, VItem):
-                self.edge_added.emit(self._drag.start.v, it.v)
-        self._drag = None
+                v2 = it
+                #self.edge_added.emit(self._drag.start.v, it.v)
+        assert v2 is not None
+        path = QPainterPath(v1.pos())
+        path.lineTo(e.scenePos())
+        colliding_verts = []
+        for it in self.items(path, Qt.IntersectsItemShape, Qt.DescendingOrder, deviceTransform=QTransform()):
+            if isinstance(it, VItem) and it not in (v1,v2):
+                colliding_verts.append(it)
+        self.edge_added.emit(v1.v,v2.v,colliding_verts)
+