From dfa8bb1e830464cd30377f22bb64471367e7593b Mon Sep 17 00:00:00 2001
From: Arindam Chaudhuri <ksharindam@gmail.com>
Date: Fri, 20 Oct 2023 09:54:48 +0530
Subject: [PATCH] fixed : hydrogens not updated if attached bond is deleted

---
 chemcanvas/tools.py | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/chemcanvas/tools.py b/chemcanvas/tools.py
index 547de74..1b942ef 100644
--- a/chemcanvas/tools.py
+++ b/chemcanvas/tools.py
@@ -295,6 +295,12 @@ def delete_objects(objects):
         bonds |= set(atom.bonds)
         marks |= set(atom.marks)
 
+    # need to redraw atoms whose bonds are deleted, and occupied valency changed
+    to_redraw = set()
+    for bond in bonds:
+        to_redraw |= set(bond.atoms)
+    to_redraw -= atoms
+
     # delete all other objects
     while marks:
         mark = marks.pop()
@@ -321,6 +327,7 @@ def delete_objects(objects):
     while modified_molecules:
         mol = modified_molecules.pop()
         if len(mol.bonds)==0:# delete lone atom
+            to_redraw -= set(mol.atoms)
             for child in mol.children:
                 child.deleteFromPaper()
             mol.paper.removeObject(mol)
@@ -329,6 +336,8 @@ def delete_objects(objects):
             # delete lone atoms
             [modified_molecules.add(mol) for mol in new_mols if len(mol.bonds)==0]
 
+    draw_objs_recursively(to_redraw)
+
 # ---------------------------- END MOVE TOOL ---------------------------