diff --git a/src/App/BottomPanel/FindReplace.tsx b/src/App/BottomPanel/FindReplace.tsx
index 818dbe2..4ea9326 100644
--- a/src/App/BottomPanel/FindReplace.tsx
+++ b/src/App/BottomPanel/FindReplace.tsx
@@ -4,6 +4,7 @@ import { usePersistentState } from "@/hooks/usePersistentState";
 
 import CloseIcon from '@mui/icons-material/Close';
 import SwapHorizIcon from '@mui/icons-material/SwapHoriz';
+import { useShortcuts } from "@/hooks/useShortcuts";
 
 type FindReplaceProps = {
   setCS: Dispatch<(oldState: VisualEditorState) => VisualEditorState>,
@@ -27,27 +28,15 @@ export function FindReplace({setCS, hide}: FindReplaceProps) {
     });
   }, [findTxt, replaceTxt]);
 
-  const onKeyDown = useCallback((e: KeyboardEvent) => {
-    if (e.key === "Enter") {
-      e.preventDefault();
-      e.stopPropagation();
-      onReplace();
-      // setModal(null);
-    }
-  }, [onReplace]);
+  useShortcuts([
+    {keys: ["Enter"], action: onReplace},
+  ])
 
   const onSwap = useCallback(() => {
     setReplaceTxt(findTxt);
     setFindText(replaceTxt);
   }, [findTxt, replaceTxt]);
 
-  useEffect(() => {
-    window.addEventListener("keydown", onKeyDown);
-    return () => {
-      window.removeEventListener("keydown", onKeyDown);
-    }
-  }, [])
-
   return <div className="toolbar toolbarGroup" style={{display: 'flex'}}>
     <input placeholder="find" value={findTxt} onChange={e  => setFindText(e.target.value)} style={{width:300}}/>
     <button tabIndex={-1} onClick={onSwap}><SwapHorizIcon fontSize="small"/></button>
diff --git a/src/App/Modals/TextDialog.tsx b/src/App/Modals/TextDialog.tsx
index 6ab731b..ead2abc 100644
--- a/src/App/Modals/TextDialog.tsx
+++ b/src/App/Modals/TextDialog.tsx
@@ -1,24 +1,20 @@
-import { Dispatch, ReactElement, SetStateAction, useState, KeyboardEvent, useEffect, useRef } from "react";
+import { Dispatch, ReactElement, SetStateAction, useState, useCallback } from "react";
 
 import { cachedParseLabel } from "@/statecharts/parser";
+import { useShortcuts } from "@/hooks/useShortcuts";
 
 export function TextDialog(props: {setModal: Dispatch<SetStateAction<ReactElement|null>>, text: string, done: (newText: string|undefined) => void}) {
   const [text, setText] = useState(props.text);
 
-  function onKeyDown(e: KeyboardEvent) {
-    if (e.key === "Enter") {
-      if (!e.shiftKey) {
-        e.preventDefault();
+  useShortcuts([
+    {keys: ["Enter"], action: useCallback(() => {
         props.done(text);
         props.setModal(null);
-      }
-    }
-    if (e.key === "Escape") {
-      props.setModal(null);
-      e.stopPropagation();
-    }
-    e.stopPropagation();
-  }
+      }, [text, props.done, props.setModal])},
+    {keys: ["Escape"], action: useCallback(() => {
+        props.setModal(null);
+      }, [props.setModal])},
+  ], false);
 
   let parseError = "";
   try {
@@ -28,7 +24,7 @@ export function TextDialog(props: {setModal: Dispatch<SetStateAction<ReactElemen
     parseError = e.message;
   }
 
-  return <div onKeyDown={onKeyDown} style={{padding: 4}}>
+  return <div style={{padding: 4}}>
     {/* Text label:<br/> */}
     <textarea autoFocus style={{fontFamily: 'Roboto', width: 400, height: 60}} onChange={e=>setText(e.target.value)} value={text} onFocus={e => e.target.select()}/>
     <br/>
@@ -39,4 +35,4 @@ export function TextDialog(props: {setModal: Dispatch<SetStateAction<ReactElemen
     {/* <br/> */}
     {/* (Tip: <kbd>Shift</kbd>+<kbd>Enter</kbd> to insert newline.) */}
   </div>;
-}
\ No newline at end of file
+}
diff --git a/src/App/SideBar/ShowAST.tsx b/src/App/SideBar/ShowAST.tsx
index 6c240ad..37e7cb9 100644
--- a/src/App/SideBar/ShowAST.tsx
+++ b/src/App/SideBar/ShowAST.tsx
@@ -4,6 +4,7 @@ import { usePersistentState } from "../../hooks/usePersistentState";
 import { ConcreteState, stateDescription, Transition, UnstableState } from "../../statecharts/abstract_syntax";
 import { Action, EventTrigger, Expression } from "../../statecharts/label_ast";
 import { KeyInfoHidden, KeyInfoVisible } from "../TopPanel/KeyInfo";
+import { useShortcuts } from '@/hooks/useShortcuts';
 
 export function ShowTransition(props: {transition: Transition}) {
   return <>➝ {stateDescription(props.transition.tgt)}</>;
@@ -49,7 +50,7 @@ export const ShowAST = memo(function ShowASTx(props: {root: ConcreteState | Unst
 });
 
 
-export function ShowInputEvents({inputEvents, onRaise, disabled, showKeys}: {inputEvents: EventTrigger[], onRaise: (e: string, p: any) => void, disabled: boolean, showKeys: boolean}) {
+export function ShowInputEvents({inputEvents, onRaise, disabled}: {inputEvents: EventTrigger[], onRaise: (e: string, p: any) => void, disabled: boolean}) {
   const raiseHandlers = inputEvents.map(({event}) => {
     return () => {
       // @ts-ignore
@@ -67,23 +68,16 @@ export function ShowInputEvents({inputEvents, onRaise, disabled, showKeys}: {inp
       onRaise(event, paramParsed);
     };
   });
-  const onKeyDown = (e: KeyboardEvent) => {
-    // don't capture keyboard events when focused on an input element:
-    // @ts-ignore
-    if (["INPUT", "TEXTAREA", "SELECT"].includes(e.target?.tagName)) return;
 
-    const n = (parseInt(e.key)+9) % 10;
-    if (raiseHandlers[n] !== undefined) {
-      raiseHandlers[n]();
-      e.stopPropagation();
-      e.preventDefault();
-    }
-  }
-  useEffect(() => {
-    window.addEventListener("keydown", onKeyDown);
-    return () => window.removeEventListener("keydown", onKeyDown);
-  }, [raiseHandlers]);
-  // const KeyInfo = showKeys ? KeyInfoVisible : KeyInfoHidden;
+  const shortcutSpec = raiseHandlers.map((handler, i) => {
+    const n = (i+1)%10;
+    return {
+      keys: [n.toString()],
+      action: handler,
+    };
+  });
+  useShortcuts(shortcutSpec);
+
   const KeyInfo = KeyInfoVisible; // always show keyboard shortcuts on input events, we can't expect the user to remember them
 
   const [inputParams, setInputParams] = usePersistentState<{[eventName:string]: string}>("inputParams", {});
diff --git a/src/App/VisualEditor/hooks/useCopyPaste.ts b/src/App/VisualEditor/hooks/useCopyPaste.ts
index 21e8f9b..1cc01e8 100644
--- a/src/App/VisualEditor/hooks/useCopyPaste.ts
+++ b/src/App/VisualEditor/hooks/useCopyPaste.ts
@@ -2,6 +2,7 @@ import { Arrow, Diamond, Rountangle, Text, History } from "@/statecharts/concret
 import { ClipboardEvent, Dispatch, SetStateAction, useCallback, useEffect } from "react";
 import { Selection, VisualEditorState } from "../VisualEditor";
 import { addV2D } from "@/util/geometry";
+import { useShortcuts } from "@/hooks/useShortcuts";
 
 // const offset = {x: 40, y: 40};
 const offset = {x: 0, y: 0};
@@ -12,6 +13,7 @@ export function useCopyPaste(makeCheckPoint: () => void, state: VisualEditorStat
     if (data) {
       try {
         const parsed = JSON.parse(data);
+        makeCheckPoint();
         setState(state => {
           try {
             let nextID = state.nextID;
@@ -49,7 +51,6 @@ export function useCopyPaste(makeCheckPoint: () => void, state: VisualEditorStat
               ...copiedTexts.map(t => ({uid: t.uid, parts: ["text"]})),
               ...copiedHistories.map(h => ({uid: h.uid, parts: ["history"]})),
             ];
-            makeCheckPoint();
             return {
               ...state,
               rountangles: [...state.rountangles, ...copiedRountangles],
@@ -72,7 +73,7 @@ export function useCopyPaste(makeCheckPoint: () => void, state: VisualEditorStat
       }
       e.preventDefault();
     }
-  }, [setState]);
+  }, [makeCheckPoint, setState]);
 
   const copyInternal = useCallback((state: VisualEditorState, selection: Selection, e: ClipboardEvent) => {
     const uidsToCopy = new Set(selection.map(shape => shape.uid));
@@ -106,6 +107,7 @@ export function useCopyPaste(makeCheckPoint: () => void, state: VisualEditorStat
   }, [state, selection]);
 
   const deleteSelection = useCallback(() => {
+    makeCheckPoint();
     setState(state => ({
       ...state,
       rountangles: state.rountangles.filter(r => !state.selection.some(rs => rs.uid === r.uid)),
@@ -115,23 +117,11 @@ export function useCopyPaste(makeCheckPoint: () => void, state: VisualEditorStat
       texts: state.texts.filter(t => !state.selection.some(ts => ts.uid === t.uid)),
       selection: [],
     }));
-  }, [setState]);
+  }, [makeCheckPoint, setState]);
 
-  const onKeyDown = (e: KeyboardEvent) => {
-    // @ts-ignore
-    if (["INPUT", "TEXTAREA", "SELECT"].includes(e.target?.tagName)) return;
-    if (e.key === "Delete") {
-      // delete selection
-      makeCheckPoint();
-      deleteSelection();
-      e.preventDefault();
-    }
-  }
-
-  useEffect(() => {
-    window.addEventListener("keydown", onKeyDown);
-    return () => window.removeEventListener("keydown", onKeyDown);
-  })
+  useShortcuts([
+    {keys: ["Delete"], action: deleteSelection},
+  ])
 
   return {onCopy, onPaste, onCut, deleteSelection};
 }
\ No newline at end of file
diff --git a/src/hooks/useShortcuts.ts b/src/hooks/useShortcuts.ts
index 13cb4e2..cafb6db 100644
--- a/src/hooks/useShortcuts.ts
+++ b/src/hooks/useShortcuts.ts
@@ -1,11 +1,15 @@
 import { useEffect } from "react";
 
-export function useShortcuts(spec: {keys: string[], action: () => void}[]) {
+export function useShortcuts(spec: {keys: string[], action: () => void}[], ignoreInputs = true) {
+  // I don't know if this is efficient, but I decided to just register one event listener for every shortcut, rather than generating one big event listener for all shortcuts.
+  // The benefit is that we don't have to memoize anything: useEffect will only be called if the action updated, and React allows calling useEffect for every item in a list as long as the list doesn't change.
   for (const {keys, action} of spec) {
     useEffect(() => {
       const handler = (e: KeyboardEvent) => {
-        // @ts-ignore: don't steal keyboard events while the user is typing in a text box, etc.
-        if (["INPUT", "TEXTAREA", "SELECT"].includes(e.target?.tagName)) return;
+        if (ignoreInputs) {
+          // @ts-ignore: don't steal keyboard events while the user is typing in a text box, etc.
+          if (["INPUT", "TEXTAREA", "SELECT"].includes(e.target?.tagName)) return;
+        }
 
         if (e.ctrlKey !== keys.includes("Ctrl")) return;
         if (e.shiftKey !== keys.includes("Shift")) return;
diff --git a/todo.txt b/todo.txt
index 6044e5c..e0f1cd1 100644
--- a/todo.txt
+++ b/todo.txt
@@ -31,7 +31,8 @@
 TODO
 
 - bugs
-    editing SC <-> Plant connections at runtime doesn't seem to work
+    (*) editing SC <-> Plant connections at runtime doesn't seem to work
+    (*) non-determinism error highlights only one of enabled transitions
 
 - maybe support:
     - explicit order of:
@@ -64,6 +65,10 @@ TODO
     - show insert mode also next to cursor
     - plot plant signals
 
+    - show error when states partially overlap?
+        useful when accidentally pasting the same data multiple times
+            (otherwise, you can't see that you have multiple states)
+
 - performance:
     maybe try this for rendering the execution trace:
         https://legacy.reactjs.org/docs/optimizing-performance.html#virtualize-long-lists