[Interactive Graph Editor] Stop cursor jumps in number input fields (#1912)

## Summary:

In order to stop cursor jumps in number fields, up I'm updating the ScrolllessNumberTextField
component to have part of the implementation of EditableControlledInput, which makes sure that
the input stays consistent until blurred.

Issue: https://khanacademy.atlassian.net/browse/LEMS-2303

## Test plan:
- Go to http://localhost:6006/?path=/story/perseuseditor-widgets-interactive-graph--interactive-graph-segments
- Scroll down to the start coords for the segments
- Clear an input and type in ".5"
- Confirm that it does NOT auto-update to 0.5 immediately
- Confirm that it auto-updates to 0.5 after moving focus off the input
- Type in "1.5"
- Move the cursor right before the "."
- Press backspace
- Confirm that the cursor does not jump

## Before and after demos

Before

https://github.com/user-attachments/assets/66c0e69d-ed12-45a7-9527-26854a676ae7

After

https://github.com/user-attachments/assets/a1e396cf-7b62-43d4-8e00-006b78e6c69a

Author: nishasy

Reviewers: benchristel, catandthemachines, anakaren-rojas

Required Reviewers:

Approved By: benchristel

Checks: ✅ Publish Storybook to Chromatic (ubuntu-latest, 20.x), ✅ Publish npm snapshot (ubuntu-latest, 20.x), ✅ Cypress (ubuntu-latest, 20.x), ✅ Check builds for changes in size (ubuntu-latest, 20.x), ✅ Lint, Typecheck, Format, and Test (ubuntu-latest, 20.x), ✅ Check for .changeset entries for all changed files (ubuntu-latest, 20.x), ✅ gerald

Pull Request URL: #1912

Author: nishasy

.changeset/neat-kiwis-relax.md

@@ -0,0 +1,5 @@
+---
+"@khanacademy/perseus-editor": patch
+---
+
+[Interactive Graph Editor] Stop cursor jumps in number input fields

packages/perseus-editor/src/components/__tests__/scrollless-number-text-field.test.tsx

@@ -53,4 +53,45 @@ describe("ScrolllessNumberTextField", () => {
         // Assert
         expect(onChange).not.toHaveBeenCalled();
     });
+
+    test("calls onFocus on focus", async () => {
+        // Arrange
+        const onFocus = jest.fn();
+        render(
+            <ScrolllessNumberTextField
+                value="42"
+                onChange={() => {}}
+                onFocus={onFocus}
+            />,
+        );
+
+        // Act
+        // Tab to focus on input
+        await userEvent.tab();
+
+        // Assert
+        expect(onFocus).toHaveBeenCalled();
+    });
+
+    test("calls onBlur on blur", async () => {
+        // Arrange
+        const onBlur = jest.fn();
+        render(
+            <ScrolllessNumberTextField
+                value="42"
+                onChange={() => {}}
+                onBlur={onBlur}
+            />,
+        );
+
+        // Tab to focus on input
+        await userEvent.tab();
+
+        // Act
+        // Tab to move focus away
+        await userEvent.tab();
+
+        // Assert
+        expect(onBlur).toHaveBeenCalled();
+    });
 });

packages/perseus-editor/src/components/scrollless-number-text-field.tsx

@@ -6,8 +6,14 @@ import type {PropsFor} from "@khanacademy/wonder-blocks-core";
 /**
  * This is a custom text field of type="number" for use in Perseus Editors.
  *
- * This makes it so that the text field's input number updates on scroll
- * without scrolling the page.
+ * This component makes it so that
+ * 1. the text field's input number updates on scroll without
+ *    scrolling the page.
+ * 2. the input is controlled as long as it does not have focus.
+ *    While it is focused, it becomes editable and emits onChange
+ *    events. This is useful to make sure that input behavior
+ *    remains predictable, rather than possibly having the cursor
+ *    jump around uenxpectedly.
  *
  * NOTE 1: Native HTML number inputs do not update the number value on scroll,
  * they only scroll the page. Inputs in React do NOT work this way (explanation
@@ -16,10 +22,14 @@ import type {PropsFor} from "@khanacademy/wonder-blocks-core";
  * the page to scroll. The behavior in this component is an improvement on
  * the React behavior, but it's the opposite of the native HTML behavior.
  *
- * NOTE 2: Firefox seems to have a custom override for this. Even with this
- * stopPropogation, Firefox matches the native HTML behavior.
+ * NOTE 2: Firefox seems to have a custom override for input scroll. Even
+ * with this stopPropogation, Firefox matches the native HTML behavior.
  */
 const ScrolllessNumberTextField = (props: PropsFor<typeof TextField>) => {
+    const {value, onChange, ...restOfProps} = props;
+    const [focused, setFocused] = React.useState(false);
+    const [wipValue, setWipValue] = React.useState("");
+
     const inputRef = React.useRef<HTMLInputElement>(null);
 
     React.useEffect(() => {
@@ -39,7 +49,29 @@ const ScrolllessNumberTextField = (props: PropsFor<typeof TextField>) => {
         };
     }, [inputRef]);
 
-    return <TextField type="number" {...props} ref={inputRef} />;
+    return (
+        <TextField
+            {...restOfProps}
+            type="number"
+            value={focused ? wipValue : value}
+            onChange={(newValue) => {
+                setWipValue(newValue);
+                onChange(newValue);
+            }}
+            onFocus={(e) => {
+                setWipValue(value);
+                setFocused(true);
+
+                props.onFocus?.(e);
+            }}
+            onBlur={(e) => {
+                setFocused(false);
+
+                props.onBlur?.(e);
+            }}
+            ref={inputRef}
+        />
+    );
 };
 
 export default ScrolllessNumberTextField;

packages/perseus-editor/src/widgets/interactive-graph-editor/locked-figures/locked-point-settings.tsx

@@ -98,6 +98,7 @@ const LockedPointSettings = (props: Props) => {
         onRemove,
         // defining point props
         showPoint,
+        error,
         expanded,
         onTogglePoint,
         onToggle,
@@ -210,6 +211,7 @@ const LockedPointSettings = (props: Props) => {
                 coord={coord}
                 style={styles.spaceUnder}
                 onChange={handleCoordChange}
+                error={!!error}
             />
 
             {/* Toggle switch */}