show inline math tooltips when cursor is just outside $ symbols

src/editor_helpers.ts

@@ -114,6 +114,31 @@ export function isWithinInlineEquationState(state: EditorState):boolean {
 }
 
 
+export function isTouchingInlineEquation(state: EditorState, pos: number):number {
+    // Returns 0 if pos is not touching a $ that marks an inline equation
+    // Returns 1 if pos+1 is inside an inline eqn
+    // Returns -1 if pos-1 is inside an inline eqn
+
+    const tree = syntaxTree(state);
+    const prevToken = tree.resolveInner(pos-1, 1).name;
+    const token = tree.resolveInner(pos, 1).name;
+    const nextToken = tree.resolveInner(pos+1, 1).name;
+
+    if (token.contains("math-end") && !(prevToken.contains("math-end")) && !(nextToken.contains("math-end"))) {
+        return -1;
+    }
+    else if (!(token.contains("math-begin")) && nextToken.contains("math-begin")) {
+        const nextNextToken = tree.resolveInner(pos+2, 1).name;
+
+        if (!(nextNextToken.contains("math-begin"))) {
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+
 export function getEquationBounds(view: EditorView | EditorState, pos?: number):{start: number, end: number} {
     const s = view instanceof EditorView ? view.state : view;
 

src/inline_math_tooltip.ts

@@ -1,6 +1,6 @@
 import {Tooltip, showTooltip, EditorView} from "@codemirror/view"
 import {StateField, EditorState} from "@codemirror/state"
-import { getEquationBounds, isWithinEquation, isWithinInlineEquationState } from "./editor_helpers";
+import { getEquationBounds, isTouchingInlineEquation, isWithinEquation, isWithinInlineEquationState } from "./editor_helpers";
 import { MarkdownRenderer } from "obsidian";
 
 export const cursorTooltipField = StateField.define<readonly Tooltip[]>({
@@ -17,9 +17,25 @@ export const cursorTooltipField = StateField.define<readonly Tooltip[]>({
 
 
 function getCursorTooltips(state: EditorState): readonly Tooltip[] {
+	const isInsideInlineEqn = (isWithinEquation(state) && isWithinInlineEquationState(state));
+	let shouldShowTooltip = isInsideInlineEqn;
+	let isTouchingInlineEqn;
+	let pos = state.selection.main.from;
+
+	if (!isInsideInlineEqn) {
+		isTouchingInlineEqn = isTouchingInlineEquation(state, pos - 1);
 
-    if (isWithinEquation(state) && isWithinInlineEquationState(state)) {
-        const bounds = getEquationBounds(state);
+		if (isTouchingInlineEqn != 0) {
+			pos += isTouchingInlineEqn;
+			shouldShowTooltip = true;
+		}
+	}
+
+
+
+    if (shouldShowTooltip) {
+
+        const bounds = getEquationBounds(state, pos);
         if (!bounds) return [];
 
         // Don't render an empty equation