Add cursor moving (#19)

frontend/obsidian-plugin/src/utils/position-to-line-and-column.ts

@@ -0,0 +1,30 @@
+/**
+ * Converts a character position in text to line and column numbers.
+ *
+ * @param text The text content to analyze
+ * @param position The character position to convert
+ * @returns An object containing line and column numbers (0-based index for line, 1-based index for column)
+ * @throws Will throw an error if the position is negative or exceeds the text length
+ */
+export function positionToLineAndColumn(
+	text: string,
+	position: number
+): { line: number; column: number } {
+	if (position < 0) {
+		throw new Error("Position cannot be negative");
+	}
+
+	if (position > text.length) {
+		throw new Error(
+			`Position ${position} exceeds text length ${text.length}`
+		);
+	}
+
+	const textUpToPosition = text.substring(0, position);
+	const lines = textUpToPosition.split("\n");
+
+	const line = lines.length - 1; // 0-based index
+	const column = lines[lines.length - 1].length + 1; // 1-based index
+
+	return { line, column };
+}