ComfyUI/web/extensions/core/editAttention.js

import { app } from "/scripts/app.js";

// Allows you to edit the attention weight by holding ctrl (or cmd) and using the up/down arrow keys

const id = "Comfy.EditAttention";
app.registerExtension({
name:id,
    init() {
        function incrementWeight(weight, delta) {
            const floatWeight = parseFloat(weight);
            if (isNaN(floatWeight)) return weight;
            const newWeight = floatWeight + delta;
            if (newWeight < 0) return "0";
            return String(Number(newWeight.toFixed(10)));
        }

        function findNearestEnclosure(text, cursorPos) {
            let start = cursorPos, end = cursorPos;
            let openCount = 0, closeCount = 0;

            // Find opening parenthesis before cursor
            while (start >= 0) {
                start--;
                if (text[start] === "(" && openCount === closeCount) break;
                if (text[start] === "(") openCount++;
                if (text[start] === ")") closeCount++;
            }
            if (start < 0) return false;

            openCount = 0;
            closeCount = 0;

            // Find closing parenthesis after cursor
            while (end < text.length) {
                if (text[end] === ")" && openCount === closeCount) break;
                if (text[end] === "(") openCount++;
                if (text[end] === ")") closeCount++;
                end++;
            }
            if (end === text.length) return false;

            return { start: start + 1, end: end };
        }

        function addWeightToParentheses(text) {
            const parenRegex = /^\((.*)\)$/;
            const parenMatch = text.match(parenRegex);

            const floatRegex = /:([+-]?(\d*\.)?\d+([eE][+-]?\d+)?)/;
            const floatMatch = text.match(floatRegex);

            if (parenMatch && !floatMatch) {
                return `(${parenMatch[1]}:1.0)`;
            } else {
                return text;
            }
        };

        function editAttention(event) {
            const inputField = event.composedPath()[0];
            const delta = 0.025;

            if (inputField.tagName !== "TEXTAREA") return;
            if (!(event.key === "ArrowUp" || event.key === "ArrowDown")) return;
            if (!event.ctrlKey && !event.metaKey) return;

            event.preventDefault();

            let start = inputField.selectionStart;
            let end = inputField.selectionEnd;
            let selectedText = inputField.value.substring(start, end);

            // If there is no selection, attempt to find the nearest enclosure
            if (!selectedText) {
                const nearestEnclosure = findNearestEnclosure(inputField.value, start);
                if (nearestEnclosure) {
                    start = nearestEnclosure.start;
                    end = nearestEnclosure.end;
                    selectedText = inputField.value.substring(start, end);
                } else {
                    return;
                }
            }

            // If the selection ends with a space, remove it
            if (selectedText[selectedText.length - 1] === " ") {
                selectedText = selectedText.substring(0, selectedText.length - 1);
                end -= 1;
            }

            // If there are parentheses left and right of the selection, select them
            if (inputField.value[start - 1] === "(" && inputField.value[end] === ")") {
                start -= 1;
                end += 1;
                selectedText = inputField.value.substring(start, end);
            }

            // If the selection is not enclosed in parentheses, add them
            if (selectedText[0] !== "(" || selectedText[selectedText.length - 1] !== ")") {
                console.log("adding parentheses", inputField.value[start], inputField.value[end], selectedText);
                selectedText = `(${selectedText})`;
            }

            // If the selection does not have a weight, add a weight of 1.0
            selectedText = addWeightToParentheses(selectedText);

            // Increment the weight
            const weightDelta = event.key === "ArrowUp" ? delta : -delta;
            const updatedText = selectedText.replace(/(.*:)(\d+(\.\d+)?)(.*)/, (match, prefix, weight, _, suffix) => {
              return prefix + incrementWeight(weight, weightDelta) + suffix;
            });

            inputField.setRangeText(updatedText, start, end, "select");
        }
        window.addEventListener("keydown", editAttention);
    },
});