stable-diffusion-webui/javascript/edit-attention.js

function keyupEditAttention(event){
	let target = event.originalTarget || event.composedPath()[0];
	if (! target.matches("[id*='_toprow'] [id*='_prompt'] textarea")) return;
	if (! (event.metaKey || event.ctrlKey)) return;

	let isPlus = event.key == "ArrowUp"
	let isMinus = event.key == "ArrowDown"
	if (!isPlus && !isMinus) return;

	let selectionStart = target.selectionStart;
	let selectionEnd = target.selectionEnd;
	let text = target.value;

    function selectCurrentParenthesisBlock(OPEN, CLOSE){
        if (selectionStart !== selectionEnd) return false;

		// Find opening parenthesis around current cursor
		const before = text.substring(0, selectionStart);
		let beforeParen = before.lastIndexOf(OPEN);
		if (beforeParen == -1) return  false;
		let beforeParenClose = before.lastIndexOf(CLOSE);
		while (beforeParenClose !== -1 && beforeParenClose > beforeParen) {
			beforeParen = before.lastIndexOf(OPEN, beforeParen - 1);
			beforeParenClose = before.lastIndexOf(CLOSE, beforeParenClose - 1);
		}

		// Find closing parenthesis around current cursor
		const after = text.substring(selectionStart);
		let afterParen = after.indexOf(CLOSE);
		if (afterParen == -1) return  false;
		let afterParenOpen = after.indexOf(OPEN);
		while (afterParenOpen !== -1 && afterParen > afterParenOpen) {
			afterParen = after.indexOf(CLOSE, afterParen + 1);
			afterParenOpen = after.indexOf(OPEN, afterParenOpen + 1);
		}
		if (beforeParen === -1 || afterParen === -1) return false;

		// Set the selection to the text between the parenthesis
		const parenContent = text.substring(beforeParen + 1, selectionStart + afterParen);
		const lastColon = parenContent.lastIndexOf(":");
		selectionStart = beforeParen + 1;
		selectionEnd = selectionStart + lastColon;
		target.setSelectionRange(selectionStart, selectionEnd);
		return true;
    }

	// If the user hasn't selected anything, let's select their current parenthesis block
    if(! selectCurrentParenthesisBlock('<', '>')){
        selectCurrentParenthesisBlock('(', ')')
    }

	event.preventDefault();

    closeCharacter = ')'
    delta = opts.keyedit_precision_attention

    if (selectionStart > 0 && text[selectionStart - 1] == '<'){
        closeCharacter = '>'
        delta = opts.keyedit_precision_extra
    } else if (selectionStart == 0 || text[selectionStart - 1] != "(") {

        // do not include spaces at the end
        while(selectionEnd > selectionStart && text[selectionEnd-1] == ' '){
            selectionEnd -= 1;
        }
        if(selectionStart == selectionEnd){
            return
        }

        text = text.slice(0, selectionStart) + "(" + text.slice(selectionStart, selectionEnd) + ":1.0)" + text.slice(selectionEnd);

        selectionStart += 1;
        selectionEnd += 1;
    }

	end = text.slice(selectionEnd + 1).indexOf(closeCharacter) + 1;
	weight = parseFloat(text.slice(selectionEnd + 1, selectionEnd + 1 + end));
	if (isNaN(weight)) return;

	weight += isPlus ? delta : -delta;
	weight = parseFloat(weight.toPrecision(12));
	if(String(weight).length == 1) weight += ".0"

	text = text.slice(0, selectionEnd + 1) + weight + text.slice(selectionEnd + 1 + end - 1);

	target.focus();
	target.value = text;
	target.selectionStart = selectionStart;
	target.selectionEnd = selectionEnd;

	updateInput(target)
}

addEventListener('keydown', (event) => {
    keyupEditAttention(event);
});