如何禁用 Tab 键切换输入框，并作为字符输入
比如就是 SF 的正文 textarea，如何实现在插入代码的时候按下 tab 键 只在代码块里缩进，而光标不会选中发布问题的提交按钮？
Dazed
10 years, 2 months ago
Answers
測試通過，行爲於 SF 編輯器幾乎一致（
"\t"
改成
" "
就完全一致了）。
順便吐槽 SF 編輯器選中多行文本沒有像 Sublime Text 那樣自動每行縮進一格。
var el = document.querySelector('textarea');
el.addEventListener("keydown", function(e) {
var keyCode = e.keyCode || e.which;
if (keyCode === 9) {
var start = el.selectionStart,
end = el.selectionEnd;
el.value = el.value.substring(0, start)
+ "\t"
+ el.value.substring(end);
el.selectionStart = el.selectionEnd = start + 1;
e.preventDefault();
}
})
參見： http://stackoverflow.com/questions/6140632/how-to-handle-tab-in-textarea
想要 Sublime Text 一樣選中多行文本按 Tab 時每行縮進一 Tab 的話可以用這段：
var el = document.querySelector('textarea');
el.addEventListener("keydown", function(e) {
var keyCode = e.keyCode || e.which;
if (keyCode === 9) {
var start = el.selectionStart,
end = el.selectionEnd,
value = el.value;
var lineStart = value.lastIndexOf('\n', start),
lineEnd = value.indexOf('\n', end),
offset = 0;
if (lineStart === -1) lineStart = 0;
if (lineEnd === -1) lineEnd = value.length;
if (lineStart === lineEnd);
else if (lineStart !== 0) lineStart += 1;
lines = value.substring(lineStart, lineEnd).split('\n');
console.log([lineStart, lineEnd], lines);
if (lines.length > 1) {
offset = lines.length;
lines = '\t' + lines.join('\n\t');
el.value = value.substring(0, lineStart) + lines + value.substring(lineEnd);
el.selectionStart = start + 1;
el.selectionEnd = end + offset;
} else {
offset = 1;
lines = lines[0];
el.value = value.substring(0, start) + '\t' + value.substring(end);
el.selectionStart = el.selectionEnd = start + offset;
}
e.preventDefault();
}
})
Eidolem
answered 10 years, 2 months ago