Does anyone know how to change the character of a textfield caret with javascript?

Like the title reads, I want to change the character of开发者_StackOverflow社区 a caret. Maybe make it a letter or something?

Thanks.

You can do something near this, but its very dificult.

1. In you textfield bind a event to keydown, for example.
2. Each char typed, you slide a floating <img> above textarea.
3. If user click in textarea, update position getting X and Y from onclick.

Obs: the font must be monospaced. Ex: if every font have 20px and user press backspace, you slide this gif to the left 20px.

EDIT

I just made a hello world, in jsfiddle.

Of course, it's an example, but test typing and use backspace and enter to see caret go back and foward.

In this example there are a lot of bugs to fix, like:

• Use of <backspace> that cleans all line

• Use of arrows that in overflow textarea margins

• Use of mouse must update caret position...

That's not possible in HTML/JavaScript.