Remove whitespace before Paste with a Max Length

Question

So I use TextInputEditText with a max length of 8 .

If I paste "1234 1234", it will become "1234 123". My goal is for it to become "12341234"

The hard part is the max length, because if I use the usual filter or onTextChange, it won't work due to the length cutted first before it trim whitespace. It will become "1234123" instead.

So I want to trim the whitespace before it pasted to the edit text.

Any idea ?

Edit : Because every commenter never read my question. Here's why onTextChanged dont work on mine. I copy "1234 1234". When I pasted, due to max length it will be converted to "1234 123". Then go to TextWatcher Listener, or RxJava Listener. So if I put it in onTextChange,beforeTextChange,or afterTextChange, it already become "1234 123", hence I can't achieve the goal of "12341234"

The hard part is the max length, because if I use the usual filter or onTextChange, it won't work due to the length cutted first before it trim whitespace. It will become "1234123" instead. — Wilson Lesley, Jun 29 '22 at 09:10
Try this thread -https://stackoverflow.com/questions/9757991/how-to-delete-instantly-space-from-an-edittext-if-a-user-presses-the-space — Sandesh Khutal, Jun 29 '22 at 09:22
The hard part is the max length, because if I use the usual filter or onTextChange, it won't work due to the length cutted first before it trim whitespace. It will become "1234123" instead. — Wilson Lesley, Jun 29 '22 at 09:57

Cheticamp · Accepted Answer · 2022-06-30T01:07:20.457

Here is an InputFilter.LengthFilter that should work:

private class MyLengthFilter(max: Int) : InputFilter.LengthFilter(max) {
    private val mMax = max

    override fun filter(
        source: CharSequence, start: Int, end: Int, dest: Spanned, dstart: Int, dend: Int
    ): CharSequence? {
        val newSource = super.filter(source, start, end, dest, dstart, dend)

        if (newSource.isNullOrEmpty()) return newSource

        // Calculate how many characters were truncated
        val truncated = (end - start) - newSource.length
        if (truncated <= 0) return newSource

        // Remove all space characters. Adjust this to change how the replacement string is adjusted.
        val noSpaceSource = source.filter { !Character.isSpaceChar(it) }
        if (noSpaceSource == source) return newSource // No white space.

        return super.filter(
            noSpaceSource, start, start + noSpaceSource.length, dest, dstart, dend
        ) ?: noSpaceSource
    }
}

Take note of the comment in InputFilter regarding spans when source is an instance of Spanned or Spannable in case it effects you.

It kinda works, but there's a weird bug where if you backspace after you hit the max length, the edit text won't be deleted. You can reproduce with example max length 10. Try to type even when it hit 10 length, then backspace. It will delete the clipboad but not the view content :\ — Wilson Lesley, Jun 30 '22 at 03:23
Oh actually the bug I mentioned above only happen in Mi 10T device... probably due to how their keyboard work... Your answer tho works fine in samsung keyboard, thanks — Wilson Lesley, Jun 30 '22 at 04:45

Remove whitespace before Paste with a Max Length

1 Answers1