Delete entire ImageSpan when the part of it is deleted

Question

I'm trying to implement Emoji's in my app and I should use short codes (like :dog:, :cat:), not unicode. I have two devices to test on and two different behaviours of EditText and ImageSpan in it.

First: Meizu PRO 6, Android 6.0 (API 23)

Everything works as I want. When you tap backspace on the spanned text, it disappears from EditText completely, because full spanned part of the string was removed.

For example, you have a "Hello :dog:" in your EditText (:dog: is replaced with a picture of the dog), you press backspace, your EditText contains only "Hello " now.

Second: Google Pixel XL, Android 9.0 (API 28)

When you tap backspace on the spanned text, you just remove the : symbol, making picture stay in EditText because it doesn't remove all spanned part of your string. But I want to remove it.

What did I try

I found this code in the other question here:

Android - Delete entire ImageSpan when part of it is deleted?

private val watcher = object : TextWatcher {
    private var spanLength = -1

    override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {
        if (start == 0) return
        if (count > after) {
            val spans =
                editableText.getSpans(start + count, start + count, ImageSpan::class.java)
            if (spans == null || spans.isEmpty()) return

            for (i in spans.indices) {
                val end = editableText.getSpanEnd(spans[i])
                if (end != start + count) continue
                val text = spans[i].source
                spanLength = text!!.length - 1
                editableText.removeSpan(spans[i])
            }
        }
    }

    override fun onTextChanged(s: CharSequence, start: Int, before: Int, after: Int) {
        if (spanLength > -1) {
            val length = spanLength
            spanLength = -1
            editableText.replace(start - length, start, "")
        }
    }

    override fun afterTextChanged(s: Editable) {}
}

It works as intended for Google Pixel XL, but completely brakes Meizu removing 2-3 pictures or even not spanned text, sometimes it throws an Exception because start - length < 0.

Is there any way to solve this?

Simply

did you got any solution? – Jetta

@Jetta wait a minute, I'll post an answer in a minute. – Simply

Answer 1

I ended up with this TextWatcher

private val watcher = object : TextWatcher {
    private var spanLength = -1
    private var spanStart = -1

    override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {
        if (start == 0) return
        if (count > after) {
            val spans =
                editableText.getSpans(start + count, start + count, EmojiSpan::class.java)
            if (spans == null || spans.isEmpty()) return

            for (i in spans.indices) {
                val end = editableText.getSpanEnd(spans[i])
                if (end != start + count) continue
                val text = spans[i].getSource()
                spanLength = text.length - 1
                spanStart = editableText.getSpanStart(spans[i])
                editableText.removeSpan(spans[i])
            }
        }
    }

    override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
        if (spanLength > -1 && spanStart != -1 && count < before) {
            val startSpan = spanStart
            val endSpan = spanStart + spanLength

            if (startSpan < 0 || endSpan > editableText.length) {
                return
            }

            spanLength = -1
            spanStart = -1
            editableText.replace(startSpan, endSpan, "")
        }
    }

    override fun afterTextChanged(s: Editable) {}
}

Looks like it works with all devices I've tried.

Simply

Thank you for answer but it's not working in Samsung S8 Oreo. How you are applying image span? what is EmojiSpan class? – Jetta

I'm using custom span with DynamicDrawableSpan as parent. I can upload snipped if you want to try. – Simply

This is my EmojiSpan class snipsave.com/denunknown/#/snippet/XX4ABLJRmF939eJTlX – Simply

Ok but it's not working for me. In my case start is always 0 when I have continues emoji(Imagespan) without space. – Jetta

I don't know, this is how i span: snipsave.com/denunknown/#/snippet/hOhdcn1L1kpHHmxqAG – Simply