display.newText blinks when updating UTF8 characters

[phoenixongogo]

I’m deving dialogue UI which display characters one by one with given delay and text.
the issue here is the “display.newText” blinks when updating UTF8 characters in simulator.
( using macOS Big Sur v11.7.1 )

Here is the code:

---

local _testStr = "♡ 你好，World ♡"
-- local _testStr = "こんにちは World"
-- local _testStr = "헬로 World"
local _textLen = string_len( _testStr )

local _opt = {
    text = "",
    x = display.contentCenterX,
    y = display.contentCenterY,
    width = 420,
    fontSize = 48,
    align = "left",
}
local _ttfText = display.newText(_opt)

local _cnt = 1;
timer.performWithDelay( 200, 
    function() 
        _cnt = _cnt + 1
        _ttfText.text = string.sub( _testStr, 1, math.min( _cnt, _textLen ))
    end,100
)

---

is there any solution to fix this? thanks in advance.

[luantiang]

If they are UTF8 strings, you may want to try using, “utf8.len” and “utf8.sub”. For example,

local _textLen = utf8.len( _testStr )
_ttfText.text = utf8.sub( _testStr, 1, math.min( _cnt, _textLen ) )

Please see Solar2D Documentation — Plugins | UTF-8 for details on the various UTF8 functions.

PS> Not sure about macOS. I can only try your snippets on my simulator/Windows. I only have Windows PC. Hope it helps, anyway.

[phoenixongogo]

It fixed the blinking issue.

Thank a lot, you saved the day!