Terminal control/Restricted width positional input/With wrapping: Difference between revisions

=={{header|Kotlin}}==

{{works with|Windows 10}}

This follows a similar approach to the Kotlin entry for the [[Terminal control/Restricted width positional input/No wrapping]] task except, of course, that the code now allows for wrapping.

<lang scala>// Kotlin Native v0.5

import kotlinx.cinterop.*

import platform.windows.*

import platform.posix.*

val ascii = 32..126

val conOut = GetStdHandle(STD_OUTPUT_HANDLE)!!

fun setCursor(p: COORD) = SetConsoleCursorPosition(conOut, p.readValue())

fun getInput(row: Short, col: Short, width: Int): String {

require(row in 0..20 && col in 0..(79 - width) && width in 1..78) { "Invalid parameter(s)" }

val coord = nativeHeap.alloc<COORD>().apply { X = col; Y = row }

setCursor(coord)

val sb = StringBuilder(width)

var wlen = 0 // length of text in editing window

var full = false

loop@ while (true) {

val ch = _getwch() // gets next character, no echo

when (ch.toInt()) {

3, 13 -> break@loop // break on Ctrl-C or enter key

8 -> { // mimic backspace

if (wlen > 0) {

print("\b \b")

sb.length--

wlen--

}

if (sb.length > wlen) {

coord.apply { X = col; Y = row }

setCursor(coord)

print(sb.toString().takeLast(width))

wlen = width

}

}

0, 224 -> _getwch() // consume extra character

in ascii -> { // echo ascii character

sb.append(ch.toChar())

if (!full) {

_putwch(ch)

wlen++

}

else if (sb.length > wlen) {

coord.apply { X = col; Y = row }

setCursor(coord)

print(sb.toString().takeLast(width))

}

}

else -> {} // igore other characters

}

full = wlen == width // wlen can't exceed width

}

nativeHeap.free(coord)

return sb.toString()

}

fun main(args: Array<String>) {

system("cls") // clear the console

val s = getInput(2, 4, 8) // Windows console row/col numbering starts at 0

memScoped {

val coord = alloc<COORD>().apply { X = 0 ; Y = 22 }

setCursor(coord)

}

println("You entered '$s'")

}</lang>