Request: Text hAlign = JUSTIFY_ALIGN

[IagoBeuller]

Would be nice if add this alignment style.

I've made this proc for making this feature for me, it behaves like the Microsoft Word.

import
 pixie,
 unicode

const
 LF = Rune(10)
 NR = Rune(0)

proc justifyArrangement*(arrangement: Arrangement, maxWidth: float32) {.raises: [].} =
 proc right(rect: Rect): float32 = rect.x + rect.w
 
 let
 runes: ptr = arrangement.runes.addr
 positions: ptr = arrangement.positions.addr
 rects: ptr = arrangement.selectionRects.addr
 lastLineId: int = arrangement.lines.len-1
 
 var
 rune, lastRune: Rune
 lastWordRuneId: int
 spacesIdx: seq[int]
 incWidth, spaceWidth, lineWidth, xOffset: float32
 
 for lineId, (start, stop) in arrangement.lines:
 lastRune = runes[stop]

 # This line must not be justified, if it's the last or if the last rune is a breakline char.
 if lineId == lastLineId or lastRune == LF:
 continue

 echo runes[start..stop]
 # Get the spaces indexes of this line to increase their width, and get the line width.
 # Spaces in the end will be pushed away the maxWidth like the Microsoft Word.
 spacesIdx = @[]
 lastRune = NR
 for rId in start..stop:
 rune = runes[rId]
 if not rune.isWhiteSpace():
 if lastRune.isWhiteSpace():
 spacesIdx.add(rId-1)
 lastWordRuneId = rId
 lastRune = rune

 lineWidth = rects[lastWordRuneId].right

 echo "Line spaces: ", spacesIdx.len
 if spacesIdx.len > 0:
 # Get the amount of pixels/units to increase each space width in the middle of the line.
 incWidth = (maxWidth - lineWidth) / spacesIdx.len.float32

 if incWidth > 0:
 spaceWidth = rects[spacesIdx[0]].w + incWidth

 # Adjust the runes X position
 xOffset = 0
 for rId in spacesIdx[0]..stop:
 positions[rId].x += xOffset
 rects[rId].x += xOffset
 
 if rId in spacesIdx:
 rects[rId].w = spaceWidth
 xOffset += incWidth