109 lines
3.2 KiB
Nim
109 lines
3.2 KiB
Nim
# takes a text buffer and a terminal buffer (terminalUtils/buffer)
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# when render() is called, rewrites the terminal buffer completely as a function of
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# of the text buffer
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import strutils
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import textBuffer
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import terminalUtils/buffer
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import terminalUtils/terminalGetInfo
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type Scroll* = ref object
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x, y: int
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proc reset*(scroll: Scroll) =
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scroll.x = 0
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scroll.y = 0
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proc render*(textBuffer: TextBuffer, termBuffer: Buffer, prompt: string, scroll: Scroll, width, height: int, edCursorY: int): int =
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# we are free to "redraw" everything everytime
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# since termBuffer double buffers
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# returns how many lines were drawn
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# GET INFO
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let (x, y) = textBuffer.getCursorPos()
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let lines = textBuffer.lines()
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let lineCount = lines.len()
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#let termWidth = termGetWidth()
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let termWidth = width
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#let termHeight = termGetHeight()
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let termHeight = height
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let promptLen = prompt.len()
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let maxTextLen = termWidth - promptLen
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# SCROLL
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const scrollOffset = 2
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# right scroll
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if x - scroll.x >= maxTextLen - scrollOffset:
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scroll.x = x - maxTextLen + scrollOffset
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# left scroll
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if x - scroll.x < 0:
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scroll.x = x
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# left scroll on backspace - TODO IMPLEMENT
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# vertical scroll
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# scroll down - when it would be out of reach
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# mode 1: by moving the location up
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# this one is based on content, not y position
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# if this one scrolls too much
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block:
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# in a block so positionY can't be used below, since it can change!
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let (_, positionY) = termBuffer.getPosition()
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if positionY > 0 and positionY + lineCount > termHeight:
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termBuffer.scroll(min(positionY + lineCount - termHeight, positionY))
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# scroll down
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# mode 2 - only if positionY is 0, so mode 1 is already done
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# this one is based on the cursor
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block:
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let (_, positionY) = termBuffer.getPosition()
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if positionY == 0 and y - scroll.y > termHeight - 1:
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scroll.y = y - termHeight + 1
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# scroll up
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if y < scroll.y:
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scroll.y = y
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# resizing the buffer if needed
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block:
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# in a block, so bufWidth and height can't be used below, since they get changed!
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let (bufWidth, bufHeight) = termBuffer.getSize()
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# prevent shrinking vertically to avoid uncleaned parts
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let desiredBufHeight = min(max(lineCount, bufHeight), termHeight)
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if bufWidth != termWidth or bufHeight != desiredBufHeight:
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termBuffer.resize(termWidth, desiredBufHeight, termWidth, termHeight)
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termBuffer.clear()
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if maxTextLen < 1:
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termBuffer.redraw()
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return # nothing will fit anyways
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let fromY = scroll.y
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# assumes that the MODE 1 scroll up has happened
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# and if lineCount doesn't fit in termheight
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# then it has already been scrolled to pos 0
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let toY = min(fromY+termHeight-1, lineCount-1)
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for i in fromY..toY:
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let line = lines[i]
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if i == 0:
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termBuffer.write(prompt)
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elif i == y:
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termBuffer.write(">" & " ".repeat(promptLen - 1))
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else:
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termBuffer.write(" ".repeat(promptLen))
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# keep what's in range
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let fromPos = scroll.x
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let toPos = min(scroll.x+maxTextLen-2, line.high())
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if fromPos <= line.high():
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termBuffer.write(line[fromPos..toPos])
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if i < toY:
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termBuffer.newLine()
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termBuffer.setCursorPos(x + promptLen - scroll.x, y - scroll.y)
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termBuffer.redraw()
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return termBuffer.getHeight()
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