git.r.bdr.sh - rbdr/dotfiles/blob - atom/packages/vim-mode/lib/scroll.coffee

   1 class Scroll
   2   isComplete: -> true
   3   isRecordable: -> false
   4   constructor: (@editorElement) ->
   5     @scrolloff = 2 # atom default
   6     @editor = @editorElement.getModel()
   7     @rows =
   8       first: @editorElement.getFirstVisibleScreenRow()
   9       last: @editorElement.getLastVisibleScreenRow()
  10       final: @editor.getLastScreenRow()
  11
  12 class ScrollDown extends Scroll
  13   execute: (count=1) ->
  14     @keepCursorOnScreen(count)
  15     @scrollUp(count)
  16
  17   keepCursorOnScreen: (count) ->
  18     {row, column} = @editor.getCursorScreenPosition()
  19     firstScreenRow = @rows.first + @scrolloff + 1
  20     if row - count <= firstScreenRow
  21       @editor.setCursorScreenPosition([firstScreenRow + count, column])
  22
  23   scrollUp: (count) ->
  24     lastScreenRow = @rows.last - @scrolloff
  25     @editor.scrollToScreenPosition([lastScreenRow + count, 0])
  26
  27 class ScrollUp extends Scroll
  28   execute: (count=1) ->
  29     @keepCursorOnScreen(count)
  30     @scrollDown(count)
  31
  32   keepCursorOnScreen: (count) ->
  33     {row, column} = @editor.getCursorScreenPosition()
  34     lastScreenRow = @rows.last - @scrolloff - 1
  35     if row + count >= lastScreenRow
  36       @editor.setCursorScreenPosition([lastScreenRow - count, column])
  37
  38   scrollDown: (count) ->
  39     firstScreenRow = @rows.first + @scrolloff
  40     @editor.scrollToScreenPosition([firstScreenRow - count, 0])
  41
  42 class ScrollCursor extends Scroll
  43   constructor: (@editorElement, @opts={}) ->
  44     super
  45     cursor = @editor.getCursorScreenPosition()
  46     @pixel = @editorElement.pixelPositionForScreenPosition(cursor).top
  47
  48 class ScrollCursorToTop extends ScrollCursor
  49   execute: ->
  50     @moveToFirstNonBlank() unless @opts.leaveCursor
  51     @scrollUp()
  52
  53   scrollUp: ->
  54     return if @rows.last is @rows.final
  55     @pixel -= (@editor.getLineHeightInPixels() * @scrolloff)
  56     @editor.setScrollTop(@pixel)
  57
  58   moveToFirstNonBlank: ->
  59     @editor.moveToFirstCharacterOfLine()
  60
  61 class ScrollCursorToMiddle extends ScrollCursor
  62   execute: ->
  63     @moveToFirstNonBlank() unless @opts.leaveCursor
  64     @scrollMiddle()
  65
  66   scrollMiddle: ->
  67     @pixel -= (@editor.getHeight() / 2)
  68     @editor.setScrollTop(@pixel)
  69
  70   moveToFirstNonBlank: ->
  71     @editor.moveToFirstCharacterOfLine()
  72
  73 class ScrollCursorToBottom extends ScrollCursor
  74   execute: ->
  75     @moveToFirstNonBlank() unless @opts.leaveCursor
  76     @scrollDown()
  77
  78   scrollDown: ->
  79     return if @rows.first is 0
  80     offset = (@editor.getLineHeightInPixels() * (@scrolloff + 1))
  81     @pixel -= (@editor.getHeight() - offset)
  82     @editor.setScrollTop(@pixel)
  83
  84   moveToFirstNonBlank: ->
  85     @editor.moveToFirstCharacterOfLine()
  86
  87 module.exports = {ScrollDown, ScrollUp, ScrollCursorToTop, ScrollCursorToMiddle,
  88   ScrollCursorToBottom}