# SETTINGS
overlay_padding = 10
+breathing_room = 30 # minimum pixels above/below cursor
timeout = (ms, cb) -> return setTimeout cb, ms
next_frame = (cb) ->
when KEY_INSERT
return false
when KEY_PAGE_UP
+ @on_page_up_key e
return false
when KEY_PAGE_DOWN
+ @on_page_down_key e
return false
when KEY_TAB
return false
else
@kill_cursor()
return
+ on_page_up_key: (e) ->
+ if @cursor?
+ screen_y = @cursor.y - @wrap2.scrollTop
+ scroll_amount = @wrap2_height - breathing_room
+ @wrap2.scrollTop = Math.max 0, @wrap2.scrollTop - scroll_amount
+ if @cursor?
+ @move_cursor_into_view screen_y + @wrap2.scrollTop
+ on_page_down_key: (e) ->
+ if @cursor?
+ screen_y = @cursor.y - @wrap2.scrollTop
+ scroll_amount = @wrap2_height - breathing_room
+ lowest_scrollpos = @wrap2.scrollHeight - @wrap2_height
+ if @wrap2.scrollTop is lowest_scrollpos # already at bottom
+ return unless @cursor?
+ # move cursor to bottom
+ new_cursor = last_cursor_position @tree
+ if new_cursor?
+ if new_cursor.n isnt @cursor.n or new_cursor.i isnt @cursor.i
+ @move_cursor new_cursor
+ return
+ @wrap2.scrollTop = Math.min lowest_scrollpos, @wrap2.scrollTop + scroll_amount
+ if @cursor?
+ @move_cursor_into_view screen_y + @wrap2.scrollTop
+ return
+ move_cursor_into_view: (y_target) ->
+ return if y_target is @cursor.y
+ was = @cursor
+ y_min = @wrap2.scrollTop
+ unless @wrap2.scrollTop is 0
+ y_min += breathing_room
+ y_max = @wrap2.scrollTop + @wrap2_height
+ unless @wrap2.scrollTop is @wrap2.scrollHeight - @wrap2_height # downmost
+ y_max -= breathing_room
+ y_target = Math.min y_target, y_max
+ y_target = Math.max y_target, y_min
+ if y_target < @cursor.y
+ finder = find_up_cursor_position
+ far_enough = (cur, target_y) ->
+ return cur.y + cur.h <= target_y
+ else
+ finder = find_down_cursor_position
+ far_enough = (cur, y_target) ->
+ return cur.y >= y_target
+ loop
+ cur = finder @tree, was, @cursor_ideal_x
+ break unless cur?
+ break if far_enough cur, y_target
+ was = cur
+ if was is @cursor
+ was = null
+ if was?
+ if was.y + was.h > y_max
+ was = null
+ else if was.y < y_min
+ was = null
+ if cur?
+ if cur.y + cur.h > y_max
+ cur = null
+ else if cur.y < y_min
+ cur = null
+ if cur? and was?
+ # both valid, pick best
+ if cur.y < y_min
+ new_cursor = was
+ else if was.y + was.h > y_max
+ new_cursor = cur
+ else if cur.y - y_target < y_target - was.y
+ new_cursor = cur
+ else
+ new_cursor = was
+ else
+ new_cursor = was ? cur
+ if new_cursor?
+ saved_ideal_x = @cursor_ideal_x
+ @move_cursor new_cursor
+ @cursor_ideal_x = saved_ideal_x
+ return
clear_dom: -> # remove all the editable content (and cursor, overlays, etc)
while @idoc.body.childNodes.length
@idoc.body.removeChild @idoc.body.childNodes[0]
@annotate cursor.n
@scroll_into_view cursor.y, height
scroll_into_view: (y, h = 0) ->
- closest = 30 # setting: smallest pixels from top/bottom of screet that's OK
y += overlay_padding # convert units from @idoc to @wrap2
# very top of document
- if y <= closest
+ if y <= breathing_room
@wrap2.scrollTop = 0
return
# very bottom of document
- if y + h >= @wrap2.scrollHeight - closest
+ if y + h >= @wrap2.scrollHeight - breathing_room
@wrap2.scrollTop = @wrap2.scrollHeight - @wrap2_height
return
# The most scrolled up (lowest value for scrollTop) that would be OK
- upmost = y + h + closest - @wrap2_height
+ upmost = y + h + breathing_room - @wrap2_height
upmost = Math.max(upmost, 0)
# the most scrolled down (highest value for scrollTop) that would be OK
- downmost = y - closest
+ downmost = y - breathing_room
downmost = Math.min(downmost, @wrap2.scrollHeight - @wrap2_height)
if upmost > downmost # means h is too big to fit
# scroll so top is visible