select.lua

   1 -- helpers for selecting portions of text
   2
   3 -- Return any intersection of the region from State.selection1 to State.cursor1 (or
   4 -- current mouse, if mouse is pressed; or recent mouse if mouse is pressed and
   5 -- currently over a drawing) with the region between {line=line_index, pos=apos}
   6 -- and {line=line_index, pos=bpos}.
   7 -- apos must be less than bpos. However State.selection1 and State.cursor1 can be in any order.
   8 -- Result: positions spos,epos between apos,bpos.
   9 function Text.clip_selection(State, line_index, apos, bpos)
  10   if State.selection1.line == nil then return nil,nil end
  11   -- min,max = sorted(State.selection1,State.cursor1)
  12   local minl,minp = State.selection1.line,State.selection1.pos
  13   local maxl,maxp
  14   if State.mouse_down then
  15     maxl,maxp = Text.mouse_pos(State)
  16   else
  17     maxl,maxp = State.cursor1.line,State.cursor1.pos
  18   end
  19   if Text.lt1({line=maxl, pos=maxp},
  20               {line=minl, pos=minp}) then
  21     minl,maxl = maxl,minl
  22     minp,maxp = maxp,minp
  23   end
  24   -- check if intervals are disjoint
  25   if line_index < minl then return nil,nil end
  26   if line_index > maxl then return nil,nil end
  27   if line_index == minl and bpos <= minp then return nil,nil end
  28   if line_index == maxl and apos >= maxp then return nil,nil end
  29   -- compare bounds more carefully (start inclusive, end exclusive)
  30   local a_ge = Text.le1({line=minl, pos=minp}, {line=line_index, pos=apos})
  31   local b_lt = Text.lt1({line=line_index, pos=bpos}, {line=maxl, pos=maxp})
  32   if a_ge and b_lt then
  33     -- fully contained
  34     return apos,bpos
  35   elseif a_ge then
  36     assert(maxl == line_index, ('maxl %d not equal to line_index %d'):format(maxl, line_index))
  37     return apos,maxp
  38   elseif b_lt then
  39     assert(minl == line_index, ('minl %d not equal to line_index %d'):format(minl, line_index))
  40     return minp,bpos
  41   else
  42     assert(minl == maxl and minl == line_index, ('minl %d, maxl %d and line_index %d are not all equal'):format(minl, maxl, line_index))
  43     return minp,maxp
  44   end
  45 end
  46
  47 -- draw highlight for line corresponding to (lo,hi) given an approximate x,y and pos on the same screen line
  48 -- Creates text objects every time, so use this sparingly.
  49 -- Returns some intermediate computation useful elsewhere.
  50 function Text.draw_highlight(State, line, x,y, pos, lo,hi)
  51   if lo then
  52     local lo_offset = Text.offset(line.data, lo)
  53     local hi_offset = Text.offset(line.data, hi)
  54     local pos_offset = Text.offset(line.data, pos)
  55     local lo_px
  56     if pos == lo then
  57       lo_px = 0
  58     else
  59       local before = line.data:sub(pos_offset, lo_offset-1)
  60       lo_px = App.width(before)
  61     end
  62     local s = line.data:sub(lo_offset, hi_offset-1)
  63     App.color(Highlight_color)
  64     love.graphics.rectangle('fill', x+lo_px,y, App.width(s),State.line_height)
  65     App.color(Text_color)
  66     return lo_px
  67   end
  68 end
  69
  70 function Text.mouse_pos(State)
  71   local x,y = App.mouse_x(), App.mouse_y()
  72   if y < State.line_cache[State.screen_top1.line].starty then
  73     return State.screen_top1.line, State.screen_top1.pos
  74   end
  75   for line_index,line in ipairs(State.lines) do
  76     if Text.in_line(State, line_index, x,y) then
  77       return line_index, Text.to_pos_on_line(State, line_index, x,y)
  78     end
  79   end
  80   return State.screen_bottom1.line, Text.pos_at_end_of_screen_line(State, State.screen_bottom1)
  81 end
  82
  83 function Text.cut_selection(State)
  84   if State.selection1.line == nil then return end
  85   local result = Text.selection(State)
  86   Text.delete_selection(State)
  87   return result
  88 end
  89
  90 function Text.delete_selection(State)
  91   if State.selection1.line == nil then return end
  92   local minl,maxl = minmax(State.selection1.line, State.cursor1.line)
  93   local before = snapshot(State, minl, maxl)
  94   Text.delete_selection_without_undo(State)
  95   record_undo_event(State, {before=before, after=snapshot(State, State.cursor1.line)})
  96 end
  97
  98 function Text.delete_selection_without_undo(State)
  99   if State.selection1.line == nil then return end
 100   -- min,max = sorted(State.selection1,State.cursor1)
 101   local minl,minp = State.selection1.line,State.selection1.pos
 102   local maxl,maxp = State.cursor1.line,State.cursor1.pos
 103   if minl > maxl then
 104     minl,maxl = maxl,minl
 105     minp,maxp = maxp,minp
 106   elseif minl == maxl then
 107     if minp > maxp then
 108       minp,maxp = maxp,minp
 109     end
 110   end
 111   -- update State.cursor1 and State.selection1
 112   State.cursor1.line = minl
 113   State.cursor1.pos = minp
 114   if Text.lt1(State.cursor1, State.screen_top1) then
 115     State.screen_top1.line = State.cursor1.line
 116     State.screen_top1.pos = Text.pos_at_start_of_screen_line(State, State.cursor1)
 117   end
 118   State.selection1 = {}
 119   -- delete everything between min (inclusive) and max (exclusive)
 120   Text.clear_screen_line_cache(State, minl)
 121   local min_offset = Text.offset(State.lines[minl].data, minp)
 122   local max_offset = Text.offset(State.lines[maxl].data, maxp)
 123   if minl == maxl then
 124 --?     print('minl == maxl')
 125     State.lines[minl].data = State.lines[minl].data:sub(1, min_offset-1)..State.lines[minl].data:sub(max_offset)
 126     return
 127   end
 128   assert(minl < maxl, ('minl %d not < maxl %d'):format(minl, maxl))
 129   local rhs = State.lines[maxl].data:sub(max_offset)
 130   for i=maxl,minl+1,-1 do
 131     table.remove(State.lines, i)
 132     table.remove(State.line_cache, i)
 133   end
 134   State.lines[minl].data = State.lines[minl].data:sub(1, min_offset-1)..rhs
 135 end
 136
 137 function Text.selection(State)
 138   if State.selection1.line == nil then return end
 139   -- min,max = sorted(State.selection1,State.cursor1)
 140   local minl,minp = State.selection1.line,State.selection1.pos
 141   local maxl,maxp = State.cursor1.line,State.cursor1.pos
 142   if minl > maxl then
 143     minl,maxl = maxl,minl
 144     minp,maxp = maxp,minp
 145   elseif minl == maxl then
 146     if minp > maxp then
 147       minp,maxp = maxp,minp
 148     end
 149   end
 150   local min_offset = Text.offset(State.lines[minl].data, minp)
 151   local max_offset = Text.offset(State.lines[maxl].data, maxp)
 152   if minl == maxl then
 153     return State.lines[minl].data:sub(min_offset, max_offset-1)
 154   end
 155   assert(minl < maxl, ('minl %d not < maxl %d'):format(minl, maxl))
 156   local result = {State.lines[minl].data:sub(min_offset)}
 157   for i=minl+1,maxl-1 do
 158     table.insert(result, State.lines[i].data)
 159   end
 160   table.insert(result, State.lines[maxl].data:sub(1, max_offset-1))
 161   return table.concat(result, '\n')
 162 end