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 App.mouse_down(1) 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 --?   print(minl,line_index,maxl, '--', minp,apos,bpos,maxp, '--', a_ge,b_lt)
  33   if a_ge and b_lt then
  34     -- fully contained
  35     return apos,bpos
  36   elseif a_ge then
  37     assert(maxl == line_index)
  38     return apos,maxp
  39   elseif b_lt then
  40     assert(minl == line_index)
  41     return minp,bpos
  42   else
  43     assert(minl == maxl and minl == line_index)
  44     return minp,maxp
  45   end
  46 end
  47
  48 -- draw highlight for line corresponding to (lo,hi) given an approximate x,y and pos on the same screen line
  49 -- Creates text objects every time, so use this sparingly.
  50 -- Returns some intermediate computation useful elsewhere.
  51 function Text.draw_highlight(State, line, x,y, pos, lo,hi)
  52   if lo then
  53     local lo_offset = Text.offset(line.data, lo)
  54     local hi_offset = Text.offset(line.data, hi)
  55     local pos_offset = Text.offset(line.data, pos)
  56     local lo_px
  57     if pos == lo then
  58       lo_px = 0
  59     else
  60       local before = line.data:sub(pos_offset, lo_offset-1)
  61       lo_px = App.width(before)
  62     end
  63 --?     print(lo,pos,hi, '--', lo_offset,pos_offset,hi_offset, '--', lo_px)
  64     local s = line.data:sub(lo_offset, hi_offset-1)
  65     App.color(Highlight_color)
  66     love.graphics.rectangle('fill', x+lo_px,y, App.width(s),State.line_height)
  67     App.color(Text_color)
  68     return lo_px
  69   end
  70 end
  71
  72 -- inefficient for some reason, so don't do it on every frame
  73 function Text.mouse_pos(State)
  74   local time = love.timer.getTime()
  75   if State.recent_mouse.time and State.recent_mouse.time > time-0.1 then
  76     return State.recent_mouse.line, State.recent_mouse.pos
  77   end
  78   State.recent_mouse.time = time
  79   local line,pos = Text.to_pos(State, App.mouse_x(), App.mouse_y())
  80   if line then
  81     State.recent_mouse.line = line
  82     State.recent_mouse.pos = pos
  83   end
  84   return State.recent_mouse.line, State.recent_mouse.pos
  85 end
  86
  87 function Text.to_pos(State, x,y)
  88   for line_index,line in ipairs(State.lines) do
  89     if line.mode == 'text' then
  90       if Text.in_line(State, line_index, x,y) then
  91         return line_index, Text.to_pos_on_line(State, line_index, x,y)
  92       end
  93     end
  94   end
  95 end
  96
  97 function Text.cut_selection(State)
  98   if State.selection1.line == nil then return end
  99   local result = Text.selection(State)
 100   Text.delete_selection(State)
 101   return result
 102 end
 103
 104 function Text.delete_selection(State)
 105   if State.selection1.line == nil then return end
 106   local minl,maxl = minmax(State.selection1.line, State.cursor1.line)
 107   local before = snapshot(State, minl, maxl)
 108   Text.delete_selection_without_undo(State)
 109   record_undo_event(State, {before=before, after=snapshot(State, State.cursor1.line)})
 110 end
 111
 112 function Text.delete_selection_without_undo(State)
 113   if State.selection1.line == nil then return end
 114   -- min,max = sorted(State.selection1,State.cursor1)
 115   local minl,minp = State.selection1.line,State.selection1.pos
 116   local maxl,maxp = State.cursor1.line,State.cursor1.pos
 117   if minl > maxl then
 118     minl,maxl = maxl,minl
 119     minp,maxp = maxp,minp
 120   elseif minl == maxl then
 121     if minp > maxp then
 122       minp,maxp = maxp,minp
 123     end
 124   end
 125   -- update State.cursor1 and State.selection1
 126   State.cursor1.line = minl
 127   State.cursor1.pos = minp
 128   if Text.lt1(State.cursor1, State.screen_top1) then
 129     State.screen_top1.line = State.cursor1.line
 130     State.screen_top1.pos = Text.pos_at_start_of_screen_line(State, State.cursor1)
 131   end
 132   State.selection1 = {}
 133   -- delete everything between min (inclusive) and max (exclusive)
 134   Text.clear_screen_line_cache(State, minl)
 135   local min_offset = Text.offset(State.lines[minl].data, minp)
 136   local max_offset = Text.offset(State.lines[maxl].data, maxp)
 137   if minl == maxl then
 138 --?     print('minl == maxl')
 139     State.lines[minl].data = State.lines[minl].data:sub(1, min_offset-1)..State.lines[minl].data:sub(max_offset)
 140     return
 141   end
 142   assert(minl < maxl)
 143   local rhs = State.lines[maxl].data:sub(max_offset)
 144   for i=maxl,minl+1,-1 do
 145     table.remove(State.lines, i)
 146     table.remove(State.line_cache, i)
 147   end
 148   State.lines[minl].data = State.lines[minl].data:sub(1, min_offset-1)..rhs
 149 end
 150
 151 function Text.selection(State)
 152   if State.selection1.line == nil then return end
 153   -- min,max = sorted(State.selection1,State.cursor1)
 154   local minl,minp = State.selection1.line,State.selection1.pos
 155   local maxl,maxp = State.cursor1.line,State.cursor1.pos
 156   if minl > maxl then
 157     minl,maxl = maxl,minl
 158     minp,maxp = maxp,minp
 159   elseif minl == maxl then
 160     if minp > maxp then
 161       minp,maxp = maxp,minp
 162     end
 163   end
 164   local min_offset = Text.offset(State.lines[minl].data, minp)
 165   local max_offset = Text.offset(State.lines[maxl].data, maxp)
 166   if minl == maxl then
 167     return State.lines[minl].data:sub(min_offset, max_offset-1)
 168   end
 169   assert(minl < maxl)
 170   local result = {State.lines[minl].data:sub(min_offset)}
 171   for i=minl+1,maxl-1 do
 172     if State.lines[i].mode == 'text' then
 173       table.insert(result, State.lines[i].data)
 174     end
 175   end
 176   table.insert(result, State.lines[maxl].data:sub(1, max_offset-1))
 177   return table.concat(result, '\n')
 178 end