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   if a_ge and b_lt then
  33     -- fully contained
  34     return apos,bpos
  35   elseif a_ge then
  36     assert(maxl == line_index)
  37     return apos,maxp
  38   elseif b_lt then
  39     assert(minl == line_index)
  40     return minp,bpos
  41   else
  42     assert(minl == maxl and minl == 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 line.mode == 'text' then
  77       if Text.in_line(State, line_index, x,y) then
  78         return line_index, Text.to_pos_on_line(State, line_index, x,y)
  79       end
  80     end
  81   end
  82   return State.screen_bottom1.line, Text.pos_at_end_of_screen_line(State, State.screen_bottom1)
  83 end
  84
  85 function Text.cut_selection(State)
  86   if State.selection1.line == nil then return end
  87   local result = Text.selection(State)
  88   Text.delete_selection(State)
  89   return result
  90 end
  91
  92 function Text.delete_selection(State)
  93   if State.selection1.line == nil then return end
  94   local minl,maxl = minmax(State.selection1.line, State.cursor1.line)
  95   local before = snapshot(State, minl, maxl)
  96   Text.delete_selection_without_undo(State)
  97   record_undo_event(State, {before=before, after=snapshot(State, State.cursor1.line)})
  98 end
  99
 100 function Text.delete_selection_without_undo(State)
 101   if State.selection1.line == nil then return end
 102   -- min,max = sorted(State.selection1,State.cursor1)
 103   local minl,minp = State.selection1.line,State.selection1.pos
 104   local maxl,maxp = State.cursor1.line,State.cursor1.pos
 105   if minl > maxl then
 106     minl,maxl = maxl,minl
 107     minp,maxp = maxp,minp
 108   elseif minl == maxl then
 109     if minp > maxp then
 110       minp,maxp = maxp,minp
 111     end
 112   end
 113   -- update State.cursor1 and State.selection1
 114   State.cursor1.line = minl
 115   State.cursor1.pos = minp
 116   if Text.lt1(State.cursor1, State.screen_top1) then
 117     State.screen_top1.line = State.cursor1.line
 118     State.screen_top1.pos = Text.pos_at_start_of_screen_line(State, State.cursor1)
 119   end
 120   State.selection1 = {}
 121   -- delete everything between min (inclusive) and max (exclusive)
 122   Text.clear_screen_line_cache(State, minl)
 123   local min_offset = Text.offset(State.lines[minl].data, minp)
 124   local max_offset = Text.offset(State.lines[maxl].data, maxp)
 125   if minl == maxl then
 126 --?     print('minl == maxl')
 127     State.lines[minl].data = State.lines[minl].data:sub(1, min_offset-1)..State.lines[minl].data:sub(max_offset)
 128     return
 129   end
 130   assert(minl < maxl)
 131   local rhs = State.lines[maxl].data:sub(max_offset)
 132   for i=maxl,minl+1,-1 do
 133     table.remove(State.lines, i)
 134     table.remove(State.line_cache, i)
 135   end
 136   State.lines[minl].data = State.lines[minl].data:sub(1, min_offset-1)..rhs
 137 end
 138
 139 function Text.selection(State)
 140   if State.selection1.line == nil then return end
 141   -- min,max = sorted(State.selection1,State.cursor1)
 142   local minl,minp = State.selection1.line,State.selection1.pos
 143   local maxl,maxp = State.cursor1.line,State.cursor1.pos
 144   if minl > maxl then
 145     minl,maxl = maxl,minl
 146     minp,maxp = maxp,minp
 147   elseif minl == maxl then
 148     if minp > maxp then
 149       minp,maxp = maxp,minp
 150     end
 151   end
 152   local min_offset = Text.offset(State.lines[minl].data, minp)
 153   local max_offset = Text.offset(State.lines[maxl].data, maxp)
 154   if minl == maxl then
 155     return State.lines[minl].data:sub(min_offset, max_offset-1)
 156   end
 157   assert(minl < maxl)
 158   local result = {State.lines[minl].data:sub(min_offset)}
 159   for i=minl+1,maxl-1 do
 160     if State.lines[i].mode == 'text' then
 161       table.insert(result, State.lines[i].data)
 162     end
 163   end
 164   table.insert(result, State.lines[maxl].data:sub(1, max_offset-1))
 165   return table.concat(result, '\n')
 166 end