search.lua

   1 -- helpers for the search bar (C-f)
   2
   3 function Text.draw_search_bar(State)
   4   local h = State.line_height+2
   5   local y = App.screen.height-h
   6   love.graphics.setColor(0.9,0.9,0.9)
   7   love.graphics.rectangle('fill', 0, y-10, App.screen.width-1, h+8)
   8   love.graphics.setColor(0.6,0.6,0.6)
   9   love.graphics.line(0, y-10, App.screen.width-1, y-10)
  10   love.graphics.setColor(1,1,1)
  11   love.graphics.rectangle('fill', 20, y-6, App.screen.width-40, h+2, 2,2)
  12   love.graphics.setColor(0.6,0.6,0.6)
  13   love.graphics.rectangle('line', 20, y-6, App.screen.width-40, h+2, 2,2)
  14   App.color(Text_color)
  15   App.screen.print(State.search_term, 25,y-5)
  16   Text.draw_cursor(State, 25+State.font:getWidth(State.search_term),y-5)
  17 end
  18
  19 function Text.search_next(State)
  20   assert(#State.search_term > 0)
  21   -- search current line from cursor
  22   local curr_pos = State.cursor1.pos
  23   local curr_line = State.lines[State.cursor1.line].data
  24   local curr_offset = Text.offset(curr_line, curr_pos)
  25   local offset = find(curr_line, State.search_term, curr_offset, --[[literal]] true)
  26   if offset then
  27     State.cursor1.pos = utf8.len(curr_line, 1, offset)
  28   end
  29   if offset == nil then
  30     -- search lines below cursor
  31     for i=State.cursor1.line+1,#State.lines do
  32       local curr_line = State.lines[i].data
  33       offset = find(curr_line, State.search_term, --[[from start]] nil, --[[literal]] true)
  34       if offset then
  35         State.cursor1 = {line=i, pos=utf8.len(curr_line, 1, offset)}
  36         break
  37       end
  38     end
  39   end
  40   if offset == nil then
  41     -- wrap around
  42     for i=1,State.cursor1.line-1 do
  43       local curr_line = State.lines[i].data
  44       offset = find(curr_line, State.search_term, --[[from start]] nil, --[[literal]] true)
  45       if offset then
  46         State.cursor1 = {line=i, pos=utf8.len(curr_line, 1, offset)}
  47         break
  48       end
  49     end
  50   end
  51   if offset == nil then
  52     -- search current line until cursor
  53     local curr_line = State.lines[State.cursor1.line].data
  54     offset = find(curr_line, State.search_term, --[[from start]] nil, --[[literal]] true)
  55     local pos = utf8.len(curr_line, 1, offset)
  56     if pos and pos < State.cursor1.pos then
  57       State.cursor1.pos = pos
  58     end
  59   end
  60   if offset == nil then
  61     State.cursor1.line = State.search_backup.cursor.line
  62     State.cursor1.pos = State.search_backup.cursor.pos
  63     State.screen_top1.line = State.search_backup.screen_top.line
  64     State.screen_top1.pos = State.search_backup.screen_top.pos
  65   end
  66   local screen_bottom1 = Text.screen_bottom1(State)
  67   if Text.lt1(State.cursor1, State.screen_top1) or Text.lt1(screen_bottom1, State.cursor1) then
  68     State.screen_top1.line = State.cursor1.line
  69     local pos = Text.pos_at_start_of_screen_line(State, State.cursor1)
  70     State.screen_top1.pos = pos
  71   end
  72 end
  73
  74 function Text.search_previous(State)
  75   assert(#State.search_term > 0)
  76   -- search current line before cursor
  77   local curr_pos = State.cursor1.pos
  78   local curr_line = State.lines[State.cursor1.line].data
  79   local curr_offset = Text.offset(curr_line, curr_pos)
  80   local offset = rfind(curr_line, State.search_term, curr_offset-1, --[[literal]] true)
  81   if offset then
  82     State.cursor1.pos = utf8.len(curr_line, 1, offset)
  83   end
  84   if offset == nil then
  85     -- search lines above cursor
  86     for i=State.cursor1.line-1,1,-1 do
  87       local curr_line = State.lines[i].data
  88       offset = rfind(curr_line, State.search_term, --[[from end]] nil, --[[literal]] true)
  89       if offset then
  90         State.cursor1 = {line=i, pos=utf8.len(curr_line, 1, offset)}
  91         break
  92       end
  93     end
  94   end
  95   if offset == nil then
  96     -- wrap around
  97     for i=#State.lines,State.cursor1.line+1,-1 do
  98       local curr_line = State.lines[i].data
  99       offset = rfind(curr_line, State.search_term, --[[from end]] nil, --[[literal]] true)
 100       if offset then
 101         State.cursor1 = {line=i, pos=utf8.len(curr_line, 1, offset)}
 102         break
 103       end
 104     end
 105   end
 106   if offset == nil then
 107     -- search current line after cursor
 108     local curr_line = State.lines[State.cursor1.line].data
 109     offset = rfind(curr_line, State.search_term, --[[from end]] nil, --[[literal]] true)
 110     local pos = utf8.len(curr_line, 1, offset)
 111     if pos and pos > State.cursor1.pos then
 112       State.cursor1.pos = pos
 113     end
 114   end
 115   if offset == nil then
 116     State.cursor1.line = State.search_backup.cursor.line
 117     State.cursor1.pos = State.search_backup.cursor.pos
 118     State.screen_top1.line = State.search_backup.screen_top.line
 119     State.screen_top1.pos = State.search_backup.screen_top.pos
 120   end
 121   local screen_bottom1 = Text.screen_bottom1(State)
 122   if Text.lt1(State.cursor1, State.screen_top1) or Text.lt1(screen_bottom1, State.cursor1) then
 123     State.screen_top1.line = State.cursor1.line
 124     local pos = Text.pos_at_start_of_screen_line(State, State.cursor1)
 125     State.screen_top1.pos = pos
 126   end
 127 end
 128
 129 function find(s, pat, i, plain)
 130   if s == nil then return end
 131   return s:find(pat, i, plain)
 132 end
 133
 134 -- TODO: avoid the expensive reverse() operations
 135 -- Particularly if we only care about literal matches, we don't need all of string.find
 136 function rfind(s, pat, i, plain)
 137   if s == nil then return end
 138   if #pat == 0 then return #s end
 139   local rs = s:reverse()
 140   local rpat = pat:reverse()
 141   if i == nil then i = #s end
 142   local ri = #s - i + 1
 143   local rendpos = rs:find(rpat, ri, plain)
 144   if rendpos == nil then return nil end
 145   local endpos = #s - rendpos + 1
 146   assert (endpos >= #pat, ('rfind: endpos %d should be >= #pat %d at this point'):format(endpos, #pat))
 147   return endpos-#pat+1
 148 end
 149
 150 function test_rfind()
 151   check_eq(rfind('abc', ''), 3, 'empty pattern')
 152   check_eq(rfind('abc', 'c'), 3, 'final char')
 153   check_eq(rfind('acbc', 'c', 3), 2, 'previous char')
 154   check_nil(rfind('abc', 'd'), 'missing char')
 155   check_nil(rfind('abc', 'c', 2), 'no more char')
 156 end