extract a couple of files

1 files changed, 153 insertions, 0 deletions

diff --git a/select.lua b/select.lua
new file mode 100644
index 0000000..fcef878
--- /dev/null
+++ b/select.lua
@@ -0,0 +1,153 @@
+-- helpers for selecting portions of text
+
+local utf8 = require 'utf8'
+
+-- Return any intersection of the region from Selection1 to Cursor1 (or
+-- current mouse, if mouse is pressed; or recent mouse if mouse is pressed and
+-- currently over a drawing) with the region between {line=line_index, pos=apos}
+-- and {line=line_index, pos=bpos}.
+-- apos must be less than bpos. However Selection1 and Cursor1 can be in any order.
+-- Result: positions spos,epos between apos,bpos.
+function Text.clip_selection(line_index, apos, bpos)
+  if Selection1.line == nil then return nil,nil end
+  -- min,max = sorted(Selection1,Cursor1)
+  local minl,minp = Selection1.line,Selection1.pos
+  local maxl,maxp
+  if love.mouse.isDown('1') then
+    maxl,maxp = Text.mouse_pos()
+  else
+    maxl,maxp = Cursor1.line,Cursor1.pos
+  end
+  if minl > maxl then
+    minl,maxl = maxl,minl
+    minp,maxp = maxp,minp
+  elseif minl == maxl then
+    if minp > maxp then
+      minp,maxp = maxp,minp
+    end
+  end
+  -- check if intervals are disjoint
+  if line_index < minl then return nil,nil end
+  if line_index > maxl then return nil,nil end
+  if line_index == minl and bpos <= minp then return nil,nil end
+  if line_index == maxl and apos >= maxp then return nil,nil end
+  -- compare bounds more carefully (start inclusive, end exclusive)
+  local a_ge = Text.le1({line=minl, pos=minp}, {line=line_index, pos=apos})
+  local b_lt = Text.lt1({line=line_index, pos=bpos}, {line=maxl, pos=maxp})
+--?   print(minl,line_index,maxl, '--', minp,apos,bpos,maxp, '--', a_ge,b_lt)
+  if a_ge and b_lt then
+    -- fully contained
+    return apos,bpos
+  elseif a_ge then
+    assert(maxl == line_index)
+    return apos,maxp
+  elseif b_lt then
+    assert(minl == line_index)
+    return minp,bpos
+  else
+    assert(minl == maxl and minl == line_index)
+    return minp,maxp
+  end
+end
+
+-- inefficient for some reason, so don't do it on every frame
+function Text.mouse_pos()
+  local time = love.timer.getTime()
+  if Recent_mouse.time and Recent_mouse.time > time-0.1 then
+    return Recent_mouse.line, Recent_mouse.pos
+  end
+  Recent_mouse.time = time
+  local line,pos = Text.to_pos(love.mouse.getX(), love.mouse.getY())
+  if line then
+    Recent_mouse.line = line
+    Recent_mouse.pos = pos
+  end
+  return Recent_mouse.line, Recent_mouse.pos
+end
+
+function Text.to_pos(x,y)
+  for line_index,line in ipairs(Lines) do
+    if line.mode == 'text' then
+      if Text.in_line(line, x,y) then
+        return line_index, Text.to_pos_on_line(line, x,y)
+      end
+    end
+  end
+end
+
+function Text.delete_selection()
+  local minl,maxl = minmax(Selection1.line, Cursor1.line)
+  local before = snapshot(minl, maxl)
+  Text.delete_selection_without_undo()
+  record_undo_event({before=before, after=snapshot(Cursor1.line)})
+end
+
+function Text.delete_selection_without_undo()
+  if Selection1.line == nil then return end
+  -- min,max = sorted(Selection1,Cursor1)
+  local minl,minp = Selection1.line,Selection1.pos
+  local maxl,maxp = Cursor1.line,Cursor1.pos
+  if minl > maxl then
+    minl,maxl = maxl,minl
+    minp,maxp = maxp,minp
+  elseif minl == maxl then
+    if minp > maxp then
+      minp,maxp = maxp,minp
+    end
+  end
+  -- update Cursor1 and Selection1
+  Cursor1.line = minl
+  Cursor1.pos = minp
+  Selection1 = {}
+  -- delete everything between min (inclusive) and max (exclusive)
+  Lines[minl].fragments = nil
+  Lines[minl].screen_line_starting_pos = nil
+  local min_offset = utf8.offset(Lines[minl].data, minp)
+  local max_offset = utf8.offset(Lines[maxl].data, maxp)
+  if minl == maxl then
+--?     print('minl == maxl')
+    Lines[minl].data = Lines[minl].data:sub(1, min_offset-1)..Lines[minl].data:sub(max_offset)
+    return
+  end
+  assert(minl < maxl)
+  local rhs = Lines[maxl].data:sub(max_offset)
+  for i=maxl,minl+1,-1 do
+    table.remove(Lines, i)
+  end
+  Lines[minl].data = Lines[minl].data:sub(1, min_offset-1)..rhs
+end
+
+function Text.selection()
+  if Selection1.line == nil then return end
+  -- min,max = sorted(Selection1,Cursor1)
+  local minl,minp = Selection1.line,Selection1.pos
+  local maxl,maxp = Cursor1.line,Cursor1.pos
+  if minl > maxl then
+    minl,maxl = maxl,minl
+    minp,maxp = maxp,minp
+  elseif minl == maxl then
+    if minp > maxp then
+      minp,maxp = maxp,minp
+    end
+  end
+  local min_offset = utf8.offset(Lines[minl].data, minp)
+  local max_offset = utf8.offset(Lines[maxl].data, maxp)
+  if minl == maxl then
+    return Lines[minl].data:sub(min_offset, max_offset-1)
+  end
+  assert(minl < maxl)
+  local result = Lines[minl].data:sub(min_offset)..'\n'
+  for i=minl+1,maxl-1 do
+    if Lines[i].mode == 'text' then
+      result = result..Lines[i].data..'\n'
+    end
+  end
+  result = result..Lines[maxl].data:sub(1, max_offset-1)
+  return result
+end
+
+function Text.cut_selection()
+  local result = Text.selection()
+  Text.delete_selection()
+  return result
+end