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|
-- text editor, particularly text drawing, horizontal wrap, vertical scrolling
Text = {}
-- draw a line starting from startpos to screen at y between State.left and State.right
-- return the final y, and position of start of final screen line drawn
function Text.draw(State, line_index, y, startpos)
local line = State.lines[line_index]
local line_cache = State.line_cache[line_index]
line_cache.starty = y
line_cache.startpos = startpos
-- wrap long lines
local x = State.left
local pos = 1
local screen_line_starting_pos = startpos
Text.compute_fragments(State, line_index)
for _, f in ipairs(line_cache.fragments) do
App.color(Text_color)
local frag, frag_text = f.data, f.text
local frag_len = utf8.len(frag)
--? print('text.draw:', frag, 'at', line_index,pos, 'after', x,y)
if pos < startpos then
-- render nothing
--? print('skipping', frag)
else
-- render fragment
local frag_width = App.width(frag_text)
if x + frag_width > State.right then
assert(x > State.left) -- no overfull lines
y = y + State.line_height
if y + State.line_height > App.screen.height then
return y, screen_line_starting_pos
end
screen_line_starting_pos = pos
x = State.left
end
if State.selection1.line then
local lo, hi = Text.clip_selection(State, line_index, pos, pos+frag_len)
Text.draw_highlight(State, line, x,y, pos, lo,hi)
end
App.screen.draw(frag_text, x,y)
-- render cursor if necessary
if line_index == State.cursor1.line then
if pos <= State.cursor1.pos and pos + frag_len > State.cursor1.pos then
if State.search_term then
if State.lines[State.cursor1.line].data:sub(State.cursor1.pos, State.cursor1.pos+utf8.len(State.search_term)-1) == State.search_term then
local lo_px = Text.draw_highlight(State, line, x,y, pos, State.cursor1.pos, State.cursor1.pos+utf8.len(State.search_term))
App.color(Text_color)
love.graphics.print(State.search_term, x+lo_px,y)
end
else
Text.draw_cursor(State, x+Text.x(frag, State.cursor1.pos-pos+1), y)
end
end
end
x = x + frag_width
end
pos = pos + frag_len
end
if State.search_term == nil then
if line_index == State.cursor1.line and State.cursor1.pos == pos then
Text.draw_cursor(State, x, y)
end
end
return y, screen_line_starting_pos
end
function Text.draw_cursor(State, x, y)
-- blink every 0.5s
if math.floor(Cursor_time*2)%2 == 0 then
App.color(Cursor_color)
love.graphics.rectangle('fill', x,y, 3,State.line_height)
App.color(Text_color)
end
State.cursor_x = x
State.cursor_y = y+State.line_height
end
function Text.populate_screen_line_starting_pos(State, line_index)
local line = State.lines[line_index]
local line_cache = State.line_cache[line_index]
if line_cache.screen_line_starting_pos then
return
end
-- duplicate some logic from Text.draw
Text.compute_fragments(State, line_index)
line_cache.screen_line_starting_pos = {1}
local x = State.left
local pos = 1
for _, f in ipairs(line_cache.fragments) do
local frag, frag_text = f.data, f.text
-- render fragment
local frag_width = App.width(frag_text)
if x + frag_width > State.right then
x = State.left
table.insert(line_cache.screen_line_starting_pos, pos)
end
x = x + frag_width
local frag_len = utf8.len(frag)
pos = pos + frag_len
end
end
function Text.compute_fragments(State, line_index)
--? print('compute_fragments', line_index, 'between', State.left, State.right)
local line = State.lines[line_index]
local line_cache = State.line_cache[line_index]
if line_cache.fragments then
return
end
line_cache.fragments = {}
local x = State.left
-- try to wrap at word boundaries
for frag in line.data:gmatch('%S*%s*') do
local frag_text = App.newText(love.graphics.getFont(), frag)
local frag_width = App.width(frag_text)
--? print('x: '..tostring(x)..'; frag_width: '..tostring(frag_width)..'; '..tostring(State.right-x)..'px to go')
while x + frag_width > State.right do
--? print(('checking whether to split fragment ^%s$ of width %d when rendering from %d'):format(frag, frag_width, x))
if (x-State.left) < 0.8 * (State.right-State.left) then
--? print('splitting')
-- long word; chop it at some letter
-- We're not going to reimplement TeX here.
local bpos = Text.nearest_pos_less_than(frag, State.right - x)
--? print('bpos', bpos)
if bpos == 0 then break end -- avoid infinite loop when window is too narrow
local boffset = Text.offset(frag, bpos+1) -- byte _after_ bpos
--? print('space for '..tostring(bpos)..' graphemes, '..tostring(boffset-1)..' bytes')
local frag1 = string.sub(frag, 1, boffset-1)
local frag1_text = App.newText(love.graphics.getFont(), frag1)
local frag1_width = App.width(frag1_text)
--? print('extracting ^'..frag1..'$ of width '..tostring(frag1_width)..'px')
assert(x + frag1_width <= State.right)
table.insert(line_cache.fragments, {data=frag1, text=frag1_text})
frag = string.sub(frag, boffset)
frag_text = App.newText(love.graphics.getFont(), frag)
frag_width = App.width(frag_text)
end
x = State.left -- new line
end
if #frag > 0 then
--? print('inserting ^'..frag..'$ of width '..tostring(frag_width)..'px')
table.insert(line_cache.fragments, {data=frag, text=frag_text})
end
x = x + frag_width
end
end
function Text.textinput(State, t)
if App.mouse_down(1) then return end
if App.ctrl_down() or App.alt_down() or App.cmd_down() then return end
local before = snapshot(State, State.cursor1.line)
--? print(State.screen_top1.line, State.screen_top1.pos, State.cursor1.line, State.cursor1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
Text.insert_at_cursor(State, t)
if State.cursor_y > App.screen.height - State.line_height then
Text.populate_screen_line_starting_pos(State, State.cursor1.line)
Text.snap_cursor_to_bottom_of_screen(State, State.left, State.right)
--? print('=>', State.screen_top1.line, State.screen_top1.pos, State.cursor1.line, State.cursor1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
end
record_undo_event(State, {before=before, after=snapshot(State, State.cursor1.line)})
end
function Text.insert_at_cursor(State, t)
local byte_offset = Text.offset(State.lines[State.cursor1.line].data, State.cursor1.pos)
State.lines[State.cursor1.line].data = string.sub(State.lines[State.cursor1.line].data, 1, byte_offset-1)..t..string.sub(State.lines[State.cursor1.line].data, byte_offset)
Text.clear_screen_line_cache(State, State.cursor1.line)
State.cursor1.pos = State.cursor1.pos+1
end
-- Don't handle any keys here that would trigger love.textinput above.
function Text.keychord_pressed(State, chord)
--? print('chord', chord, State.selection1.line, State.selection1.pos)
--== shortcuts that mutate text
if chord == 'return' then
local before_line = State.cursor1.line
local before = snapshot(State, before_line)
Text.insert_return(State)
State.selection1 = {}
if State.cursor_y > App.screen.height - State.line_height then
Text.snap_cursor_to_bottom_of_screen(State, State.left, State.right)
end
schedule_save(State)
record_undo_event(State, {before=before, after=snapshot(State, before_line, State.cursor1.line)})
elseif chord == 'tab' then
local before = snapshot(State, State.cursor1.line)
--? print(State.screen_top1.line, State.screen_top1.pos, State.cursor1.line, State.cursor1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
Text.insert_at_cursor(State, '\t')
if State.cursor_y > App.screen.height - State.line_height then
Text.populate_screen_line_starting_pos(State, State.cursor1.line)
Text.snap_cursor_to_bottom_of_screen(State, State.left, State.right)
--? print('=>', State.screen_top1.line, State.screen_top1.pos, State.cursor1.line, State.cursor1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
end
schedule_save(State)
record_undo_event(State, {before=before, after=snapshot(State, State.cursor1.line)})
elseif chord == 'backspace' then
if State.selection1.line then
Text.delete_selection(State, State.left, State.right)
schedule_save(State)
return
end
local before
if State.cursor1.pos > 1 then
before = snapshot(State, State.cursor1.line)
local byte_start = utf8.offset(State.lines[State.cursor1.line].data, State.cursor1.pos-1)
local byte_end = utf8.offset(State.lines[State.cursor1.line].data, State.cursor1.pos)
if byte_start then
if byte_end then
State.lines[State.cursor1.line].data = string.sub(State.lines[State.cursor1.line].data, 1, byte_start-1)..string.sub(State.lines[State.cursor1.line].data, byte_end)
else
State.lines[State.cursor1.line].data = string.sub(State.lines[State.cursor1.line].data, 1, byte_start-1)
end
State.cursor1.pos = State.cursor1.pos-1
end
elseif State.cursor1.line > 1 then
before = snapshot(State, State.cursor1.line-1, State.cursor1.line)
-- join lines
State.cursor1.pos = utf8.len(State.lines[State.cursor1.line-1].data)+1
State.lines[State.cursor1.line-1].data = State.lines[State.cursor1.line-1].data..State.lines[State.cursor1.line].data
table.remove(State.lines, State.cursor1.line)
table.remove(State.line_cache, State.cursor1.line)
State.cursor1.line = State.cursor1.line-1
end
if State.screen_top1.line > #State.lines then
Text.populate_screen_line_starting_pos(State, #State.lines)
local line_cache = State.line_cache[#State.line_cache]
State.screen_top1 = {line=#State.lines, pos=line_cache.screen_line_starting_pos[#line_cache.screen_line_starting_pos]}
elseif Text.lt1(State.cursor1, State.screen_top1) then
local top2 = Text.to2(State, State.screen_top1)
top2 = Text.previous_screen_line(State, top2, State.left, State.right)
State.screen_top1 = Text.to1(State, top2)
Text.redraw_all(State) -- if we're scrolling, reclaim all fragments to avoid memory leaks
end
Text.clear_screen_line_cache(State, State.cursor1.line)
assert(Text.le1(State.screen_top1, State.cursor1))
schedule_save(State)
record_undo_event(State, {before=before, after=snapshot(State, State.cursor1.line)})
elseif chord == 'delete' then
if State.selection1.line then
Text.delete_selection(State, State.left, State.right)
schedule_save(State)
return
end
local before
if State.cursor1.pos <= utf8.len(State.lines[State.cursor1.line].data) then
before = snapshot(State, State.cursor1.line)
else
before = snapshot(State, State.cursor1.line, State.cursor1.line+1)
end
if State.cursor1.pos <= utf8.len(State.lines[State.cursor1.line].data) then
local byte_start = utf8.offset(State.lines[State.cursor1.line].data, State.cursor1.pos)
local byte_end = utf8.offset(State.lines[State.cursor1.line].data, State.cursor1.pos+1)
if byte_start then
if byte_end then
State.lines[State.cursor1.line].data = string.sub(State.lines[State.cursor1.line].data, 1, byte_start-1)..string.sub(State.lines[State.cursor1.line].data, byte_end)
else
State.lines[State.cursor1.line].data = string.sub(State.lines[State.cursor1.line].data, 1, byte_start-1)
end
-- no change to State.cursor1.pos
end
elseif State.cursor1.line < #State.lines then
-- join lines
State.lines[State.cursor1.line].data = State.lines[State.cursor1.line].data..State.lines[State.cursor1.line+1].data
table.remove(State.lines, State.cursor1.line+1)
table.remove(State.line_cache, State.cursor1.line+1)
end
Text.clear_screen_line_cache(State, State.cursor1.line)
schedule_save(State)
record_undo_event(State, {before=before, after=snapshot(State, State.cursor1.line)})
--== shortcuts that move the cursor
elseif chord == 'left' then
Text.left(State)
State.selection1 = {}
elseif chord == 'right' then
Text.right(State)
State.selection1 = {}
elseif chord == 'S-left' then
if State.selection1.line == nil then
State.selection1 = {line=State.cursor1.line, pos=State.cursor1.pos}
end
Text.left(State)
elseif chord == 'S-right' then
if State.selection1.line == nil then
State.selection1 = {line=State.cursor1.line, pos=State.cursor1.pos}
end
Text.right(State)
-- C- hotkeys reserved for drawings, so we'll use M-
elseif chord == 'M-left' then
Text.word_left(State)
State.selection1 = {}
elseif chord == 'M-right' then
Text.word_right(State)
State.selection1 = {}
elseif chord == 'M-S-left' then
if State.selection1.line == nil then
State.selection1 = {line=State.cursor1.line, pos=State.cursor1.pos}
end
Text.word_left(State)
elseif chord == 'M-S-right' then
if State.selection1.line == nil then
State.selection1 = {line=State.cursor1.line, pos=State.cursor1.pos}
end
Text.word_right(State)
elseif chord == 'home' then
Text.start_of_line(State)
State.selection1 = {}
elseif chord == 'end' then
Text.end_of_line(State)
State.selection1 = {}
elseif chord == 'S-home' then
if State.selection1.line == nil then
State.selection1 = {line=State.cursor1.line, pos=State.cursor1.pos}
end
Text.start_of_line(State)
elseif chord == 'S-end' then
if State.selection1.line == nil then
State.selection1 = {line=State.cursor1.line, pos=State.cursor1.pos}
end
Text.end_of_line(State)
elseif chord == 'up' then
Text.up(State)
State.selection1 = {}
elseif chord == 'down' then
Text.down(State)
State.selection1 = {}
elseif chord == 'S-up' then
if State.selection1.line == nil then
State.selection1 = {line=State.cursor1.line, pos=State.cursor1.pos}
end
Text.up(State)
elseif chord == 'S-down' then
if State.selection1.line == nil then
State.selection1 = {line=State.cursor1.line, pos=State.cursor1.pos}
end
Text.down(State)
elseif chord == 'pageup' then
Text.pageup(State)
State.selection1 = {}
elseif chord == 'pagedown' then
Text.pagedown(State)
State.selection1 = {}
elseif chord == 'S-pageup' then
if State.selection1.line == nil then
State.selection1 = {line=State.cursor1.line, pos=State.cursor1.pos}
end
Text.pageup(State)
elseif chord == 'S-pagedown' then
if State.selection1.line == nil then
State.selection1 = {line=State.cursor1.line, pos=State.cursor1.pos}
end
Text.pagedown(State)
end
end
function Text.insert_return(State)
local byte_offset = Text.offset(State.lines[State.cursor1.line].data, State.cursor1.pos)
table.insert(State.lines, State.cursor1.line+1, {data=string.sub(State.lines[State.cursor1.line].data, byte_offset)})
table.insert(State.line_cache, State.cursor1.line+1, {})
State.lines[State.cursor1.line].data = string.sub(State.lines[State.cursor1.line].data, 1, byte_offset-1)
Text.clear_screen_line_cache(State, State.cursor1.line)
State.cursor1 = {line=State.cursor1.line+1, pos=1}
end
function Text.pageup(State)
--? print('pageup')
-- duplicate some logic from love.draw
local top2 = Text.to2(State, State.screen_top1)
--? print(App.screen.height)
local y = App.screen.height - State.line_height
while y >= State.top do
--? print(y, top2.line, top2.screen_line, top2.screen_pos)
if State.screen_top1.line == 1 and State.screen_top1.pos == 1 then break end
y = y - State.line_height
top2 = Text.previous_screen_line(State, top2)
end
State.screen_top1 = Text.to1(State, top2)
State.cursor1 = {line=State.screen_top1.line, pos=State.screen_top1.pos}
Text.move_cursor_down_to_next_text_line_while_scrolling_again_if_necessary(State)
--? print(State.cursor1.line, State.cursor1.pos, State.screen_top1.line, State.screen_top1.pos)
--? print('pageup end')
end
function Text.pagedown(State)
--? print('pagedown')
-- If a line/paragraph gets to a page boundary, I often want to scroll
-- before I get to the bottom.
-- However, only do this if it makes forward progress.
local bot2 = Text.to2(State, State.screen_bottom1)
if bot2.screen_line > 1 then
bot2.screen_line = math.max(bot2.screen_line-10, 1)
end
local new_top1 = Text.to1(State, bot2)
if Text.lt1(State.screen_top1, new_top1) then
State.screen_top1 = new_top1
else
State.screen_top1 = {line=State.screen_bottom1.line, pos=State.screen_bottom1.pos}
end
--? print('setting top to', State.screen_top1.line, State.screen_top1.pos)
State.cursor1 = {line=State.screen_top1.line, pos=State.screen_top1.pos}
Text.move_cursor_down_to_next_text_line_while_scrolling_again_if_necessary(State)
--? print('top now', State.screen_top1.line)
Text.redraw_all(State) -- if we're scrolling, reclaim all fragments to avoid memory leaks
--? print('pagedown end')
end
function Text.up(State)
--? print('up', State.cursor1.line, State.cursor1.pos, State.screen_top1.line, State.screen_top1.pos)
local screen_line_starting_pos, screen_line_index = Text.pos_at_start_of_screen_line(State, State.cursor1)
if screen_line_starting_pos == 1 then
--? print('cursor is at first screen line of its line')
-- line is done; skip to previous text line
if State.cursor1.line > 1 then
local new_cursor_line = State.cursor1.line-1
--? print('found previous text line')
State.cursor1.line = new_cursor_line
Text.populate_screen_line_starting_pos(State, State.cursor1.line)
-- previous text line found, pick its final screen line
--? print('has multiple screen lines')
local screen_line_starting_pos = State.line_cache[State.cursor1.line].screen_line_starting_pos
--? print(#screen_line_starting_pos)
screen_line_starting_pos = screen_line_starting_pos[#screen_line_starting_pos]
local screen_line_starting_byte_offset = Text.offset(State.lines[State.cursor1.line].data, screen_line_starting_pos)
local s = string.sub(State.lines[State.cursor1.line].data, screen_line_starting_byte_offset)
State.cursor1.pos = screen_line_starting_pos + Text.nearest_cursor_pos(s, State.cursor_x, State.left) - 1
end
else
-- move up one screen line in current line
assert(screen_line_index > 1)
local new_screen_line_starting_pos = State.line_cache[State.cursor1.line].screen_line_starting_pos[screen_line_index-1]
local new_screen_line_starting_byte_offset = Text.offset(State.lines[State.cursor1.line].data, new_screen_line_starting_pos)
local s = string.sub(State.lines[State.cursor1.line].data, new_screen_line_starting_byte_offset)
State.cursor1.pos = new_screen_line_starting_pos + Text.nearest_cursor_pos(s, State.cursor_x, State.left) - 1
--? print('cursor pos is now '..tostring(State.cursor1.pos))
end
if Text.lt1(State.cursor1, State.screen_top1) then
local top2 = Text.to2(State, State.screen_top1)
top2 = Text.previous_screen_line(State, top2)
State.screen_top1 = Text.to1(State, top2)
end
end
function Text.down(State)
--? print('down', State.cursor1.line, State.cursor1.pos, State.screen_top1.line, State.screen_top1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
if Text.cursor_at_final_screen_line(State) then
-- line is done, skip to next text line
--? print('cursor at final screen line of its line')
if State.cursor1.line < #State.lines then
local new_cursor_line = State.cursor1.line+1
State.cursor1.line = new_cursor_line
State.cursor1.pos = Text.nearest_cursor_pos(State.lines[State.cursor1.line].data, State.cursor_x, State.left)
--? print(State.cursor1.pos)
end
if State.cursor1.line > State.screen_bottom1.line then
--? print('screen top before:', State.screen_top1.line, State.screen_top1.pos)
--? print('scroll up preserving cursor')
Text.snap_cursor_to_bottom_of_screen(State)
--? print('screen top after:', State.screen_top1.line, State.screen_top1.pos)
end
else
-- move down one screen line in current line
local scroll_down = Text.le1(State.screen_bottom1, State.cursor1)
--? print('cursor is NOT at final screen line of its line')
local screen_line_starting_pos, screen_line_index = Text.pos_at_start_of_screen_line(State, State.cursor1)
Text.populate_screen_line_starting_pos(State, State.cursor1.line)
local new_screen_line_starting_pos = State.line_cache[State.cursor1.line].screen_line_starting_pos[screen_line_index+1]
--? print('switching pos of screen line at cursor from '..tostring(screen_line_starting_pos)..' to '..tostring(new_screen_line_starting_pos))
local new_screen_line_starting_byte_offset = Text.offset(State.lines[State.cursor1.line].data, new_screen_line_starting_pos)
local s = string.sub(State.lines[State.cursor1.line].data, new_screen_line_starting_byte_offset)
State.cursor1.pos = new_screen_line_starting_pos + Text.nearest_cursor_pos(s, State.cursor_x, State.left) - 1
--? print('cursor pos is now', State.cursor1.line, State.cursor1.pos)
if scroll_down then
--? print('scroll up preserving cursor')
Text.snap_cursor_to_bottom_of_screen(State)
--? print('screen top after:', State.screen_top1.line, State.screen_top1.pos)
end
end
--? print('=>', State.cursor1.line, State.cursor1.pos, State.screen_top1.line, State.screen_top1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
end
function Text.start_of_line(State)
State.cursor1.pos = 1
if Text.lt1(State.cursor1, State.screen_top1) then
State.screen_top1 = {line=State.cursor1.line, pos=State.cursor1.pos} -- copy
end
end
function Text.end_of_line(State)
State.cursor1.pos = utf8.len(State.lines[State.cursor1.line].data) + 1
if Text.cursor_out_of_screen(State) then
Text.snap_cursor_to_bottom_of_screen(State)
end
end
function Text.word_left(State)
-- skip some whitespace
while true do
if State.cursor1.pos == 1 then
break
end
if Text.match(State.lines[State.cursor1.line].data, State.cursor1.pos-1, '%S') then
break
end
Text.left(State)
end
-- skip some non-whitespace
while true do
Text.left(State)
if State.cursor1.pos == 1 then
break
end
assert(State.cursor1.pos > 1)
if Text.match(State.lines[State.cursor1.line].data, State.cursor1.pos-1, '%s') then
break
end
end
end
function Text.word_right(State)
-- skip some whitespace
while true do
if State.cursor1.pos > utf8.len(State.lines[State.cursor1.line].data) then
break
end
if Text.match(State.lines[State.cursor1.line].data, State.cursor1.pos, '%S') then
break
end
Text.right_without_scroll(State)
end
while true do
Text.right_without_scroll(State)
if State.cursor1.pos > utf8.len(State.lines[State.cursor1.line].data) then
break
end
if Text.match(State.lines[State.cursor1.line].data, State.cursor1.pos, '%s') then
break
end
end
if Text.cursor_out_of_screen(State) then
Text.snap_cursor_to_bottom_of_screen(State)
end
end
function Text.match(s, pos, pat)
local start_offset = Text.offset(s, pos)
assert(start_offset)
local end_offset = Text.offset(s, pos+1)
assert(end_offset > start_offset)
local curr = s:sub(start_offset, end_offset-1)
return curr:match(pat)
end
function Text.left(State)
if State.cursor1.pos > 1 then
State.cursor1.pos = State.cursor1.pos-1
elseif State.cursor1.line > 1 then
State.cursor1.line = State.cursor1.line-1
State.cursor1.pos = utf8.len(State.lines[State.cursor1.line].data) + 1
end
if Text.lt1(State.cursor1, State.screen_top1) then
local top2 = Text.to2(State, State.screen_top1)
top2 = Text.previous_screen_line(State, top2)
State.screen_top1 = Text.to1(State, top2)
end
end
function Text.right(State)
Text.right_without_scroll(State)
if Text.cursor_out_of_screen(State) then
Text.snap_cursor_to_bottom_of_screen(State)
end
end
function Text.right_without_scroll(State)
if State.cursor1.pos <= utf8.len(State.lines[State.cursor1.line].data) then
State.cursor1.pos = State.cursor1.pos+1
elseif State.cursor1.line <= #State.lines-1 then
State.cursor1.line = State.cursor1.line+1
State.cursor1.pos = 1
end
end
function Text.pos_at_start_of_screen_line(State, loc1)
Text.populate_screen_line_starting_pos(State, loc1.line)
local line_cache = State.line_cache[loc1.line]
for i=#line_cache.screen_line_starting_pos,1,-1 do
local spos = line_cache.screen_line_starting_pos[i]
if spos <= loc1.pos then
return spos,i
end
end
assert(false)
end
function Text.cursor_at_final_screen_line(State)
Text.populate_screen_line_starting_pos(State, State.cursor1.line)
local screen_lines = State.line_cache[State.cursor1.line].screen_line_starting_pos
--? print(screen_lines[#screen_lines], State.cursor1.pos)
return screen_lines[#screen_lines] <= State.cursor1.pos
end
function Text.move_cursor_down_to_next_text_line_while_scrolling_again_if_necessary(State)
if State.top > App.screen.height - State.line_height then
--? print('scroll up')
Text.snap_cursor_to_bottom_of_screen(State)
end
end
-- should never modify State.cursor1
function Text.snap_cursor_to_bottom_of_screen(State)
--? print('to2:', State.cursor1.line, State.cursor1.pos)
local top2 = Text.to2(State, State.cursor1)
--? print('to2: =>', top2.line, top2.screen_line, top2.screen_pos)
-- slide to start of screen line
top2.screen_pos = 1 -- start of screen line
--? print('snap', State.screen_top1.line, State.screen_top1.pos, State.screen_top1.posB, State.cursor1.line, State.cursor1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
--? print('cursor pos '..tostring(State.cursor1.pos)..' is on the #'..tostring(top2.screen_line)..' screen line down')
local y = App.screen.height - State.line_height
-- duplicate some logic from love.draw
while true do
--? print(y, 'top2:', top2.line, top2.screen_line, top2.screen_pos)
if top2.line == 1 and top2.screen_line == 1 then break end
local h = State.line_height
if y - h < State.top then
break
end
y = y - h
top2 = Text.previous_screen_line(State, top2)
end
--? print('top2 finally:', top2.line, top2.screen_line, top2.screen_pos)
State.screen_top1 = Text.to1(State, top2)
--? print('top1 finally:', State.screen_top1.line, State.screen_top1.pos)
--? print('snap =>', State.screen_top1.line, State.screen_top1.pos, State.cursor1.line, State.cursor1.pos, State.screen_bottom1.line, State.screen_bottom1.pos)
Text.redraw_all(State) -- if we're scrolling, reclaim all fragments to avoid memory leaks
end
function Text.in_line(State, line_index, x,y)
local line = State.lines[line_index]
local line_cache = State.line_cache[line_index]
if line_cache.starty == nil then return false end -- outside current page
if y < line_cache.starty then return false end
Text.populate_screen_line_starting_pos(State, line_index)
return y < line_cache.starty + State.line_height*(#line_cache.screen_line_starting_pos - Text.screen_line_index(line_cache.screen_line_starting_pos, line_cache.startpos) + 1)
end
-- convert mx,my in pixels to schema-1 coordinates
function Text.to_pos_on_line(State, line_index, mx, my)
local line = State.lines[line_index]
local line_cache = State.line_cache[line_index]
assert(my >= line_cache.starty)
-- duplicate some logic from Text.draw
local y = line_cache.starty
local start_screen_line_index = Text.screen_line_index(line_cache.screen_line_starting_pos, line_cache.startpos)
for screen_line_index = start_screen_line_index,#line_cache.screen_line_starting_pos do
local screen_line_starting_pos = line_cache.screen_line_starting_pos[screen_line_index]
local screen_line_starting_byte_offset = Text.offset(line.data, screen_line_starting_pos)
--? print('iter', y, screen_line_index, screen_line_starting_pos, string.sub(line.data, screen_line_starting_byte_offset))
local nexty = y + State.line_height
if my < nexty then
-- On all wrapped screen lines but the final one, clicks past end of
-- line position cursor on final character of screen line.
-- (The final screen line positions past end of screen line as always.)
if screen_line_index < #line_cache.screen_line_starting_pos and mx > State.left + Text.screen_line_width(State, line_index, screen_line_index) then
--? print('past end of non-final line; return')
return line_cache.screen_line_starting_pos[screen_line_index+1]-1
end
local s = string.sub(line.data, screen_line_starting_byte_offset)
--? print('return', mx, Text.nearest_cursor_pos(s, mx, State.left), '=>', screen_line_starting_pos + Text.nearest_cursor_pos(s, mx, State.left) - 1)
return screen_line_starting_pos + Text.nearest_cursor_pos(s, mx, State.left) - 1
end
y = nexty
end
assert(false)
end
function Text.screen_line_width(State, line_index, i)
local line = State.lines[line_index]
local line_cache = State.line_cache[line_index]
local start_pos = line_cache.screen_line_starting_pos[i]
local start_offset = Text.offset(line.data, start_pos)
local screen_line
if i < #line_cache.screen_line_starting_pos then
local past_end_pos = line_cache.screen_line_starting_pos[i+1]
local past_end_offset = Text.offset(line.data, past_end_pos)
screen_line = string.sub(line.data, start_offset, past_end_offset-1)
else
screen_line = string.sub(line.data, start_pos)
end
local screen_line_text = App.newText(love.graphics.getFont(), screen_line)
return App.width(screen_line_text)
end
function Text.screen_line_index(screen_line_starting_pos, pos)
for i = #screen_line_starting_pos,1,-1 do
if screen_line_starting_pos[i] <= pos then
return i
end
end
end
-- convert x pixel coordinate to pos
-- oblivious to wrapping
-- result: 1 to len+1
function Text.nearest_cursor_pos(line, x, left)
if x < left then
return 1
end
local len = utf8.len(line)
local max_x = left+Text.x(line, len+1)
if x > max_x then
return len+1
end
local leftpos, rightpos = 1, len+1
--? print('-- nearest', x)
while true do
--? print('nearest', x, '^'..line..'$', leftpos, rightpos)
if leftpos == rightpos then
return leftpos
end
local curr = math.floor((leftpos+rightpos)/2)
local currxmin = left+Text.x(line, curr)
local currxmax = left+Text.x(line, curr+1)
--? print('nearest', x, leftpos, rightpos, curr, currxmin, currxmax)
if currxmin <= x and x < currxmax then
if x-currxmin < currxmax-x then
return curr
else
return curr+1
end
end
if leftpos >= rightpos-1 then
return rightpos
end
if currxmin > x then
rightpos = curr
else
leftpos = curr
end
end
assert(false)
end
-- return the nearest index of line (in utf8 code points) which lies entirely
-- within x pixels of the left margin
-- result: 0 to len+1
function Text.nearest_pos_less_than(line, x)
--? print('', '-- nearest_pos_less_than', line, x)
local len = utf8.len(line)
local max_x = Text.x_after(line, len)
if x > max_x then
return len+1
end
local left, right = 0, len+1
while true do
local curr = math.floor((left+right)/2)
local currxmin = Text.x_after(line, curr+1)
local currxmax = Text.x_after(line, curr+2)
--? print('', x, left, right, curr, currxmin, currxmax)
if currxmin <= x and x < currxmax then
return curr
end
if left >= right-1 then
return left
end
if currxmin > x then
right = curr
else
left = curr
end
end
assert(false)
end
function Text.x_after(s, pos)
local offset = Text.offset(s, math.min(pos+1, #s+1))
local s_before = s:sub(1, offset-1)
--? print('^'..s_before..'$')
local text_before = App.newText(love.graphics.getFont(), s_before)
return App.width(text_before)
end
function Text.x(s, pos)
local offset = Text.offset(s, pos)
local s_before = s:sub(1, offset-1)
local text_before = App.newText(love.graphics.getFont(), s_before)
return App.width(text_before)
end
function Text.to2(State, loc1)
local result = {line=loc1.line}
local line_cache = State.line_cache[loc1.line]
Text.populate_screen_line_starting_pos(State, loc1.line)
for i=#line_cache.screen_line_starting_pos,1,-1 do
local spos = line_cache.screen_line_starting_pos[i]
if spos <= loc1.pos then
result.screen_line = i
result.screen_pos = loc1.pos - spos + 1
break
end
end
assert(result.screen_pos)
return result
end
function Text.to1(State, loc2)
local result = {line=loc2.line, pos=loc2.screen_pos}
if loc2.screen_line > 1 then
result.pos = State.line_cache[loc2.line].screen_line_starting_pos[loc2.screen_line] + loc2.screen_pos - 1
end
return result
end
function Text.eq1(a, b)
return a.line == b.line and a.pos == b.pos
end
function Text.lt1(a, b)
if a.line < b.line then
return true
end
if a.line > b.line then
return false
end
return a.pos < b.pos
end
function Text.le1(a, b)
if a.line < b.line then
return true
end
if a.line > b.line then
return false
end
return a.pos <= b.pos
end
function Text.offset(s, pos1)
if pos1 == 1 then return 1 end
local result = utf8.offset(s, pos1)
if result == nil then
print(pos1, #s, s)
end
assert(result)
return result
end
function Text.previous_screen_line(State, loc2)
if loc2.screen_line > 1 then
return {line=loc2.line, screen_line=loc2.screen_line-1, screen_pos=1}
elseif loc2.line == 1 then
return loc2
else
local l = State.lines[loc2.line-1]
Text.populate_screen_line_starting_pos(State, loc2.line-1)
return {line=loc2.line-1, screen_line=#State.line_cache[loc2.line-1].screen_line_starting_pos, screen_pos=1}
end
end
-- resize helper
function Text.tweak_screen_top_and_cursor(State)
--? print('a', State.selection1.line)
if State.screen_top1.pos == 1 then return end
Text.populate_screen_line_starting_pos(State, State.screen_top1.line)
local line = State.lines[State.screen_top1.line]
local line_cache = State.line_cache[State.screen_top1.line]
for i=2,#line_cache.screen_line_starting_pos do
local pos = line_cache.screen_line_starting_pos[i]
if pos == State.screen_top1.pos then
break
end
if pos > State.screen_top1.pos then
-- make sure screen top is at start of a screen line
local prev = line_cache.screen_line_starting_pos[i-1]
if State.screen_top1.pos - prev < pos - State.screen_top1.pos then
State.screen_top1.pos = prev
else
State.screen_top1.pos = pos
end
break
end
end
-- make sure cursor is on screen
if Text.lt1(State.cursor1, State.screen_top1) then
State.cursor1 = {line=State.screen_top1.line, pos=State.screen_top1.pos}
elseif State.cursor1.line >= State.screen_bottom1.line then
--? print('too low')
if Text.cursor_out_of_screen(State) then
--? print('tweak')
State.cursor1 = {
line=State.screen_bottom1.line,
pos=Text.to_pos_on_line(State, State.screen_bottom1.line, State.right-5, App.screen.height-5),
}
end
end
end
-- slightly expensive since it redraws the screen
function Text.cursor_out_of_screen(State)
App.draw()
return State.cursor_y == nil
-- this approach is cheaper and almost works, except on the final screen
-- where file ends above bottom of screen
--? local botpos = Text.pos_at_start_of_screen_line(State, State.cursor1)
--? local botline1 = {line=State.cursor1.line, pos=botpos}
--? return Text.lt1(State.screen_bottom1, botline1)
end
function Text.redraw_all(State)
--? print('clearing fragments')
State.line_cache = {}
for i=1,#State.lines do
State.line_cache[i] = {}
end
end
function Text.clear_screen_line_cache(State, line_index)
State.line_cache[line_index].fragments = nil
State.line_cache[line_index].screen_line_starting_pos = nil
end
function trim(s)
return s:gsub('^%s+', ''):gsub('%s+$', '')
end
function ltrim(s)
return s:gsub('^%s+', '')
end
function rtrim(s)
return s:gsub('%s+$', '')
end
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