pull a couple more functions into subx-common - mu - Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.

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author	Kartik Agaram <vc@akkartik.com>	2019-07-08 13:03:10 -0700
committer	Kartik Agaram <vc@akkartik.com>	2019-07-08 13:03:10 -0700
commit	de3d48163eadc77e2c0a0ed5951ae012bc940d7d (patch)
tree	01f83abc64cd6910753eb6f13451e7410a15e7d3 /subx/examples/ex8.subx
parent	925fc490d2ce8b8d411de87bd0af5b3a8a704213 (diff)
download	mu-de3d48163eadc77e2c0a0ed5951ae012bc940d7d.tar.gz

pull a couple more functions into subx-common

Diffstat (limited to 'subx/examples/ex8.subx')

0 files changed, 0 insertions, 0 deletions

-- 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 y for the next line, and position of start of final screen line drawn function Text.draw(State, line_index, y, startpos) --? print('text.draw', line_index, y) 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 final_screen_line_starting_pos = startpos -- track value to return Text.populate_screen_line_starting_pos(State, line_index) assert(#line_cache.screen_line_starting_pos >= 1) for i=1,#line_cache.screen_line_starting_pos do local pos = line_cache.screen_line_starting_pos[i] if pos < startpos then -- render nothing else final_screen_line_starting_pos = pos local screen_line = Text.screen_line(line, line_cache, i) --? print('text.draw:', screen_line, 'at', line_index,pos, 'after', x,y) local frag_len = utf8.len(screen_line) -- render any highlights if State.selection1.line then local lo, hi = Text.clip_selection(State, line_index, pos, pos+frag_len) Text.draw_highlight(State, line, State.left,y, pos, lo,hi) end if line_index == State.cursor1.line then -- render search highlight or cursor if State.search_term then local data = State.lines[State.cursor1.line].data local cursor_offset = Text.offset(data, State.cursor1.pos) if data:sub(cursor_offset, cursor_offset+#State.search_term-1) == State.search_term then local save_selection = State.selection1 State.selection1 = {line=line_index, pos=State.cursor1.pos+utf8.len(State.search_term)} local lo, hi = Text.clip_selection(State, line_index, pos, pos+frag_len) Text.draw_highlight(State, line, State.left,y, pos, lo,hi) State.selection1 = save_selection end else if pos <= State.cursor1.pos and pos + frag_len > State.cursor1.pos then Text.draw_cursor(State, State.left+Text.x(screen_line, State.cursor1.pos-pos+1), y) elseif pos + frag_len == State.cursor1.pos then -- Show cursor at end of line. -- This place also catches end of wrapping screen lines. That doesn't seem worth distinguishing. -- It seems useful to see a cursor whether your eye is on the left or right margin. Text.draw_cursor(State, State.left+Text.x(screen_line, State.cursor1.pos-pos+1), y) end end end -- render fragment App.color(Text_color) App.screen.print(screen_line, State.left,y) y = y + State.line_height if y >= App.screen.height then break end end end return y, final_screen_line_starting_pos end function Text.screen_line(line, line_cache, i) local pos = line_cache.screen_line_starting_pos[i] local offset = Text.offset(line.data, pos) if i >= #line_cache.screen_line_starting_pos then return line.data:sub(offset) end local endpos = line_cache.screen_line_starting_pos[i+1]-1 local end_offset = Text.offset(line.data, endpos) return line.data:sub(offset, end_offset) 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) 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 line_cache.screen_line_starting_pos = {1} local x = 0 local pos = 1 -- try to wrap at word boundaries for frag in line.data:gmatch('%S*%s*') do local frag_width = App.width(frag) --? print('-- frag:', frag, pos, x, frag_width, State.width) while x + frag_width > State.width do --? print('frag:', frag, pos, x, frag_width, State.width) if x < 0.8 * State.width then -- long word; chop it at some letter -- We're not going to reimplement TeX here. local bpos = Text.nearest_pos_less_than(frag, State.width - x) -- everything works if bpos == 0, but is a little inefficient pos = pos + bpos local boffset = Text.offset(frag, bpos+1) -- byte _after_ bpos frag = string.sub(frag, boffset) --? if bpos > 0 then --? print('after chop:', frag) --? end frag_width = App.width(frag) end --? print('screen line:', pos) table.insert(line_cache.screen_line_starting_pos, pos) x = 0 -- new screen line end x = x + frag_width pos = pos + utf8.len(frag) end end function Text.text_input(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) 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 text_input above. function Text.keychord_press(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 State.screen_top1 = { line=State.cursor1.line, pos=Text.pos_at_start_of_screen_line(State, State.cursor1), } 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, pos=nil} 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 State.screen_top1 = { line=State.cursor1.line, pos=Text.pos_at_start_of_screen_line(State, State.cursor1), } Text.redraw_all(State) -- if we're scrolling, reclaim all fragments to avoid memory leaks 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) assert(State.cursor1.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 State.screen_top1 = { line=State.cursor1.line, pos=Text.pos_at_start_of_screen_line(State, State.cursor1), } Text.redraw_all(State) -- if we're scrolling, reclaim all fragments to avoid memory leaks 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 -- result: pos, index of screen line 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.pos_at_end_of_screen_line(State, loc1) Text.populate_screen_line_starting_pos(State, loc1.line) local line_cache = State.line_cache[loc1.line] local most_recent_final_pos = utf8.len(State.lines[loc1.line].data)+1 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 most_recent_final_pos end most_recent_final_pos = spos-1 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.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 return App.width(screen_line) 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..'$', leftpos, rightpos) if leftpos == rightpos then return leftpos end local curr = math.floor((leftpos+rightpos)/2) local currxmin = left+Text.x(line, curr) local currxmax = left+Text.x(line, curr+1) --? print('nearest', x, leftpos, rightpos, curr, currxmin, currxmax) if currxmin <= x and x < currxmax then if x-currxmin < currxmax-x then return curr else return curr+1 end end if leftpos >= rightpos-1 then return rightpos end if currxmin > x then rightpos = curr else leftpos = curr end end assert(false) end -- return the nearest index of line (in utf8 code points) which lies entirely -- within x pixels of the left margin -- result: 0 to len+1 function Text.nearest_pos_less_than(line, x) --? print('', '-- nearest_pos_less_than', line, x) local len = utf8.len(line) local max_x = Text.x_after(line, len) if x > max_x then return len+1 end local left, right = 0, len+1 while true do local curr = math.floor((left+right)/2) local currxmin = Text.x_after(line, curr+1) local currxmax = Text.x_after(line, curr+2) --? print('', x, left, right, curr, currxmin, currxmax) if currxmin <= x and x < currxmax then return curr end if left >= right-1 then return left end if currxmin > x then right = curr else left = curr end end assert(false) end function Text.x_after(s, pos) local offset = Text.offset(s, math.min(pos+1, #s+1)) local s_before = s:sub(1, offset-1) --? print('^'..s_before..'$') return App.width(s_before) end function Text.x(s, pos) local offset = Text.offset(s, pos) local s_before = s:sub(1, offset-1) return App.width(s_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) 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) edit.draw(State) 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].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 function starts_with(s, prefix) if #s < #prefix then return false end for i=1,#prefix do if s:sub(i,i) ~= prefix:sub(i,i) then return false end end return true end function ends_with(s, suffix) if #s < #suffix then return false end for i=0,#suffix-1 do if s:sub(#s-i,#s-i) ~= suffix:sub(#suffix-i,#suffix-i) then return false end end return true end


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