source_edit.lua

   1 -- some constants people might like to tweak
   2 Text_color = {r=0, g=0, b=0}
   3 Cursor_color = {r=1, g=0, b=0}
   4 Hyperlink_decoration_color = {r=0.4, g=0.4, b=1}
   5 Stroke_color = {r=0, g=0, b=0}
   6 Current_stroke_color = {r=0.7, g=0.7, b=0.7}  -- in process of being drawn
   7 Current_name_background_color = {r=1, g=0, b=0, a=0.1}  -- name currently being edited
   8 Focus_stroke_color = {r=1, g=0, b=0}  -- what mouse is hovering over
   9 Highlight_color = {r=0.7, g=0.7, b=0.9}  -- selected text
  10 Line_number_color = {r=0.6, g=0.6, b=0.6}
  11 Icon_color = {r=0.7, g=0.7, b=0.7}  -- color of current mode icon in drawings
  12 Help_color = {r=0, g=0.5, b=0}
  13 Help_background_color = {r=0, g=0.5, b=0, a=0.1}
  14
  15 Margin_top = 15
  16 Margin_left = 25
  17 Margin_right = 25
  18
  19 Drawing_padding_top = 10
  20 Drawing_padding_bottom = 10
  21 Drawing_padding_height = Drawing_padding_top + Drawing_padding_bottom
  22
  23 Same_point_distance = 4  -- pixel distance at which two points are considered the same
  24
  25 edit = {}
  26
  27 -- run in both tests and a real run
  28 function edit.initialize_state(top, left, right, font_height, line_height)  -- currently always draws to bottom of screen
  29   local result = {
  30     -- a line is either text or a drawing
  31     -- a text is a table with:
  32     --    mode = 'text',
  33     --    string data,
  34     -- a drawing is a table with:
  35     --    mode = 'drawing'
  36     --    a (y) coord in pixels (updated while painting screen),
  37     --    a (h)eight,
  38     --    an array of points, and
  39     --    an array of shapes
  40     -- a shape is a table containing:
  41     --    a mode
  42     --    an array points for mode 'freehand' (raw x,y coords; freehand drawings don't pollute the points array of a drawing)
  43     --    an array vertices for mode 'polygon', 'rectangle', 'square'
  44     --    p1, p2 for mode 'line'
  45     --    center, radius for mode 'circle'
  46     --    center, radius, start_angle, end_angle for mode 'arc'
  47     -- Unless otherwise specified, coord fields are normalized; a drawing is always 256 units wide
  48     -- The field names are carefully chosen so that switching modes in midstream
  49     -- remembers previously entered points where that makes sense.
  50     lines = {{mode='text', data=''}},  -- array of lines
  51
  52     -- Lines can be too long to fit on screen, in which case they _wrap_ into
  53     -- multiple _screen lines_.
  54
  55     -- rendering wrapped text lines needs some additional short-lived data per line:
  56     --   startpos, the index of data the line starts rendering from, can only be >1 for topmost line on screen
  57     --   starty, the y coord in pixels the line starts rendering from
  58     --   fragments: snippets of the line guaranteed to not straddle screen lines
  59     --   screen_line_starting_pos: optional array of grapheme indices if it wraps over more than one screen line
  60     line_cache = {},
  61
  62     -- Given wrapping, any potential location for the text cursor can be described in two ways:
  63     -- * schema 1: As a combination of line index and position within a line (in utf8 codepoint units)
  64     -- * schema 2: As a combination of line index, screen line index within the line, and a position within the screen line.
  65     --
  66     -- Most of the time we'll only persist positions in schema 1, translating to
  67     -- schema 2 when that's convenient.
  68     --
  69     -- Make sure these coordinates are never aliased, so that changing one causes
  70     -- action at a distance.
  71     screen_top1 = {line=1, pos=1},  -- position of start of screen line at top of screen
  72     cursor1 = {line=1, pos=1},  -- position of cursor
  73     screen_bottom1 = {line=1, pos=1},  -- position of start of screen line at bottom of screen
  74
  75     selection1 = {},
  76     -- some extra state to compute selection between mouse press and release
  77     old_cursor1 = nil,
  78     old_selection1 = nil,
  79     mousepress_shift = nil,
  80
  81     -- cursor coordinates in pixels
  82     cursor_x = 0,
  83     cursor_y = 0,
  84
  85     current_drawing_mode = 'line',
  86     previous_drawing_mode = nil,  -- extra state for some ephemeral modes like moving/deleting/naming points
  87
  88     font_height = font_height,
  89     line_height = line_height,
  90
  91     top = top,
  92     left = math.floor(left),
  93     right = math.floor(right),
  94     width = right-left,
  95
  96     filename = love.filesystem.getSourceBaseDirectory()..'/lines.txt',  -- '/' should work even on Windows
  97     next_save = nil,
  98
  99     -- undo
 100     history = {},
 101     next_history = 1,
 102
 103     -- search
 104     search_term = nil,
 105     search_backup = nil,  -- stuff to restore when cancelling search
 106   }
 107   return result
 108 end  -- App.initialize_state
 109
 110 function edit.check_locs(State)
 111   -- if State is inconsistent (i.e. file changed by some other program),
 112   --   throw away all cursor state entirely
 113   if edit.invalid1(State, State.screen_top1)
 114       or edit.invalid1(State, State.cursor1)
 115       or not edit.cursor_on_text(State)
 116       or not Text.le1(State.screen_top1, State.cursor1) then
 117     State.screen_top1 = {line=1, pos=1}
 118     edit.put_cursor_on_first_text_line(State)
 119   end
 120 end
 121
 122 function edit.invalid1(State, loc1)
 123   if loc1.line > #State.lines then return true end
 124   local l = State.lines[loc1.line]
 125   if l.mode ~= 'text' then return false end  -- pos is irrelevant to validity for a drawing line
 126   return loc1.pos > #State.lines[loc1.line].data
 127 end
 128
 129 function edit.cursor_on_text(State)
 130   return State.cursor1.line <= #State.lines
 131       and State.lines[State.cursor1.line].mode == 'text'
 132 end
 133
 134 function edit.put_cursor_on_first_text_line(State)
 135   for i,line in ipairs(State.lines) do
 136     if line.mode == 'text' then
 137       State.cursor1 = {line=i, pos=1}
 138       break
 139     end
 140   end
 141 end
 142
 143 function edit.draw(State, hide_cursor)
 144   State.button_handlers = {}
 145   App.color(Text_color)
 146   if #State.lines ~= #State.line_cache then
 147     print(('line_cache is out of date; %d when it should be %d'):format(#State.line_cache, #State.lines))
 148     assert(false)
 149   end
 150   if not Text.le1(State.screen_top1, State.cursor1) then
 151     print(State.screen_top1.line, State.screen_top1.pos, State.cursor1.line, State.cursor1.pos)
 152     assert(false)
 153   end
 154   State.cursor_x = nil
 155   State.cursor_y = nil
 156   local y = State.top
 157   local screen_bottom1 = {line=nil, pos=nil}
 158 --?   print('== draw')
 159   for line_index = State.screen_top1.line,#State.lines do
 160     local line = State.lines[line_index]
 161 --?     print('draw:', y, line_index, line)
 162     if y + State.line_height > App.screen.height then break end
 163     screen_bottom1.line = line_index
 164     if line.mode == 'text' then
 165 --?       print('text.draw', y, line_index)
 166       local startpos = 1
 167       if line_index == State.screen_top1.line then
 168         startpos = State.screen_top1.pos
 169       end
 170       if line.data == '' then
 171         -- button to insert new drawing
 172         button(State, 'draw', {x=4, y=y+4, w=12,h=12, color={1,1,0},
 173           icon = icon.insert_drawing,
 174           onpress1 = function()
 175                        Drawing.before = snapshot(State, line_index-1, line_index)
 176                        table.insert(State.lines, line_index, {mode='drawing', y=y, h=256/2, points={}, shapes={}, pending={}})
 177                        table.insert(State.line_cache, line_index, {})
 178                        if State.cursor1.line >= line_index then
 179                          State.cursor1.line = State.cursor1.line+1
 180                        end
 181                        schedule_save(State)
 182                        record_undo_event(State, {before=Drawing.before, after=snapshot(State, line_index-1, line_index+1)})
 183                      end,
 184         })
 185       end
 186       y, screen_bottom1.pos = Text.draw(State, line_index, y, startpos, hide_cursor)
 187 --?       print('=> y', y)
 188     elseif line.mode == 'drawing' then
 189       y = y+Drawing_padding_top
 190       Drawing.draw(State, line_index, y)
 191       y = y + Drawing.pixels(line.h, State.width) + Drawing_padding_bottom
 192     else
 193       print(line.mode)
 194       assert(false)
 195     end
 196   end
 197   State.screen_bottom1 = screen_bottom1
 198   if State.search_term then
 199     Text.draw_search_bar(State)
 200   end
 201 end
 202
 203 function edit.update(State, dt)
 204   Drawing.update(State, dt)
 205   if State.next_save and State.next_save < Current_time then
 206     save_to_disk(State)
 207     State.next_save = nil
 208   end
 209 end
 210
 211 function schedule_save(State)
 212   if State.next_save == nil then
 213     State.next_save = Current_time + 3  -- short enough that you're likely to still remember what you did
 214   end
 215 end
 216
 217 function edit.quit(State)
 218   -- make sure to save before quitting
 219   if State.next_save then
 220     save_to_disk(State)
 221     -- give some time for the OS to flush everything to disk
 222     love.timer.sleep(0.1)
 223   end
 224 end
 225
 226 function edit.mouse_press(State, x,y, mouse_button)
 227   if State.search_term then return end
 228 --?   print_and_log(('edit.mouse_press: cursor at %d,%d'):format(State.cursor1.line, State.cursor1.pos))
 229   if mouse_press_consumed_by_any_button_handler(State, x,y, mouse_button) then
 230     -- press on a button and it returned 'true' to short-circuit
 231     return
 232   end
 233
 234   if y < State.top then
 235     State.old_cursor1 = State.cursor1
 236     State.old_selection1 = State.selection1
 237     State.mousepress_shift = App.shift_down()
 238     State.selection1 = {
 239         line=State.screen_top1.line,
 240         pos=State.screen_top1.pos,
 241     }
 242     return
 243   end
 244
 245   for line_index,line in ipairs(State.lines) do
 246     if line.mode == 'text' then
 247       if Text.in_line(State, line_index, x,y) then
 248         -- delicate dance between cursor, selection and old cursor/selection
 249         -- scenarios:
 250         --  regular press+release: sets cursor, clears selection
 251         --  shift press+release:
 252         --    sets selection to old cursor if not set otherwise leaves it untouched
 253         --    sets cursor
 254         --  press and hold to start a selection: sets selection on press, cursor on release
 255         --  press and hold, then press shift: ignore shift
 256         --    i.e. mouse_release should never look at shift state
 257 --?         print_and_log(('edit.mouse_press: in line %d'):format(line_index))
 258         State.old_cursor1 = State.cursor1
 259         State.old_selection1 = State.selection1
 260         State.mousepress_shift = App.shift_down()
 261         State.selection1 = {
 262             line=line_index,
 263             pos=Text.to_pos_on_line(State, line_index, x, y),
 264         }
 265         return
 266       end
 267     elseif line.mode == 'drawing' then
 268       local line_cache = State.line_cache[line_index]
 269       if Drawing.in_drawing(line, line_cache, x, y, State.left,State.right) then
 270         State.lines.current_drawing_index = line_index
 271         State.lines.current_drawing = line
 272         Drawing.before = snapshot(State, line_index)
 273         Drawing.mouse_press(State, line_index, x,y, mouse_button)
 274         return
 275       end
 276     end
 277   end
 278
 279   -- still here? click is below all screen lines
 280   State.old_cursor1 = State.cursor1
 281   State.old_selection1 = State.selection1
 282   State.mousepress_shift = App.shift_down()
 283   State.selection1 = {
 284       line=State.screen_bottom1.line,
 285       pos=Text.pos_at_end_of_screen_line(State, State.screen_bottom1),
 286   }
 287 end
 288
 289 function edit.mouse_release(State, x,y, mouse_button)
 290   if State.search_term then return end
 291 --?   print_and_log(('edit.mouse_release: cursor at %d,%d'):format(State.cursor1.line, State.cursor1.pos))
 292   if State.lines.current_drawing then
 293     Drawing.mouse_release(State, x,y, mouse_button)
 294     schedule_save(State)
 295     if Drawing.before then
 296       record_undo_event(State, {before=Drawing.before, after=snapshot(State, State.lines.current_drawing_index)})
 297       Drawing.before = nil
 298     end
 299   else
 300 --?     print_and_log('edit.mouse_release: no current drawing')
 301     for line_index,line in ipairs(State.lines) do
 302       if line.mode == 'text' then
 303         if Text.in_line(State, line_index, x,y) then
 304 --?           print_and_log(('edit.mouse_release: in line %d'):format(line_index))
 305           State.cursor1 = {
 306               line=line_index,
 307               pos=Text.to_pos_on_line(State, line_index, x, y),
 308           }
 309 --?           print_and_log(('edit.mouse_release: cursor now %d,%d'):format(State.cursor1.line, State.cursor1.pos))
 310           if State.mousepress_shift then
 311             if State.old_selection1.line == nil then
 312               State.selection1 = State.old_cursor1
 313             else
 314               State.selection1 = State.old_selection1
 315             end
 316           end
 317           State.old_cursor1, State.old_selection1, State.mousepress_shift = nil
 318           if eq(State.cursor1, State.selection1) then
 319             State.selection1 = {}
 320           end
 321           break
 322         end
 323       end
 324     end
 325 --?     print_and_log(('edit.mouse_release: finally selection %s,%s cursor %d,%d'):format(tostring(State.selection1.line), tostring(State.selection1.pos), State.cursor1.line, State.cursor1.pos))
 326   end
 327 end
 328
 329 function edit.mouse_wheel_move(State, dx,dy)
 330   if dy > 0 then
 331     State.cursor1 = {line=State.screen_top1.line, pos=State.screen_top1.pos}
 332     for i=1,math.floor(dy) do
 333       Text.up(State)
 334     end
 335   elseif dy < 0 then
 336     State.cursor1 = {line=State.screen_bottom1.line, pos=State.screen_bottom1.pos}
 337     for i=1,math.floor(-dy) do
 338       Text.down(State)
 339     end
 340   end
 341 end
 342
 343 function edit.text_input(State, t)
 344 --?   print('text input', t)
 345   if State.search_term then
 346     State.search_term = State.search_term..t
 347     Text.search_next(State)
 348   elseif State.lines.current_drawing and State.current_drawing_mode == 'name' then
 349     local before = snapshot(State, State.lines.current_drawing_index)
 350     local drawing = State.lines.current_drawing
 351     local p = drawing.points[drawing.pending.target_point]
 352     p.name = p.name..t
 353     record_undo_event(State, {before=before, after=snapshot(State, State.lines.current_drawing_index)})
 354   else
 355     local drawing_index, drawing = Drawing.current_drawing(State)
 356     if drawing_index == nil then
 357       for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 358       Text.text_input(State, t)
 359     end
 360   end
 361   schedule_save(State)
 362 end
 363
 364 function edit.keychord_press(State, chord, key)
 365   if State.selection1.line and
 366       not State.lines.current_drawing and
 367       -- printable character created using shift key => delete selection
 368       -- (we're not creating any ctrl-shift- or alt-shift- combinations using regular/printable keys)
 369       (not App.shift_down() or utf8.len(key) == 1) and
 370       chord ~= 'C-a' and chord ~= 'C-c' and chord ~= 'C-x' and chord ~= 'backspace' and chord ~= 'delete' and chord ~= 'C-z' and chord ~= 'C-y' and not App.is_cursor_movement(chord) then
 371     Text.delete_selection(State, State.left, State.right)
 372   end
 373   if State.search_term then
 374     for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 375     if chord == 'escape' then
 376       State.search_term = nil
 377       State.cursor1 = State.search_backup.cursor
 378       State.screen_top1 = State.search_backup.screen_top
 379       State.search_backup = nil
 380       Text.redraw_all(State)  -- if we're scrolling, reclaim all fragments to avoid memory leaks
 381     elseif chord == 'return' then
 382       State.search_term = nil
 383       State.search_backup = nil
 384     elseif chord == 'backspace' then
 385       local len = utf8.len(State.search_term)
 386       local byte_offset = Text.offset(State.search_term, len)
 387       State.search_term = string.sub(State.search_term, 1, byte_offset-1)
 388     elseif chord == 'down' then
 389       State.cursor1.pos = State.cursor1.pos+1
 390       Text.search_next(State)
 391     elseif chord == 'up' then
 392       Text.search_previous(State)
 393     end
 394     return
 395   elseif chord == 'C-f' then
 396     State.search_term = ''
 397     State.search_backup = {
 398       cursor={line=State.cursor1.line, pos=State.cursor1.pos},
 399       screen_top={line=State.screen_top1.line, pos=State.screen_top1.pos},
 400     }
 401   -- zoom
 402   elseif chord == 'C-=' then
 403     edit.update_font_settings(State, State.font_height+2)
 404     Text.redraw_all(State)
 405   elseif chord == 'C--' then
 406     if State.font_height > 2 then
 407       edit.update_font_settings(State, State.font_height-2)
 408       Text.redraw_all(State)
 409     end
 410   elseif chord == 'C-0' then
 411     edit.update_font_settings(State, 20)
 412     Text.redraw_all(State)
 413   -- undo
 414   elseif chord == 'C-z' then
 415     for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 416     local event = undo_event(State)
 417     if event then
 418       local src = event.before
 419       State.screen_top1 = deepcopy(src.screen_top)
 420       State.cursor1 = deepcopy(src.cursor)
 421       State.selection1 = deepcopy(src.selection)
 422       patch(State.lines, event.after, event.before)
 423       patch_placeholders(State.line_cache, event.after, event.before)
 424       -- invalidate various cached bits of lines
 425       State.lines.current_drawing = nil
 426       -- if we're scrolling, reclaim all fragments to avoid memory leaks
 427       Text.redraw_all(State)
 428       schedule_save(State)
 429     end
 430   elseif chord == 'C-y' then
 431     for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 432     local event = redo_event(State)
 433     if event then
 434       local src = event.after
 435       State.screen_top1 = deepcopy(src.screen_top)
 436       State.cursor1 = deepcopy(src.cursor)
 437       State.selection1 = deepcopy(src.selection)
 438       patch(State.lines, event.before, event.after)
 439       -- invalidate various cached bits of lines
 440       State.lines.current_drawing = nil
 441       -- if we're scrolling, reclaim all fragments to avoid memory leaks
 442       Text.redraw_all(State)
 443       schedule_save(State)
 444     end
 445   -- clipboard
 446   elseif chord == 'C-a' then
 447     State.selection1 = {line=1, pos=1}
 448     State.cursor1 = {line=#State.lines, pos=utf8.len(State.lines[#State.lines].data)+1}
 449   elseif chord == 'C-c' then
 450     local s = Text.selection(State)
 451     if s then
 452       App.set_clipboard(s)
 453     end
 454   elseif chord == 'C-x' then
 455     for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 456     local s = Text.cut_selection(State, State.left, State.right)
 457     if s then
 458       App.set_clipboard(s)
 459     end
 460     schedule_save(State)
 461   elseif chord == 'C-v' then
 462     for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 463     -- We don't have a good sense of when to scroll, so we'll be conservative
 464     -- and sometimes scroll when we didn't quite need to.
 465     local before_line = State.cursor1.line
 466     local before = snapshot(State, before_line)
 467     local clipboard_data = App.get_clipboard()
 468     for _,code in utf8.codes(clipboard_data) do
 469       local c = utf8.char(code)
 470       if c == '\n' then
 471         Text.insert_return(State)
 472       else
 473         Text.insert_at_cursor(State, c)
 474       end
 475     end
 476     if Text.cursor_out_of_screen(State) then
 477       Text.snap_cursor_to_bottom_of_screen(State, State.left, State.right)
 478     end
 479     schedule_save(State)
 480     record_undo_event(State, {before=before, after=snapshot(State, before_line, State.cursor1.line)})
 481   -- dispatch to drawing or text
 482   elseif App.mouse_down(1) or chord:sub(1,2) == 'C-' then
 483     -- DON'T reset line_cache.starty here
 484     local drawing_index, drawing = Drawing.current_drawing(State)
 485     if drawing_index then
 486       local before = snapshot(State, drawing_index)
 487       Drawing.keychord_press(State, chord)
 488       record_undo_event(State, {before=before, after=snapshot(State, drawing_index)})
 489       schedule_save(State)
 490     end
 491   elseif chord == 'escape' and not App.mouse_down(1) then
 492     for _,line in ipairs(State.lines) do
 493       if line.mode == 'drawing' then
 494         line.show_help = false
 495       end
 496     end
 497   elseif State.lines.current_drawing and State.current_drawing_mode == 'name' then
 498     if chord == 'return' then
 499       State.current_drawing_mode = State.previous_drawing_mode
 500       State.previous_drawing_mode = nil
 501     else
 502       local before = snapshot(State, State.lines.current_drawing_index)
 503       local drawing = State.lines.current_drawing
 504       local p = drawing.points[drawing.pending.target_point]
 505       if chord == 'escape' then
 506         p.name = nil
 507         record_undo_event(State, {before=before, after=snapshot(State, State.lines.current_drawing_index)})
 508       elseif chord == 'backspace' then
 509         local len = utf8.len(p.name)
 510         if len > 0 then
 511           local byte_offset = Text.offset(p.name, len-1)
 512           if len == 1 then byte_offset = 0 end
 513           p.name = string.sub(p.name, 1, byte_offset)
 514           record_undo_event(State, {before=before, after=snapshot(State, State.lines.current_drawing_index)})
 515         end
 516       end
 517     end
 518     schedule_save(State)
 519   else
 520     for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 521     Text.keychord_press(State, chord)
 522   end
 523 end
 524
 525 function edit.key_release(State, key, scancode)
 526 end
 527
 528 function edit.update_font_settings(State, font_height)
 529   State.font_height = font_height
 530   love.graphics.setFont(love.graphics.newFont(State.font_height))
 531   State.line_height = math.floor(font_height*1.3)
 532 end
 533
 534 --== some methods for tests
 535
 536 -- Insulate tests from some key globals so I don't have to change the vast
 537 -- majority of tests when they're modified for the real app.
 538 Test_margin_left = 25
 539 Test_margin_right = 0
 540
 541 function edit.initialize_test_state()
 542   -- if you change these values, tests will start failing
 543   return edit.initialize_state(
 544       15,  -- top margin
 545       Test_margin_left,
 546       App.screen.width - Test_margin_right,
 547       14,  -- font height assuming default LÖVE font
 548       15)  -- line height
 549 end
 550
 551 -- all text_input events are also keypresses
 552 -- TODO: handle chords of multiple keys
 553 function edit.run_after_text_input(State, t)
 554   edit.keychord_press(State, t)
 555   edit.text_input(State, t)
 556   edit.key_release(State, t)
 557   App.screen.contents = {}
 558   edit.update(State, 0)
 559   edit.draw(State)
 560 end
 561
 562 -- not all keys are text_input
 563 function edit.run_after_keychord(State, chord)
 564   edit.keychord_press(State, chord)
 565   edit.key_release(State, chord)
 566   App.screen.contents = {}
 567   edit.update(State, 0)
 568   edit.draw(State)
 569 end
 570
 571 function edit.run_after_mouse_click(State, x,y, mouse_button)
 572   App.fake_mouse_press(x,y, mouse_button)
 573   edit.mouse_press(State, x,y, mouse_button)
 574   App.fake_mouse_release(x,y, mouse_button)
 575   edit.mouse_release(State, x,y, mouse_button)
 576   App.screen.contents = {}
 577   edit.update(State, 0)
 578   edit.draw(State)
 579 end
 580
 581 function edit.run_after_mouse_press(State, x,y, mouse_button)
 582   App.fake_mouse_press(x,y, mouse_button)
 583   edit.mouse_press(State, x,y, mouse_button)
 584   App.screen.contents = {}
 585   edit.update(State, 0)
 586   edit.draw(State)
 587 end
 588
 589 function edit.run_after_mouse_release(State, x,y, mouse_button)
 590   App.fake_mouse_release(x,y, mouse_button)
 591   edit.mouse_release(State, x,y, mouse_button)
 592   App.screen.contents = {}
 593   edit.update(State, 0)
 594   edit.draw(State)
 595 end