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),  -- left margin for text; line numbers go to the left of this
  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     State.cursor1 = {line=1, pos=1}
 119     edit.put_cursor_on_next_text_line(State)
 120   end
 121 end
 122
 123 function edit.invalid1(State, loc1)
 124   if loc1.line > #State.lines then return true end
 125   local l = State.lines[loc1.line]
 126   if l.mode ~= 'text' then return false end  -- pos is irrelevant to validity for a drawing line
 127   return loc1.pos > #State.lines[loc1.line].data
 128 end
 129
 130 function edit.cursor_on_text(State)
 131   return State.cursor1.line <= #State.lines
 132       and State.lines[State.cursor1.line].mode == 'text'
 133 end
 134
 135 function edit.put_cursor_on_next_text_line(State)
 136   while true do
 137   if State.cursor1.line >= #State.lines then
 138     break
 139   end
 140   if State.lines[State.cursor1.line].mode == 'text' then
 141     break
 142   end
 143   State.cursor1.line = State.cursor1.line+1
 144   State.cursor1.pos = 1
 145   end
 146 end
 147
 148 function edit.draw(State, hide_cursor, show_line_numbers)
 149   State.button_handlers = {}
 150   App.color(Text_color)
 151   if #State.lines ~= #State.line_cache then
 152     print(('line_cache is out of date; %d when it should be %d'):format(#State.line_cache, #State.lines))
 153     assert(false)
 154   end
 155   if not Text.le1(State.screen_top1, State.cursor1) then
 156     print(State.screen_top1.line, State.screen_top1.pos, State.cursor1.line, State.cursor1.pos)
 157     assert(false)
 158   end
 159   State.cursor_x = nil
 160   State.cursor_y = nil
 161   local y = State.top
 162   local screen_bottom1 = {line=nil, pos=nil}
 163 --?   print('== draw')
 164   for line_index = State.screen_top1.line,#State.lines do
 165     local line = State.lines[line_index]
 166 --?     print('draw:', y, line_index, line)
 167     if y + State.line_height > App.screen.height then break end
 168     screen_bottom1.line = line_index
 169     if line.mode == 'text' then
 170 --?       print('text.draw', y, line_index)
 171       local startpos = 1
 172       if line_index == State.screen_top1.line then
 173         startpos = State.screen_top1.pos
 174       end
 175       if line.data == '' then
 176         -- button to insert new drawing
 177         local buttonx = State.left-Margin_left+4
 178         if show_line_numbers then
 179           buttonx = 4  -- HACK: position draw buttons at a fixed x on screen
 180         end
 181         button(State, 'draw', {x=buttonx, y=y+4, w=12,h=12, color={1,1,0},
 182           icon = icon.insert_drawing,
 183           onpress1 = function()
 184                        Drawing.before = snapshot(State, line_index-1, line_index)
 185                        table.insert(State.lines, line_index, {mode='drawing', y=y, h=256/2, points={}, shapes={}, pending={}})
 186                        table.insert(State.line_cache, line_index, {})
 187                        if State.cursor1.line >= line_index then
 188                          State.cursor1.line = State.cursor1.line+1
 189                        end
 190                        schedule_save(State)
 191                        record_undo_event(State, {before=Drawing.before, after=snapshot(State, line_index-1, line_index+1)})
 192                      end,
 193         })
 194       end
 195       y, screen_bottom1.pos = Text.draw(State, line_index, y, startpos, hide_cursor, show_line_numbers)
 196 --?       print('=> y', y)
 197     elseif line.mode == 'drawing' then
 198       y = y+Drawing_padding_top
 199       Drawing.draw(State, line_index, y)
 200       y = y + Drawing.pixels(line.h, State.width) + Drawing_padding_bottom
 201     else
 202       print(line.mode)
 203       assert(false)
 204     end
 205   end
 206   State.screen_bottom1 = screen_bottom1
 207   if State.search_term then
 208     Text.draw_search_bar(State)
 209   end
 210 end
 211
 212 function edit.update(State, dt)
 213   Drawing.update(State, dt)
 214   if State.next_save and State.next_save < Current_time then
 215     save_to_disk(State)
 216     State.next_save = nil
 217   end
 218 end
 219
 220 function schedule_save(State)
 221   if State.next_save == nil then
 222     State.next_save = Current_time + 3  -- short enough that you're likely to still remember what you did
 223   end
 224 end
 225
 226 function edit.quit(State)
 227   -- make sure to save before quitting
 228   if State.next_save then
 229     save_to_disk(State)
 230     -- give some time for the OS to flush everything to disk
 231     love.timer.sleep(0.1)
 232   end
 233 end
 234
 235 function edit.mouse_press(State, x,y, mouse_button)
 236   if State.search_term then return end
 237 --?   print_and_log(('edit.mouse_press: cursor at %d,%d'):format(State.cursor1.line, State.cursor1.pos))
 238   if mouse_press_consumed_by_any_button_handler(State, x,y, mouse_button) then
 239     -- press on a button and it returned 'true' to short-circuit
 240     return
 241   end
 242
 243   if y < State.top then
 244     State.old_cursor1 = State.cursor1
 245     State.old_selection1 = State.selection1
 246     State.mousepress_shift = App.shift_down()
 247     State.selection1 = {
 248         line=State.screen_top1.line,
 249         pos=State.screen_top1.pos,
 250     }
 251     return
 252   end
 253
 254   for line_index,line in ipairs(State.lines) do
 255     if line.mode == 'text' then
 256       if Text.in_line(State, line_index, x,y) then
 257         -- delicate dance between cursor, selection and old cursor/selection
 258         -- scenarios:
 259         --  regular press+release: sets cursor, clears selection
 260         --  shift press+release:
 261         --    sets selection to old cursor if not set otherwise leaves it untouched
 262         --    sets cursor
 263         --  press and hold to start a selection: sets selection on press, cursor on release
 264         --  press and hold, then press shift: ignore shift
 265         --    i.e. mouse_release should never look at shift state
 266 --?         print_and_log(('edit.mouse_press: in line %d'):format(line_index))
 267         State.old_cursor1 = State.cursor1
 268         State.old_selection1 = State.selection1
 269         State.mousepress_shift = App.shift_down()
 270         State.selection1 = {
 271             line=line_index,
 272             pos=Text.to_pos_on_line(State, line_index, x, y),
 273         }
 274         return
 275       end
 276     elseif line.mode == 'drawing' then
 277       local line_cache = State.line_cache[line_index]
 278       if Drawing.in_drawing(line, line_cache, x, y, State.left,State.right) then
 279         State.lines.current_drawing_index = line_index
 280         State.lines.current_drawing = line
 281         Drawing.before = snapshot(State, line_index)
 282         Drawing.mouse_press(State, line_index, x,y, mouse_button)
 283         return
 284       end
 285     end
 286   end
 287
 288   -- still here? click is below all screen lines
 289   State.old_cursor1 = State.cursor1
 290   State.old_selection1 = State.selection1
 291   State.mousepress_shift = App.shift_down()
 292   State.selection1 = {
 293       line=State.screen_bottom1.line,
 294       pos=Text.pos_at_end_of_screen_line(State, State.screen_bottom1),
 295   }
 296 end
 297
 298 function edit.mouse_release(State, x,y, mouse_button)
 299   if State.search_term then return end
 300 --?   print_and_log(('edit.mouse_release: cursor at %d,%d'):format(State.cursor1.line, State.cursor1.pos))
 301   if State.lines.current_drawing then
 302     Drawing.mouse_release(State, x,y, mouse_button)
 303     schedule_save(State)
 304     if Drawing.before then
 305       record_undo_event(State, {before=Drawing.before, after=snapshot(State, State.lines.current_drawing_index)})
 306       Drawing.before = nil
 307     end
 308   else
 309 --?     print_and_log('edit.mouse_release: no current drawing')
 310     for line_index,line in ipairs(State.lines) do
 311       if line.mode == 'text' then
 312         if Text.in_line(State, line_index, x,y) then
 313 --?           print_and_log(('edit.mouse_release: in line %d'):format(line_index))
 314           State.cursor1 = {
 315               line=line_index,
 316               pos=Text.to_pos_on_line(State, line_index, x, y),
 317           }
 318 --?           print_and_log(('edit.mouse_release: cursor now %d,%d'):format(State.cursor1.line, State.cursor1.pos))
 319           if State.mousepress_shift then
 320             if State.old_selection1.line == nil then
 321               State.selection1 = State.old_cursor1
 322             else
 323               State.selection1 = State.old_selection1
 324             end
 325           end
 326           State.old_cursor1, State.old_selection1, State.mousepress_shift = nil
 327           if eq(State.cursor1, State.selection1) then
 328             State.selection1 = {}
 329           end
 330           break
 331         end
 332       end
 333     end
 334 --?     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))
 335   end
 336 end
 337
 338 function edit.mouse_wheel_move(State, dx,dy)
 339   if dy > 0 then
 340     State.cursor1 = {line=State.screen_top1.line, pos=State.screen_top1.pos}
 341     edit.put_cursor_on_next_text_line(State)
 342     for i=1,math.floor(dy) do
 343       Text.up(State)
 344     end
 345   elseif dy < 0 then
 346     State.cursor1 = {line=State.screen_bottom1.line, pos=State.screen_bottom1.pos}
 347     edit.put_cursor_on_next_text_line(State)
 348     for i=1,math.floor(-dy) do
 349       Text.down(State)
 350     end
 351   end
 352 end
 353
 354 function edit.text_input(State, t)
 355 --?   print('text input', t)
 356   if State.search_term then
 357     State.search_term = State.search_term..t
 358     Text.search_next(State)
 359   elseif State.lines.current_drawing and State.current_drawing_mode == 'name' then
 360     local before = snapshot(State, State.lines.current_drawing_index)
 361     local drawing = State.lines.current_drawing
 362     local p = drawing.points[drawing.pending.target_point]
 363     p.name = p.name..t
 364     record_undo_event(State, {before=before, after=snapshot(State, State.lines.current_drawing_index)})
 365   else
 366     local drawing_index, drawing = Drawing.current_drawing(State)
 367     if drawing_index == nil then
 368       for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 369       Text.text_input(State, t)
 370     end
 371   end
 372   schedule_save(State)
 373 end
 374
 375 function edit.keychord_press(State, chord, key)
 376   if State.selection1.line and
 377       not State.lines.current_drawing and
 378       -- printable character created using shift key => delete selection
 379       -- (we're not creating any ctrl-shift- or alt-shift- combinations using regular/printable keys)
 380       (not App.shift_down() or utf8.len(key) == 1) and
 381       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
 382     Text.delete_selection(State, State.left, State.right)
 383   end
 384   if State.search_term then
 385     for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 386     if chord == 'escape' then
 387       State.search_term = nil
 388       State.cursor1 = State.search_backup.cursor
 389       State.screen_top1 = State.search_backup.screen_top
 390       State.search_backup = nil
 391       Text.redraw_all(State)  -- if we're scrolling, reclaim all fragments to avoid memory leaks
 392     elseif chord == 'return' then
 393       State.search_term = nil
 394       State.search_backup = nil
 395     elseif chord == 'backspace' then
 396       local len = utf8.len(State.search_term)
 397       local byte_offset = Text.offset(State.search_term, len)
 398       State.search_term = string.sub(State.search_term, 1, byte_offset-1)
 399     elseif chord == 'down' then
 400       State.cursor1.pos = State.cursor1.pos+1
 401       Text.search_next(State)
 402     elseif chord == 'up' then
 403       Text.search_previous(State)
 404     end
 405     return
 406   elseif chord == 'C-f' then
 407     State.search_term = ''
 408     State.search_backup = {
 409       cursor={line=State.cursor1.line, pos=State.cursor1.pos},
 410       screen_top={line=State.screen_top1.line, pos=State.screen_top1.pos},
 411     }
 412   -- zoom
 413   elseif chord == 'C-=' then
 414     edit.update_font_settings(State, State.font_height+2)
 415     Text.redraw_all(State)
 416   elseif chord == 'C--' then
 417     if State.font_height > 2 then
 418       edit.update_font_settings(State, State.font_height-2)
 419       Text.redraw_all(State)
 420     end
 421   elseif chord == 'C-0' then
 422     edit.update_font_settings(State, 20)
 423     Text.redraw_all(State)
 424   -- undo
 425   elseif chord == 'C-z' then
 426     for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 427     local event = undo_event(State)
 428     if event then
 429       local src = event.before
 430       State.screen_top1 = deepcopy(src.screen_top)
 431       State.cursor1 = deepcopy(src.cursor)
 432       State.selection1 = deepcopy(src.selection)
 433       patch(State.lines, event.after, event.before)
 434       patch_placeholders(State.line_cache, event.after, event.before)
 435       -- invalidate various cached bits of lines
 436       State.lines.current_drawing = nil
 437       -- if we're scrolling, reclaim all fragments to avoid memory leaks
 438       Text.redraw_all(State)
 439       schedule_save(State)
 440     end
 441   elseif chord == 'C-y' then
 442     for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 443     local event = redo_event(State)
 444     if event then
 445       local src = event.after
 446       State.screen_top1 = deepcopy(src.screen_top)
 447       State.cursor1 = deepcopy(src.cursor)
 448       State.selection1 = deepcopy(src.selection)
 449       patch(State.lines, event.before, event.after)
 450       -- invalidate various cached bits of lines
 451       State.lines.current_drawing = nil
 452       -- if we're scrolling, reclaim all fragments to avoid memory leaks
 453       Text.redraw_all(State)
 454       schedule_save(State)
 455     end
 456   -- clipboard
 457   elseif chord == 'C-a' then
 458     State.selection1 = {line=1, pos=1}
 459     State.cursor1 = {line=#State.lines, pos=utf8.len(State.lines[#State.lines].data)+1}
 460   elseif chord == 'C-c' then
 461     local s = Text.selection(State)
 462     if s then
 463       App.set_clipboard(s)
 464     end
 465   elseif chord == 'C-x' then
 466     for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 467     local s = Text.cut_selection(State, State.left, State.right)
 468     if s then
 469       App.set_clipboard(s)
 470     end
 471     schedule_save(State)
 472   elseif chord == 'C-v' then
 473     for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 474     -- We don't have a good sense of when to scroll, so we'll be conservative
 475     -- and sometimes scroll when we didn't quite need to.
 476     local before_line = State.cursor1.line
 477     local before = snapshot(State, before_line)
 478     local clipboard_data = App.get_clipboard()
 479     for _,code in utf8.codes(clipboard_data) do
 480       local c = utf8.char(code)
 481       if c == '\n' then
 482         Text.insert_return(State)
 483       else
 484         Text.insert_at_cursor(State, c)
 485       end
 486     end
 487     if Text.cursor_out_of_screen(State) then
 488       Text.snap_cursor_to_bottom_of_screen(State, State.left, State.right)
 489     end
 490     schedule_save(State)
 491     record_undo_event(State, {before=before, after=snapshot(State, before_line, State.cursor1.line)})
 492   -- dispatch to drawing or text
 493   elseif App.mouse_down(1) or chord:sub(1,2) == 'C-' then
 494     -- DON'T reset line_cache.starty here
 495     local drawing_index, drawing = Drawing.current_drawing(State)
 496     if drawing_index then
 497       local before = snapshot(State, drawing_index)
 498       Drawing.keychord_press(State, chord)
 499       record_undo_event(State, {before=before, after=snapshot(State, drawing_index)})
 500       schedule_save(State)
 501     end
 502   elseif chord == 'escape' and not App.mouse_down(1) then
 503     for _,line in ipairs(State.lines) do
 504       if line.mode == 'drawing' then
 505         line.show_help = false
 506       end
 507     end
 508   elseif State.lines.current_drawing and State.current_drawing_mode == 'name' then
 509     if chord == 'return' then
 510       State.current_drawing_mode = State.previous_drawing_mode
 511       State.previous_drawing_mode = nil
 512     else
 513       local before = snapshot(State, State.lines.current_drawing_index)
 514       local drawing = State.lines.current_drawing
 515       local p = drawing.points[drawing.pending.target_point]
 516       if chord == 'escape' then
 517         p.name = nil
 518         record_undo_event(State, {before=before, after=snapshot(State, State.lines.current_drawing_index)})
 519       elseif chord == 'backspace' then
 520         local len = utf8.len(p.name)
 521         if len > 0 then
 522           local byte_offset = Text.offset(p.name, len-1)
 523           if len == 1 then byte_offset = 0 end
 524           p.name = string.sub(p.name, 1, byte_offset)
 525           record_undo_event(State, {before=before, after=snapshot(State, State.lines.current_drawing_index)})
 526         end
 527       end
 528     end
 529     schedule_save(State)
 530   else
 531     for _,line_cache in ipairs(State.line_cache) do line_cache.starty = nil end  -- just in case we scroll
 532     Text.keychord_press(State, chord)
 533   end
 534 end
 535
 536 function edit.key_release(State, key, scancode)
 537 end
 538
 539 function edit.update_font_settings(State, font_height)
 540   State.font_height = font_height
 541   love.graphics.setFont(love.graphics.newFont(State.font_height))
 542   State.line_height = math.floor(font_height*1.3)
 543 end
 544
 545 --== some methods for tests
 546
 547 -- Insulate tests from some key globals so I don't have to change the vast
 548 -- majority of tests when they're modified for the real app.
 549 Test_margin_left = 25
 550 Test_margin_right = 0
 551
 552 function edit.initialize_test_state()
 553   -- if you change these values, tests will start failing
 554   return edit.initialize_state(
 555       15,  -- top margin
 556       Test_margin_left,
 557       App.screen.width - Test_margin_right,
 558       14,  -- font height assuming default LÖVE font
 559       15)  -- line height
 560 end
 561
 562 -- all text_input events are also keypresses
 563 -- TODO: handle chords of multiple keys
 564 function edit.run_after_text_input(State, t)
 565   edit.keychord_press(State, t)
 566   edit.text_input(State, t)
 567   edit.key_release(State, t)
 568   App.screen.contents = {}
 569   edit.update(State, 0)
 570   edit.draw(State)
 571 end
 572
 573 -- not all keys are text_input
 574 function edit.run_after_keychord(State, chord)
 575   edit.keychord_press(State, chord)
 576   edit.key_release(State, chord)
 577   App.screen.contents = {}
 578   edit.update(State, 0)
 579   edit.draw(State)
 580 end
 581
 582 function edit.run_after_mouse_click(State, x,y, mouse_button)
 583   App.fake_mouse_press(x,y, mouse_button)
 584   edit.mouse_press(State, x,y, mouse_button)
 585   App.fake_mouse_release(x,y, mouse_button)
 586   edit.mouse_release(State, x,y, mouse_button)
 587   App.screen.contents = {}
 588   edit.update(State, 0)
 589   edit.draw(State)
 590 end
 591
 592 function edit.run_after_mouse_press(State, x,y, mouse_button)
 593   App.fake_mouse_press(x,y, mouse_button)
 594   edit.mouse_press(State, x,y, mouse_button)
 595   App.screen.contents = {}
 596   edit.update(State, 0)
 597   edit.draw(State)
 598 end
 599
 600 function edit.run_after_mouse_release(State, x,y, mouse_button)
 601   App.fake_mouse_release(x,y, mouse_button)
 602   edit.mouse_release(State, x,y, mouse_button)
 603   App.screen.contents = {}
 604   edit.update(State, 0)
 605   edit.draw(State)
 606 end