experiment: new edit namespace

Still lots to do, but the eventual hope is that this will make this
project's code easier to reuse from other LÖVE projects.

One gotcha: even as we start putting code more aggressively into nested
tables, tests must remain at the top-level. Otherwise they won't run.

1 files changed, 446 insertions, 0 deletions

diff --git a/edit.lua b/edit.lua
new file mode 100644
index 0000000..8ecbf24
--- /dev/null
+++ b/edit.lua
@@ -0,0 +1,446 @@
+utf8 = require 'utf8'
+
+require 'file'
+require 'button'
+require 'text'
+require 'drawing'
+require 'geom'
+require 'help'
+require 'icons'
+
+edit = {}
+
+-- run in both tests and a real run
+function edit.initialize_globals()
+-- a line is either text or a drawing
+-- a text is a table with:
+--    mode = 'text',
+--    string data,
+--    startpos, the index of data the line starts rendering from (if currently on screen), can only be >1 for topmost line on screen
+--    starty, the y coord in pixels
+--    some cached data that's blown away and recomputed when data changes:
+--      fragments: snippets of rendered love.graphics.Text, guaranteed to not wrap
+--      screen_line_starting_pos: optional array of grapheme indices if it wraps over more than one screen line
+-- a drawing is a table with:
+--    mode = 'drawing'
+--    a (y) coord in pixels (updated while painting screen),
+--    a (h)eight,
+--    an array of points, and
+--    an array of shapes
+-- a shape is a table containing:
+--    a mode
+--    an array points for mode 'freehand' (raw x,y coords; freehand drawings don't pollute the points array of a drawing)
+--    an array vertices for mode 'polygon', 'rectangle', 'square'
+--    p1, p2 for mode 'line'
+--    center, radius for mode 'circle'
+--    center, radius, start_angle, end_angle for mode 'arc'
+-- Unless otherwise specified, coord fields are normalized; a drawing is always 256 units wide
+-- The field names are carefully chosen so that switching modes in midstream
+-- remembers previously entered points where that makes sense.
+Lines = {{mode='text', data=''}}
+
+-- Lines can be too long to fit on screen, in which case they _wrap_ into
+-- multiple _screen lines_.
+--
+-- Therefore, any potential location for the cursor can be described in two ways:
+-- * schema 1: As a combination of line index and position within a line (in utf8 codepoint units)
+-- * schema 2: As a combination of line index, screen line index within the line, and a position within the screen line.
+--
+-- Most of the time we'll only persist positions in schema 1, translating to
+-- schema 2 when that's convenient.
+--
+-- Make sure these coordinates are never aliased, so that changing one causes
+-- action at a distance.
+Screen_top1 = {line=1, pos=1}  -- position of start of screen line at top of screen
+Cursor1 = {line=1, pos=1}  -- position of cursor
+Screen_bottom1 = {line=1, pos=1}  -- position of start of screen line at bottom of screen
+
+Selection1 = {}
+Old_cursor1, Old_selection1, Mousepress_shift = nil  -- some extra state to compute selection between mouse press and release
+Recent_mouse = {}  -- when selecting text, avoid recomputing some state on every single frame
+
+Cursor_x, Cursor_y = 0, 0  -- in pixels
+
+Current_drawing_mode = 'line'
+Previous_drawing_mode = nil
+
+-- values for tests
+Font_height = 14
+Line_height = 15
+-- widest possible character width
+Em = App.newText(love.graphics.getFont(), 'm')
+
+Margin_top = 15
+Margin_left = 25
+Margin_right = 25
+Margin_width = Margin_left + Margin_right
+
+Drawing_padding_top = 10
+Drawing_padding_bottom = 10
+Drawing_padding_height = Drawing_padding_top + Drawing_padding_bottom
+
+Filename = love.filesystem.getUserDirectory()..'/lines.txt'
+Next_save = nil
+
+-- undo
+History = {}
+Next_history = 1
+
+-- search
+Search_term = nil
+Search_text = nil
+Search_backup = nil  -- stuff to restore when cancelling search
+
+-- resize
+Last_resize_time = nil
+
+-- blinking cursor
+Cursor_time = 0
+
+end  -- App.initialize_globals
+
+function edit.draw()
+  Button_handlers = {}
+
+  love.graphics.setColor(0, 0, 0)
+--?   print(Screen_top1.line, Screen_top1.pos, Cursor1.line, Cursor1.pos)
+  assert(Text.le1(Screen_top1, Cursor1))
+  Cursor_y = -1
+  local y = Margin_top
+--?   print('== draw')
+  for line_index = Screen_top1.line,#Lines do
+    local line = Lines[line_index]
+--?     print('draw:', y, line_index, line)
+    if y + Line_height > App.screen.height then break end
+    Screen_bottom1.line = line_index
+    if line.mode == 'text' and line.data == '' then
+      line.starty = y
+      line.startpos = 1
+      -- insert new drawing
+      button('draw', {x=4,y=y+4, w=12,h=12, color={1,1,0},
+        icon = icon.insert_drawing,
+        onpress1 = function()
+                     Drawing.before = snapshot(line_index-1, line_index)
+                     table.insert(Lines, line_index, {mode='drawing', y=y, h=256/2, points={}, shapes={}, pending={}})
+                     if Cursor1.line >= line_index then
+                       Cursor1.line = Cursor1.line+1
+                     end
+                     schedule_save()
+                     record_undo_event({before=Drawing.before, after=snapshot(line_index-1, line_index+1)})
+                   end
+      })
+      if Search_term == nil then
+        if line_index == Cursor1.line then
+          Text.draw_cursor(Margin_left, y)
+        end
+      end
+      Screen_bottom1.pos = Screen_top1.pos
+      y = y + Line_height
+    elseif line.mode == 'drawing' then
+      y = y+Drawing_padding_top
+      line.y = y
+      Drawing.draw(line)
+      y = y + Drawing.pixels(line.h) + Drawing_padding_bottom
+    else
+      line.starty = y
+      line.startpos = 1
+      if line_index == Screen_top1.line then
+        line.startpos = Screen_top1.pos
+      end
+--?       print('text.draw', y, line_index)
+      y, Screen_bottom1.pos = Text.draw(line, line_index, line.starty, Margin_left, App.screen.width-Margin_right)
+      y = y + Line_height
+--?       print('=> y', y)
+    end
+  end
+  if Cursor_y == -1 then
+    Cursor_y = App.screen.height
+  end
+--?   print('screen bottom: '..tostring(Screen_bottom1.pos)..' in '..tostring(Lines[Screen_bottom1.line].data))
+  if Search_term then
+    Text.draw_search_bar()
+  end
+end
+
+function edit.update(dt)
+  Cursor_time = Cursor_time + dt
+  -- some hysteresis while resizing
+  if Last_resize_time then
+    if App.getTime() - Last_resize_time < 0.1 then
+      return
+    else
+      Last_resize_time = nil
+    end
+  end
+  Drawing.update(dt)
+  if Next_save and Next_save < App.getTime() then
+    save_to_disk(Lines, Filename)
+    Next_save = nil
+  end
+end
+
+function schedule_save()
+  if Next_save == nil then
+    Next_save = App.getTime() + 3  -- short enough that you're likely to still remember what you did
+  end
+end
+
+function edit.quit()
+  -- make sure to save before quitting
+  if Next_save then
+    save_to_disk(Lines, Filename)
+  end
+end
+
+function edit.mouse_pressed(x,y, mouse_button)
+  if Search_term then return end
+  -- ensure cursor is visible immediately after it moves
+  Cursor_time = 0
+--?   print('press', Selection1.line, Selection1.pos)
+  propagate_to_button_handlers(x,y, mouse_button)
+
+  for line_index,line in ipairs(Lines) do
+    if line.mode == 'text' then
+      if Text.in_line(line, x,y, Margin_left, App.screen.width-Margin_right) then
+        -- delicate dance between cursor, selection and old cursor/selection
+        -- scenarios:
+        --  regular press+release: sets cursor, clears selection
+        --  shift press+release:
+        --    sets selection to old cursor if not set otherwise leaves it untouched
+        --    sets cursor
+        --  press and hold to start a selection: sets selection on press, cursor on release
+        --  press and hold, then press shift: ignore shift
+        --    i.e. mousereleased should never look at shift state
+        Old_cursor1 = Cursor1
+        Old_selection1 = Selection1
+        Mousepress_shift = App.shift_down()
+        Selection1 = {
+            line=line_index,
+            pos=Text.to_pos_on_line(line, x, y, Margin_left, App.screen.width-Margin_right),
+        }
+--?         print('selection', Selection1.line, Selection1.pos)
+        break
+      end
+    elseif line.mode == 'drawing' then
+      if Drawing.in_drawing(line, x, y) then
+        Lines.current_drawing_index = line_index
+        Lines.current_drawing = line
+        Drawing.before = snapshot(line_index)
+        Drawing.mouse_pressed(line, x,y, mouse_button)
+        break
+      end
+    end
+  end
+end
+
+function edit.mouse_released(x,y, mouse_button)
+  if Search_term then return end
+--?   print('release')
+  -- ensure cursor is visible immediately after it moves
+  Cursor_time = 0
+  if Lines.current_drawing then
+    Drawing.mouse_released(x,y, mouse_button)
+    schedule_save()
+    if Drawing.before then
+      record_undo_event({before=Drawing.before, after=snapshot(Lines.current_drawing_index)})
+      Drawing.before = nil
+    end
+  else
+    for line_index,line in ipairs(Lines) do
+      if line.mode == 'text' then
+        if Text.in_line(line, x,y, Margin_left, App.screen.width-Margin_right) then
+--?           print('reset selection')
+          Cursor1 = {
+              line=line_index,
+              pos=Text.to_pos_on_line(line, x, y, Margin_left, App.screen.width-Margin_right),
+          }
+--?           print('cursor', Cursor1.line, Cursor1.pos)
+          if Mousepress_shift then
+            if Old_selection1.line == nil then
+              Selection1 = Old_cursor1
+            else
+              Selection1 = Old_selection1
+            end
+          end
+          Old_cursor1, Old_selection1, Mousepress_shift = nil
+          if eq(Cursor1, Selection1) then
+            Selection1 = {}
+          end
+          break
+        end
+      end
+    end
+--?     print('selection:', Selection1.line, Selection1.pos)
+  end
+end
+
+function edit.textinput(t)
+  -- ensure cursor is visible immediately after it moves
+  Cursor_time = 0
+  for _,line in ipairs(Lines) do line.y = nil end  -- just in case we scroll
+  if Search_term then
+    Search_term = Search_term..t
+    Search_text = nil
+    Text.search_next()
+  elseif Current_drawing_mode == 'name' then
+    local before = snapshot(Lines.current_drawing_index)
+    local drawing = Lines.current_drawing
+    local p = drawing.points[drawing.pending.target_point]
+    p.name = p.name..t
+    record_undo_event({before=before, after=snapshot(Lines.current_drawing_index)})
+  else
+    Text.textinput(t)
+  end
+  schedule_save()
+end
+
+function edit.keychord_pressed(chord, key)
+  -- ensure cursor is visible immediately after it moves
+  Cursor_time = 0
+  if Selection1.line and
+      not Lines.current_drawing and
+      -- printable character created using shift key => delete selection
+      -- (we're not creating any ctrl-shift- or alt-shift- combinations using regular/printable keys)
+      (not App.shift_down() or utf8.len(key) == 1) and
+      chord ~= 'C-c' and chord ~= 'C-x' and chord ~= 'backspace' and backspace ~= 'delete' and not App.is_cursor_movement(chord) then
+    Text.delete_selection(Margin_left, App.screen.width-Margin_right)
+  end
+  if Search_term then
+    if chord == 'escape' then
+      Search_term = nil
+      Search_text = nil
+      Cursor1 = Search_backup.cursor
+      Screen_top1 = Search_backup.screen_top
+      Search_backup = nil
+      Text.redraw_all()  -- if we're scrolling, reclaim all fragments to avoid memory leaks
+    elseif chord == 'return' then
+      Search_term = nil
+      Search_text = nil
+      Search_backup = nil
+    elseif chord == 'backspace' then
+      local len = utf8.len(Search_term)
+      local byte_offset = Text.offset(Search_term, len)
+      Search_term = string.sub(Search_term, 1, byte_offset-1)
+      Search_text = nil
+    elseif chord == 'down' then
+      Cursor1.pos = Cursor1.pos+1
+      Text.search_next()
+    elseif chord == 'up' then
+      Text.search_previous()
+    end
+    return
+  elseif chord == 'C-f' then
+    Search_term = ''
+    Search_backup = {cursor={line=Cursor1.line, pos=Cursor1.pos}, screen_top={line=Screen_top1.line, pos=Screen_top1.pos}}
+    assert(Search_text == nil)
+  elseif chord == 'C-=' then
+    initialize_font_settings(Font_height+2)
+    Text.redraw_all()
+  elseif chord == 'C--' then
+    initialize_font_settings(Font_height-2)
+    Text.redraw_all()
+  elseif chord == 'C-0' then
+    initialize_font_settings(20)
+    Text.redraw_all()
+  elseif chord == 'C-z' then
+    for _,line in ipairs(Lines) do line.y = nil end  -- just in case we scroll
+    local event = undo_event()
+    if event then
+      local src = event.before
+      Screen_top1 = deepcopy(src.screen_top)
+      Cursor1 = deepcopy(src.cursor)
+      Selection1 = deepcopy(src.selection)
+      patch(Lines, event.after, event.before)
+      Text.redraw_all()  -- if we're scrolling, reclaim all fragments to avoid memory leaks
+      schedule_save()
+    end
+  elseif chord == 'C-y' then
+    for _,line in ipairs(Lines) do line.y = nil end  -- just in case we scroll
+    local event = redo_event()
+    if event then
+      local src = event.after
+      Screen_top1 = deepcopy(src.screen_top)
+      Cursor1 = deepcopy(src.cursor)
+      Selection1 = deepcopy(src.selection)
+      patch(Lines, event.before, event.after)
+      Text.redraw_all()  -- if we're scrolling, reclaim all fragments to avoid memory leaks
+      schedule_save()
+    end
+  -- clipboard
+  elseif chord == 'C-c' then
+    for _,line in ipairs(Lines) do line.y = nil end  -- just in case we scroll
+    local s = Text.selection()
+    if s then
+      App.setClipboardText(s)
+    end
+  elseif chord == 'C-x' then
+    for _,line in ipairs(Lines) do line.y = nil end  -- just in case we scroll
+    local s = Text.cut_selection(Margin_left, App.screen.width-Margin_right)
+    if s then
+      App.setClipboardText(s)
+    end
+    schedule_save()
+  elseif chord == 'C-v' then
+    for _,line in ipairs(Lines) do line.y = nil end  -- just in case we scroll
+    -- We don't have a good sense of when to scroll, so we'll be conservative
+    -- and sometimes scroll when we didn't quite need to.
+    local before_line = Cursor1.line
+    local before = snapshot(before_line)
+    local clipboard_data = App.getClipboardText()
+    for _,code in utf8.codes(clipboard_data) do
+      local c = utf8.char(code)
+      if c == '\n' then
+        Text.insert_return()
+      else
+        Text.insert_at_cursor(c)
+      end
+    end
+    if Text.cursor_past_screen_bottom() then
+      Text.snap_cursor_to_bottom_of_screen(Margin_left, App.screen.height-Margin_right)
+    end
+    schedule_save()
+    record_undo_event({before=before, after=snapshot(before_line, Cursor1.line)})
+  -- dispatch to drawing or text
+  elseif App.mouse_down(1) or chord:sub(1,2) == 'C-' then
+    -- DON'T reset line.y here
+    local drawing_index, drawing = Drawing.current_drawing()
+    if drawing_index then
+      local before = snapshot(drawing_index)
+      Drawing.keychord_pressed(chord)
+      record_undo_event({before=before, after=snapshot(drawing_index)})
+      schedule_save()
+    end
+  elseif chord == 'escape' and not App.mouse_down(1) then
+    for _,line in ipairs(Lines) do
+      if line.mode == 'drawing' then
+        line.show_help = false
+      end
+    end
+  elseif Current_drawing_mode == 'name' then
+    if chord == 'return' then
+      Current_drawing_mode = Previous_drawing_mode
+      Previous_drawing_mode = nil
+    else
+      local before = snapshot(Lines.current_drawing_index)
+      local drawing = Lines.current_drawing
+      local p = drawing.points[drawing.pending.target_point]
+      if chord == 'escape' then
+        p.name = nil
+        record_undo_event({before=before, after=snapshot(Lines.current_drawing_index)})
+      elseif chord == 'backspace' then
+        local len = utf8.len(p.name)
+        local byte_offset = Text.offset(p.name, len-1)
+        if len == 1 then byte_offset = 0 end
+        p.name = string.sub(p.name, 1, byte_offset)
+        record_undo_event({before=before, after=snapshot(Lines.current_drawing_index)})
+      end
+    end
+    schedule_save()
+  else
+    for _,line in ipairs(Lines) do line.y = nil end  -- just in case we scroll
+    Text.keychord_pressed(chord)
+  end
+end
+
+function edit.key_released(key, scancode)
+end