view.love/main.lua
Kartik K. Agaram 8d5ac5da75 keep one screen line of overlap on pagedown
I'm now extracting the concern of computing
line.screen_line_starting_pos out of Text.draw. Earlier
I had to make sure I ran through the whole line to compute
screen_line_starting_pos, but that had the side-effect of updating
Screen_bottom1.pos as well with lines that had never been rendered.

In this process I hit my first bug due to an accidental global. It
doesn't show up in the patch because I accidentally deleted a local
declaration. (I thought I didn't need screen_line_starting_pos anymore,
deleted everywhere, then brought it back everywhere from the bottom of
the function up, but forgot to put back the very first occurrence.)

The amount of yoyoing this caused between App.draw and Text.draw, I very
much have spaghetti on my hands.

Accidental globals are _terrible_ in a program with tests. Cross test
contamination X-(
2022-05-23 22:51:52 -07:00

270 lines
8.8 KiB
Lua

local utf8 = require 'utf8'
require 'app'
require 'test'
require 'keychord'
require 'file'
require 'button'
local Text = require 'text'
local Drawing = require 'drawing'
local geom = require 'geom'
require 'help'
require 'icons'
function App.initialize(arg)
love.keyboard.setTextInput(true) -- bring up keyboard on touch screen
love.keyboard.setKeyRepeat(true)
-- globals
-- a line is either text or a drawing
-- a text is a table with:
-- mode = 'text'
-- string data
-- 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'
-- p1, p2, arrow-mode for mode 'arrow-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.
--
-- Open question: how to maintain Sketchpad-style constraints? Answer for now:
-- we don't. Constraints operate only for the duration of a drawing operation.
-- We'll continue to persist them just to keep the option open to continue
-- solving for them. But for now, this is a program to create static drawings
-- once, and read them passively thereafter.
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.
Cursor1 = {line=1, pos=1} -- position of cursor
Screen_top1 = {line=1, pos=1} -- position of start of screen line at top of screen
Screen_bottom1 = {line=1, pos=1} -- position of start of screen line at bottom of screen
-- maximize window
love.window.setMode(0, 0) -- maximize
App.screen.width, App.screen.height = love.window.getMode()
-- shrink slightly to account for window decoration
App.screen.width = App.screen.width-100
App.screen.height = App.screen.height-100
love.window.setMode(App.screen.width, App.screen.height)
--? App.screen.width = 120
--? App.screen.height = 200
--? love.window.setMode(App.screen.width, App.screen.height)
Cursor_x, Cursor_y = 0, 0 -- in pixels
Current_drawing_mode = 'line'
Previous_drawing_mode = nil
-- maximum width available to either text or drawings, in pixels
Line_width = math.floor(App.screen.width/2/40)*40
--? Line_width = 100
Zoom = 1.5
Filename = love.filesystem.getUserDirectory()..'/lines.txt'
Debug_main = false
-- still in App.initialize
if #arg > 0 then
Filename = arg[1]
end
Lines = load_from_disk(Filename)
for i,line in ipairs(Lines) do
if line.mode == 'text' then
Cursor1.line = i
break
end
end
love.window.setTitle('Text with Lines - '..Filename)
end -- App.initialize
function App.filedropped(file)
Filename = file:getFilename()
file:open('r')
Lines = load_from_file(file)
file:close()
for i,line in ipairs(Lines) do
if line.mode == 'text' then
Cursor1.line = i
break
end
end
love.window.setTitle('Text with Lines - '..Filename)
end
function App.draw()
Button_handlers = {}
love.graphics.setColor(1, 1, 1)
love.graphics.rectangle('fill', 0, 0, App.screen.width-1, App.screen.height-1)
love.graphics.setColor(0, 0, 0)
for line_index,line in ipairs(Lines) do
line.y = nil
end
local y = 15
if Debug_main then print('== draw') end
for line_index,line in ipairs(Lines) do
--? print(y, line_index, line)
if Debug_main then print('draw:', line_index, y) end
if y + math.floor(15*Zoom) > App.screen.height then break end
--? print('a')
if line_index >= Screen_top1.line then
Screen_bottom1.line = line_index
if line.mode == 'text' and line.data == '' then
line.y = y
button('draw', {x=4,y=y+4, w=12,h=12, color={1,1,0},
icon = icon.insert_drawing,
onpress1 = function()
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
end})
if line_index == Cursor1.line then
Text.draw_cursor(25, y)
end
y = y + math.floor(15*Zoom) -- text height
elseif line.mode == 'drawing' then
y = y+10 -- padding
line.y = y
Drawing.draw(line)
y = y + Drawing.pixels(line.h) + 10 -- padding
else
if Debug_main then print('text') end
line.y = y
y, Screen_bottom1.pos = Text.draw(line, Line_width, line_index)
y = y + math.floor(15*Zoom) -- text height
if Debug_main then print('aa', y) end
end
end
end
Debug_main = false
--? print('screen bottom: '..tostring(Screen_bottom1.pos)..' in '..tostring(Lines[Screen_bottom1.line].data))
--? os.exit(1)
end
function App.update(dt)
Drawing.update(dt)
end
function App.mousepressed(x,y, mouse_button)
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) then
Text.move_cursor(line_index, line, x, y)
end
elseif line.mode == 'drawing' then
if Drawing.in_drawing(line, x, y) then
Drawing.mouse_pressed(line, x,y, button)
end
end
end
end
function App.mousereleased(x,y, button)
Drawing.mouse_released(x,y, button)
end
function App.textinput(t)
if Current_drawing_mode == 'name' then
local drawing = Lines.current
local p = drawing.points[drawing.pending.target_point]
p.name = p.name..t
else
Text.textinput(t)
end
save_to_disk(Lines, Filename)
end
function App.keychord_pressed(chord)
--? Debug_main = true
if love.mouse.isDown('1') or chord:sub(1,2) == 'C-' then
Drawing.keychord_pressed(chord)
elseif chord == 'escape' and love.mouse.isDown('1') then
local drawing = Drawing.current_drawing()
if drawing then
drawing.pending = {}
end
elseif chord == 'escape' and not love.mouse.isDown('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 drawing = Lines.current
local p = drawing.points[drawing.pending.target_point]
if chord == 'escape' then
p.name = nil
elseif chord == 'backspace' then
local len = utf8.len(p.name)
local byte_offset = utf8.offset(p.name, len-1)
p.name = string.sub(p.name, 1, byte_offset)
end
end
save_to_disk(Lines, Filename)
elseif chord == 'pagedown' then
Screen_top1.line = Screen_bottom1.line
Screen_top1.pos = Screen_bottom1.pos
--? print('setting top to', Screen_top1.line, Screen_top1.pos)
Cursor1.line = Screen_top1.line
Cursor1.pos = Screen_top1.pos
Text.move_cursor_down_to_next_text_line_while_scrolling_again_if_necessary()
--? print('top now', Screen_top1.line)
elseif chord == 'pageup' then
-- duplicate some logic from love.draw
local top2 = Text.to2(Screen_top1)
--? print(App.screen.height)
local y = App.screen.height - math.floor(15*Zoom)
while y >= 15 do
--? print(y, top2.line)
if Screen_top1.line == 1 and Screen_top1.pos == 1 then break end
if Lines[Screen_top1.line].mode == 'text' then
y = y - math.floor(15*Zoom)
elseif Lines[Screen_top1.line].mode == 'drawing' then
y = y - 20 - Drawing.pixels(Lines[Screen_top1.line].h)
end
top2 = Text.previous_screen_line(top2)
end
Screen_top1 = Text.to1(top2)
Cursor1.line = Screen_top1.line
Cursor1.pos = Screen_top1.pos
Text.move_cursor_down_to_next_text_line_while_scrolling_again_if_necessary()
--? print(Cursor1.line, Cursor1.pos, Screen_top1.line, Screen_top1.pos)
else
Text.keychord_pressed(chord)
end
end
function App.keyreleased(key, scancode)
end