## the basic editor data structure, and how it displays text to the screen
# temporary main for this layer: just render the given text at the given
# screen dimensions, then stop
def! main text:text [
local-scope
load-ingredients
open-console
hide-screen 0/screen
new-editor text, 0/screen, 0/left, 5/right
show-screen 0/screen
wait-for-event 0/console
close-console
]
scenario editor-initially-prints-text-to-screen [
assume-screen 10/width, 5/height
run [
1:text <- new [abc]
new-editor 1:text, screen:&:screen, 0/left, 10/right
]
screen-should-contain [
# top line of screen reserved for menu
. .
.abc .
. .
]
]
container editor [
# editable text: doubly linked list of characters (head contains a special sentinel)
data:&:duplex-list:char
top-of-screen:&:duplex-list:char
bottom-of-screen:&:duplex-list:char
# location before cursor inside data
before-cursor:&:duplex-list:char
# raw bounds of display area on screen
# always displays from row 1 (leaving row 0 for a menu) and at most until bottom of screen
left:num
right:num
bottom:num
# raw screen coordinates of cursor
cursor-row:num
cursor-column:num
]
# creates a new editor widget and renders its initial appearance to screen
# top/left/right constrain the screen area available to the new editor
# right is exclusive
def new-editor s:text, screen:&:screen, left:num, right:num -> result:&:editor, screen:&:screen [
local-scope
load-ingredients
# no clipping of bounds
right <- subtract right, 1
result <- new editor:type
# initialize screen-related fields
*result <- put *result, left:offset, left
*result <- put *result, right:offset, right
# initialize cursor coordinates
*result <- put *result, cursor-row:offset, 1/top
*result <- put *result, cursor-column:offset, left
# initialize empty contents
init:&:duplex-list:char <- push 167/§, 0/tail
*result <- put *result, data:offset, init
*result <- put *result, top-of-screen:offset, init
*result <- put *result, before-cursor:offset, init
result <- insert-text result, s
# initial render to screen, just for some old tests
_, _, screen, result <- render screen, result
<editor-initialization>
]
def insert-text editor:&:editor, text:text -> editor:&:editor [
local-scope
load-ingredients
# early exit if text is empty
return-unless text, editor/same-as-ingredient:0
len:num <- length *text
return-unless len, editor/same-as-ingredient:0
idx:num <- copy 0
# now we can start appending the rest, character by character
curr:&:duplex-list:char <- get *editor, data:offset
{
done?:bool <- greater-or-equal idx, len
break-if done?
c:char <- index *text, idx
insert c, curr
# next iter
curr <- next curr
idx <- add idx, 1
loop
}
return editor/same-as-ingredient:0
]
scenario editor-initializes-without-data [
assume-screen 5/width, 3/height
run [
1:&:editor <- new-editor 0/data, screen:&:screen, 2/left, 5/right
2:editor <- copy *1:&:editor
]
memory-should-contain [
# 2 (data) <- just the § sentinel
# 3 (top of screen) <- the § sentinel
4 <- 0 # bottom-of-screen; null since text fits on screen
# 5 (before cursor) <- the § sentinel
6 <- 2 # left
7 <- 4 # right (inclusive)
8 <- 1 # bottom
9 <- 1 # cursor row
10 <- 2 # cursor column
]
screen-should-contain [
. .
. .
. .
]
]
# Assumes cursor should be at coordinates (cursor-row, cursor-column) and
# updates before-cursor to match. Might also move coordinates if they're
# outside text.
def render screen:&:screen, editor:&:editor -> last-row:num, last-column:num, screen:&:screen, editor:&:editor [
local-scope
load-ingredients
return-unless editor, 1/top, 0/left, screen/same-as-ingredient:0, editor/same-as-ingredient:1
left:num <- get *editor, left:offset
screen-height:num <- screen-height screen
right:num <- get *editor, right:offset
# traversing editor
curr:&:duplex-list:char <- get *editor, top-of-screen:offset
prev:&:duplex-list:char <- copy curr # just in case curr becomes null and we can't compute prev
curr <- next curr
# traversing screen
+render-loop-initialization
color:num <- copy 7/white
row:num <- copy 1/top
column:num <- copy left
cursor-row:num <- get *editor, cursor-row:offset
cursor-column:num <- get *editor, cursor-column:offset
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
screen <- move-cursor screen, row, column
{
+next-character
break-unless curr
off-screen?:bool <- greater-or-equal row, screen-height
break-if off-screen?
# update editor.before-cursor
# Doing so at the start of each iteration ensures it stays one step behind
# the current character.
{
at-cursor-row?:bool <- equal row, cursor-row
break-unless at-cursor-row?
at-cursor?:bool <- equal column, cursor-column
break-unless at-cursor?
before-cursor <- copy prev
}
c:char <- get *curr, value:offset
<character-c-received>
{
# newline? move to left rather than 0
newline?:bool <- equal c, 10/newline
break-unless newline?
# adjust cursor if necessary
{
at-cursor-row?:bool <- equal row, cursor-row
break-unless at-cursor-row?
left-of-cursor?:bool <- lesser-than column, cursor-column
break-unless left-of-cursor?
cursor-column <- copy column
before-cursor <- prev curr
}
# clear rest of line in this window
clear-line-until screen, right
# skip to next line
row <- add row, 1
column <- copy left
screen <- move-cursor screen, row, column
curr <- next curr
prev <- next prev
loop +next-character:label
}
{
# at right? wrap. even if there's only one more letter left; we need
# room for clicking on the cursor after it.
at-right?:bool <- equal column, right
break-unless at-right?
# print wrap icon
wrap-icon:char <- copy 8617/loop-back-to-left
print screen, wrap-icon, 245/grey
column <- copy left
row <- add row, 1
screen <- move-cursor screen, row, column
# don't increment curr
loop +next-character:label
}
print screen, c, color
curr <- next curr
prev <- next prev
column <- add column, 1
loop
}
# save first character off-screen
*editor <- put *editor, bottom-of-screen:offset, curr
# is cursor to the right of the last line? move to end
{
at-cursor-row?:bool <- equal row, cursor-row
cursor-outside-line?:bool <- lesser-or-equal column, cursor-column
before-cursor-on-same-line?:bool <- and at-cursor-row?, cursor-outside-line?
above-cursor-row?:bool <- lesser-than row, cursor-row
before-cursor?:bool <- or before-cursor-on-same-line?, above-cursor-row?
break-unless before-cursor?
cursor-row <- copy row
cursor-column <- copy column
before-cursor <- copy prev
}
*editor <- put *editor, bottom:offset, row
*editor <- put *editor, cursor-row:offset, cursor-row
*editor <- put *editor, cursor-column:offset, cursor-column
*editor <- put *editor, before-cursor:offset, before-cursor
return row, column, screen/same-as-ingredient:0, editor/same-as-ingredient:1
]
def clear-screen-from screen:&:screen, row:num, column:num, left:num, right:num -> screen:&:screen [
local-scope
load-ingredients
# if it's the real screen, use the optimized primitive
{
break-if screen
clear-display-from row, column, left, right
return screen/same-as-ingredient:0
}
# if not, go the slower route
screen <- move-cursor screen, row, column
clear-line-until screen, right
clear-rest-of-screen screen, row, left, right
return screen/same-as-ingredient:0
]
def clear-rest-of-screen screen:&:screen, row:num, left:num, right:num -> screen:&:screen [
local-scope
load-ingredients
row <- add row, 1
screen <- move-cursor screen, row, left
screen-height:num <- screen-height screen
{
at-bottom-of-screen?:bool <- greater-or-equal row, screen-height
break-if at-bottom-of-screen?
screen <- move-cursor screen, row, left
clear-line-until screen, right
row <- add row, 1
loop
}
]
scenario editor-initially-prints-multiple-lines [
assume-screen 5/width, 5/height
run [
s:text <- new [abc
def]
new-editor s:text, screen:&:screen, 0/left, 5/right
]
screen-should-contain [
. .
.abc .
.def .
. .
]
]
scenario editor-initially-handles-offsets [
assume-screen 5/width, 5/height
run [
s:text <- new [abc]
new-editor s:text, screen:&:screen, 1/left, 5/right
]
screen-should-contain [
. .
. abc .
. .
]
]
scenario editor-initially-prints-multiple-lines-at-offset [
assume-screen 5/width, 5/height
run [
s:text <- new [abc
def]
new-editor s:text, screen:&:screen, 1/left, 5/right
]
screen-should-contain [
. .
. abc .
. def .
. .
]
]
scenario editor-initially-wraps-long-lines [
assume-screen 5/width, 5/height
run [
s:text <- new [abc def]
new-editor s:text, screen:&:screen, 0/left, 5/right
]
screen-should-contain [
. .
.abc ↩.
.def .
. .
]
screen-should-contain-in-color 245/grey [
. .
. ↩.
. .
. .
]
]
scenario editor-initially-wraps-barely-long-lines [
assume-screen 5/width, 5/height
run [
s:text <- new [abcde]
new-editor s:text, screen:&:screen, 0/left, 5/right
]
# still wrap, even though the line would fit. We need room to click on the
# end of the line
screen-should-contain [
. .
.abcd↩.
.e .
. .
]
screen-should-contain-in-color 245/grey [
. .
. ↩.
. .
. .
]
]
scenario editor-initializes-empty-text [
assume-screen 5/width, 5/height
run [
1:text <- new []
2:&:editor <- new-editor 1:text, screen:&:screen, 0/left, 5/right
3:num <- get *2:&:editor, cursor-row:offset
4:num <- get *2:&:editor, cursor-column:offset
]
screen-should-contain [
. .
. .
. .
]
memory-should-contain [
3 <- 1 # cursor row
4 <- 0 # cursor column
]
]
# just a little color for mu code
scenario render-colors-comments [
assume-screen 5/width, 5/height
run [
s:text <- new [abc
# de
f]
new-editor s:text, screen:&:screen, 0/left, 5/right
]
screen-should-contain [
. .
.abc .
.# de .
.f .
. .
]
screen-should-contain-in-color 12/lightblue, [
. .
. .
.# de .
. .
. .
]
screen-should-contain-in-color 7/white, [
. .
.abc .
. .
.f .
. .
]
]
after <character-c-received> [
color <- get-color color, c
]
# so far the previous color is all the information we need; that may change
def get-color color:num, c:char -> color:num [
local-scope
load-ingredients
color-is-white?:bool <- equal color, 7/white
# if color is white and next character is '#', switch color to blue
{
break-unless color-is-white?
starting-comment?:bool <- equal c, 35/#
break-unless starting-comment?
trace 90, [app], [switch color back to blue]
color <- copy 12/lightblue
jump +exit:label
}
# if color is blue and next character is newline, switch color to white
{
color-is-blue?:bool <- equal color, 12/lightblue
break-unless color-is-blue?
ending-comment?:bool <- equal c, 10/newline
break-unless ending-comment?
trace 90, [app], [switch color back to white]
color <- copy 7/white
jump +exit:label
}
# if color is white (no comments) and next character is '<', switch color to red
{
break-unless color-is-white?
starting-assignment?:bool <- equal c, 60/<
break-unless starting-assignment?
color <- copy 1/red
jump +exit:label
}
# if color is red and next character is space, switch color to white
{
color-is-red?:bool <- equal color, 1/red
break-unless color-is-red?
ending-assignment?:bool <- equal c, 32/space
break-unless ending-assignment?
color <- copy 7/white
jump +exit:label
}
# otherwise no change
+exit
return color
]
scenario render-colors-assignment [
assume-screen 8/width, 5/height
run [
s:text <- new [abc
d <- e
f]
new-editor s:text, screen:&:screen, 0/left, 8/right
]
screen-should-contain [
. .
.abc .
.d <- e .
.f .
. .
]
screen-should-contain-in-color 1/red, [
. .
. .
. <- .
. .
. .
]
]