# Editor widget: takes a string and screen coordinates, modifying them in place.
recipe main [
default-space:address:array:location <- new location:type, 30:literal
open-console
width:number <- display-width
height:number <- display-height
divider:number, _ <- divide-with-remainder width:number, 2:literal
draw-vertical 0:literal/screen, divider:number, 0:literal/top, height:number
in:address:array:character <- new [abcdef
def
ghi
jkl
]
editor:address:editor-data <- new-editor in:address:array:character, 0:literal/screen, 0:literal/top, 0:literal/left, divider:number/right
event-loop 0:literal/screen, 0:literal/events, editor:address:editor-data
close-console
]
scenario editor-initially-prints-string-to-screen [
assume-screen 10:literal/width, 5:literal/height
run [
s:address:array:character <- new [abc]
new-editor s:address:array:character, screen:address, 0:literal/top, 0:literal/left, 5:literal/right
]
screen-should-contain [
.abc .
. .
]
]
## In which we introduce the editor data structure, and show how it displays
## text to the screen.
container editor-data [
# doubly linked list of characters (head contains a special marker)
data:address:duplex-list
# location of top-left of screen inside data (scrolling)
top-of-screen:address:duplex-list
# location before cursor inside data
before-cursor:address:duplex-list
screen:address:screen
# raw bounds of display area on screen
top:number
left:number
bottom:number
right:number
# raw screen coordinates of cursor
cursor-row:number
cursor-column:number
]
# editor:address, screen:address <- new-editor s:address:array:character, screen:address, top:number, left:number, bottom:number
# 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.
recipe new-editor [
default-space:address:array:location <- new location:type, 30:literal
s:address:array:character <- next-ingredient
screen:address <- next-ingredient
# no clipping of bounds
top:number <- next-ingredient
left:number <- next-ingredient
right:number <- next-ingredient
right:number <- subtract right:number, 1:literal
result:address:editor-data <- new editor-data:type
d:address:address:duplex-list <- get-address result:address:editor-data/deref, data:offset
d:address:address:duplex-list/deref <- push-duplex 167:literal/§, 0:literal/tail
#? $print d:address:address:duplex-list/deref, [
#? ] #? 1
# initialize screen-related fields
sc:address:address:screen <- get-address result:address:editor-data/deref, screen:offset
sc:address:address:screen/deref <- copy screen:address
x:address:number <- get-address result:address:editor-data/deref, top:offset
x:address:number/deref <- copy top:number
x:address:number <- get-address result:address:editor-data/deref, left:offset
x:address:number/deref <- copy left:number
x:address:number <- get-address result:address:editor-data/deref, right:offset
x:address:number/deref <- copy right:number
# bottom = top (in case of early exit)
x:address:number <- get-address result:address:editor-data/deref, bottom:offset
x:address:number/deref <- copy top:number
# initialize cursor
x:address:number <- get-address result:address:editor-data/deref, cursor-row:offset
x:address:number/deref <- copy top:number
x:address:number <- get-address result:address:editor-data/deref, cursor-column:offset
x:address:number/deref <- copy left:number
# early exit if s is empty
reply-unless s:address:array:character, result:address:editor-data
len:number <- length s:address:array:character/deref
reply-unless len:number, result:address:editor-data
idx:number <- copy 0:literal
# s is guaranteed to have at least one character, so initialize result's
# duplex-list
init:address:address:duplex-list <- get-address result:address:editor-data/deref, top-of-screen:offset
init:address:address:duplex-list/deref <- copy d:address:address:duplex-list/deref
curr:address:duplex-list <- copy init:address:address:duplex-list/deref
# now we can start appending the rest, character by character
{
#? $print idx:number, [ vs ], len:number, [
#? ] #? 1
#? $print [append to ], curr:address:duplex-list, [
#? ] #? 1
done?:boolean <- greater-or-equal idx:number, len:number
break-if done?:boolean
c:character <- index s:address:array:character/deref, idx:number
#? $print [aa: ], c:character, [
#? ] #? 1
insert-duplex c:character, curr:address:duplex-list
# next iter
curr:address:duplex-list <- next-duplex curr:address:duplex-list
idx:number <- add idx:number, 1:literal
loop
}
# initialize cursor to top of screen
y:address:address:duplex-list <- get-address result:address:editor-data/deref, before-cursor:offset
y:address:address:duplex-list/deref <- copy init:address:address:duplex-list/deref
# perform initial rendering to screen
bottom:address:number <- get-address result:address:editor-data/deref, bottom:offset
result:address:editor-data <- render result:address:editor-data
reply result:address:editor-data
]
scenario editor-initializes-without-data [
assume-screen 5:literal/width, 3:literal/height
run [
1:address:editor-data <- new-editor 0:literal/data, screen:address, 1:literal/top, 2:literal/left, 5:literal/right
2:editor-data <- copy 1:address:editor-data/deref
]
memory-should-contain [
# 2 <- just the § marker
3 <- 0 # pointer into data to top of screen
# 4 (before cursor) <- the § marker
# 5 <- screen
6 <- 1 # top
7 <- 2 # left
8 <- 1 # bottom
9 <- 4 # right (inclusive)
10 <- 1 # cursor row
11 <- 2 # cursor column
]
screen-should-contain [
. .
. .
. .
]
]
recipe render [
default-space:address:array:location <- new location:type, 30:literal
editor:address:editor-data <- next-ingredient
#? $print [=== render
#? ] #? 1
screen:address <- get editor:address:editor-data/deref, screen:offset
top:number <- get editor:address:editor-data/deref, top:offset
left:number <- get editor:address:editor-data/deref, left:offset
screen-height:number <- screen-height screen:address
right:number <- get editor:address:editor-data/deref, right:offset
# traversing editor
curr:address:duplex-list <- get editor:address:editor-data/deref, top-of-screen:offset
curr:address:duplex-list <- next-duplex curr:address:duplex-list
# traversing screen
row:number <- copy top:number
column:number <- copy left:number
cursor-row:number <- get editor:address:editor-data/deref, cursor-row:offset
cursor-column:number <- get editor:address:editor-data/deref, cursor-column:offset
move-cursor screen:address, row:number, column:number
{
+next-character
#? $print curr:address:duplex-list, [
#? ] #? 1
break-unless curr:address:duplex-list
off-screen?:boolean <- greater-or-equal row:number, screen-height:number
break-if off-screen?:boolean
# update before-cursor at the start of each iteration, and row/column at the end
{
at-cursor-row?:boolean <- equal row:number, cursor-row:number
break-unless at-cursor-row?:boolean
at-cursor?:boolean <- equal column:number, cursor-column:number
break-unless at-cursor?:boolean
before-cursor:address:address:duplex-list <- get-address editor:address:editor-data/deref, before-cursor:offset
before-cursor:address:address:duplex-list/deref <- prev-duplex curr:address:duplex-list
}
c:character <- get curr:address:duplex-list/deref, value:offset
#? $print [rendering ], c:character, [
#? ] #? 1
{
# newline? move to left rather than 0
newline?:boolean <- equal c:character, 10:literal/newline
break-unless newline?:boolean
row:number <- add row:number, 1:literal
column:number <- copy left:number
clear-line screen:address
move-cursor screen:address, row:number, column:number
curr:address:duplex-list <- next-duplex curr:address:duplex-list
loop +next-character:label
}
{
# at right? more than one letter left in the line? wrap
at-right?:boolean <- equal column:number, right:number
break-unless at-right?:boolean
next-node:address:duplex-list <- next-duplex curr:address:duplex-list
break-unless next-node:address:duplex-list
next:character <- get next-node:address:duplex-list/deref, value:offset
next-character-is-newline?:boolean <- equal next:character, 10:literal/newline
break-if next-character-is-newline?:boolean
# wrap
print-character screen:address, 8617:literal/loop-back-to-left, 245:literal/grey
column:number <- copy left:number
row:number <- add row:number, 1:literal
move-cursor screen:address, row:number, column:number
# don't increment curr
loop +next-character:label
}
print-character screen:address, c:character
curr:address:duplex-list <- next-duplex curr:address:duplex-list
column:number <- add column:number, 1:literal
loop
}
# bottom = row
bottom:address:number <- get-address editor:address:editor-data/deref, bottom:offset
bottom:address:number/deref <- copy row:number
# update cursor
cursor-row:number <- get editor:address:editor-data/deref, cursor-row:offset
cursor-column:number <- get editor:address:editor-data/deref, cursor-column:offset
move-cursor screen:address, cursor-row:number, cursor-column:number
reply editor:address:editor-data/same-as-ingredient:0
]
scenario editor-initially-prints-multiple-lines [
assume-screen 5:literal/width, 3:literal/height
run [
s:address:array:character <- new [abc
def]
new-editor s:address:array:character, screen:address, 0:literal/top, 0:literal/left, 5:literal/right
]
screen-should-contain [
.abc .
.def .
. .
]
]
scenario editor-initially-handles-offsets [
assume-screen 5:literal/width, 3:literal/height
run [
s:address:array:character <- new [abc]
new-editor s:address:array:character, screen:address, 0:literal/top, 1:literal/left, 5:literal/right
]
screen-should-contain [
. abc .
. .
. .
]
]
scenario editor-initially-prints-multiple-lines-at-offset [
assume-screen 5:literal/width, 3:literal/height
run [
s:address:array:character <- new [abc
def]
new-editor s:address:array:character, screen:address, 0:literal/top, 1:literal/left, 5:literal/right
]
screen-should-contain [
. abc .
. def .
. .
]
]
scenario editor-initially-wraps-long-lines [
assume-screen 5:literal/width, 3:literal/height
run [
s:address:array:character <- new [abc def]
new-editor s:address:array:character, screen:address, 0:literal/top, 0:literal/left, 5:literal/right
]
screen-should-contain [
.abc ↩.
.def .
. .
]
screen-should-contain-in-color, 245:literal/grey [
. ↩.
. .
. .
]
]
## handling events from the keyboard and mouse
recipe event-loop [
default-space:address:array:location <- new location:type, 30:literal
screen:address <- next-ingredient
console:address <- next-ingredient
editor:address:editor-data <- next-ingredient
{
+next-event
e:event, console:address, found?:boolean, quit?:boolean <- read-event console:address
loop-unless found?:boolean
break-if quit?:boolean # only in tests
trace [app], [next-event]
# mouse clicks
{
t:address:touch-event <- maybe-convert e:event, touch:variant
break-unless t:address:touch-event
editor:address:editor-data <- move-cursor-in-editor editor:address:editor-data, t:address:touch-event/deref
loop +next-event:label
}
# typing regular characters
{
c:address:character <- maybe-convert e:event, text:variant
break-unless c:address:character
editor:address:editor-data <- insert-at-cursor editor:address:editor-data, c:address:character/deref
loop +next-event:label
}
# otherwise it's a special key to control the editor
k:address:number <- maybe-convert e:event, keycode:variant
assert k:address:number, [event was of unknown type; neither keyboard nor mouse]
loop
}
]
recipe move-cursor-in-editor [
default-space:address:array:location <- new location:type, 30:literal
editor:address:editor-data <- next-ingredient
t:touch-event <- next-ingredient
# update cursor
cursor-row:address:number <- get-address editor:address:editor-data/deref, cursor-row:offset
cursor-row:address:number/deref <- get t:touch-event, row:offset
cursor-column:address:number <- get-address editor:address:editor-data/deref, cursor-column:offset
cursor-column:address:number/deref <- get t:touch-event, column:offset
render editor:address:editor-data
reply editor:address:editor-data/same-as-ingredient:0
]
recipe insert-at-cursor [
default-space:address:array:location <- new location:type, 30:literal
editor:address:editor-data <- next-ingredient
c:character <- next-ingredient
before-cursor:address:address:duplex-list <- get-address editor:address:editor-data/deref, before-cursor:offset
d:address:duplex-list <- get editor:address:editor-data/deref, data:offset
#? $print before-cursor:address:address:duplex-list/deref, [ ], d:address:duplex-list, [
#? ] #? 1
#? $print [inserting ], c:character, [
#? ] #? 1
insert-duplex c:character, before-cursor:address:address:duplex-list/deref
# update cursor: if newline, move cursor to start of next line
# todo: bottom of screen
{
newline?:boolean <- equal c:character, 10:literal/newline
break-unless newline?:boolean
cursor-row:address:number <- get-address editor:address:editor-data/deref, cursor-row:offset
cursor-row:address:number/deref <- add cursor-row:address:number/deref, 1:literal
cursor-column:address:number <- get-address editor:address:editor-data/deref, cursor-column:offset
cursor-column:address:number/deref <- copy 0:literal
break +render:label
}
# otherwise move cursor right
cursor-column:address:number <- get-address editor:address:editor-data/deref, cursor-column:offset
cursor-column:address:number/deref <- add cursor-column:address:number/deref, 1:literal
+render
render editor:address:editor-data
reply editor:address:editor-data/same-as-ingredient:0
]
scenario editor-handles-empty-event-queue [
assume-screen 10:literal/width, 5:literal/height
assume-console []
run [
s:address:array:character <- new [abc]
editor:address:editor-data <- new-editor s:address:array:character, screen:address, 0:literal/top, 0:literal/left, 5:literal/right
event-loop screen:address, console:address, editor:address:editor-data
]
screen-should-contain [
.abc .
. .
]
]
scenario editor-handles-mouse-clicks [
assume-screen 10:literal/width, 5:literal/height
assume-console [
left-click 0, 1
]
run [
1:address:array:character <- new [abc]
2:address:editor-data <- new-editor 1:address:array:character, screen:address, 0:literal/top, 0:literal/left, 5:literal/right
event-loop screen:address, console:address, 2:address:editor-data
3:number <- get 2:address:editor-data/deref, cursor-row:offset
4:number <- get 2:address:editor-data/deref, cursor-column:offset
]
screen-should-contain [
.abc .
. .
]
memory-should-contain [
3 <- 0 # cursor is at row 0..
4 <- 1 # ..and column 1
]
]
scenario editor-inserts-characters-at-cursor [
assume-screen 10:literal/width, 5:literal/height
assume-console [
type [0]
left-click 0, 2
type [d]
]
run [
1:address:array:character <- new [abc]
2:address:editor-data <- new-editor 1:address:array:character, screen:address, 0:literal/top, 0:literal/left, 5:literal/right
event-loop screen:address, console:address, 2:address:editor-data
]
screen-should-contain [
.0adbc .
. .
]
]
scenario editor-moves-cursor-after-inserting-characters [
assume-screen 10:literal/width, 5:literal/height
assume-console [
type [01]
]
run [
1:address:array:character <- new [abc]
2:address:editor-data <- new-editor 1:address:array:character, screen:address, 0:literal/top, 0:literal/left, 5:literal/right
event-loop screen:address, console:address, 2:address:editor-data
]
screen-should-contain [
.01abc .
. .
]
]
scenario editor-moves-cursor-down-after-inserting-newline [
assume-screen 10:literal/width, 5:literal/height
assume-console [
type [0
1]
]
run [
1:address:array:character <- new [abc]
2:address:editor-data <- new-editor 1:address:array:character, screen:address, 0:literal/top, 0:literal/left, 5:literal/right
event-loop screen:address, console:address, 2:address:editor-data
]
screen-should-contain [
.0 .
.1abc .
. .
]
]
## helpers for drawing editor borders
recipe draw-box [
default-space:address:array:location <- new location:type, 30:literal
screen:address <- next-ingredient
top:number <- next-ingredient
left:number <- next-ingredient
bottom:number <- next-ingredient
right:number <- next-ingredient
color:number, color-found?:boolean <- next-ingredient
{
# default color to white
break-if color-found?:boolean
color:number <- copy 245:literal/grey
}
# top border
draw-horizontal screen:address, top:number, left:number, right:number, color:number
draw-horizontal screen:address, bottom:number, left:number, right:number, color:number
draw-vertical screen:address, left:number, top:number, bottom:number, color:number
draw-vertical screen:address, right:number, top:number, bottom:number, color:number
draw-top-left screen:address, top:number, left:number, color:number
draw-top-right screen:address, top:number, right:number, color:number
draw-bottom-left screen:address, bottom:number, left:number, color:number
draw-bottom-right screen:address, bottom:number, right:number, color:number
# position cursor inside box
move-cursor screen:address, top:number, left:number
cursor-down screen:address
cursor-right screen:address
]
recipe draw-horizontal [
default-space:address:array:location <- new location:type, 30:literal
screen:address <- next-ingredient
row:number <- next-ingredient
x:number <- next-ingredient
right:number <- next-ingredient
color:number, color-found?:boolean <- next-ingredient
{
# default color to white
break-if color-found?:boolean
color:number <- copy 245:literal/grey
}
move-cursor screen:address, row:number, x:number
{
continue?:boolean <- lesser-than x:number, right:number
break-unless continue?:boolean
print-character screen:address, 9472:literal/horizontal, color:number
x:number <- add x:number, 1:literal
loop
}
]
recipe draw-vertical [
default-space:address:array:location <- new location:type, 30:literal
screen:address <- next-ingredient
col:number <- next-ingredient
x:number <- next-ingredient
bottom:number <- next-ingredient
color:number, color-found?:boolean <- next-ingredient
{
# default color to white
break-if color-found?:boolean
color:number <- copy 245:literal/grey
}
{
continue?:boolean <- lesser-than x:number, bottom:number
break-unless continue?:boolean
move-cursor screen:address, x:number, col:number
print-character screen:address, 9474:literal/vertical, color:number
x:number <- add x:number, 1:literal
loop
}
]
recipe draw-top-left [
default-space:address:array:location <- new location:type, 30:literal
screen:address <- next-ingredient
top:number <- next-ingredient
left:number <- next-ingredient
color:number, color-found?:boolean <- next-ingredient
{
# default color to white
break-if color-found?:boolean
color:number <- copy 245:literal/grey
}
move-cursor screen:address, top:number, left:number
print-character screen:address, 9484:literal/down-right, color:number
]
recipe draw-top-right [
default-space:address:array:location <- new location:type, 30:literal
screen:address <- next-ingredient
top:number <- next-ingredient
right:number <- next-ingredient
color:number, color-found?:boolean <- next-ingredient
{
# default color to white
break-if color-found?:boolean
color:number <- copy 245:literal/grey
}
move-cursor screen:address, top:number, right:number
print-character screen:address, 9488:literal/down-left, color:number
]
recipe draw-bottom-left [
default-space:address:array:location <- new location:type, 30:literal
screen:address <- next-ingredient
bottom:number <- next-ingredient
left:number <- next-ingredient
color:number, color-found?:boolean <- next-ingredient
{
# default color to white
break-if color-found?:boolean
color:number <- copy 245:literal/grey
}
move-cursor screen:address, bottom:number, left:number
print-character screen:address, 9492:literal/up-right, color:number
]
recipe draw-bottom-right [
default-space:address:array:location <- new location:type, 30:literal
screen:address <- next-ingredient
bottom:number <- next-ingredient
right:number <- next-ingredient
color:number, color-found?:boolean <- next-ingredient
{
# default color to white
break-if color-found?:boolean
color:number <- copy 245:literal/grey
}
move-cursor screen:address, bottom:number, right:number
print-character screen:address, 9496:literal/up-left, color:number
]