## special shortcuts for manipulating the editor
# Some keys on the keyboard generate unicode characters, others generate
# terminfo key codes. We need to modify different places in the two cases.
# tab - insert two spaces
scenario editor-inserts-two-spaces-on-tab [
local-scope
assume-screen 10/width, 5/height
# just one character in final line
s:text <- new [ab
cd]
e:&:editor <- new-editor s, screen, 0/left, 5/right
assume-console [
press tab
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
. ab .
.cd .
]
]
after <handle-special-character> [
{
tab?:bool <- equal c, 9/tab
break-unless tab?
<insert-character-begin>
editor, screen, go-render?:bool <- insert-at-cursor editor, 32/space, screen
editor, screen, go-render?:bool <- insert-at-cursor editor, 32/space, screen
<insert-character-end>
go-render? <- copy 1/true
return
}
]
# backspace - delete character before cursor
scenario editor-handles-backspace-key [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abc], screen, 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
left-click 1, 1
press backspace
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.bc .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
memory-should-contain [
4 <- 1
5 <- 0
]
check-trace-count-for-label 3, [print-character] # length of original line to overwrite
]
after <handle-special-character> [
{
delete-previous-character?:bool <- equal c, 8/backspace
break-unless delete-previous-character?
<backspace-character-begin>
editor, screen, go-render?:bool, backspaced-cell:&:duplex-list:char <- delete-before-cursor editor, screen
<backspace-character-end>
return
}
]
# return values:
# go-render? - whether caller needs to update the screen
# backspaced-cell - value deleted (or 0 if nothing was deleted) so we can save it for undo, etc.
def delete-before-cursor editor:&:editor, screen:&:screen -> editor:&:editor, screen:&:screen, go-render?:bool, backspaced-cell:&:duplex-list:char [
local-scope
load-ingredients
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
data:&:duplex-list:char <- get *editor, data:offset
# if at start of text (before-cursor at § sentinel), return
prev:&:duplex-list:char <- prev before-cursor
go-render?, backspaced-cell <- copy 0/no-more-render, 0/nothing-deleted
return-unless prev
trace 10, [app], [delete-before-cursor]
original-row:num <- get *editor, cursor-row:offset
editor, scroll?:bool <- move-cursor-coordinates-left editor
backspaced-cell:&:duplex-list:char <- copy before-cursor
data <- remove before-cursor, data # will also neatly trim next/prev pointers in backspaced-cell/before-cursor
before-cursor <- copy prev
*editor <- put *editor, before-cursor:offset, before-cursor
go-render? <- copy 1/true
return-if scroll?
screen-width:num <- screen-width screen
cursor-row:num <- get *editor, cursor-row:offset
cursor-column:num <- get *editor, cursor-column:offset
# did we just backspace over a newline?
same-row?:bool <- equal cursor-row, original-row
go-render? <- copy 1/true
return-unless same-row?
left:num <- get *editor, left:offset
right:num <- get *editor, right:offset
curr:&:duplex-list:char <- next before-cursor
screen <- move-cursor screen, cursor-row, cursor-column
curr-column:num <- copy cursor-column
{
# hit right margin? give up and let caller render
at-right?:bool <- greater-or-equal curr-column, right
go-render? <- copy 1/true
return-if at-right?
break-unless curr
# newline? done.
currc:char <- get *curr, value:offset
at-newline?:bool <- equal currc, 10/newline
break-if at-newline?
screen <- print screen, currc
curr-column <- add curr-column, 1
curr <- next curr
loop
}
# we're guaranteed not to be at the right margin
space:char <- copy 32/space
screen <- print screen, space
go-render? <- copy 0/false
]
def move-cursor-coordinates-left editor:&:editor -> editor:&:editor, go-render?:bool [
local-scope
load-ingredients
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
cursor-row:num <- get *editor, cursor-row:offset
cursor-column:num <- get *editor, cursor-column:offset
left:num <- get *editor, left:offset
# if not at left margin, move one character left
{
at-left-margin?:bool <- equal cursor-column, left
break-if at-left-margin?
trace 10, [app], [decrementing cursor column]
cursor-column <- subtract cursor-column, 1
*editor <- put *editor, cursor-column:offset, cursor-column
go-render? <- copy 0/false
return
}
# if at left margin, we must move to previous row:
top-of-screen?:bool <- equal cursor-row, 1 # exclude menu bar
go-render?:bool <- copy 0/false
{
break-if top-of-screen?
cursor-row <- subtract cursor-row, 1
*editor <- put *editor, cursor-row:offset, cursor-row
}
{
break-unless top-of-screen?
<scroll-up>
go-render? <- copy 1/true
}
{
# case 1: if previous character was newline, figure out how long the previous line is
previous-character:char <- get *before-cursor, value:offset
previous-character-is-newline?:bool <- equal previous-character, 10/newline
break-unless previous-character-is-newline?
# compute length of previous line
trace 10, [app], [switching to previous line]
d:&:duplex-list:char <- get *editor, data:offset
end-of-line:num <- previous-line-length before-cursor, d
right:num <- get *editor, right:offset
width:num <- subtract right, left
wrap?:bool <- greater-than end-of-line, width
{
break-unless wrap?
_, column-offset:num <- divide-with-remainder end-of-line, width
cursor-column <- add left, column-offset
*editor <- put *editor, cursor-column:offset, cursor-column
}
{
break-if wrap?
cursor-column <- add left, end-of-line
*editor <- put *editor, cursor-column:offset, cursor-column
}
return
}
# case 2: if previous-character was not newline, we're just at a wrapped line
trace 10, [app], [wrapping to previous line]
right:num <- get *editor, right:offset
cursor-column <- subtract right, 1 # leave room for wrap icon
*editor <- put *editor, cursor-column:offset, cursor-column
]
# takes a pointer 'curr' into the doubly-linked list and its sentinel, counts
# the length of the previous line before the 'curr' pointer.
def previous-line-length curr:&:duplex-list:char, start:&:duplex-list:char -> result:num [
local-scope
load-ingredients
result:num <- copy 0
return-unless curr
at-start?:bool <- equal curr, start
return-if at-start?
{
curr <- prev curr
break-unless curr
at-start?:bool <- equal curr, start
break-if at-start?
c:char <- get *curr, value:offset
at-newline?:bool <- equal c, 10/newline
break-if at-newline?
result <- add result, 1
loop
}
]
scenario editor-clears-last-line-on-backspace [
local-scope
assume-screen 10/width, 5/height
# just one character in final line
s:text <- new [ab
cd]
e:&:editor <- new-editor s, screen, 0/left, 10/right
assume-console [
left-click 2, 0 # cursor at only character in final line
press backspace
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.abcd .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
memory-should-contain [
4 <- 1
5 <- 2
]
]
scenario editor-joins-and-wraps-lines-on-backspace [
local-scope
assume-screen 10/width, 5/height
# initialize editor with two long-ish but non-wrapping lines
s:text <- new [abc def
ghi jkl]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# position the cursor at the start of the second and hit backspace
assume-console [
left-click 2, 0
press backspace
]
run [
editor-event-loop screen, console, e
]
# resulting single line should wrap correctly
screen-should-contain [
. .
.abc defgh↩.
.i jkl .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-wraps-long-lines-on-backspace [
local-scope
assume-screen 10/width, 5/height
# initialize editor in part of the screen with a long line
e:&:editor <- new-editor [abc def ghij], screen, 0/left, 8/right
editor-render screen, e
# confirm that it wraps
screen-should-contain [
. .
.abc def↩ .
. ghij .
.┈┈┈┈┈┈┈┈ .
]
$clear-trace
# position the cursor somewhere in the middle of the top screen line and hit backspace
assume-console [
left-click 1, 4
press backspace
]
run [
editor-event-loop screen, console, e
]
# resulting single line should wrap correctly and not overflow its bounds
screen-should-contain [
. .
.abcdef ↩ .
.ghij .
.┈┈┈┈┈┈┈┈ .
. .
]
]
# delete - delete character at cursor
scenario editor-handles-delete-key [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abc], screen, 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
press delete
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.bc .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 3, [print-character] # length of original line to overwrite
$clear-trace
assume-console [
press delete
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.c .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 2, [print-character] # new length to overwrite
]
after <handle-special-key> [
{
delete-next-character?:bool <- equal k, 65522/delete
break-unless delete-next-character?
<delete-character-begin>
editor, screen, go-render?:bool, deleted-cell:&:duplex-list:char <- delete-at-cursor editor, screen
<delete-character-end>
return
}
]
def delete-at-cursor editor:&:editor, screen:&:screen -> editor:&:editor, screen:&:screen, go-render?:bool, deleted-cell:&:duplex-list:char [
local-scope
load-ingredients
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
data:&:duplex-list:char <- get *editor, data:offset
deleted-cell:&:duplex-list:char <- next before-cursor
go-render? <- copy 0/false
return-unless deleted-cell
currc:char <- get *deleted-cell, value:offset
data <- remove deleted-cell, data
deleted-newline?:bool <- equal currc, 10/newline
go-render? <- copy 1/true
return-if deleted-newline?
# wasn't a newline? render rest of line
curr:&:duplex-list:char <- next before-cursor # refresh after remove above
cursor-row:num <- get *editor, cursor-row:offset
cursor-column:num <- get *editor, cursor-column:offset
screen <- move-cursor screen, cursor-row, cursor-column
curr-column:num <- copy cursor-column
screen-width:num <- screen-width screen
{
# hit right margin? give up and let caller render
at-right?:bool <- greater-or-equal curr-column, screen-width
go-render? <- copy 1/true
return-if at-right?
break-unless curr
# newline? done.
currc:char <- get *curr, value:offset
at-newline?:bool <- equal currc, 10/newline
break-if at-newline?
screen <- print screen, currc
curr-column <- add curr-column, 1
curr <- next curr
loop
}
# we're guaranteed not to be at the right margin
space:char <- copy 32/space
screen <- print screen, space
go-render? <- copy 0/false
]
# right arrow
scenario editor-moves-cursor-right-with-key [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abc], screen, 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
press right-arrow
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.a0bc .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 3, [print-character] # 0 and following characters
]
after <handle-special-key> [
{
move-to-next-character?:bool <- equal k, 65514/right-arrow
break-unless move-to-next-character?
# if not at end of text
next-cursor:&:duplex-list:char <- next before-cursor
break-unless next-cursor
# scan to next character
<move-cursor-begin>
before-cursor <- copy next-cursor
*editor <- put *editor, before-cursor:offset, before-cursor
editor, go-render?:bool <- move-cursor-coordinates-right editor, screen-height
screen <- move-cursor screen, cursor-row, cursor-column
undo-coalesce-tag:num <- copy 2/right-arrow
<move-cursor-end>
return
}
]
def move-cursor-coordinates-right editor:&:editor, screen-height:num -> editor:&:editor, go-render?:bool [
local-scope
load-ingredients
before-cursor:&:duplex-list:char <- get *editor before-cursor:offset
cursor-row:num <- get *editor, cursor-row:offset
cursor-column:num <- get *editor, cursor-column:offset
left:num <- get *editor, left:offset
right:num <- get *editor, right:offset
# if crossed a newline, move cursor to start of next row
{
old-cursor-character:char <- get *before-cursor, value:offset
was-at-newline?:bool <- equal old-cursor-character, 10/newline
break-unless was-at-newline?
cursor-row <- add cursor-row, 1
*editor <- put *editor, cursor-row:offset, cursor-row
cursor-column <- copy left
*editor <- put *editor, cursor-column:offset, cursor-column
below-screen?:bool <- greater-or-equal cursor-row, screen-height # must be equal
go-render? <- copy 0/false
return-unless below-screen?
<scroll-down>
cursor-row <- subtract cursor-row, 1 # bring back into screen range
*editor <- put *editor, cursor-row:offset, cursor-row
go-render? <- copy 1/true
return
}
# if the line wraps, move cursor to start of next row
{
# if we're at the column just before the wrap indicator
wrap-column:num <- subtract right, 1
at-wrap?:bool <- equal cursor-column, wrap-column
break-unless at-wrap?
# and if next character isn't newline
next:&:duplex-list:char <- next before-cursor
break-unless next
next-character:char <- get *next, value:offset
newline?:bool <- equal next-character, 10/newline
break-if newline?
cursor-row <- add cursor-row, 1
*editor <- put *editor, cursor-row:offset, cursor-row
cursor-column <- copy left
*editor <- put *editor, cursor-column:offset, cursor-column
below-screen?:bool <- greater-or-equal cursor-row, screen-height # must be equal
return-unless below-screen?, editor/same-as-ingredient:0, 0/no-more-render
<scroll-down>
cursor-row <- subtract cursor-row, 1 # bring back into screen range
*editor <- put *editor, cursor-row:offset, cursor-row
go-render? <- copy 1/true
return
}
# otherwise move cursor one character right
cursor-column <- add cursor-column, 1
*editor <- put *editor, cursor-column:offset, cursor-column
go-render? <- copy 0/false
]
scenario editor-moves-cursor-to-next-line-with-right-arrow [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
d]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# type right-arrow a few times to get to start of second line
assume-console [
press right-arrow
press right-arrow
press right-arrow
press right-arrow # next line
]
run [
editor-event-loop screen, console, e
]
check-trace-count-for-label 0, [print-character]
# type something and ensure it goes where it should
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.abc .
.0d .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 2, [print-character] # new length of second line
]
scenario editor-moves-cursor-to-next-line-with-right-arrow-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
d]
e:&:editor <- new-editor s, screen, 1/left, 10/right
editor-render screen, e
assume-console [
press right-arrow
press right-arrow
press right-arrow
press right-arrow # next line
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
. abc .
. 0d .
. ┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-moves-cursor-to-next-wrapped-line-with-right-arrow [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abcdef], screen, 0/left, 5/right
editor-render screen, e
$clear-trace
assume-console [
left-click 1, 3
press right-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
.abcd↩ .
.ef .
.┈┈┈┈┈ .
. .
]
memory-should-contain [
3 <- 2
4 <- 0
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-cursor-to-next-wrapped-line-with-right-arrow-2 [
local-scope
assume-screen 10/width, 5/height
# line just barely wrapping
e:&:editor <- new-editor [abcde], screen, 0/left, 5/right
editor-render screen, e
$clear-trace
# position cursor at last character before wrap and hit right-arrow
assume-console [
left-click 1, 3
press right-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 2
4 <- 0
]
# now hit right arrow again
assume-console [
press right-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 2
4 <- 1
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-cursor-to-next-wrapped-line-with-right-arrow-3 [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abcdef], screen, 1/left, 6/right
editor-render screen, e
$clear-trace
assume-console [
left-click 1, 4
press right-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
screen-should-contain [
. .
. abcd↩ .
. ef .
. ┈┈┈┈┈ .
. .
]
memory-should-contain [
3 <- 2
4 <- 1
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-cursor-to-next-line-with-right-arrow-at-end-of-line [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
d]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# move to end of line, press right-arrow, type a character
assume-console [
left-click 1, 3
press right-arrow
type [0]
]
run [
editor-event-loop screen, console, e
]
# new character should be in next line
screen-should-contain [
. .
.abc .
.0d .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 2, [print-character]
]
# todo: ctrl-right: next word-end
# left arrow
scenario editor-moves-cursor-left-with-key [
local-scope
assume-screen 10/width, 5/height
e:&:editor <- new-editor [abc], screen, 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
left-click 1, 2
press left-arrow
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.a0bc .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 3, [print-character]
]
after <handle-special-key> [
{
move-to-previous-character?:bool <- equal k, 65515/left-arrow
break-unless move-to-previous-character?
trace 10, [app], [left arrow]
# if not at start of text (before-cursor at § sentinel)
prev:&:duplex-list:char <- prev before-cursor
go-render? <- copy 0/false
return-unless prev
<move-cursor-begin>
editor, go-render? <- move-cursor-coordinates-left editor
before-cursor <- copy prev
*editor <- put *editor, before-cursor:offset, before-cursor
undo-coalesce-tag:num <- copy 1/left-arrow
<move-cursor-end>
return
}
]
scenario editor-moves-cursor-to-previous-line-with-left-arrow-at-start-of-line [
local-scope
assume-screen 10/width, 5/height
# initialize editor with two lines
s:text <- new [abc
d]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# position cursor at start of second line (so there's no previous newline)
assume-console [
left-click 2, 0
press left-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1
4 <- 3
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-cursor-to-previous-line-with-left-arrow-at-start-of-line-2 [
local-scope
assume-screen 10/width, 5/height
# initialize editor with three lines
s:text <- new [abc
def
g]
e:&:editor <- new-editor s:text, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# position cursor further down (so there's a newline before the character at
# the cursor)
assume-console [
left-click 3, 0
press left-arrow
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.abc .
.def0 .
.g .
.┈┈┈┈┈┈┈┈┈┈.
]
check-trace-count-for-label 1, [print-character] # just the '0'
]
scenario editor-moves-cursor-to-previous-line-with-left-arrow-at-start-of-line-3 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
def
g]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# position cursor at start of text, press left-arrow, then type a character
assume-console [
left-click 1, 0
press left-arrow
type [0]
]
run [
editor-event-loop screen, console, e
]
# left-arrow should have had no effect
screen-should-contain [
. .
.0abc .
.def .
.g .
.┈┈┈┈┈┈┈┈┈┈.
]
check-trace-count-for-label 4, [print-character] # length of first line
]
scenario editor-moves-cursor-to-previous-line-with-left-arrow-at-start-of-line-4 [
local-scope
assume-screen 10/width, 5/height
# initialize editor with text containing an empty line
s:text <- new [abc
d]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e:&:editor
$clear-trace
# position cursor right after empty line
assume-console [
left-click 3, 0
press left-arrow
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.abc .
.0 .
.d .
.┈┈┈┈┈┈┈┈┈┈.
]
check-trace-count-for-label 1, [print-character] # just the '0'
]
scenario editor-moves-across-screen-lines-across-wrap-with-left-arrow [
local-scope
assume-screen 10/width, 5/height
# initialize editor with a wrapping line
e:&:editor <- new-editor [abcdef], screen, 0/left, 5/right
editor-render screen, e
$clear-trace
screen-should-contain [
. .
.abcd↩ .
.ef .
.┈┈┈┈┈ .
. .
]
# position cursor right after empty line
assume-console [
left-click 2, 0
press left-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1 # previous row
4 <- 3 # right margin except wrap icon
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-across-screen-lines-to-wrapping-line-with-left-arrow [
local-scope
assume-screen 10/width, 5/height
# initialize editor with a wrapping line followed by a second line
s:text <- new [abcdef
g]
e:&:editor <- new-editor s, screen, 0/left, 5/right
editor-render screen, e
$clear-trace
screen-should-contain [
. .
.abcd↩ .
.ef .
.g .
.┈┈┈┈┈ .
]
# position cursor right after empty line
assume-console [
left-click 3, 0
press left-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 2 # previous row
4 <- 2 # end of wrapped line
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-across-screen-lines-to-non-wrapping-line-with-left-arrow [
local-scope
assume-screen 10/width, 5/height
# initialize editor with a line on the verge of wrapping, followed by a second line
s:text <- new [abcd
e]
e:&:editor <- new-editor s, screen, 0/left, 5/right
editor-render screen, e
$clear-trace
screen-should-contain [
. .
.abcd .
.e .
.┈┈┈┈┈ .
. .
]
# position cursor right after empty line
assume-console [
left-click 2, 0
press left-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1 # previous row
4 <- 4 # end of wrapped line
]
check-trace-count-for-label 0, [print-character]
]
# todo: ctrl-left: previous word-start
# up arrow
scenario editor-moves-to-previous-line-with-up-arrow [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
def]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
left-click 2, 1
press up-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1
4 <- 1
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.a0bc .
.def .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
after <handle-special-key> [
{
move-to-previous-line?:bool <- equal k, 65517/up-arrow
break-unless move-to-previous-line?
<move-cursor-begin>
editor, go-render? <- move-to-previous-line editor
undo-coalesce-tag:num <- copy 3/up-arrow
<move-cursor-end>
return
}
]
def move-to-previous-line editor:&:editor -> editor:&:editor, go-render?:bool [
local-scope
load-ingredients
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
left:num <- get *editor, left:offset
right:num <- get *editor, right:offset
already-at-top?:bool <- lesser-or-equal cursor-row, 1/top
{
# if cursor not at top, move it
break-if already-at-top?
# if not at newline, move to start of line (previous newline)
# then scan back another line
# if either step fails, give up without modifying cursor or coordinates
curr:&:duplex-list:char <- copy before-cursor
{
old:&:duplex-list:char <- copy curr
c2:char <- get *curr, value:offset
at-newline?:bool <- equal c2, 10/newline
break-if at-newline?
curr:&:duplex-list:char <- before-previous-line curr, editor
no-motion?:bool <- equal curr, old
go-render? <- copy 0/false
return-if no-motion?
}
{
old <- copy curr
curr <- before-previous-line curr, editor
no-motion?:bool <- equal curr, old
go-render? <- copy 0/false
return-if no-motion?
}
before-cursor <- copy curr
*editor <- put *editor, before-cursor:offset, before-cursor
cursor-row <- subtract cursor-row, 1
*editor <- put *editor, cursor-row:offset, cursor-row
# scan ahead to right column or until end of line
target-column:num <- copy cursor-column
cursor-column <- copy left
*editor <- put *editor, cursor-column:offset, cursor-column
{
done?:bool <- greater-or-equal cursor-column, target-column
break-if done?
curr:&:duplex-list:char <- next before-cursor
break-unless curr
currc:char <- get *curr, value:offset
at-newline?:bool <- equal currc, 10/newline
break-if at-newline?
#
before-cursor <- copy curr
*editor <- put *editor, before-cursor:offset, before-cursor
cursor-column <- add cursor-column, 1
*editor <- put *editor, cursor-column:offset, cursor-column
loop
}
go-render? <- copy 0/false
return
}
{
# if cursor already at top, scroll up
break-unless already-at-top?
<scroll-up>
go-render? <- copy 1/true
return
}
]
scenario editor-adjusts-column-at-previous-line [
local-scope
assume-screen 10/width, 5/height
s:text <- new [ab
def]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
left-click 2, 3
press up-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1
4 <- 2
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.ab0 .
.def .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-adjusts-column-at-empty-line [
local-scope
assume-screen 10/width, 5/height
s:text <- new [
def]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
left-click 2, 3
press up-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 1
4 <- 0
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.0 .
.def .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-moves-to-previous-line-from-left-margin [
local-scope
assume-screen 10/width, 5/height
# start out with three lines
s:text <- new [abc
def
ghi]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# click on the third line and hit up-arrow, so you end up just after a newline
assume-console [
left-click 3, 0
press up-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 2
4 <- 0
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.abc .
.0def .
.ghi .
.┈┈┈┈┈┈┈┈┈┈.
]
]
# down arrow
scenario editor-moves-to-next-line-with-down-arrow [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
def]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# cursor starts out at (1, 0)
assume-console [
press down-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# ..and ends at (2, 0)
memory-should-contain [
3 <- 2
4 <- 0
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.abc .
.0def .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
after <handle-special-key> [
{
move-to-next-line?:bool <- equal k, 65516/down-arrow
break-unless move-to-next-line?
<move-cursor-begin>
editor, go-render? <- move-to-next-line editor, screen-height
undo-coalesce-tag:num <- copy 4/down-arrow
<move-cursor-end>
return
}
]
def move-to-next-line editor:&:editor, screen-height:num -> editor:&:editor, go-render?:bool [
local-scope
load-ingredients
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
left:num <- get *editor, left:offset
right:num <- get *editor, right:offset
last-line:num <- subtract screen-height, 1
already-at-bottom?:bool <- greater-or-equal cursor-row, last-line
{
# if cursor not at bottom, move it
break-if already-at-bottom?
# scan to start of next line, then to right column or until end of line
max:num <- subtract right, left
next-line:&:duplex-list:char <- before-start-of-next-line before-cursor, max
{
# already at end of buffer? try to scroll up (so we can see more
# warnings or sandboxes below)
no-motion?:bool <- equal next-line, before-cursor
break-unless no-motion?
scroll?:bool <- greater-than cursor-row, 1
break-if scroll?, +try-to-scroll
go-render? <- copy 0/false
return
}
cursor-row <- add cursor-row, 1
*editor <- put *editor, cursor-row:offset, cursor-row
before-cursor <- copy next-line
*editor <- put *editor, before-cursor:offset, before-cursor
target-column:num <- copy cursor-column
cursor-column <- copy left
*editor <- put *editor, cursor-column:offset, cursor-column
{
done?:bool <- greater-or-equal cursor-column, target-column
break-if done?
curr:&:duplex-list:char <- next before-cursor
break-unless curr
currc:char <- get *curr, value:offset
at-newline?:bool <- equal currc, 10/newline
break-if at-newline?
#
before-cursor <- copy curr
*editor <- put *editor, before-cursor:offset, before-cursor
cursor-column <- add cursor-column, 1
*editor <- put *editor, cursor-column:offset, cursor-column
loop
}
go-render? <- copy 0/false
return
}
+try-to-scroll
<scroll-down>
go-render? <- copy 1/true
]
scenario editor-adjusts-column-at-next-line [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
de]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
assume-console [
left-click 1, 3
press down-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
3 <- 2
4 <- 2
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.abc .
.de0 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
# ctrl-a/home - move cursor to start of line
scenario editor-moves-to-start-of-line-with-ctrl-a [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on second line, press ctrl-a
assume-console [
left-click 2, 3
press ctrl-a
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
# cursor moves to start of line
memory-should-contain [
4 <- 2
5 <- 0
]
check-trace-count-for-label 0, [print-character]
]
after <handle-special-character> [
{
move-to-start-of-line?:bool <- equal c, 1/ctrl-a
break-unless move-to-start-of-line?
<move-cursor-begin>
move-to-start-of-line editor
undo-coalesce-tag:num <- copy 0/never
<move-cursor-end>
go-render? <- copy 0/false
return
}
]
after <handle-special-key> [
{
move-to-start-of-line?:bool <- equal k, 65521/home
break-unless move-to-start-of-line?
<move-cursor-begin>
move-to-start-of-line editor
undo-coalesce-tag:num <- copy 0/never
<move-cursor-end>
go-render? <- copy 0/false
return
}
]
def move-to-start-of-line editor:&:editor -> editor:&:editor [
local-scope
load-ingredients
# update cursor column
left:num <- get *editor, left:offset
cursor-column:num <- copy left
*editor <- put *editor, cursor-column:offset, cursor-column
# update before-cursor
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
init:&:duplex-list:char <- get *editor, data:offset
# while not at start of line, move
{
at-start-of-text?:bool <- equal before-cursor, init
break-if at-start-of-text?
prev:char <- get *before-cursor, value:offset
at-start-of-line?:bool <- equal prev, 10/newline
break-if at-start-of-line?
before-cursor <- prev before-cursor
*editor <- put *editor, before-cursor:offset, before-cursor
assert before-cursor, [move-to-start-of-line tried to move before start of text]
loop
}
]
scenario editor-moves-to-start-of-line-with-ctrl-a-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on first line (no newline before), press ctrl-a
assume-console [
left-click 1, 3
press ctrl-a
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
# cursor moves to start of line
memory-should-contain [
4 <- 1
5 <- 0
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-to-start-of-line-with-home [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
$clear-trace
# start on second line, press 'home'
assume-console [
left-click 2, 3
press home
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# cursor moves to start of line
memory-should-contain [
3 <- 2
4 <- 0
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-to-start-of-line-with-home-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on first line (no newline before), press 'home'
assume-console [
left-click 1, 3
press home
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# cursor moves to start of line
memory-should-contain [
3 <- 1
4 <- 0
]
check-trace-count-for-label 0, [print-character]
]
# ctrl-e/end - move cursor to end of line
scenario editor-moves-to-end-of-line-with-ctrl-e [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on first line, press ctrl-e
assume-console [
left-click 1, 1
press ctrl-e
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
# cursor moves to end of line
memory-should-contain [
4 <- 1
5 <- 3
]
check-trace-count-for-label 0, [print-character]
# editor inserts future characters at cursor
assume-console [
type [z]
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
memory-should-contain [
4 <- 1
5 <- 4
]
screen-should-contain [
. .
.123z .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
check-trace-count-for-label 1, [print-character]
]
after <handle-special-character> [
{
move-to-end-of-line?:bool <- equal c, 5/ctrl-e
break-unless move-to-end-of-line?
<move-cursor-begin>
move-to-end-of-line editor
undo-coalesce-tag:num <- copy 0/never
<move-cursor-end>
go-render? <- copy 0/false
return
}
]
after <handle-special-key> [
{
move-to-end-of-line?:bool <- equal k, 65520/end
break-unless move-to-end-of-line?
<move-cursor-begin>
move-to-end-of-line editor
undo-coalesce-tag:num <- copy 0/never
<move-cursor-end>
go-render? <- copy 0/false
return
}
]
def move-to-end-of-line editor:&:editor -> editor:&:editor [
local-scope
load-ingredients
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
cursor-column:num <- get *editor, cursor-column:offset
# while not at start of line, move
{
next:&:duplex-list:char <- next before-cursor
break-unless next # end of text
nextc:char <- get *next, value:offset
at-end-of-line?:bool <- equal nextc, 10/newline
break-if at-end-of-line?
before-cursor <- copy next
*editor <- put *editor, before-cursor:offset, before-cursor
cursor-column <- add cursor-column, 1
*editor <- put *editor, cursor-column:offset, cursor-column
loop
}
]
scenario editor-moves-to-end-of-line-with-ctrl-e-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on second line (no newline after), press ctrl-e
assume-console [
left-click 2, 1
press ctrl-e
]
run [
editor-event-loop screen, console, e
4:num/raw <- get *e, cursor-row:offset
5:num/raw <- get *e, cursor-column:offset
]
# cursor moves to end of line
memory-should-contain [
4 <- 2
5 <- 3
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-to-end-of-line-with-end [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on first line, press 'end'
assume-console [
left-click 1, 1
press end
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# cursor moves to end of line
memory-should-contain [
3 <- 1
4 <- 3
]
check-trace-count-for-label 0, [print-character]
]
scenario editor-moves-to-end-of-line-with-end-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# start on second line (no newline after), press 'end'
assume-console [
left-click 2, 1
press end
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# cursor moves to end of line
memory-should-contain [
3 <- 2
4 <- 3
]
check-trace-count-for-label 0, [print-character]
]
# ctrl-u - delete text from start of line until (but not at) cursor
scenario editor-deletes-to-start-of-line-with-ctrl-u [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
# start on second line, press ctrl-u
assume-console [
left-click 2, 2
press ctrl-u
]
run [
editor-event-loop screen, console, e
]
# cursor deletes to start of line
screen-should-contain [
. .
.123 .
.6 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
after <handle-special-character> [
{
delete-to-start-of-line?:bool <- equal c, 21/ctrl-u
break-unless delete-to-start-of-line?
<delete-to-start-of-line-begin>
deleted-cells:&:duplex-list:char <- delete-to-start-of-line editor
<delete-to-start-of-line-end>
go-render? <- copy 1/true
return
}
]
def delete-to-start-of-line editor:&:editor -> result:&:duplex-list:char, editor:&:editor [
local-scope
load-ingredients
# compute range to delete
init:&:duplex-list:char <- get *editor, data:offset
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
start:&:duplex-list:char <- copy before-cursor
end:&:duplex-list:char <- next before-cursor
{
at-start-of-text?:bool <- equal start, init
break-if at-start-of-text?
curr:char <- get *start, value:offset
at-start-of-line?:bool <- equal curr, 10/newline
break-if at-start-of-line?
start <- prev start
assert start, [delete-to-start-of-line tried to move before start of text]
loop
}
# snip it out
result:&:duplex-list:char <- next start
remove-between start, end
# adjust cursor
before-cursor <- copy start
*editor <- put *editor, before-cursor:offset, before-cursor
left:num <- get *editor, left:offset
*editor <- put *editor, cursor-column:offset, left
]
scenario editor-deletes-to-start-of-line-with-ctrl-u-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
# start on first line (no newline before), press ctrl-u
assume-console [
left-click 1, 2
press ctrl-u
]
run [
editor-event-loop screen, console, e
]
# cursor deletes to start of line
screen-should-contain [
. .
.3 .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-deletes-to-start-of-line-with-ctrl-u-3 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
# start past end of line, press ctrl-u
assume-console [
left-click 1, 3
press ctrl-u
]
run [
editor-event-loop screen, console, e
]
# cursor deletes to start of line
screen-should-contain [
. .
. .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-deletes-to-start-of-final-line-with-ctrl-u [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
# start past end of final line, press ctrl-u
assume-console [
left-click 2, 3
press ctrl-u
]
run [
editor-event-loop screen, console, e
]
# cursor deletes to start of line
screen-should-contain [
. .
.123 .
. .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
# ctrl-k - delete text from cursor to end of line (but not the newline)
scenario editor-deletes-to-end-of-line-with-ctrl-k [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
# start on first line, press ctrl-k
assume-console [
left-click 1, 1
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# cursor deletes to end of line
screen-should-contain [
. .
.1 .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
after <handle-special-character> [
{
delete-to-end-of-line?:bool <- equal c, 11/ctrl-k
break-unless delete-to-end-of-line?
<delete-to-end-of-line-begin>
deleted-cells:&:duplex-list:char <- delete-to-end-of-line editor
<delete-to-end-of-line-end>
go-render? <- copy 1/true
return
}
]
def delete-to-end-of-line editor:&:editor -> result:&:duplex-list:char, editor:&:editor [
local-scope
load-ingredients
# compute range to delete
start:&:duplex-list:char <- get *editor, before-cursor:offset
end:&:duplex-list:char <- next start
{
at-end-of-text?:bool <- equal end, 0/null
break-if at-end-of-text?
curr:char <- get *end, value:offset
at-end-of-line?:bool <- equal curr, 10/newline
break-if at-end-of-line?
end <- next end
loop
}
# snip it out
result <- next start
remove-between start, end
]
scenario editor-deletes-to-end-of-line-with-ctrl-k-2 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
# start on second line (no newline after), press ctrl-k
assume-console [
left-click 2, 1
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# cursor deletes to end of line
screen-should-contain [
. .
.123 .
.4 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-deletes-to-end-of-line-with-ctrl-k-3 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
# start at end of line
assume-console [
left-click 1, 2
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# cursor deletes just last character
screen-should-contain [
. .
.12 .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-deletes-to-end-of-line-with-ctrl-k-4 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
# start past end of line
assume-console [
left-click 1, 3
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# cursor deletes nothing
screen-should-contain [
. .
.123 .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-deletes-to-end-of-line-with-ctrl-k-5 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
# start at end of text
assume-console [
left-click 2, 2
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# cursor deletes just the final character
screen-should-contain [
. .
.123 .
.45 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-deletes-to-end-of-line-with-ctrl-k-6 [
local-scope
assume-screen 10/width, 5/height
s:text <- new [123
456]
e:&:editor <- new-editor s, screen, 0/left, 10/right
# start past end of text
assume-console [
left-click 2, 3
press ctrl-k
]
run [
editor-event-loop screen, console, e
]
# cursor deletes nothing
screen-should-contain [
. .
.123 .
.456 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
# cursor-down can scroll if necessary
scenario editor-can-scroll-down-using-arrow-keys [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 10/width, 4/height
# initialize editor with >3 lines
s:text <- new [a
b
c
d]
e:&:editor <- new-editor s, screen, 0/left, 10/right
screen-should-contain [
. .
.a .
.b .
.c .
]
# position cursor at last line, then try to move further down
assume-console [
left-click 3, 0
press down-arrow
]
run [
editor-event-loop screen, console, e
]
# screen slides by one line
screen-should-contain [
. .
.b .
.c .
.d .
]
]
after <scroll-down> [
trace 10, [app], [scroll down]
top-of-screen:&:duplex-list:char <- get *editor, top-of-screen:offset
left:num <- get *editor, left:offset
right:num <- get *editor, right:offset
max:num <- subtract right, left
old-top:&:duplex-list:char <- copy top-of-screen
top-of-screen <- before-start-of-next-line top-of-screen, max
*editor <- put *editor, top-of-screen:offset, top-of-screen
no-movement?:bool <- equal old-top, top-of-screen
go-render? <- copy 0/false
return-if no-movement?
]
# takes a pointer into the doubly-linked list, scans ahead at most 'max'
# positions until the next newline
# beware: never return null pointer.
def before-start-of-next-line original:&:duplex-list:char, max:num -> curr:&:duplex-list:char [
local-scope
load-ingredients
count:num <- copy 0
curr:&:duplex-list:char <- copy original
# skip the initial newline if it exists
{
c:char <- get *curr, value:offset
at-newline?:bool <- equal c, 10/newline
break-unless at-newline?
curr <- next curr
count <- add count, 1
}
{
return-unless curr, original
done?:bool <- greater-or-equal count, max
break-if done?
c:char <- get *curr, value:offset
at-newline?:bool <- equal c, 10/newline
break-if at-newline?
curr <- next curr
count <- add count, 1
loop
}
return-unless curr, original
return curr
]
scenario editor-scrolls-down-past-wrapped-line-using-arrow-keys [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 10/width, 4/height
# initialize editor with a long, wrapped line and more than a screen of
# other lines
s:text <- new [abcdef
g
h
i]
e:&:editor <- new-editor s, screen, 0/left, 5/right
screen-should-contain [
. .
.abcd↩ .
.ef .
.g .
]
# position cursor at last line, then try to move further down
assume-console [
left-click 3, 0
press down-arrow
]
run [
editor-event-loop screen, console, e
]
# screen shows partial wrapped line
screen-should-contain [
. .
.ef .
.g .
.h .
]
]
scenario editor-scrolls-down-past-wrapped-line-using-arrow-keys-2 [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 10/width, 4/height
# editor starts with a long line wrapping twice
s:text <- new [abcdefghij
k
l
m]
e:&:editor <- new-editor s, screen, 0/left, 5/right
# position cursor at last line, then try to move further down
assume-console [
left-click 3, 0
press down-arrow
]
run [
editor-event-loop screen, console, e
]
# screen shows partial wrapped line containing a wrap icon
screen-should-contain [
. .
.efgh↩ .
.ij .
.k .
]
# scroll down again
assume-console [
press down-arrow
]
run [
editor-event-loop screen, console, e
]
# screen shows partial wrapped line
screen-should-contain [
. .
.ij .
.k .
.l .
]
]
scenario editor-scrolls-down-when-line-wraps [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 5/width, 4/height
# editor contains a long line in the third line
s:text <- new [a
b
cdef]
e:&:editor <- new-editor s, screen, 0/left, 5/right
# position cursor at end, type a character
assume-console [
left-click 3, 4
type [g]
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# screen scrolls
screen-should-contain [
. .
.b .
.cdef↩.
.g .
]
memory-should-contain [
3 <- 3
4 <- 1
]
]
scenario editor-scrolls-down-on-newline [
local-scope
assume-screen 5/width, 4/height
# position cursor after last line and type newline
s:text <- new [a
b
c]
e:&:editor <- new-editor s, screen, 0/left, 5/right
assume-console [
left-click 3, 4
type [
]
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# screen scrolls
screen-should-contain [
. .
.b .
.c .
. .
]
memory-should-contain [
3 <- 3
4 <- 0
]
]
scenario editor-scrolls-down-on-right-arrow [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 5/width, 4/height
# editor contains a wrapped line
s:text <- new [a
b
cdefgh]
e:&:editor <- new-editor s, screen, 0/left, 5/right
# position cursor at end of screen and try to move right
assume-console [
left-click 3, 3
press right-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# screen scrolls
screen-should-contain [
. .
.b .
.cdef↩.
.gh .
]
memory-should-contain [
3 <- 3
4 <- 0
]
]
scenario editor-scrolls-down-on-right-arrow-2 [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 5/width, 4/height
# editor contains more lines than can fit on screen
s:text <- new [a
b
c
d]
e:&:editor <- new-editor s, screen, 0/left, 5/right
# position cursor at end of screen and try to move right
assume-console [
left-click 3, 3
press right-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# screen scrolls
screen-should-contain [
. .
.b .
.c .
.d .
]
memory-should-contain [
3 <- 3
4 <- 0
]
]
scenario editor-scrolls-at-end-on-down-arrow [
local-scope
assume-screen 10/width, 5/height
s:text <- new [abc
de]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
$clear-trace
# try to move down past end of text
assume-console [
left-click 2, 0
press down-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# screen should scroll, moving cursor to end of text
memory-should-contain [
3 <- 1
4 <- 2
]
assume-console [
type [0]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.de0 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
# try to move down again
$clear-trace
assume-console [
left-click 2, 0
press down-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# screen stops scrolling because cursor is already at top
memory-should-contain [
3 <- 1
4 <- 3
]
check-trace-count-for-label 0, [print-character]
assume-console [
type [1]
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.de01 .
.┈┈┈┈┈┈┈┈┈┈.
. .
]
]
scenario editor-combines-page-and-line-scroll [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 10/width, 4/height
# initialize editor with a few pages of lines
s:text <- new [a
b
c
d
e
f
g]
e:&:editor <- new-editor s, screen, 0/left, 5/right
# scroll down one page and one line
assume-console [
press page-down
left-click 3, 0
press down-arrow
]
run [
editor-event-loop screen, console, e
]
# screen scrolls down 3 lines
screen-should-contain [
. .
.d .
.e .
.f .
]
]
# cursor-up can scroll if necessary
scenario editor-can-scroll-up-using-arrow-keys [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 10/width, 4/height
# initialize editor with >3 lines
s:text <- new [a
b
c
d]
e:&:editor <- new-editor s, screen, 0/left, 10/right
screen-should-contain [
. .
.a .
.b .
.c .
]
# position cursor at top of second page, then try to move up
assume-console [
press page-down
press up-arrow
]
run [
editor-event-loop screen, console, e
]
# screen slides by one line
screen-should-contain [
. .
.b .
.c .
.d .
]
]
after <scroll-up> [
trace 10, [app], [scroll up]
top-of-screen:&:duplex-list:char <- get *editor, top-of-screen:offset
old-top:&:duplex-list:char <- copy top-of-screen
top-of-screen <- before-previous-line top-of-screen, editor
*editor <- put *editor, top-of-screen:offset, top-of-screen
no-movement?:bool <- equal old-top, top-of-screen
go-render? <- copy 0/false
return-if no-movement?
]
# takes a pointer into the doubly-linked list, scans back to before start of
# previous *wrapped* line
# beware: never return null pointer
def before-previous-line in:&:duplex-list:char, editor:&:editor -> out:&:duplex-list:char [
local-scope
load-ingredients
curr:&:duplex-list:char <- copy in
c:char <- get *curr, value:offset
# compute max, number of characters to skip
# 1 + len%(width-1)
# except rotate second term to vary from 1 to width-1 rather than 0 to width-2
left:num <- get *editor, left:offset
right:num <- get *editor, right:offset
max-line-length:num <- subtract right, left, -1/exclusive-right, 1/wrap-icon
sentinel:&:duplex-list:char <- get *editor, data:offset
len:num <- previous-line-length curr, sentinel
{
break-if len
# empty line; just skip this newline
prev:&:duplex-list:char <- prev curr
return-unless prev, curr
return prev
}
_, max:num <- divide-with-remainder len, max-line-length
# remainder 0 => scan one width-worth
{
break-if max
max <- copy max-line-length
}
max <- add max, 1
count:num <- copy 0
# skip 'max' characters
{
done?:bool <- greater-or-equal count, max
break-if done?
prev:&:duplex-list:char <- prev curr
break-unless prev
curr <- copy prev
count <- add count, 1
loop
}
return curr
]
scenario editor-scrolls-up-past-wrapped-line-using-arrow-keys [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 10/width, 4/height
# initialize editor with a long, wrapped line and more than a screen of
# other lines
s:text <- new [abcdef
g
h
i]
e:&:editor <- new-editor s, screen, 0/left, 5/right
screen-should-contain [
. .
.abcd↩ .
.ef .
.g .
]
# position cursor at top of second page, just below wrapped line
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.g .
.h .
.i .
]
# now move up one line
assume-console [
press up-arrow
]
run [
editor-event-loop screen, console, e
]
# screen shows partial wrapped line
screen-should-contain [
. .
.ef .
.g .
.h .
]
]
scenario editor-scrolls-up-past-wrapped-line-using-arrow-keys-2 [
local-scope
# screen has 1 line for menu + 4 lines
assume-screen 10/width, 5/height
# editor starts with a long line wrapping twice, occupying 3 of the 4 lines
s:text <- new [abcdefghij
k
l
m]
e:&:editor <- new-editor s, screen, 0/left, 5/right
# position cursor at top of second page
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.k .
.l .
.m .
.┈┈┈┈┈ .
]
# move up one line
assume-console [
press up-arrow
]
run [
editor-event-loop screen, console, e
]
# screen shows partial wrapped line
screen-should-contain [
. .
.ij .
.k .
.l .
.m .
]
# move up a second line
assume-console [
press up-arrow
]
run [
editor-event-loop screen, console, e
]
# screen shows partial wrapped line
screen-should-contain [
. .
.efgh↩ .
.ij .
.k .
.l .
]
# move up a third line
assume-console [
press up-arrow
]
run [
editor-event-loop screen, console, e
]
# screen shows partial wrapped line
screen-should-contain [
. .
.abcd↩ .
.efgh↩ .
.ij .
.k .
]
]
# same as editor-scrolls-up-past-wrapped-line-using-arrow-keys but length
# slightly off, just to prevent over-training
scenario editor-scrolls-up-past-wrapped-line-using-arrow-keys-3 [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 10/width, 4/height
# initialize editor with a long, wrapped line and more than a screen of
# other lines
s:text <- new [abcdef
g
h
i]
e:&:editor <- new-editor s, screen, 0/left, 6/right
screen-should-contain [
. .
.abcde↩ .
.f .
.g .
]
# position cursor at top of second page, just below wrapped line
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.g .
.h .
.i .
]
# now move up one line
assume-console [
press up-arrow
]
run [
editor-event-loop screen, console, e
]
# screen shows partial wrapped line
screen-should-contain [
. .
.f .
.g .
.h .
]
]
# check empty lines
scenario editor-scrolls-up-past-wrapped-line-using-arrow-keys-4 [
local-scope
assume-screen 10/width, 4/height
# initialize editor with some lines around an empty line
s:text <- new [a
b
c
d
e]
e:&:editor <- new-editor s, screen, 0/left, 6/right
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
. .
.c .
.d .
]
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.d .
.e .
.┈┈┈┈┈┈ .
]
assume-console [
press page-up
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
. .
.c .
.d .
]
]
scenario editor-scrolls-up-on-left-arrow [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 5/width, 4/height
# editor contains >3 lines
s:text <- new [a
b
c
d
e]
e:&:editor <- new-editor s, screen, 0/left, 5/right
# position cursor at top of second page
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.c .
.d .
.e .
]
# now try to move left
assume-console [
press left-arrow
]
run [
editor-event-loop screen, console, e
3:num/raw <- get *e, cursor-row:offset
4:num/raw <- get *e, cursor-column:offset
]
# screen scrolls
screen-should-contain [
. .
.b .
.c .
.d .
]
memory-should-contain [
3 <- 1
4 <- 1
]
]
scenario editor-can-scroll-up-to-start-of-file [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 10/width, 4/height
# initialize editor with >3 lines
s:text <- new [a
b
c
d]
e:&:editor <- new-editor s, screen, 0/left, 10/right
screen-should-contain [
. .
.a .
.b .
.c .
]
# position cursor at top of second page, then try to move up to start of
# text
assume-console [
press page-down
press up-arrow
press up-arrow
]
run [
editor-event-loop screen, console, e
]
# screen slides by one line
screen-should-contain [
. .
.a .
.b .
.c .
]
# try to move up again
assume-console [
press up-arrow
]
run [
editor-event-loop screen, console, e
]
# screen remains unchanged
screen-should-contain [
. .
.a .
.b .
.c .
]
]
# ctrl-f/page-down - render next page if it exists
scenario editor-can-scroll [
local-scope
assume-screen 10/width, 4/height
s:text <- new [a
b
c
d]
e:&:editor <- new-editor s, screen, 0/left, 10/right
screen-should-contain [
. .
.a .
.b .
.c .
]
# scroll down
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
# screen shows next page
screen-should-contain [
. .
.c .
.d .
.┈┈┈┈┈┈┈┈┈┈.
]
]
after <handle-special-character> [
{
page-down?:bool <- equal c, 6/ctrl-f
break-unless page-down?
old-top:&:duplex-list:char <- get *editor, top-of-screen:offset
<move-cursor-begin>
page-down editor
undo-coalesce-tag:num <- copy 0/never
<move-cursor-end>
top-of-screen:&:duplex-list:char <- get *editor, top-of-screen:offset
no-movement?:bool <- equal top-of-screen, old-top
go-render? <- not no-movement?
return
}
]
after <handle-special-key> [
{
page-down?:bool <- equal k, 65518/page-down
break-unless page-down?
old-top:&:duplex-list:char <- get *editor, top-of-screen:offset
<move-cursor-begin>
page-down editor
undo-coalesce-tag:num <- copy 0/never
<move-cursor-end>
top-of-screen:&:duplex-list:char <- get *editor, top-of-screen:offset
no-movement?:bool <- equal top-of-screen, old-top
go-render? <- not no-movement?
return
}
]
# page-down skips entire wrapped lines, so it can't scroll past lines
# taking up the entire screen
def page-down editor:&:editor -> editor:&:editor [
local-scope
load-ingredients
# if editor contents don't overflow screen, do nothing
bottom-of-screen:&:duplex-list:char <- get *editor, bottom-of-screen:offset
return-unless bottom-of-screen
# if not, position cursor at final character
before-cursor:&:duplex-list:char <- get *editor, before-cursor:offset
before-cursor:&:duplex-list:char <- prev bottom-of-screen
*editor <- put *editor, before-cursor:offset, before-cursor
# keep one line in common with previous page
{
last:char <- get *before-cursor, value:offset
newline?:bool <- equal last, 10/newline
break-unless newline?:bool
before-cursor <- prev before-cursor
*editor <- put *editor, before-cursor:offset, before-cursor
}
# move cursor and top-of-screen to start of that line
move-to-start-of-line editor
before-cursor <- get *editor, before-cursor:offset
*editor <- put *editor, top-of-screen:offset, before-cursor
]
scenario editor-does-not-scroll-past-end [
local-scope
assume-screen 10/width, 4/height
s:text <- new [a
b]
e:&:editor <- new-editor s, screen, 0/left, 10/right
editor-render screen, e
screen-should-contain [
. .
.a .
.b .
.┈┈┈┈┈┈┈┈┈┈.
]
# scroll down
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
# screen remains unmodified
screen-should-contain [
. .
.a .
.b .
.┈┈┈┈┈┈┈┈┈┈.
]
]
scenario editor-starts-next-page-at-start-of-wrapped-line [
local-scope
# screen has 1 line for menu + 3 lines for text
assume-screen 10/width, 4/height
# editor contains a long last line
s:text <- new [a
b
cdefgh]
# editor screen triggers wrap of last line
e:&:editor <- new-editor s, screen, 0/left, 4/right
# some part of last line is not displayed
screen-should-contain [
. .
.a .
.b .
.cde↩ .
]
# scroll down
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
# screen shows entire wrapped line
screen-should-contain [
. .
.cde↩ .
.fgh .
.┈┈┈┈ .
]
]
scenario editor-starts-next-page-at-start-of-wrapped-line-2 [
local-scope
# screen has 1 line for menu + 3 lines for text
assume-screen 10/width, 4/height
# editor contains a very long line that occupies last two lines of screen
# and still has something left over
s:text <- new [a
bcdefgh]
e:&:editor <- new-editor s, screen, 0/left, 4/right
# some part of last line is not displayed
screen-should-contain [
. .
.a .
.bcd↩ .
.efg↩ .
]
# scroll down
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
# screen shows entire wrapped line
screen-should-contain [
. .
.bcd↩ .
.efg↩ .
.h .
]
]
# ctrl-b/page-up - render previous page if it exists
scenario editor-can-scroll-up [
local-scope
assume-screen 10/width, 4/height
s:text <- new [a
b
c
d]
e:&:editor <- new-editor s, screen, 0/left, 10/right
screen-should-contain [
. .
.a .
.b .
.c .
]
# scroll down
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
# screen shows next page
screen-should-contain [
. .
.c .
.d .
.┈┈┈┈┈┈┈┈┈┈.
]
# scroll back up
assume-console [
press page-up
]
run [
editor-event-loop screen, console, e
]
# screen shows original page again
screen-should-contain [
. .
.a .
.b .
.c .
]
]
after <handle-special-character> [
{
page-up?:bool <- equal c, 2/ctrl-b
break-unless page-up?
old-top:&:duplex-list:char <- get *editor, top-of-screen:offset
<move-cursor-begin>
editor <- page-up editor, screen-height
undo-coalesce-tag:num <- copy 0/never
<move-cursor-end>
top-of-screen:&:duplex-list:char <- get *editor, top-of-screen:offset
no-movement?:bool <- equal top-of-screen, old-top
go-render? <- not no-movement?
return
}
]
after <handle-special-key> [
{
page-up?:bool <- equal k, 65519/page-up
break-unless page-up?
old-top:&:duplex-list:char <- get *editor, top-of-screen:offset
<move-cursor-begin>
editor <- page-up editor, screen-height
undo-coalesce-tag:num <- copy 0/never
<move-cursor-end>
top-of-screen:&:duplex-list:char <- get *editor, top-of-screen:offset
no-movement?:bool <- equal top-of-screen, old-top
# don't bother re-rendering if nothing changed. todo: test this
go-render? <- not no-movement?
return
}
]
def page-up editor:&:editor, screen-height:num -> editor:&:editor [
local-scope
load-ingredients
max:num <- subtract screen-height, 1/menu-bar, 1/overlapping-line
count:num <- copy 0
top-of-screen:&:duplex-list:char <- get *editor, top-of-screen:offset
{
done?:bool <- greater-or-equal count, max
break-if done?
prev:&:duplex-list:char <- before-previous-line top-of-screen, editor
break-unless prev
top-of-screen <- copy prev
*editor <- put *editor, top-of-screen:offset, top-of-screen
count <- add count, 1
loop
}
]
scenario editor-can-scroll-up-multiple-pages [
local-scope
# screen has 1 line for menu + 3 lines
assume-screen 10/width, 4/height
# initialize editor with 8 lines
s:text <- new [a
b
c
d
e
f
g
h]
e:&:editor <- new-editor s, screen, 0/left, 10/right
screen-should-contain [
. .
.a .
.b .
.c .
]
# scroll down two pages
assume-console [
press page-down
press page-down
]
run [
editor-event-loop screen, console, e
]
# screen shows third page
screen-should-contain [
. .
.e .
.f .
.g .
]
# scroll up
assume-console [
press page-up
]
run [
editor-event-loop screen, console, e
]
# screen shows second page
screen-should-contain [
. .
.c .
.d .
.e .
]
# scroll up again
assume-console [
press page-up
]
run [
editor-event-loop screen, console, e
]
# screen shows original page again
screen-should-contain [
. .
.a .
.b .
.c .
]
]
scenario editor-can-scroll-up-wrapped-lines [
local-scope
# screen has 1 line for menu + 5 lines for text
assume-screen 10/width, 6/height
# editor contains a long line in the first page
s:text <- new [a
b
cdefgh
i
j
k
l
m
n
o]
# editor screen triggers wrap of last line
e:&:editor <- new-editor s, screen, 0/left, 4/right
# some part of last line is not displayed
screen-should-contain [
. .
.a .
.b .
.cde↩ .
.fgh .
.i .
]
# scroll down a page and a line
assume-console [
press page-down
left-click 5, 0
press down-arrow
]
run [
editor-event-loop screen, console, e
]
# screen shows entire wrapped line
screen-should-contain [
. .
.j .
.k .
.l .
.m .
.n .
]
# now scroll up one page
assume-console [
press page-up
]
run [
editor-event-loop screen, console, e
]
# screen resets
screen-should-contain [
. .
.b .
.cde↩ .
.fgh .
.i .
.j .
]
]
scenario editor-can-scroll-up-wrapped-lines-2 [
local-scope
# screen has 1 line for menu + 3 lines for text
assume-screen 10/width, 4/height
# editor contains a very long line that occupies last two lines of screen
# and still has something left over
s:text <- new [a
bcdefgh]
e:&:editor <- new-editor s, screen, 0/left, 4/right
# some part of last line is not displayed
screen-should-contain [
. .
.a .
.bcd↩ .
.efg↩ .
]
# scroll down
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
# screen shows entire wrapped line
screen-should-contain [
. .
.bcd↩ .
.efg↩ .
.h .
]
# scroll back up
assume-console [
press page-up
]
run [
editor-event-loop screen, console, e
]
# screen resets
screen-should-contain [
. .
.a .
.bcd↩ .
.efg↩ .
]
]
scenario editor-can-scroll-up-past-nonempty-lines [
local-scope
assume-screen 10/width, 4/height
# text with empty line in second screen
s:text <- new [axx
bxx
cxx
dxx
exx
fxx
gxx
hxx
]
e:&:editor <- new-editor s, screen, 0/left, 4/right
screen-should-contain [
. .
.axx .
.bxx .
.cxx .
]
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.cxx .
.dxx .
.exx .
]
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.exx .
.fxx .
.gxx .
]
# scroll back up past empty line
assume-console [
press page-up
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.cxx .
.dxx .
.exx .
]
]
scenario editor-can-scroll-up-past-empty-lines [
local-scope
assume-screen 10/width, 4/height
# text with empty line in second screen
s:text <- new [axy
bxy
cxy
dxy
exy
fxy
gxy
]
e:&:editor <- new-editor s, screen, 0/left, 4/right
screen-should-contain [
. .
.axy .
.bxy .
.cxy .
]
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.cxy .
. .
.dxy .
]
assume-console [
press page-down
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.dxy .
.exy .
.fxy .
]
# scroll back up past empty line
assume-console [
press page-up
]
run [
editor-event-loop screen, console, e
]
screen-should-contain [
. .
.cxy .
. .
.dxy .
]
]