bugfix: down arrow doesn't scroll up unnecessarily

[?]

May 24, 2022, 10:01 PM

V5MJRFOZRVVDCPOWTLXPHS2HZBZKOOCPPKFMRP6MWZN6N62QLFAAC

Dependencies

[2] MDXGMZU2 disable all debug prints
[3] 2POFQQLW keep cursor on screen when pressing 'down'
[4] 3OKKTUT4 up and down arrow now moving by screen line where possible
[5] PR4KIAZD first stab at equally hacky cursor down support
[6] TRNWIQN6 more precise height calculation when scrolling up as much as possible while keeping cursor on screen
[7] 2RXZ3PGO beginning of a new approach to scroll+wrap
[8] ESETRNLB bugfix: printing the first part of a line at the bottom made it seem non-wrapping
[9] PYGMASTV disable some debug prints
[10] SVJZZDC3 snapshot - no, that's all wrong
[*] BULPIBEG beginnings of a module for the text editor
[*] IMEJA43L snapshot
[*] XOAHJ6M3 similar tests for cursor up

Change contents

edit in text.lua at line 313

[13.4789]

[14.279]

end

function test_page_down_followed_by_down_arrow_does_not_scroll_screen_up()
io.write('\ntest_page_down_followed_by_down_arrow_does_not_scroll_screen_up')
App.screen.init{width=25+30, height=60}
Lines = load_array{'abc', 'def', 'ghijkl', 'mno'}
Line_width = App.screen.width
Cursor1 = {line=3, pos=1}
Screen_top1 = {line=1, pos=1}
Screen_bottom1 = {}
Zoom = 1
local screen_top_margin = 15 -- pixels
local line_height = math.floor(15*Zoom) -- pixels
App.draw()
local y = screen_top_margin
App.screen.check(y, 'abc', 'F - test_page_down_followed_by_down_arrow_does_not_scroll_screen_up/baseline/screen:1')
y = y + line_height
App.screen.check(y, 'def', 'F - test_page_down_followed_by_down_arrow_does_not_scroll_screen_up/baseline/screen:2')
y = y + line_height
App.screen.check(y, 'ghijk', 'F - test_page_down_followed_by_down_arrow_does_not_scroll_screen_up/baseline/screen:3')
-- after hitting pagedown the screen scrolls down to start of a long line
App.run_after_keychord('pagedown')
check_eq(Screen_top1.line, 3, 'F - test_page_down_followed_by_down_arrow_does_not_scroll_screen_up/baseline2/screen_top')
check_eq(Cursor1.line, 3, 'F - test_page_down_followed_by_down_arrow_does_not_scroll_screen_up/baseline2/cursor:line')
check_eq(Cursor1.pos, 1, 'F - test_page_down_followed_by_down_arrow_does_not_scroll_screen_up/baseline2/cursor:pos')
-- after hitting down arrow the screen doesn't scroll down further, and certainly doesn't scroll up
App.run_after_keychord('down')
check_eq(Screen_top1.line, 3, 'F - test_page_down_followed_by_down_arrow_does_not_scroll_screen_up/screen_top')
check_eq(Cursor1.line, 3, 'F - test_page_down_followed_by_down_arrow_does_not_scroll_screen_up/cursor:line')
check_eq(Cursor1.pos, 6, 'F - test_page_down_followed_by_down_arrow_does_not_scroll_screen_up/cursor:pos')
y = screen_top_margin
App.screen.check(y, 'ghijk', 'F - test_page_down_followed_by_down_arrow_does_not_scroll_screen_up/screen:1')
y = y + line_height
App.screen.check(y, 'l', 'F - test_page_down_followed_by_down_arrow_does_not_scroll_screen_up/screen:2')
y = y + line_height
App.screen.check(y, 'mno', 'F - test_page_down_followed_by_down_arrow_does_not_scroll_screen_up/screen:3')
edit in text.lua at line 835

[3.983]

[2.928]

local scroll_up = false
if Cursor1.line > Screen_bottom1.line or (Cursor1.line == Screen_bottom1.line and Cursor1.pos >= Screen_bottom1.pos) then
scroll_up = true
end
replacement in text.lua at line 846

[3.61]→[3.6141:6179](∅→∅),[3.982]→[3.6141:6179](∅→∅),[2.1208]→[3.6141:6179](∅→∅),[3.6141]→[3.6141:6179](∅→∅),[3.6179]→[2.1209:1256](∅→∅),[3.108]→[3.1620:1666](∅→∅),[3.158]→[3.1620:1666](∅→∅),[3.1026]→[3.1620:1666](∅→∅),[2.1256]→[3.1620:1666](∅→∅),[3.1511]→[3.1620:1666](∅→∅),[3.1620]→[3.1620:1666](∅→∅),[3.1666]→[2.1257:1329](∅→∅)

Screen_top1.line = Cursor1.line
--? print('scroll up preserving cursor')
Text.scroll_up_while_cursor_on_screen()
--? print('screen top after:', Screen_top1.line, Screen_top1.pos)

[2.1208]

[3.1313]

if scroll_up then
Screen_top1.line = Cursor1.line
--? print('scroll up preserving cursor')
Text.scroll_up_while_cursor_on_screen()
--? print('screen top after:', Screen_top1.line, Screen_top1.pos)
end