akkartik/techmeet.love - Change NP5DODWMHP22MO6Z3B6NYDR7C3DLV2BD4NKT2RFFFOSIDPC3ZPWQC

experiment: never compute viewport from screen_top

I think this works!

So the cause of all my trouble was a historical accident: I thought of computing viewport from screen_top before I thought of bring_cursor_of_cursor_pane_in_view. Turning the symbolic dependency DAG of variables into a graph turns out to be no end of trouble, where A sometimes depends on B and B sometimes on A.

Let's see if we uncover any issues.

Created by Kartik K. Agaram on January 4, 2023

NP5DODWMHP22MO6Z3B6NYDR7C3DLV2BD4NKT2RFFFOSIDPC3ZPWQC

Dependencies

In channels

main

Change contents

Replacement in run.lua at line 285 [6.178044]
B:BD[4.12677] → [5.195:223]
```
function plan_draw(options)
```
[4.12677]
[7.17]
```
function plan_draw()
```

Deletion in run.lua at line 311 [6.178044]

B:BD[8.53] → [5.258:342]

∅:D[9.193] → [4.13809:13950]

∅:D[10.337] → [4.13809:13950]

∅:D[5.342] → [4.13809:13950]

∅:D[11.415] → [4.13809:13950]

∅:D[8.2295] → [4.13809:13950]

B:BD[4.13809] → [4.13809:13950]

∅:D[12.359] → [4.13950:14046]

B:BD[4.13950] → [4.13950:14046]

          if should_update_screen_top(column_index, pane_index, pane, options) then
            if body_sy < Display_settings.y then
              pane.screen_top1, y_offset = schema1_of_y(pane, Display_settings.y - body_sy)
            else
              pane.screen_top1 = {line=1, pos=1}
            end
          end

Replacement in run.lua at line 312 [6.178044]

B:BD[4.14093] → [4.14093:14129]

            pane.top = Margin_above

[4.14093]

[4.14129]

            pane.screen_top1, y_offset = schema1_of_y(pane, Display_settings.y - body_sy)
            pane.top = 0

Replacement in run.lua at line 315 [6.178044]

B:BD[4.14144] → [4.14144:14211]

            pane.top = body_sy - Display_settings.y + Margin_above

[4.14144]

[4.14211]

            pane.screen_top1 = {line=1, pos=1}
            pane.top = body_sy - Display_settings.y

Replacement in run.lua at line 318 [6.178044]

B:BD[4.14225] → [4.14225:14282]

          pane.top = Header_height + pane.top - y_offset

[4.14225]

[4.14282]

          pane.top = Header_height + Margin_above + pane.top - y_offset

Deletion in run.lua at line 340 [6.178044]
B:BD[13.847] → [5.343:418]
B:BD[5.418] → [14.17:58]
∅:D[14.58] → [4.15024:15138]
∅:D[10.413] → [4.15024:15138]
∅:D[5.418] → [4.15024:15138]
∅:D[11.499] → [4.15024:15138]
∅:D[8.2379] → [4.15024:15138]
B:BD[4.15024] → [4.15024:15138]
B:BD[4.15138] → [15.17:73]
∅:D[15.73] → [4.15470:15475]
∅:D[14.99] → [4.15470:15475]
∅:D[11.531] → [4.15470:15475]
∅:D[10.746] → [4.15470:15475]
∅:D[5.751] → [4.15470:15475]
∅:D[8.2411] → [4.15470:15475]
B:BD[4.15470] → [4.15470:15475]
```
function should_update_screen_top(column_index, pane_index, pane, options)
  if options == nil then return true end
  if column_index ~= Cursor_pane.col then return true end
  if pane_index ~= Cursor_pane.row then return true end
  return not options.preserve_screen_top_of_cursor_pane
end
```

Replacement in run.lua at line 797 [6.178044]

B:BD[16.1181] → [2.193:286]

            local screen_top_updated = maybe_update_screen_top_of_cursor_pane(pane, old_top)

[16.1181]

[5.870]

            if chord == 'backspace' or chord == 'up' or chord == 'left' then
              bring_cursor_of_cursor_pane_in_view('up')
            else
              bring_cursor_of_cursor_pane_in_view('down')
            end

Replacement in run.lua at line 803 [6.178044]

B:BD[5.901] → [2.287:364]

            plan_draw{preserve_screen_top_of_cursor_pane=screen_top_updated}

[5.901]

[8.3123]

            plan_draw()

Deletion in run.lua at line 1135 [6.178044]

B:BD[4.43276] → [4.43276:43287]

B:BD[4.43287] → [2.365:399]

∅:D[2.399] → [4.43287:43350]

∅:D[10.1715] → [4.43287:43350]

B:BD[4.43287] → [4.43287:43350]

∅:D[12.2075] → [17.143:243]

B:BD[17.143] → [17.143:243]

B:BD[17.243] → [2.400:592]

∅:D[2.592] → [18.557:640]

∅:D[12.2271] → [18.557:640]

B:BD[18.557] → [18.557:640]

B:BD[18.640] → [3.17:172]

∅:D[3.172] → [18.719:766]

B:BD[18.719] → [18.719:766]

∅:D[18.766] → [17.397:597]

∅:D[12.2289] → [17.397:597]

B:BD[17.397] → [17.397:597]

B:BD[17.597] → [2.593:702]

  end
end
-- return whether update happened
function maybe_update_screen_top_of_cursor_pane(pane, old_top)
  local cursor_sy = up_edge_sy(Cursor_pane.col, Cursor_pane.row) + y_of_schema1(pane, pane.cursor1)
  if not eq(old_top, pane.screen_top1) and eq(old_top, {line=1, pos=1}) and pane.top > Header_height and cursor_sy - Display_settings.y > App.screen.height - Header_height  - Line_height then
    -- updating screen_top1 can be jarring if the pane had room above it on screen
    -- the editor updates screen_top1, then we update viewport based on screen_top1, and it goes from somewhere lower down to all the way at top of screen
    -- prefer to pan the surface when possible
    pane.screen_top1 = old_top
    bring_cursor_of_cursor_pane_in_view('down')
    Surface.cursor_on_screen_check = true  -- cursor was on screen before keystroke, so it should remain on screen after
    return false  -- bring_cursor_of_cursor_pane_in_view updated Display_settings.y but not pane.screen_top1

Deletion in run.lua at line 1136 [6.178044]

B:BD[2.708] → [2.708:1030]

∅:D[2.1030] → [18.1089:1095]

B:BD[18.1089] → [18.1089:1095]

B:BD[18.1095] → [2.1031:1059]

  local screen_top_updated = not eq(old_top, pane.screen_top1)
  if screen_top_updated then
    Display_settings.y = up_edge_sy(Cursor_pane.col, Cursor_pane.row) + y_of_schema1(pane, pane.screen_top1)
    Surface.cursor_on_screen_check = true  -- cursor was on screen before keystroke, so it should remain on screen after
  end
  return screen_top_updated