Page down and page up do not work in Jupyter notebooks

[oscarrutt]

Issue Type: Bug

Page down and page up in Jupyter windows doesn't work. If no cell is in edit mode, either it does nothing or jumps haphazardly between cells. Other times, it tries to scroll a ways and then seems to choke on a plot, then backs up to where it was. If a cell is in edit mode, with a text cursor in it, then no scrolling happens. I am on an Apple laptop where the page down and page up functions are accomplished with Function-downarrow and Function-uparrow.

Also, the scroll-to-top and scroll-to-bottom, Command-uparrow and Command-downarrow, do not work if a cell is in edit mode.

VS Code version: Code 1.63.0 (7db1a2b, 2021-12-07T05:15:48.091Z)
OS version: Darwin x64 15.6.0
Restricted Mode: No

System Info

Item	Value
CPUs	Intel(R) Core(TM)2 Duo CPU P8600 @ 2.40GHz (2 x 2400)
GPU Status	2d_canvas: unavailable_software gpu_compositing: disabled_software metal: disabled_off multiple_raster_threads: disabled_off oop_rasterization: disabled_off opengl: disabled_off rasterization: disabled_software skia_renderer: disabled_off_ok video_decode: disabled_software webgl: unavailable_software webgl2: unavailable_software
Load (avg)	3, 3, 3
Memory (System)	8.00GB (0.02GB free)
Process Argv
Screen Reader	no
VM	0%

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[leftys]

Confirming, scrolling in Jupyter notebooks is pretty buggy.

[rebornix]

Thank you both for the feedback, there are two issues here. One is allowing pagedown/up/cmd+up/down to work whether the focus is in the cell editor or not. This can be archived by tweaking the when clauses. For example, we can add following keybindings to your keybindings file to archive a consistent page down experience

{
	"command": "list.focusPageDown",
	"key": "pagedown",
	"when": "editorTextFocus && inputFocus && notebookEditorFocused"
}

The other issue is the page down can jump up and down. This is due to the fact that we don't know the height of cells until rendered, which is something we should polish.

[lovettchris]

I also find this a big problem, I'm getting RSI spinning the mouse wheel. Page down seems to get stuck in a cell then it won't work any more. Took me a long time to realize "escape" removes the keyboard focus from the cell, then page down works again - but this has a bit of a discoverability problem...

[kiyoon]

Even when you escape and focus the cell, the page up down doesn't scroll the page. Instead, it moves cell focus up and down. This is really annoying when the cell and the output are big enough to fill the screen, and you're not able to even scroll through the output. Mouse scroll works and manually dragging the scroll bar works fine. You can already scroll through the cells with arrows or j/k bindings. It shouldn't be difficult to implement scrolling with page up/down without changing the focus of the cell.