RFC: btdu.ui.browser: reorder "Selected" and "Viewing" info panes

[intelfx]

Summary

I have noticed that when I'm exploring the directory hierarchy btdu has built, my eyes are constantly moving back and forth between the cursor position (on the left, most likely in the upper half of the screen) and the info pane representing the entry under cursor (on the bottom right).

This means that the view point has to travel across all of the screen and I often find myself looking the top info pane only to realize that it's not the one I should be looking at.

Perhaps it would be more ergonomic to switch them, considering that most of the time the height of the file list is less than 3/4 of the screen?

Attached is a totally unscientific comparison of the existing and new behavior.

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Existing behavior

Proposed behavior

[CyberShadow]

Acknowledging the problem. But also, I think it that it makes more sense for the answer to "where am I and what do I do now" to come before the one to "what is the thing under the cursor".

Looking at how things are laid out in your screenshot, I think that (at least in that circumstance) it might make sense to move the info panels to the left side, which should help both cases.

What do you think?

[intelfx]

If you move both panels to the left side, you end up with the same problem just with less absolute amount of eye movement. Arguably it might be even worse, because the irrelevant-to-the-cursor "Viewing" panel will end up even closer to the eye point, which means that the user's eye sight will be even more prone to "catching" the wrong panel by accident.

(Unless you suggest moving just one of the panels to the left, ending up with a three-pane layout?..)

[intelfx]

I think it that it makes more sense for the answer to "where am I and what do I do now" to come before the one to "what is the thing under the cursor"

The problem with this reasoning is that the question of "where am I and what do I do now" only needs to be answered once per screen, but the question of "what is the thing under the cursor" needs to be answered many times per screen — unless the user has a laser focus on a specific path (but then btdu likely isn't the right tool for the job anyway).

Additionally, the main listing does not show tolerances (i.e. the ± part), so if the user is interested in these values, then they pretty much have to iterate over all entries in the list and answer the second question for each entry.

[CyberShadow]

If you move both panels to the left side, you end up with the same problem just with less absolute amount of eye movement.

I think that's a nice improvement on its own. Can you try the latest next and see how that feels to you?

Arguably it might be even worse, because the irrelevant-to-the-cursor "Viewing" panel will end up even closer to the eye point, which means that the user's eye sight will be even more prone to "catching" the wrong panel by accident.

Having tried it, it doesn't seem to be much of a problem. The "Viewing" panel is more static than the "Selected" panel, which is updated more obviously when you move the cursor around.

Additionally, the main listing does not show tolerances (i.e. the ± part), so if the user is interested in these values, then they pretty much have to iterate over all entries in the list and answer the second question for each entry.

Thinking on this, I realized that we were missing an opportunity to represent the error range visually on the bars, so I added a commit which draws question marks over the uncertainty range.