Improve editor history navigation: merge locations

[bpasero]

There are some scenarios where our editor history navigation is not ideal.

Example: Goto definition

1. go to definition to jump somewhere else and produce a history entry
2. from the place where you end up, click around a little bit (not more than 5 lines away)
3. jump back
4. jump forward

=> you end up at the original place (the definition) instead of the last location you were before going back

Example: Exploring code

1. click into a line
2. click 3 lines below
3. click 3 lines below
4. jump back

=> you end up not in the original line from 1. but in the one from 2.

Both issues can be solved by smartly merging a history entry with the current position if it does not qualify for a new location.

/cc @egamma

[egamma]

@bpasero here is some more feedback and the scenario from Anders.

The difference here is that VS collapses any number of consecutive cursor navigation commands into a single nav history event. That’s the thing that is missing in VS Code. The current 5 line threshold has no intuitive meaning so it just seems like the cursor is randomly hopping back through code you’ve visited.

Here’s a common scenario: I’m on a call to some method and I want to see what it does. So I go to definition using F12. Then I (randomly) cursor around in the method reading the code and possibly F12 again. This may repeat several levels. When I have finally seen enough I want to quickly navigate back to the original spot. I absolutely don’t care about the individual cursor moves between the F12 jumps. In fact, they’re nothing but noise. But VS Code insists on taking me through them (or rather some indeterminate subset of them). That’s irritating. The VS behavior is much more sensible here.

[bpasero]

The difference here is that VS collapses any number of consecutive cursor navigation commands into a single nav history event. That’s the thing that is missing in VS Code. The current 5 line threshold has no intuitive meaning so it just seems like the cursor is randomly hopping back through code you’ve visited.

@egamma I am not sure that is the desired behaviour though. If I understand correctly, VS folds multiple goto definition commands happening consecutively into one navigation event. But what if the user wants to navigate back to one of those navigation stops in between?

@stevencl can you share more insights how VS navigation works?

[cristianhosu]

@bpasero if I may, from what I understand, actually VS just ignores cursor movement and keeps in the history only navigation events (through Go to definition. I believe this would be a desired behavior, as I also feel this frustration.
@egamma When was this feature added to VS? I am currently working with VS 2015 and it does not have it :)

I could start a PR regarding this if we can clarify how exactly it should behave

[bpasero]

@cristianhosu it seems the logic is more complex. I see that there is no history entries added when moving around in a file but as soon as I edit the file, all those locations are being added. Could it be that only if you edit a file, a lot more history entries pop up? That is why I would like to read a documentation on this feature rather then finding out by trying :)

[cristianhosu]

I'll do some digging until you receive the necessary documentation. After that we can talk about how to implement this.

…

On Jun 22, 2017 08:45, "Benjamin Pasero" ***@***.***> wrote: @cristianhosu <https://github.com/cristianhosu> it seems the logic is more complex. I see that there is no history entries added when moving around in a file but as soon as I edit the file, all those locations are being added. Could it be that only if you edit a file, a lot more history entries pop up? That is why I would like to read a documentation on this feature rather then finding out by trying :) — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#29027 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AQ3E7pgKDUT2_WwmfZQLDnk4BnIpD4ewks5sGf93gaJpZM4N-bfi> .

[bpasero]

Related from #5208: only store a position in history from a mouseclick but not from keyboard navigation.

[bpasero]

Pushed a couple of changes:

• threshold is now 10 lines (like VS)
• locations get merged when navigation is not hitting the threshold
• we no longer aggressively reveal the location in center to avoid scrolling spam

[Chillee]

@bpasero Just wanted to note that this solves a couple of fairly annoying issues on the VSCode side. VSCodeVim/Vim#1688, VSCodeVim/Vim#1850, and VSCodeVim/Vim#1933.

Thanks!

[bpasero]

@Chillee happy to hear that! Let me know if there are still rough edges with the history.