Hi @max-radin,

That is interesting, because I think the code that seems to break here is newer than the issue #997.
Ooops. Might have broken something there.

I am currently looking at the log-mode propagation from another angle... I currently think that it might be better to tell the ViewBox about the requested log mode settings from inside PlotItem.updateLogMode that should have the information for both axes. The AxisItems don't really have a need to know about both orientations.

Doesn't each of the four potential axes set both x and y mode individually, now?

Ah, sorry, I missed the actual broken bit here.

While I am not sure if setLogMode is ever called directly, do you think this can work so that

• two arguments are treated as x and y, and AxisItem.logMode is extracted from the correct one, like you have now
• a single argument directly controls AxisItem.logMode as before
  ?

Hi @NilsNemitz, one way we could support the old single-argument behavior would be to do something like

def setLogMode(self, *args, **kwargs):
  if len(args) == 1 or 'log' in kwargs:
    # do the old thing
  else:
    # do the new thing

That way calling setLogMode(True) will control log mode along the direction of the axis while still allowing setLogMode(x=True) to control log mode in the x direction.

Pros:

• Backwards compatibility with any user code that called AxisItem.logMode
• Provides an easy way to set the log mode along an axis without having to check its orientation

Cons:

• The behavior of AxisItem.logMode will be different from PlotItem.logMode.
• The function signature and logic in AxisItem.logMode will be a bit more complicated.

Do you think this makes sense to do? I'm pretty new to the codebase so I don't really have a sense of how these methods typically get used.

I think that is a good idea.
You probably do not need to check for the log keyword, that is probably not commonly used in a single-parameter function call.
So the simple distinction of one argument / two arguments might make it work.
Then it has the same functionality as other items when called by PlotItem (with two parameters).
And the old single parameter, possibly user-accessible interface still works to set log mode along the axis alignment.

@NilsNemitz just pushed a commit that adds backwards compatibility for the single argument case. thanks!

@max-radin thanks for the PR! This LGTM, merging. @NilsNemitz thanks for reviewing!