default location meaningful for dataset

[martinschorb]

Hi,

the default "location" that MoBIE shows upon launch should make sense in context of the active dataset.
So, when a dataset is loaded, the default location should be optionally specified in the dataset.json or if no value is present there fall back to the center of the current image.

[constantinpape]

This is fully specified by the view with name default. So you can set whatever default location you like with that view.

[martinschorb]

Where does that arbitrary value come from if no default location is specified in the view?
In my view, either that default location should be mandatory in a view or if it is not provided, the value shown in the viewer should automatically be set to something useful.

[constantinpape]

Where does that arbitrary value come from if no default location is specified in the view?

There is some BDV internal logic to compute it. If you are not happy with the result you need to set it in the default view via the viewerTransform.

In my view, either that default location should be mandatory in a view

No, we don't want the viewerTransform to be mandatory, there are many cases where we don't want it to be specified in a view.

or if it is not provided, the value shown in the viewer should automatically be set to something useful.

In most cases the default view computed by bdv is very reasonable. But it's a heuristic, so it can only do so much. So, like I said, if it's not sufficient you can over-write it with the viewerTransform.

[martinschorb]

Note that I am not referring to "position", this is about the "location" UI element that in my case shows

{"position":[120.5,115.3,201.5]}

as default value.
This makes no sense for the current dataset/view.

I could not find "location" anywhere in either the dataset schema or the support functions.
(except for "tableDataLocation" which is something different)

[constantinpape]

Note that I am not referring to "position", this is about the "location" UI element that in my case shows

Ah ok, sorry I forgot that even existed. Yes, that is completely unrelated to the default view. I don't know where the default values for this come from; we don't have anything for it right now in the json. I agree that these values should either be something sensible or maybe we also don't need a default for that.

@tischi where are the defaults for the "location" UI element coming from right now?

[tischi]

where are the defaults for the "location" UI element coming from right now?

I think the default values still point to the "right eye" of the platy 🤣
I have an emotionally very hard time changing this as this is such a classic..... 😫

[constantinpape]

This should def. be updated, and I would classify the current behaviour as a bug.
I see three possible options

1. use the default position computed by BDV
2. just leave this empty by default
3. add an (optional) field to dataset.json to specify this.

[martinschorb]

I would vote for 3.
Additionally, if the JSON field does not exist, the input GUI field should be hidden.
If the JSON field exists but is empty -> 2

[constantinpape]

@tischi should we add defaultPosition to the dataset.json and use it to populate the location menu?
And leave it blank if defaultPosition is not given?

[constantinpape]

I would vote for 3. Additionally, if the JSON field does not exist, the input GUI field should be hidden. If the JSON field exists but is empty -> 2

We should still implement this. I will add defaultPosition to the dataset.json now and push it onto a platybrowser branch. cc @tischi.

[constantinpape]

@tischi I called the field defaultLocation now to be more accurate with the viewer.
I have added it for the platybrowser here: mobie/platybrowser-project#89