lttng / lttng-scope

A trace viewer and analyzer for LTTng kernel and user space traces
https://lttng.org/beta/#lttng-scope
Eclipse Public License 1.0
28 stars 6 forks source link

Event table should allow range selection of events #67

Open PSRCode opened 6 years ago

ghost commented 6 years ago

Should it really?

Right now the single-event-selection binds to a framework-level range selection of a single timestamp, corresponding to the event's timestamp. If we allow multi-selection in the table, then should we bind it to a corresponding framework-level range selection? Probably, so it stays consistent, no?

But if we do that, then comes the weird part: that means we have to bind framework-level range selections to multi-selections in the event table. Which in turns means that every time you select a time range in any view, you end up with an event table that shows all its events highlighted. When everything is highlighted, nothing stands out.

I'd be tempted to allow the table to only support single selections, and to have a range-selection in the framework to simply select the event at the start time of the selection, not the whole range. I'm of course very open to suggestions, but we should keep the framework-time-range <-> event table multi-select duality in mind.

PSRCode commented 6 years ago

All other widget allow a range selection but the event table should not ?

Isn't the value of the current selection paradigm to "highlight" across the board the selected time range?

Which in turns means that every time you select a time range in any view, you end up with an event table > that shows all its events highlighted. When everything is highlighted, nothing stands out.

This depends on the visible range of the event table widget. You could say the same for the thread widget with a small visible range inside a larger selection. Everything will be blue.

ghost commented 6 years ago

You could say the same for the thread widget with a small visible range inside a larger selection. Everything will be blue.

Very true. However with a time-based widget you can zoom out. With the event table, you cannot zoom out, you are confined to a very very limited range. This fundamentally different to other zoomable time-based view, which is why I'm tempted to think range selections should behave differently.

PSRCode commented 6 years ago

Following IRL discussion: A partial solution here could be the introduction of a format style (light blue or the color of the selection in all opther widget) for rows comprised inside the current global selection.

This would decouple us from the "selection" paradigm of the table.

A follow-up could be to have a "commit selection to global state" for the event table allowing a user to move around and click/select inside the table without disturbing all other widget. This would go hand in hand with the support of multi selection/zone of interest.