ListBox scrolling start to be slow… and strange

I am starting to experiment a slow and strange behavior with a ListBox.

Strange ?
It looks a bit like what I believe is an iOS behavior: i use a finger on the touchpad (on a MacBook Pro from 2014-12) and the scroll goes slowly, but takes time…

After I checked the number of Rows and the file size, it appeared that I had around 8,000 Rows and the file is around 900KB.

Then, two or three days ellapsed and I checked the same project with around 100 Rows (or 200…), an amount that looks like more than 5 “screens”, vertically: the behavior is the same (slow and strange).

I left 2015r1 and tried with 2015r4.1: same behavior.

This appears on the current El Capitan and El Capitan PB3 (is it 4 ? The one I upgraded to last week or the week before…).

Ideas ?

One obvious question I would ask myself would be: Do I really need to show 8000 rows at the same time?
You should create some kind of pagination for your design.

Don’t know why it’s slow at 100 rows though, that seems wierd.

No: you are right !

I discovered that because of the slow and strange behavior.

In fact, in the project (and csv file) development, I added a function that insert missing Rows and it worked fine (too fine apparently).

Of course, this allowed me to not add a Row at a time, but the drawback was what I discovered: >8,000 Rows !

Nota: The working file define 6 entries a week and in that case, started in 1928-08 and ended in 1953 (or 1954).
Once the Add Missing Entries feature was working fine, I saved a new version with all the Rows and continue to fill it with data (day titles, end date when appropriate, clearing the Missing tag, adding a summary, etc.).
I completely forgot the “how many rows do I have in my file / ListBox ?”
And since open / save process is fast (not noticeable)…

The speed goes a bit like a bicycle wheel when it is upside down and you make the wheel “run”: it takes a lot of time to slow down and to stop.

To stop the ListBox “run”, I have to press cmd-.

Whilst this may not point o anything I have an app (a SQLite database manager) that uses a few list boxes within. One of my databases has more that 30,000 rows of data and this takes about 5 seconds to populate. The scrolling is no problem at all.

I don’t think that the size of the listbox (number of rows) is the issue here.

Just my 2p worth!


Thanks for the input Simon.

The populate part is fast.

The scrolling is…

I will check this afternoon what happens with other OS X version (I will boot and try on older versions).

I will also move the Windows version / csv / db files and check what happens on Windows 8.1 (slow) laptop.

BTW: The stand alone was compiled many times (after I added new code), so it cannot be a bad compile (for whatever something like that can (?) happens).