sap.ui.table.Table: visibleRowCountMode:Auto and variable row heights causes scrollbar to get clipped

[cmastrandrea]

OpenUI5 version: latest

Browser/version (+device/version): All common browsers, latest versions

Any other tested browsers/devices(OK/FAIL):

URL (minimal example if possible): http://jsbin.com/mocuke/2/edit?html,css,output

User/password (if required and possible - do not post any confidential information here):

Steps to reproduce the problem:
1.Use scrollbar to scroll all the way down through the list.
2.Note that about 1/2 of the scrollbar gets clipped at the bottom, and the remaining rows are not scrolled into view.

What is the expected result? Expected that the scrollbar would be scaled appropriately and not get clipped.

What happens instead? The scrollbar changes height during the scrolling and doesn't seem to account for the variable row heights.

Any other information? (attach screenshot if possible)

[Michadelic]

Hello cmastandrea,

i added another internal ticket for this issue: 1580010732
We will take a look at this issue and get back to you here.

Thanks for reporting all these issues to us, that's great!

Kind Regards,

Michael

[SebastianRied]

Hi cmastandrea,

unfortunately we can't provide a fix here due to how the table is designed to work, let me try to give some details:
The tables of the sap.ui.table library aim for huge amount of data (i.e. lots of rows). Since it would break the performance to have own controls for each row, the table simply reuses the controls of the rows. It's just the context which is changed by scrolling. Since there is no real scroll area, the table can just only take the length of the binding, the number of visible rows of the table and the current height of the table (influenced by the controls of the row template and their current content) and calculate a scrollbar length which gets applied. This happens in a delayedCall of 250ms - therefore it can happen in unlucky circumstances that the scrollbar length is not set correctly. However, when the row height remains stable, this delayedCall gives a real performance boost. Maybe you've noticed that the table never clips a row, it always shows the complete control - this exactly due to the concept of reusing controls.

I understand that you dislike the current behavior of changing table height, scrollbar length and sometimes not reaching the last row of the table (caused by different row heights). Hence I'd propose to use the sap.m.Table for variable row heights. The sap.m.Table could be placed inside a scroll container with a fixed height. However, the sap.m.Table is not meant for mass-data since it would render the complete data as a table. You can reduce the margins of the controls inside the sap.m.Table by setting the style class sapUiSizeCompact to make the m.Table better fit on desktops.

Best regards
Sebastian