UITableView scrolling in iOS Simulator is choppy if display scaling is enabled

Originator:joshavant
Number:rdar://23222419 Date Originated:22-Oct-2015
Status:Duplicate of 23119664 Resolved:
Product:Developer Tools Product Version:Xcode Version 7.0.1 (7A1001), iOS Simulator 9.0
Classification:UI/Usability Reproducible:Always
 
Summary:
While interacting with a UITableView in iOS Simulator on an attached display with display scaling turned on, the UITableView does not scroll smoothly.

When display scaling is turned down to the 'smallest' setting (i.e. Larger Text), the UITableView appears to scroll smoothly again. However, if display scaling is set to any other value, the UITableView will not scroll smoothly.

This is an important problem during development, because it causes an otherwise acceptably implemented UITableView to present as one with performance problems.

Steps to Reproduce:
1. Attach a display which requires scaling to a MacBook or MacBook Pro

2. Go to System Preferences -> Displays

3. For the attached display, ensure that Scaling is set to any value except for the leftmost, unscaled value (i.e. Larger Text).

4. Run an app in iOS Simulator with a UITableView

5. Scroll the UITableView

Expected Results:
The UITableView scrolls smoothly

Actual Results:
The UITableView scrolls choppy, unless the scaling value is set to the leftmost, unscaled value (i.e. Larger Text)

Version:
Xcode Version 7.0.1 (7A1001), iOS Simulator 9.0

Notes:


Configuration:
Monoprice 4K 28" MPCP28UHD with display scaling enabled (middle value... 'Looks like 2560x1440')

Attachments:

Comments

Apple Developer Relations09-Nov-2015 11:02 AM

Engineering has determined that your bug report is a duplicate of another issue and will be closed.

The open or closed status of the original bug report your issue was duplicated to appears in the yellow "Duplicate of XXXXXXXX" section of the bug reporter user interface. This section appears near the top of the right column's bug detail view just under the bug number, title, state, product and rank.

If you have any questions or concerns, please update your report directly here: http://bugreport.apple.com/.

By joshavant at Nov. 9, 2015, 7:42 p.m. (reply...)

Attached are the requested videos.

Observe in 'mbp_display.mov' that the UITableView scrolls smoothly.

Observe in 'external_display.mov' that the UITableView scrolls very choppy.

Both videos are the same exact code, with the app re-run in iOS Simulator on different displays.

Also attached are my 'external_display_settings.png'. When I configure the settings for my external display to 'Larger Text' (leftmost) setting, the UITableView will return to expected, smooth scrolling behavior (like on the Macbook Pro display). On any other setting, it is choppy.

'external_display.mov', 'mbp_display.mov' and 'external_display_settings.png' were successfully uploaded.

ATTACHMENTS:

mbp_display.mov - https://vid.me/RRw7

external_display.mov - https://vid.me/BB7D

external_display_settings.png - http://imgur.com/SAV6NSs

By joshavant at Nov. 3, 2015, 6:57 p.m. (reply...)

Apple Developer Relations28-Oct-2015 02:04 PM

We need more information to investigate this issue.

Please provide a screen recording video showing the issue (in both good and bad states).

https://developer.apple.com/bug-reporting/mac/misc/#screenrecording

Please provide your response or results by updating your bug report.

By joshavant at Nov. 3, 2015, 6:54 p.m. (reply...)

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