Bug 154816 – Spurious resize events fired when resuming device

• Status: NEW
• Component: DOM

[Ashley Gullen]

URL: http://www.scirra.com/labs/bugs/iosviewport/resume.html

Steps to reproduce:
1. Visit the given URL in portrait orientation.
(note: it may start up with the wrong display due to bug 154815)
2. Press the device power button to put it to sleep. Do not change its orientation until waking it up again.
3. Wake it up again and unlock it.
4. Note the events listed in Safari.

Observed result:
Safari fires spurious resize events. E.g. it will log something like (on an iPad Air 2):

Startup: 980 x 1225 [note probably incorrect due to bug 154815]
visibilitychange event (hidden): 768 x 960
resize event: 1024 x 704
orientationchange event: 1024 x 704
resize event: 768 x 960
orientationchange event: 768 x 960
visibilitychange event (visible): 768 x 960

Note these events fire resize/orientationchange for landscape orientation followed immediately by portrait orientation upon waking. This is misleading since the device did not really change size or orientation.

Note the same happens in landscape orientation, but it first fires events for portrait orientation followed by landscape orientation.

Expected result:
No spurious events, e.g. a log similar to:

Startup: 768 x 960
visibilitychange event (hidden): 768 x 960
visibilitychange event (visible): 768 x 960

or alternatively, a single resize event that indicates the same size again like this:

Startup: 768 x 960
visibilitychange event (hidden): 768 x 960
resize event: 768 x 960
orientationchange event: 768 x 960
visibilitychange event (visible): 768 x 960

[Ashley Gullen]

Note not all devices are affected. Of those I have access to:

iPad Pro: affected
iPad Air 2: affected
iPad 3: not affected
iPad 2: not affected
iPhone 4S: not affected

Note "not affected" means it does not fire any resize or orientationchange events at all when following the above steps. E.g. the iPad 3 logs:

Startup: 768 x 960
visibilitychange event (hidden): 768 x 960
visibilitychange event (visible): 768 x 960

[Radar WebKit Bug Importer]

<rdar://problem/24924448>

[Lucas Forschler]

Mass move bugs into the DOM component.