mobile: android splash screen (and issue 513) opacity weirdness

[Lubomir I. Ivanov]

On 16 November 2017 at 23:06, Jan Mulder <jlmulder at xs4all.nl> wrote:
> While investigating issue #513 ([Bug] Mobile: Startup splash screens display
> 2 different background color (Black then White) I found the commit that
> introduces this splash screen stuff (04e994b57558ed9). First, let me reset
> the complexity on GitHub from low to high :-) as the issue is related to the
> app bootstrap phase on device, and there is exactly one color defines in
> that whole process (which is white background), so where the black
> background phase is coming from is still is a mystery to me.
>
> Reading mentioned commit and the referenced internet page, and carefully
> reading the code in main.qml I find 2 opacity related pieces of code
> commented out (by Tomaz), telling "ApplicationWindow has no Opacity calls no
> more." (commit 4db80aa1a404dc). Hmm, weird. I just looked at the Qt docs:
> opacity on ApplicationWindow is a property since Qt 5.1, Tomaz: there is
> probably something I do not understand, but can you explain that commit?
>
> I enabled that opacity code again. No visible effect, so I change the
> fade-in animation to 10 sec (yes ridiculous long, but ease to spot while
> running the app). No visible fade in anywhere. Question for Dirk: as
> original author, have you ever seen that fade in?
>
> The referenced internet page (from commit 04e994b57558ed9), also explains
> that there needs to be a QML Loader object, and we do not have one. (So, I
> believe there was never a fade-in animation). I added one ... and suddenly
> ... I have a nice 10 seconds opacity fade-in of the app :-) That is: on
> desktop.
>
> And now it gets even more confusing. Running this changed code on Android,
> results in numerous (probably 10000 (milliseconds)) error strings in the
> log: "This plugin does not support setting window opacity". So, a piece of
> Qt code is called that is not implemented for Android. But ... the current
> app has some transparency features, for example the toast notifications. So
> where is that coming from? Anybody knows?
>

given that message, i would say that the support for ApplicationWindow
opacity is not available on Android and the calls should be removed.
i couldn't see a screenshot from the original issue report, and
clearly i did not understand what the reported means. do you have a
screenshot or a GIF/video for the two different colors?

since ApplicationWindow is first set to "visible = false", and only
set to "visible = true" on Component.onCompleted(), this might create
something in those lines.

lubomir
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