Android Question Recent Apps List - Blank Images

[RichardN]

Test device: Samsung S22 Ultra

I have noticed that when scrolling through the system 'recent' apps that some (but not all) apps compiled in B4A only show empty images where others appear as the user last saw them. A white rectangle surmounted by the app icon is all that appears in the scrolling display.

Is this purely a system function as it appears to be confined to my B4A apps. Do we have any control over it?

 

[Erel]

Are you removing the views when the activity is paused?

The OS takes a screenshot when the app is paused.

 

[RichardN]

No.... The only code in Activity_Pause is saving some values using KVS.

The OS takes a screenshot when the app is paused.

I agree that is what should be happening but what is being presented does not support that idea.

The behaviour is observed in both portrait and landscape. I have experimented with both Designer and Manifest settings to try to change the behaviour with no result.

The attached project is a completely cut-down version without libraries or data. It continues to exhibit the behaviour.

 

[agraham]

Perhaps it is phone or timing dependent. Although I have seen blank images in Recent Apps your test app displays fine in Recent Apps on my Redmi Note 9 Pro, Surface Duo and Pixel 4a. I've seen this on other apps than B4A apps. In doing this test I see that K-9 Mail on the Surface Duo in Recent Apps shows an all black image. Swiping it away and restarting K-9 Mail and it shows as expected in Recent Apps - so it's not only B4A apps.

 

[RichardN]

This does not appear to be related to memory-hungry apps or the Activity life-cycle. I opened a page-full of apps on the device and a minority (not necessarily B4A) are presenting as either black or white rectangles. The selection varies from lightweight to heavyweight without any logical connection.

I can however report that all the system apps are correctly presented! The mystery remains.

 

[asales]

No problem in a Galaxy A71 (but with Android 11).

To what for is this line in the manifest?
<meta-data android:name="com.samsung.android.icon_container.has_icon_container" android:value="true"/>

 

[RichardN]

The manifest entry is to prevent full-size icons being squeezed into the standard 'Squircle' shape on Samsung devices.

I have tried both with and without the manifest entry....... It makes no difference to the 'Recent Apps' presentation. Reading around Android websites this behaviour has been reported both on other devices AND earlier versions of the OS.