Bug 399905

Summary: Wallpaper cache
Product: [Plasma] plasmashell Reporter: Matthew Trescott <matthewtrescott>
Component: Image & Slideshow wallpaper pluginsAssignee: Marco Martin <notmart>
Status: CONFIRMED ---    
Severity: wishlist CC: bugseforuns, Edward.Viesel, kde, kde, matejm98mthw, nate, plasma-bugs
Priority: NOR    
Version: 5.14.1   
Target Milestone: 1.0   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Matthew Trescott 2018-10-16 23:53:41 UTC 
SUMMARY
Plasma should copy any image file a user selects for a wallpaper to some location (probably in ~/.local or ~/.config) so that the desktop background is not dependent on a file in the user's personal folders.

Why? Think about it this way. Most non-tech savvy users view the computer as something that "has a mind of its own." To make it easier for such people to use computers, user interfaces and operating systems should be designed to minimize users' encounters with behavior that reflects computers' lack of ability to actually think. Some users barely understand the concept of a file, much less the importance operating systems place on a file's unique name. One cannot honestly expect such users to realize that the desktop wallpaper is actually an image file stored somewhere in the filesystem. To such users, the wallpaper is a completely separate entity, and it needs to be treated as such. If they say, "make this picture my wallpaper," it had better stay that way---you can't assume that they intend to change their desktop wallpaper when, three weeks later (by which time they've forgotten what that file is anyway), they decide to clear out all their old files and in so doing, delete their desktop wallpaper file.

(Side note: I wish I didn't have to justify these kinds of things, but it seems that there is a defensive attitude toward reports of unintuitive UI behavior, rather than an attempt at empathy toward users here on Bugzilla.)

STEPS TO REPRODUCE
1. Download or take a picture and place it somewhere in your home directory (e.g. Downloads)
2. Right-click on the desktop and hit "Configure Desktop" then "Add Image..."
3. Select the downloaded image.
4. Apply the changes, then delete the downloaded image.
5. Log out and log back in

OBSERVED RESULT
The desktop reverts to the default wallpaper image.

EXPECTED RESULT
The desktop retains the user's settings, regardless of whether the user has deleted the image. (This is the behavior on Windows.)

SOFTWARE VERSIONS
(available in About System)
KDE Plasma Version: 5.14.1
KDE Frameworks Version: 5.51.0
Qt Version: 5.11.2
Comment 1 Matej Mrenica 2018-10-17 07:17:04 UTC 
I can confirm this. Also Ubuntu (Gnome) has this fixed.
Comment 2 Kai Uwe Broulik 2018-10-17 07:20:40 UTC 
> I wish I didn't have to justify these kinds of things, but it seems that there is a defensive attitude toward reports of unintuitive UI behavior

Deleting a file makes it gone, this is fundamental computer behavior.

Anyway, I agree that we could copy the wallpaper into a cache location, since it might have been downloaded into a /tmp location or selected from a network share and thus gone after a restart without user interaction. However, it's not feasible for the slideshow wallpaper, just the one for single images.
Comment 3 Matthew Trescott 2018-10-17 11:09:54 UTC 
Kai, this is the kind of response I'm talking about. Perhaps you don't have as much experience helping people use their computers. You have to try to look at things from their perspective, and I can can tell you from experience that explaining "fundamental computer behavior" doesn't work.
Comment 4 David Edmundson 2018-10-31 02:45:34 UTC 
Note that we've had multiple reports about us not running updating a cache if a file on disk at a given path has changed which is the exact opposite of this.
Comment 5 Nate Graham 2019-11-14 02:31:23 UTC 
*** Bug 408223 has been marked as a duplicate of this bug. ***
Comment 6 Nate Graham 2020-01-16 23:27:26 UTC 
I've submitted a patch to fix this: https://phabricator.kde.org/D26720
Comment 7 Nate Graham 2020-10-05 21:53:36 UTC 
*** Bug 424226 has been marked as a duplicate of this bug. ***