Re: Images disappear after Display Resolution Change

[Tom Sheffler]

That looks like a good approach.  FWIW - I have found that the 
NSApplicationDidChangeScreenParametersNotification
is also listened for in NSWindow which gets the window’s new NSScreen and (i 
think) redraws the window.  But I
couldn’t find anything in NSWindow.m that might trigger image caches being 
emptied or recalculated.

> On Dec 30, 2023, at 8:23 AM, Ondrej Florian <onflapp@yahoo.com> wrote:
> 
> I think I managed to fix the problem by clearing NSImage cache after 
> receiving NSApplicationDidChangeScreenParametersNotification
> 
> Please see:
> https://github.com/onflapp/libs-gui/commit/2b6a26b2f013d79971165abf7b10a56b5e42c619
>  
> 
> There is still problem with GWorkspace though.
> Non-scaled icons works fine but scaled icons (e.g. list / browser view) do 
> not.
> 
> 
> On 2023-12-29 22:23:45 +0100 Gregory Casamento <greg.casamento@gmail.com> 
> wrote:
> 
>> Would it be possible for you to file a bug for this on GitHub?  The proper
>> place is https://github.org/gnustep/libs-gui under the “Issues” tab.
>> 
>> Gregory Casamento
>> GNUstep Lead Developer / OLC, Principal Consultant
>> http://www.gnustep.org - http://heronsperch.blogspot.com
>> https://www.patreon.com/bePatron?u=352392 - Become a Patron
>> https://www.openhub.net/languages/objective_c - OpenHub standings
>> 
>> 
>> On Fri, Dec 29, 2023 at 15:58 Paulo Delgado <paulo@paulodelgado.com> wrote:
>> 
>>> I noticed something similar happened to me on a clean Debian installation
>>> whenever the computer came back from sleep. Images and icons were all gone,
>>> also wallpaper (which gworkspace manages in my installation).
>> 
>> 
>>> PD
>> 
>>>> On Dec 29, 2023, at 1:52 PM, Ondrej Florian <onflapp@yahoo.com> wrote:
>>>> 
>>>> This also happens (sometimes) when you attach external display..
>>>> It is certainly related to change of display resolution and easily
>>> reproducible by invoking xrandr.
>>>> 
>>>> I guess that GNUstep is caching some kind of data that needs to be
>>> invalidated.
>>>> 
>>>> 
>>>>> On 2023-12-28 14:25:21 +0100 Sebastian Reitenbach <
>>> sebastia@l00-bugdead-prods.de> wrote:
>>>>> 
>>>>> Hi,
>>>>> 
>>>>> On Tuesday, December 26, 2023 19:52 CET, Tom Sheffler
>>>>> <tom.sheffler@gmail.com> wrote:
>>>>> 
>>>>>> I’ve recently installed gs-desktop (from
>>> github.com/onflapp/gs-desktop/
>>>>>> <http://github.com/onflapp/gs-desktop/>) on Debian 12 into a clean
>>>>>> partition in a System76 laptop.  It all works very nicely as a desktop
>>>>>> environment.
>>>>> 
>>>>>> I have noticed an annoying problem when I change resolutions - I seem
>>> to do
>>>>>> this often: when I plug in an external monitor I size things one way,
>>> and
>>>>>> when not connected I size the display another way.  I’ve investigated
>>> the
>>>>>> problem, and do not have a good fix. I’m hoping that by sharing my
>>>>>> experience here someone might be able to shed some light on the
>>> subject.
>>>>> 
>>>>> 
>>>>>> Upon resizing the main screen, icons and images disappear.  The
>>> commands I
>>>>>> use are
>>>>> 
>>>>>>   - xrandr —output eDP-1 —mode 1400x1050
>>>>>>   - xrandr —output eDP-1 —mode 1600x900
>>>>> 
>>>>>> After changing resolutions, images and icons in the following apps have
>>>>>> been seen to dissappear
>>>>>>  - GWorkspace
>>>>>>  - Gorm
>>>>>>  - nextspace/Preferences
>>>>>>  - gs-desktop/Applications/VolMon
>>>>>>  - gs-desktop/Applications/MountUp
>>>>> 
>>>>>> The picture below shows two versions of GWorkspace FileViewer.  The
>>> one on
>>>>>> top is GWorkspace installed “as-is” and shown after changing the
>>>>>> resolution of the display.  The large icons and the small icons are all
>>>>>> gone.  They do not reappear after any amount of fiddling with controls
>>> or
>>>>>> themes I attempt.
>>>>> 
>>>>>> The bottom FileViewer is a modified copy of GWorkspace that has been
>>>>>> changed to add a new menu item called “Redraw” that does a couple of
>>>>>> things.  It deletes image caches in various places and then calls
>>> [NSApp
>>>>>> updateWindows].  This does not immediately fix the images, but after
>>>>>> scolling around the images get refreshed as the caches are rebuilt.
>>>>>> The two “DIFF” files attached in this message show what code
>>>>>> modifications I made to support the “Redraw” menu item.
>>>>> 
>>>>>> While clearing the caches helps fix the problem, I don’t really believe
>>>>>> I’m on totally the right track for a permanent fix across applications.
>>>>>> So I’m looking for suggestions or other insights.  Or at least that
>>> this
>>>>>> info helps someone else one day.
>>>>> 
>>>>>> ===
>>>>> 
>>>>>> I”ve also investigated an entirely different track, changing the
>>>>>> following line in NSImage.m
>>>>>>    _cacheMode = NSImageCacheDefault;
>>>>>> to
>>>>>>    _cacheMode = NSImageCacheNever;
>>>>> 
>>>>>> and rebuilding.  In GWorkspace, this fixes the Large icons, but breaks
>>> the
>>>>>> Small icons.  It does, however, also fix the module images in the
>>>>>> Nextspace/Preferences app so that they do not disappear upon resolution
>>>>>> changes.
>>>>> 
>>>>>> Thanks,
>>>>>> T
>>>>> 
>>>>> just recently, a few weeks ago, I exchanged my desktops Nvidia card,
>>> with 2
>>>>> monitors (2xHD), with a AMD based graphics car, and a single monitor
>>> UWQHD.
>>>>> I'm on OpenBSD, using latest gnustep releases, and after suspend/resume
>>>>> cycle, I see the same.
>>>>> Haven't had time to dig into it, thought might be because of graphics
>>> GPU
>>>>> driver change, or resolution change etc.
>>>>> But it's only GNUstep applications that loose the images, most notably
>>>>> GWorkspace.
>>>>> 
>>>>> Sebastian
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>> 
>>>> 
>> 
>> 
>> 
>