[Panel-devel] PhotoFrame plasmoid, plasma performances & the Zen

[Sven Burmeister]

Hi!

On Dienstag, 10. Juli 2007, Robert Knight wrote:
> > The users will surely try to load some of their 6+
> > megapixels photos, and rotate and stack them on the desktop
>
> Perhaps scale the photo when it is first loaded and save the scaled
> image in the Plasmoid's data directory.  This also solves the problem
> of a photo from a remote Url which would have to be re-downloaded each
> time the Plasmoid was opened.

I think it might be a nice little feature if there was an option to always 
re-download the image.

If the user just wants to put an image from the web into the frame, i.e. 
instead of "save to disk" and then "load into frame" just drop it onto the 
desktop, there is no need to re-download or re-process it each time.

I am not sure whether the user should be asked where to save the image, since 
it might be a picture s/he wants to add to his album and put into the frame. 
However, the user might expect that if s/he changes the picture he dropped 
onto the frame, i.e. replaces it on the harddisk by another file with the 
same filename, the frame should be updated too. So one would have to check 
the hash of the picture-source in order to know whether to use the cached 
version, or re-process it.

Another scenario is that the user wants the picture from that url downloaded 
each time, i.e. refresh the image, like a "one picture per session webcam" in 
order to always know whether the girl-friend abroad got a new haircut. ;)

In the latter case the plasmoid could cache the image, display the cached 
image when starting and refresh it when the download and processing of the 
new picture is done.

> Ouch.  Rotation probably ought to be implemented in the main
> Plasma::Applet class or a delegate, instead of requiring each Plasmoid
> to handle that itself.  Much like resizing and moving.  Rotation seems
> to be a bit of a performance sore-point in QGraphicsView generally.
> The Troll behind the magic mentioned the same problems with rotated
> widgets in his blog about exciting widgets-on-a-canvas research.

Do you mean Quasar would also be slow on this?

Sven