Run blocking photo edit operations in background threads

[Calum Pringle]

When an image is cropped, even if the processing is instant, the transition from original image to the new, cropped one, should be smooth.

I suggest that upon selection of "ok", an activity spinner will fade in in the centre of the screen (for a minimum length of time e.g. 2s) whilst behind it the original image crossfades to that of the new, cropped image.

Attached is a screenshot showing this detail.

[Charles Lindsay (chaz-yorba)]

Once we implement proper "recrop", where after you've cropped once and you reenter the crop tool you're shown the original with the crop rectangle preset to where you had previously cropped, are we going to do anything for the mirror case of going from the cropped to the original? In other words, you're describing what to do when you hit crop and the photo shrinks to the cropped region, but what should we do when you enter the crop tool and the photo expands to the original size?

Also I'll need the spinning graphic to implement this feature -- I'm afraid making a dummy spinning gif is beyond my level of expertise in GIMP.

[Calum Pringle (calumpringle)]

Yes the opposite direction should also have a brief spinner and crossfade. The spinner will be part of the toolkit, I'll ask Chris to provide something though.

[Adam Dingle (adam-yorba)]

Once the spinner is available we'll use it both for cropping and for autoenhance (see bug #1018972), where we're currently using a placeholder spinner graphic. On that bug, Eric wrote

    note that the spinner graphic needs to be an MNG formatted animation, because that's what Qt supports.

So, Chris: if you can give us an MNG that would be great. If not, we can probably figure out how to convert from another format (such as a series of PNGs).

[Eric Gregory (eric-yorba)]

For the record, ImageMagick/GraphicsMagick can build an MNG from a series of PNGs.

Say you have frame01.png, frame02.png, etc. and want a 100ms delay between each frame. The command to build the animation is:
convert -delay 100 frame*.png animation.mng

[Jim Nelson (yorba-jim)]

I believe a progress bar was added to the SDK. Presumably a spinner widget should be added as well.

[Jim Nelson (yorba-jim)]

Eric informs me that a spinner is in the SDK. Now Gallery needs to display it while running the editing operations in the background.

[PS Jenkins bot (ps-jenkins)]

Fix committed into lp:gallery-app at revision None, scheduled for release in gallery-app, milestone ubuntu-13.04-month-5

[Launchpad Janitor (janitor)]

This bug was fixed in the package gallery-app - 0.0.67+13.10.20130729-0ubuntu1

---------------
gallery-app (0.0.67+13.10.20130729-0ubuntu1) saucy; urgency=low

  [ Guenter Schwann ]
  * Run edit operations in a background task. (LP: #1011710)

  [ Ubuntu daily release ]
  * Automatic snapshot from revision 788
 -- Ubuntu daily release <email address hidden> Mon, 29 Jul 2013 08:17:31 +0000