[Digikam-devel] extragear/graphics/digikam

[Marcel Wiesweg]

>
> First feedback :
>
> I suspect a thread lock conflict between histogram tab and IE...
>
> The problem come when image histogram tab is visible on main interface and
> when IE is started, especially with large files. Sometime histogram
> computation faild, sometime digikam crash with an indeep glibc error. If
> histogram tab from main interface isn't visible, there is no problem.
>
> To reproduce it, select an album with a large list of big image (PNG, TIFF,
> or RAW), toogle on histogram tab from main interface, select the first
> album item, and launch IE. Toogle IE window always visible , reduce IE
> window size to see main interface window, and change current image from
> current album using IE tool bar.
>

I just committed one fix, but at least one remains, and while fixing this one 
I noticed some more issues where I need your opinion.

1) To me it seems selecting with the mouse in the histogram widget is broken. 
Initially, the whole widget is selected (drawn in black). A single click does 
not deselect, but does weird things.
Is this a bug or a feature? If this is a bug, I will fix this tomorrow so that
- dragging the mouse selects a range
- single click without dragging clears selection
- initially, no selection is drawn and range is the full histogram.
I have some code for this here because I needed to disentangle this a bit 
anyway because there is currently an infinite loop when the loaded image is 
null (fixed, not yet committed)

2) If there are any more threading issues (The problems I fixed might have led 
to what you described above), they need definitely be sorted out.
Apart from that however, I cannot accept that loading in IE takes twice as 
long if the histogram tab in main view is open. I would like to add a very 
simple caching mechanism so that the histogram from main window does not need 
to load the image itself. I am thinking of a central place where canvas says 
"I have loaded this image right now", then sends its signals, the main view 
histogram copies the image, and then canvas will withdraw its image data 
again.
Is that okay with you?

Marcel