[Digikam-devel] extragear/graphics/digikam

[Gilles Caulier]

Le Samedi 7 Janvier 2006 00:14, Marcel Wiesweg a écrit :
> > 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? 

A bug, since histogram widget support 16 bits image. This bug is already in my 
TODO list. I have hacked a little this part and i have identified that there 
is a signal/slot problem between hiwtogram widget and color side bar tab.

> 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)

ok. You can do it.

>
> 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?

hum, i think that IE must always in hight priority to load an image. if 
histogram widget currently load image data and user want open an image in IE, 
this last one must pausing histogramwidget image loading...

Caching mecanism is a good way too. It's used in imlib2 implementation...

Gilles

>
> Marcel

-- 
Gilles Caulier