[Digikam-devel] extragear/graphics/digikam

[Marcel Wiesweg]

Hi,

I just put this commit into SVN, see the message on the mailing list for 
complete changelog.
I think I have to elaborate on some points.


> - Image Editor and Showfoto
>    - adapt DImgInterface to threaded image loading
>    - add appropriate signals and slots to all three layers (DImgInterface,
> Canvas, ImageWindow and Showfoto) - split loading and saving functions in
> two parts in all three layers - for saving, some information needs to be
> stored across asynchronous calls which was previously stored in local
> variables.
>      Added appropriate members respectively SavingContext classes (in
> ImageWindow, Showfoto). 

I just split the function in two parts and made the local variables which are 
used in the second part member variables. In ImageWindow and Showfoto, where 
there are more than one such variable, I introduced a class which bundles 
them to keep things clear. Neither the naming of these variables nor the 
functions as such have been changed.

>    - put in hooks for progress info display 
>    - added preliminary code to wait on asynchronous saving, needed for
> promptUserSave() - added a modal progress dialog
>        - needs to be tested and fixed, see TODO below

This is a problem I had not thought of. In promptUserSave(), a return value is 
needed from the save() functions. As far as I see, at least when 
promptUserSave is called from closeEvent(), this cannot be avoided.
So we need to wait in this function till slotSavingFinished is called, 
essentially this means waiting for event delivery in the event queue.

My Qt experience ends here, I am lacking a deeper understanding for things 
like enter_loop, qt_enter_modal, modal dialogs and such. I just put in a 
modal dialog which is closed in finishSaving in the hope that this works, but 
this needs testing.

It is probably better to use the standard, still-to-be-written progress 
display and use some other means for synchronizing, something like Digikam 
SyncJob?


>    - fix creation of ImageWindow singleton upon exiting
>      (checking for imageWindow() would create the instance if not yet done)
>
> TODO:
>    - add progress display to status bar
>    - disable actions when saving (all actions?) and loading (not all
> actions, e.g. selecting another image must be possible and abort loading) -
> test, think about and fix waiting on save() in promptUserSave() - more
> thorough testing

There are TODOs in the relevant places (imagewindow.cpp, showfoto.cpp)
When saving, no other actions should be possible IMO.
Loading can safely be aborted, so next/previous buttons and the thumb bar 
should be usable. On the other nything that changes image data, starting 
image plugins etc. should not be possible.

>    - fix a bug when fast switching through list in IE. First add disabling
> of actions. 

I have found a bug there probably, still unsure where but I don't think it is 
in the infrastructure. Will fix this when the disabling of actions is done 
and there is always a clean state, and the bug still appears.

> - still some debug statements active 
>

Marcel