https://github.com/inverse-inc/sogo/commit/11920f592c8a144e80b4be8b2f8b2b586fe4a33e

Tasks are not movable per drag and drop.

Also you only can use multi-column view for drag and drop of events into other calendars.
This should work independant of the selected view.

Ok for tasks.

It works with all views for me.

Using Iceweasel 30 (probably also Firefox) I cannot move any events from the day/week/month/multicolumn views to other calendars (it works from the event list though, as well as between columns in the multi column view).

In Chrome, moving events works fine. What browsers did you test against?

Both issues should be fixed.

Problems still exist in Firefox/Iceweasel 30.

1. Dragging events mostly works, but when trying to drop them, the calendar does not always accept the dragged item. This is visible by the highlighting of the calendar item disappearing. Moving on the item or out of it (to the next calendar and back) helps. If the cursor position changes a lot (touchpad) drag and drop is pretty much unusable. This is not a problem for mail, only appears when dragging events.

2. Dragging tasks is still not possible in Firefox/Iceweasel 30. Works fine in Chrome, though. We did note though that when trying to drag a task item (which does not work, right arrow in screenshot) some icon appears in the month overview in the left bar (left arrow). Only disappears when reloading the tab.

Can you try this patch?

https://github.com/inverse-inc/sogo/commit/5b886e5c4dab6bdf486f937df8bb234c4902f50c.diff

I tried your patch, but now it is worse.
Before I could drag and drop events from the search list to calendars.
Now I only get the same behaviour as with tasks (shown in the above picture Auswahl_001.png)

When dragging an event from a View it is a little bit better.
It only deselects the target folder for dropping, if you move your cursor/mouse over the dragging icon.
Reason for this seems to be,that this icon is moved in steps, not continiously with the dragging cursor/mouse.
And it seems to catch the focus?

Hope this description is clear enough and helps a bit.

I no longer have any problem with Firefox 31 and the latest version of SchedulerUI.js. Are you sure you've properly updated the JavaScript file?

Just got the nightlies 2.2.7.20140804 installed and retested.
With these Drag&Drop for tasks and events works.
Also the deselects of the target folder are gone.

Seems that I was missing another change than the one in 0002759:0007378 which affeted this behaviour.
(I double checked my changes of SchedulerUI.js before)

@Jens Erat : I was able to reproduce and isolate the cause of the bug you found when dragging an event from the calendar view over the calendar list on the left panel. I made a quick fix about it:

https://github.com/inverse-inc/sogo/commit/03152ea3d4cbf39ef8a5340e865d038bc899877f

Thank you for your feedback
-Alexandre