Clipboard and selection in wayland.

[Bill Spitzak]

On 03/11/2013 07:56 PM, Yichao Yu wrote:

> It may depends on how you define selecting but the point here is the
> content you start dragging should never clear the current PRIMARY
> selection (use x11 name to avoid ambiguity), e.g. if you drag the
> flower in the weston dnd demo, that shouldn't change what you are
> going to middle-button paste next.

That is interesting but I have not seen any real api's that do that. In 
all cases they change the selection to the item being dragged (just 
tried this on various file managers including Windows, and "drag" of an 
icon always leaves it selected so that Ctrl+C copies it, and I believe 
anything that changes what Ctrl+C will copy should also change what 
middle-button-paste does. However I do think it is ok to be able to 
distinguish these selections.

My primary concern is that applications be strongly encouraged to treat 
middle-button-click and a "drop" the same, in that exactly the same data 
is accepted and it works exactly the same in both cases. This is best 
done by making the api shared so programs are encouraged to do the same 
thing.

What I really am trying to say is that on a range of "similarity" the 3 
apis should be something like this:

    cut&paste .............................. middle-button-paste .. dnd

What should be avoided is the X mistake of making dnd be the "different" 
one, which is why there are so many broken programs that confuse cut & 
paste and middle-button-paste. Everything would be much better if all 
those programs instead confused dnd and middle-button paste.

Mostly this means that the api for the target to retrieve the data for 
dnd and for middle-button-paste should be IDENTICAL (except for an 
integer saying "which"), and the source should be able to set the data 
with identical api's, including the ability to say that the selection 
and drag & drop are the same data and thus only set it once.