Re: Drag and drop is dead, long live drab and throw :)

["Mark R. Bowyer" <Moredhel earthling net>]

>From: Alastair B Roberts <abr@tardis.ed.ac.uk>
>To: gnome-devel-list@gnome.org

>On Fri, 18 Jun 1999, Mark R. Bowyer wrote:

>> Surely we can take a leaf from Gesture research here.  For a drag, the mouse 
>> has started to decelerate before we release the button.  For a throw, the 
>> button is released while the mouse is still accelerating.  This is how we 
>> drop and throw in real life, it should work that way on-screen, too.
>
>Sounds like a good idea, but
>
>(a) how easy would this be to implement?

It's been a long time since I've done this kind of code, but I think you just 
record the difference between each positional value you read and note the delta. 
It's used to calculate how far to move the mouse if acceleration is on in 
Windoze and many Xservers already...


>(b) it was mentioned previously in this thread about the inaccuracy of
>    the modern mouse (especially after its been used for a while). I
>    fear that the average mouse will not accelerate and deaccelerate
>    accurately enough to reliably detect. Remember the basic HCI
>    (human computer interaction) principle: speed and accuracy are
>    tradeoffs. If one has to accelerate the mouse to throw an icon,
>    the accuracy of the placement will be very much decreased. Just
>    a thought.

Not sure if this is true or not.  But it should be possible to allow for a 
tunable huristic so that the user can slide a slider to differentiate between a 
drop and a throw for their own setup and hand movements?

>A previous poster mentioned holding down ALT to enable "throws". This
>sounds like the best idea so far.

Holding down ALT while clicking the first mouse button equates to moving the 
window below the mouse on most every Xserver I've used =OZ  Doesn't stop us 
using another key though.

Ta,

-------My opinion - Not sane, intelligent or necessarily useful-------
o o                                      mailto:Moredhel@earthling.net 
/v\ark R. Bowyer.  http://i.am/Moredhel  mailto:Mark.Bowyer@UK.Sun.COM
`-'         "Everything is true, for a given value of 'true'" - PTerry