Re: [Texmacs-dev] Patches: copy/paste and selection handling.

[Joris van der Hoeven]

On Sat, Apr 18, 2009 at 09:57:58AM +0100, Norbert Nemec wrote:
> >The "standard" middle-click behaviour (also implemented in Emacs)
> >is evil in many ways and especially in the context of TeXmacs:
> >  1) The cursor position where you paste is not indicated when pasting.
> >  
> Some editors offer something like a "phantom-cursor" that moves along 
> with the mouse cursor as a gray "shadow" to indicate the place where the 
> cursor would be placed on a left-click. This would also help greatly for 
> a middle click. Of course, this would mean major surgery in TeXmacs. 
> Otherwise, however, I do not see how you would want to improve the 
> situation here.

The old behaviour was: first position your mouse with a left click or
the keyboard and then middle click. This is safe: you know beforehand
where the material gets pasted.

Another drawback of the standard: pasting is a quite critical editing
operations, because it alters a lot of content. Now positioning with
the mouse is delicate: if you are in a train, then it easily occurs
that you move the mouse by a few pixels. Therefore, it is not nice that
a quite critical editing operations requires very precise user control
over the mouse.

> >  2) This could be fixed by displaying a cursor on mouse press, but this is
> >     still not nice: as soon as you click, you are obliged to paste,
> >     even if you are unable to position at the correct position by mouse.
> >     This lack of robustness bad independently from 1).
> >  
> >  3) Impossible to paste at certain logical positions which correspond
> >     to the same graphical positions (TeXmacs specific, does not occur in 
> >     Emacs).
> >  
> OK, the impossibilty to paste certain content in certain positions is 
> specific to TeXmacs. I don't see, however, why this makes the 
> middle-click evil. On middle click, the cursor is first positioned just 
> like with the left-click and then the content it attempted to be pasted. 
> If this is impossible, it is simply not done and the middle-click simply 
> has the same effect as a left-click.

No, the situation is worse: when you position the mouse wrongly,
pasting might still be a valid operation, just giving the wrong result.
I was not referring to the impossibilty to paste certain content in
certain positions, but rather the impossibility to position the cursor
at certain points using the mouse. For instance, in the markup

        Hi <strong|<em|there>>,

you can position the cursor inside stong but not emphasized text
using the keyboard, but not using the mouse. Also, in mathematical
formulas with lots of scripts, it can be hard to position the cursor
using the mouse.

> >So there are many motivations behind the original behaviour of
> >the middle mouse click. But well, if it is not standard...
> >The new implementation will just make middle mouse clicking
> >useless for myself.
> >  
> Maybe the following idea would help:
> 
> How about making Shift-middle-click perform a mouse-paste without cursor 
> repositioning? You could then first place the cursor exactly where you 
> want and shift-middle-click anywhere in the TeXmacs-window to paste to 
> this position.

Yes, this would be OK.