Re: Emacs 26: Code that fixes mouse-drag-and-drop-region to work across frames

[Robert Weiner]

On Wed, Oct 18, 2017 at 8:43 PM, Tak Kunihiro <address@hidden> wrote:

>>>  I tried the revised `mouse-drag-and-drop-region' on Emacs -Q
>>>  26.0.90 on macOS 10.9.5. I can drag text within a frame but cannot
>>>  do so among frames. I think I miss something. Do you have idea?
>>
> ​I see the issue now; the standard Emacs code does not handle
> cross-frame drags well. Replace the mouse-set-point function from
> mouse.el with the version below

GNU Emacs 27.0.50 (build 1, x86_64-apple-darwin13.4.0, NS appkit-1265.21 Version 10.9.5 (Build 13F1911)) of 2017-10-17
Emacs -Q

I cannot drag text among frames yet.  I think I still miss something.
Can you show recipe that starts from emacs -Q?

​See if adding this fixes it:

    ;; From mouse-position:

    ;;    f = SELECTED_FRAME ();

    ;;    XSETFRAME (lispy_dummy, f);

    ;;  It seems like the XSETFRAME macro is not properly copying the value of f on initial frame selection under the macOS window system.

    ;;  The problem occurs on other systems as well, e.g. Emacs 25.2 under Windows 7.

    ;;  The function below is a temporary fix for this.

    (setq mouse-position-function

  (lambda (frame-x-dot-y)

    "Under macOS, mouse-position and mouse-pixel-position sometimes fail to return the selected-frame (returning the prior frame instead); fix that here."

    (if frame-x-dot-y (setcar frame-x-dot-y (selected-frame)))

    frame-x-dot-y))​