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

[Robert Weiner]

On Mon, Oct 16, 2017 at 9:45 AM, Robert Weiner <address@hidden> wrote:

On Fri, Oct 13, 2017 at 5:57 AM, 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?

​The yellow visual rectangle of the text being dragged seems to get stuck at the source frame but if you continue your drag and release in another frame with a non-read-only buffer, your text should be properly dropped there.  Is this what you did?  Try it a couple different times to ensure there is not some initialization warm up problem.

​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 and then the yellow rectangle of text will follow you to the drag release frame and your drag-and-drops should work as you expect (with the mouse-drag-and-drop-region changes from before).  -- Bob​

(defun mouse-set-point (event &optional promote-to-region)

  "Move point to the position clicked on with the mouse.

This should be bound to a mouse click event type.

If PROMOTE-TO-REGION is non-nil and event is a multiple-click,

select the corresponding element around point, with the resulting position of

point determined by `mouse-select-region-move-to-beginning'."

  (interactive "e\np")

  (let ((start-w-or-f (posn-window (event-start event)))

(end-w-or-f   (posn-window (event-end event))))

    (if (framep start-w-or-f)

(with-selected-frame start-w-or-f (setq start-w-or-f (selected-window))))

    (if (framep end-w-or-f)

(with-selected-frame end-w-or-f (setq end-w-or-f (selected-window))))

    (if (and (window-minibuffer-p start-w-or-f)

     (not (minibuffer-window-active-p start-w-or-f)))

;; Select the ending frame only, not the window pressed within.

(select-frame (window-frame end-w-or-f))

      ;; Give temporary modes such as isearch a chance to turn off.

      (run-hooks 'mouse-leave-buffer-hook)

      (if (and promote-to-region (> (event-click-count event) 1))

  (progn (mouse-set-region event)

(when (and (boundp 'mouse-select-region-move-to-beginning)

    mouse-select-region-move-to-beginning)

   (when (> (posn-point (event-start event)) (region-beginning))

     (exchange-point-and-mark))))

;; Use event-end in case called from mouse-drag-region.

;; If EVENT is a click, event-end and event-start give same value.

(if (and (window-minibuffer-p end-w-or-f)

(not (minibuffer-window-active-p end-w-or-f)))

    ;; Select the ending frame only, not the window pressed within.

    (select-frame (window-frame end-w-or-f))

  (condition-case ()

      (posn-set-point (event-end event))

    (error (select-frame (window-frame end-w-or-f)))))))))