master 6b93e16e436 1/2: Add new option to 'register-use-preview'

[Eli Zaretskii]

branch: master
commit 6b93e16e436735003d49a5a2ab451394937ee76c
Author: Thierry Volpiatto <thievol@posteo.net>
Commit: Eli Zaretskii <eliz@gnu.org>

    Add new option to 'register-use-preview'
    
    When set to 'insist', exit minibuffer with same key as
    register name, instead of pressing RET.  E.g., pressing
    "a" selects register "a", then pressing "a" again exits
    the minibuffer.
    
    * lisp/register.el (register-use-preview): New option 'insist'.
    (register-read-with-preview-fancy): Handle new option.
    * doc/emacs/regs.texi: Document it.
    * etc/NEWS: Mention 'insist'.  (Bug#68654)
---
 doc/emacs/regs.texi |  5 +++++
 etc/NEWS            |  2 +-
 lisp/register.el    | 18 ++++++++++++++++--
 3 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/doc/emacs/regs.texi b/doc/emacs/regs.texi
index fdcddbbc739..c30bcc37999 100644
--- a/doc/emacs/regs.texi
+++ b/doc/emacs/regs.texi
@@ -71,6 +71,11 @@ by @code{insert-register} will only show registers whose 
values can be
 inserted into the buffer, omitting registers which hold window
 configurations, positions, and other un-insertable values.
 
+@item insist
+This value is like @code{t}, but in addition of pressing @key{RET} to
+exit with the choosen value, you can press the same key as the name of
+register.
+
 @item nil
 This value requests behavior similar to @code{traditional}, but the
 preview is shown without delay, and is filtered according to the
diff --git a/etc/NEWS b/etc/NEWS
index 7e30cda7226..e854873b8d0 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -639,7 +639,7 @@ This allows to customize different switches for different 
remote machines.
 +++
 *** New mode of prompting for register names and showing preview.
 The new user option 'register-use-preview' can be customized to the
-value t to request a different user interface of prompting for
+value t or insist to request a different user interface of prompting for
 register names and previewing the registers: Emacs will require
 confirmation for overwriting the value of a register, and will show
 the preview of registers without delay.  You can also customize this
diff --git a/lisp/register.el b/lisp/register.el
index f5b0365dec2..73d1b24b231 100644
--- a/lisp/register.el
+++ b/lisp/register.el
@@ -131,7 +131,11 @@ to the value of `register--read-with-preview-function'.")
 (defcustom register-use-preview 'traditional
   "Whether to show register preview when modifying registers.
 
-When set to `t', show a preview buffer with navigation and highlighting.
+When set to `t', show a preview buffer with navigation and
+highlighting.
+When set to \\='insist behave as with `t' but allow exiting minibuffer
+by pressing a second time the selected register, e.g pressing \"a\"
+select register \"a\" and pressing again \"a\" exit minibuffer.
 When nil, show a preview buffer without navigation and highlighting, and
 exit the minibuffer immediately after inserting response in minibuffer.
 When set to \\='never, behave as with nil, but with no preview buffer at
@@ -141,6 +145,7 @@ according to `register-preview-delay'; this preserves the 
traditional
 behavior of Emacs 29 and before."
   :type '(choice
           (const :tag "Use preview" t)
+          (const :tag "Use preview and exit on second hit" insist)
           (const :tag "Use quick preview" nil)
           (const :tag "Never use preview" never)
           (const :tag "Basic preview like Emacs-29" traditional))
@@ -541,7 +546,12 @@ or \\='never."
                                              (member new strs))
                                          new old))
                          (delete-minibuffer-contents)
-                         (insert input)))
+                         (insert input)
+                         ;; Exit minibuffer on second hit
+                         ;; when *-use-preview == insist.
+                         (when (and (string= new old)
+                                    (eq register-use-preview 'insist))
+                           (setq noconfirm t))))
                      (when (and smatch (not (string= input ""))
                                 (not (member input strs)))
                        (setq input "")
@@ -551,6 +561,10 @@ or \\='never."
                        (setq pat input))))
                  (if (setq win (get-buffer-window buffer))
                      (with-selected-window win
+                       (when noconfirm
+                         ;; Happen only when
+                         ;; *-use-preview == insist.
+                         (exit-minibuffer))
                        (let ((ov (make-overlay
                                   (point-min) (point-min)))
                              ;; Allow upper-case and lower-case letters