[elpa] externals/transient 7e45a57ec8 030/366: No longer depend on lv to display the transient buffer

[Jonas Bernoulli]

branch: externals/transient
commit 7e45a57ec81185631fe763733f64c99021df2a06
Author: Jonas Bernoulli <jonas@bernoul.li>
Commit: Jonas Bernoulli <jonas@bernoul.li>

    No longer depend on lv to display the transient buffer
---
 default.mk          |  1 -
 docs/CHANGELOG      |  4 +++
 docs/transient.org  | 32 ++++++++++++++++++-----
 docs/transient.texi | 33 ++++++++++++++++++-----
 lisp/transient.el   | 75 +++++++++++++++++++++++++++++++++++++++++++++++------
 5 files changed, 124 insertions(+), 21 deletions(-)

diff --git a/default.mk b/default.mk
index 82bee06299..2294eb9c34 100644
--- a/default.mk
+++ b/default.mk
@@ -4,7 +4,6 @@ ELS   = $(PKG).el
 ELCS  = $(ELS:.el=.elc)
 
 DEPS  = dash
-DEPS += hydra # for lv.el
 
 EMACS      ?= emacs
 EMACS_ARGS ?=
diff --git a/docs/CHANGELOG b/docs/CHANGELOG
index c593c0fd22..32db5f4376 100644
--- a/docs/CHANGELOG
+++ b/docs/CHANGELOG
@@ -1,6 +1,10 @@
 # -*- mode: org -*-
 * v0.2.0    UNRELEASED
 
+- The new option ~transient-display-buffer-action~ allows users to
+  specify how a window is selected to display the transient popup
+  buffer.  The ~lv~ library is no longer used.  #17
+
 - The window that was selected before the transient window was shown
   is no longer re-selected before calling a suffix that exits the
   transient.  If a suffix changes the selected window unintentionally,
diff --git a/docs/transient.org b/docs/transient.org
index 85bbfacca4..809c09dfe2 100644
--- a/docs/transient.org
+++ b/docs/transient.org
@@ -8,7 +8,7 @@
 #+TEXINFO_DIR_CATEGORY: Emacs
 #+TEXINFO_DIR_TITLE: Transient: (transient).
 #+TEXINFO_DIR_DESC: Transient Commands
-#+SUBTITLE: for version 0.1.0 (v0.1.0-23-g6467626+1)
+#+SUBTITLE: for version 0.1.0 (v0.1.0-28-g625683c+1)
 
 #+TEXINFO_DEFFN: t
 #+OPTIONS: H:4 num:4 toc:2
@@ -37,7 +37,7 @@ Calling a suffix command usually causes the transient to be 
exited
 but suffix commands can also be configured to not exit the transient.
 
 #+TEXINFO: @noindent
-This manual is for Transient version 0.1.0 (v0.1.0-23-g6467626+1).
+This manual is for Transient version 0.1.0 (v0.1.0-28-g625683c+1).
 
 #+BEGIN_QUOTE
 Copyright (C) 2018-2019 Jonas Bernoulli <jonas@bernoul.li>
@@ -502,6 +502,28 @@ as many additional suffixes as you hoped.)
   sequence.  If a number, behave as for ~nil~ but also show the commands
   after that many seconds of inactivity.
 
+- User Option: transient-display-buffer-action
+
+  This option specifies the action used to display the transient popup
+  buffer.  The transient popup buffer is displayed in a window using
+  ~(display-buffer buf transient-display-buffer-action)~.
+
+  The value of this option has the form ~(FUNCTION . ALIST)~, where
+  FUNCTION is a function or a list of functions.  Each such function
+  should accept two arguments: a buffer to display and an alist of the
+  same form as ALIST.  See [[info:elisp#Choosing Window]].
+
+  The default is ~(display-buffer-in-side-window (side . bottom))~.
+  This displays the window at the bottom of the selected frame.
+  Another useful value is ~(display-buffer-below-selected)~.  This is
+  what ~magit-popup~ used by default.  For more alternatives see
+  [[info:elisp#Display Action Functions]].
+
+  It may be possible to display the window in another frame, but
+  whether that works in practice depends on the window-manager.
+  If the window manager selects the new window (Emacs frame),
+  then it doesn't work.
+
 - User Option: transient-highlight-mismatched-keys
 
   This option controls whether key bindings of infix commands that do
@@ -1746,10 +1768,8 @@ Hydra (see https://github.com/abo-abo/hydra) is another 
package that
 provides features similar to those of Transient.
 
 Both packages use transient keymaps to make a set of commands
-temporarily available and the ~lv~ library to show these commands in a
-popup buffer, which looks like it is using the echo area (but without
-actually using the echo area).  The author of Hydra is also the author
-of ~lv~, which is maintained in the same repository.
+temporarily available and show the available commands in a popup
+buffer.
 
 A Hydra "body" is equivalent to a Transient "prefix" and a Hydra
 "head" is equivalent to a Transient "suffix".  Hydra has no equivalent
diff --git a/docs/transient.texi b/docs/transient.texi
index 0aa2e2ccbb..befba1b9f1 100644
--- a/docs/transient.texi
+++ b/docs/transient.texi
@@ -31,7 +31,7 @@ General Public License for more details.
 @finalout
 @titlepage
 @title Transient User and Developer Manual
-@subtitle for version 0.1.0 (v0.1.0-23-g6467626+1)
+@subtitle for version 0.1.0 (v0.1.0-28-g625683c+1)
 @author Jonas Bernoulli
 @page
 @vskip 0pt plus 1filll
@@ -65,7 +65,7 @@ Calling a suffix command usually causes the transient to be 
exited
 but suffix commands can also be configured to not exit the transient.
 
 @noindent
-This manual is for Transient version 0.1.0 (v0.1.0-23-g6467626+1).
+This manual is for Transient version 0.1.0 (v0.1.0-28-g625683c+1).
 
 @quotation
 Copyright (C) 2018-2019 Jonas Bernoulli <jonas@@bernoul.li>
@@ -659,6 +659,29 @@ sequence.  If a number, behave as for @code{nil} but also 
show the commands
 after that many seconds of inactivity.
 @end defopt
 
+@defopt transient-display-buffer-action
+
+This option specifies the action used to display the transient popup
+buffer.  The transient popup buffer is displayed in a window using
+@code{(display-buffer buf transient-display-buffer-action)}.
+
+The value of this option has the form @code{(FUNCTION . ALIST)}, where
+FUNCTION is a function or a list of functions.  Each such function
+should accept two arguments: a buffer to display and an alist of the
+same form as ALIST@.  See @ref{Choosing Window,,,elisp,}.
+
+The default is @code{(display-buffer-in-side-window (side . bottom))}.
+This displays the window at the bottom of the selected frame.
+Another useful value is @code{(display-buffer-below-selected)}.  This is
+what @code{magit-popup} used by default.  For more alternatives see
+@ref{Display Action Functions,,,elisp,}.
+
+It may be possible to display the window in another frame, but
+whether that works in practice depends on the window-manager.
+If the window manager selects the new window (Emacs frame),
+then it doesn't work.
+@end defopt
+
 @defopt transient-highlight-mismatched-keys
 
 This option controls whether key bindings of infix commands that do
@@ -2110,10 +2133,8 @@ Hydra (see @uref{https://github.com/abo-abo/hydra}) is 
another package that
 provides features similar to those of Transient.
 
 Both packages use transient keymaps to make a set of commands
-temporarily available and the @code{lv} library to show these commands in a
-popup buffer, which looks like it is using the echo area (but without
-actually using the echo area).  The author of Hydra is also the author
-of @code{lv}, which is maintained in the same repository.
+temporarily available and show the available commands in a popup
+buffer.
 
 A Hydra "body" is equivalent to a Transient "prefix" and a Hydra
 "head" is equivalent to a Transient "suffix".  Hydra has no equivalent
diff --git a/lisp/transient.el b/lisp/transient.el
index 1e176402d3..a4db1422c3 100644
--- a/lisp/transient.el
+++ b/lisp/transient.el
@@ -4,7 +4,7 @@
 
 ;; Author: Jonas Bernoulli <jonas@bernoul.li>
 ;; Homepage: https://github.com/magit/transient
-;; Package-Requires: ((emacs "25.1") (dash "2.15.0") (lv "0.14.0"))
+;; Package-Requires: ((emacs "25.1") (dash "2.15.0"))
 ;; Keywords: bindings
 
 ;; This file is not part of GNU Emacs.
@@ -51,7 +51,6 @@
 (require 'dash)
 (require 'eieio)
 (require 'format-spec)
-(require 'lv)
 
 (eval-when-compile
   (require 'subr-x))
@@ -83,6 +82,35 @@ or when the user explicitly requests it."
                  (const  :tag "on demand" nil)
                  (number :tag "after delay" 1)))
 
+(defcustom transient-display-buffer-action
+  '(display-buffer-in-side-window (side . bottom))
+  "The action used to display the transient popup buffer.
+
+The transient popup buffer is displayed in a window using
+
+  \(display-buffer buf transient-display-buffer-action)
+
+The value of this option has the form (FUNCTION . ALIST),
+where FUNCTION is a function or a list of functions.  Each such
+function should accept two arguments: a buffer to display and
+an alist of the same form as ALIST.  See `display-buffer' for
+details.
+
+The default is (display-buffer-in-side-window (side . bottom)).
+This displays the window at the bottom of the selected frame.
+Another useful value is (display-buffer-below-selected).  This
+is what `magit-popup' used by default.  For more alternatives
+see info node `(elisp)Display Action Functions'.
+
+It may be possible to display the window in another frame, but
+whether that works in practice depends on the window-manager.
+If the window manager selects the new window (Emacs frame),
+then it doesn't work."
+  :package-version '(transient . "0.2.0")
+  :group 'transient
+  :type '(cons (choice function (repeat :tag "Functions" function))
+               alist))
+
 (defcustom transient-show-common-commands nil
   "Whether to show common transient suffixes in the popup buffer.
 
@@ -270,6 +298,13 @@ See info node `(transient)Enabling and Disabling 
Suffixes'."
 See info node `(transient)Enabling and Disabling Suffixes'."
   :group 'transient-faces)
 
+(defface transient-separator
+  '((((class color) (background light)) :background "grey80")
+    (((class color) (background  dark)) :background "grey30"))
+  "Face used to draw line below transient popup window.
+Only the background color is significant."
+  :group 'transient-faces)
+
 ;;; Persistence
 
 (defun transient--read-file-contents (file)
@@ -921,6 +956,8 @@ variable instead.")
 
 (defvar transient--stack nil)
 
+(defvar transient--window nil)
+
 (defvar transient--debug nil "Whether put debug information into *Messages*.")
 
 (defvar transient--history nil)
@@ -1456,6 +1493,12 @@ EDIT may be non-nil."
   (setq transient--layout nil)
   (setq transient--suffixes nil))
 
+(defun transient--delete-window ()
+  (when (window-live-p transient--window)
+    (let ((buf (window-buffer transient--window)))
+      (delete-window transient--window)
+      (kill-buffer buf))))
+
 (defun transient--export ()
   (setq current-transient-prefix transient--prefix)
   (setq current-transient-command (oref transient--prefix command))
@@ -2181,15 +2224,31 @@ have a history of their own.")
 (defun transient--show ()
   (transient--timer-cancel)
   (setq transient--showp t)
-  (let ((transient--source-buffer (current-buffer)))
-    (with-temp-buffer
+  (let ((transient--source-buffer (current-buffer))
+        (buf (get-buffer-create " *transient*")))
+    (unless (window-live-p transient--window)
+      (setq transient--window
+            (display-buffer buf transient-display-buffer-action)))
+    (with-selected-window transient--window
+      (erase-buffer)
+      (set-window-hscroll transient--window 0)
+      (set-window-dedicated-p transient--window t)
+      (set-window-parameter transient--window 'no-other-window t)
+      (setq window-size-fixed t)
+      (setq mode-line-format nil)
+      (setq cursor-type nil)
+      (setq display-line-numbers nil)
+      (setq show-trailing-whitespace nil)
       (transient--insert-groups)
       (when (or transient--helpp transient--editp)
         (transient--insert-help))
-      (delete-trailing-whitespace)
-      (let ((lv-force-update t)
-            (lv-use-separator t))
-        (lv-message "%s" (buffer-string))))))
+      (insert
+       (propertize "__" 'face 'transient-separator 'display '(space :height 
(1)))
+       (propertize "\n" 'face 'transient-separator 'line-height t))
+      (let ((window-resize-pixelwise t)
+            (window-size-fixed nil))
+        (fit-window-to-buffer nil nil 1))
+      (goto-char (point-min)))))
 
 (defun transient--insert-groups ()
   (let ((groups (cl-mapcan (lambda (group)