[elpa] externals/ement 27929d80ff 2/2: Add: (ement-room-timestamp-header-align)

[ELPA Syncer]

branch: externals/ement
commit 27929d80ff2d9ea01b3f5ca673a9190956d06ea9
Author: Adam Porter <adam@alphapapa.net>
Commit: Adam Porter <adam@alphapapa.net>

    Add: (ement-room-timestamp-header-align)
    
    And use in (ement-room--pp-thing).
---
 README.org    |  8 +++++++-
 ement-room.el | 33 +++++++++++++++++++++++++--------
 2 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/README.org b/README.org
index 6a92a2c200..6a3fdf5917 100644
--- a/README.org
+++ b/README.org
@@ -297,7 +297,13 @@ Note that, while ~matrix-client~ remains usable, and 
probably will for some time
 
 ** 0.9-pre
 
-Nothing new yet.
+*Additions*
+
++ Option ~ement-room-timestamp-header-align~ controls how timestamp headers 
are aligned in room buffers.
+
+*Changes*
+
++ Using new option ~ement-room-timestamp-header-align~, timestamp headers 
default to right-aligned.  (With default settings, this keeps them near message 
timestamps and makes for a cleaner appearance.)
 
 ** 0.8.2
 
diff --git a/ement-room.el b/ement-room.el
index f1b0b98a0a..0808729adf 100644
--- a/ement-room.el
+++ b/ement-room.el
@@ -223,6 +223,12 @@ In that case, sender names are aligned to the margin 
edge.")
   "Options for room buffers."
   :group 'ement)
 
+(defcustom ement-room-timestamp-header-align 'right
+  "Where to align timestamp headers."
+  :type '(choice (const :tag "Left" left)
+                 (const :tag "Center" center)
+                 (const :tag "Right" right)))
+
 ;;;;; Faces
 
 (defface ement-room-name
@@ -3119,14 +3125,25 @@ seconds."
      (insert (propertize (ement--format-user thing)
                          'display ement-room-username-display-property)))
     (`(ts ,(and (pred numberp) ts)) ;; Insert a date header.
-     (insert
-      (if (equal ement-room-timestamp-header-format 
ement-room-timestamp-header-with-date-format)
-          ;; HACK: Rather than using another variable, compare the format 
strings to
-          ;; determine whether the date is changing: if so, add a newline 
before the header.
-          "\n"
-        "")
-      (propertize (format-time-string ement-room-timestamp-header-format ts)
-                  'face 'ement-room-timestamp-header)))
+     (let* ((string (format-time-string ement-room-timestamp-header-format ts))
+            (width (string-width string))
+            (maybe-newline (if (equal ement-room-timestamp-header-format 
ement-room-timestamp-header-with-date-format)
+                               ;; HACK: Rather than using another variable, 
compare the format strings to
+                               ;; determine whether the date is changing: if 
so, add a newline before the header.
+                               (progn
+                                 (cl-incf width 3)
+                                 "\n")
+                             ""))
+            (alignment-space (pcase ement-room-timestamp-header-align
+                               ('right (propertize " "
+                                                   'display `(space :align-to 
(- text ,(1+ width)))))
+                               ('center (propertize " "
+                                                    'display `(space :align-to 
(- center ,(/ (1+ width) 2)))))
+                               (_ " "))))
+       (insert maybe-newline
+               alignment-space
+               (propertize string
+                           'face 'ement-room-timestamp-header))))
     ((or 'ement-room-read-receipt-marker 'ement-room-fully-read-marker)
      (insert (propertize " "
                          'display '(space :width text :height (1))