org-dblock-write:columnview: Write width specifications

* lisp/org-colview.el (org-dblock-write:columnview): When writing
table, write width specifications as well and apply them.
* testing/lisp/test-org-colview.el (test-org-colview/dblock): Add
test.
* etc/ORG-NEWS (=colview= dynamic block now writes column width
specifications): Document the change.

Link: https://orgmode.org/list/87r1015w30.fsf@localhost

etc/ORG-NEWS

@@ -984,6 +984,36 @@ properties, links to headlines in the file can also be made more
 robust by using the file id instead of the file path.
 
 ** New features
+*** =colview= dynamic block now writes column width specifications
+
+When column format contains width specifications, =colview= dynamic
+block now writes these specifications as column width in the generated
+tables and automatically shrinks the columns on display.
+
+Example:
+
+: * PROYECTO EMACS
+: :PROPERTIES:
+: :COLUMNS:  %10ITEM(PROJECT)
+: :END:
+:
+: Before
+:
+: #+BEGIN: columnview :id local
+: | PROJECT        |
+: |----------------|
+: | PROYECTO EMACS |
+: #+END:
+:
+: After
+:
+: #+BEGIN: columnview :id local
+: | <10>           |
+: | PROJECT        |
+: |----------------|
+: | PROYECTO EMACS |
+: #+END:
+
 *** =ob-tangle.el=: New flag to remove tangle targets before writing
 
 When ~org-babel-tangle-remove-file-before-write~ is set to ~t~ the

lisp/org-colview.el

@@ -1559,7 +1559,10 @@ PARAMS is a property list of parameters:
 					 (plist-get params :skip-empty-rows)
 					 (plist-get params :exclude-tags)
 					 (plist-get params :format)
-					 view-pos))))))
+					 view-pos)))))
+        (width-specs
+         (mapcar (lambda (spec) (nth 2 spec))
+                 org-columns-current-fmt-compiled)))
     (when table
       ;; Prune level information from the table.  Also normalize
       ;; headings: remove stars, add indentation entities, if
@@ -1595,6 +1598,11 @@ PARAMS is a property list of parameters:
 		(append (mapcar (lambda (x) (if (eq 'hline x) x (cons "" x)))
 				table)
 			(list (cons "/" (make-list size "<>")))))))
+      (when (seq-find #'identity width-specs)
+        ;; There are width specifiers in column format.  Pass them
+        ;; to the resulting table, adding alignment field as the first
+        ;; row.
+        (push (mapcar (lambda (width) (when width (format "<%d>" width))) width-specs) table))
       (let ((content-lines (org-split-string (plist-get params :content) "\n"))
 	    recalc)
 	;; Insert affiliated keywords before the table.
@@ -1616,7 +1624,9 @@ PARAMS is a property list of parameters:
 		(insert "\n" line)
 		(unless recalc (setq recalc t))))))
 	(when recalc (org-table-recalculate 'all t))
-	(org-table-align)))))
+	(org-table-align)
+        (when (seq-find #'identity width-specs)
+          (org-table-shrink))))))
 
 ;;;###autoload
 (defun org-columns-insert-dblock ()

testing/lisp/test-org-colview.el

@@ -1422,6 +1422,19 @@
         "* H\n:PROPERTIES:\n:A: 1\n:END:\n<point>#+BEGIN: columnview\n#+END:"
       (let ((org-columns-default-format "%ITEM %A")) (org-update-dblock))
       (buffer-substring-no-properties (point) (point-max)))))
+  ;; Test column widths.
+  (should
+   (equal
+    "#+BEGIN: columnview
+| <5>  |
+| ITEM |
+|------|
+| H    |
+#+END:"
+    (org-test-with-temp-text
+        "* H\n<point>#+BEGIN: columnview\n#+END:"
+      (let ((org-columns-default-format "%5ITEM")) (org-update-dblock))
+      (buffer-substring-no-properties (point) (point-max)))))
   ;; Properties are case insensitive.
   (should
    (equal