From a4181d0db197471f697e6d9659ad9f112d351b95 Mon Sep 17 00:00:00 2001
From: Kinneyzhang <kinneyzhang666@gmail.com>
Date: Mon, 31 Aug 2026 15:26:41 +0800
Subject: [PATCH] perf: flatten fixed-width table headers

---
 etaf-ui-table.el       | 39 +++++++++++++++++++++++++++++++--------
 tests/etaf-ui-tests.el |  8 ++++++++
 2 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/etaf-ui-table.el b/etaf-ui-table.el
index e8fdddc..008d3f2 100644
--- a/etaf-ui-table.el
+++ b/etaf-ui-table.el
@@ -69,21 +69,44 @@
            (etaf-ui--column-value column :key))
        column))))))
 
+(defun etaf-ui--table-fixed-header-text (columns)
+  "Return one fixed-width header string for COLUMNS, or nil."
+  (when (and columns
+             (cl-every
+              (lambda (column)
+                (let ((width (etaf-ui--column-value column :width)))
+                  (and (integerp width) (> width 0))))
+              columns))
+    (mapconcat
+     (lambda (column)
+       (let* ((width (etaf-ui--column-value column :width))
+              (value
+               (etaf-ui--table-fit-text
+                (or (etaf-ui--column-value column :label)
+                    (etaf-ui--column-value column :key))
+                column)))
+         (concat value
+                 (make-string (max 0 (- width (string-width value))) ?\s))))
+     columns " ")))
+
 (defun etaf-ui--table-header (columns)
   "Return a Table header row for COLUMNS."
-  (let ((theme (etaf-ui--style-tokens :ui-table-border)))
+  (let ((theme (etaf-ui--style-tokens :ui-table-border))
+        (fixed-text (etaf-ui--table-fixed-header-text columns)))
     (etaf-node
      'row
      (list :class "etaf-table-header"
            :border-bottom-width 1 :border-bottom-style 'solid
            :border-bottom-color (plist-get theme :ui-table-border))
-     (cl-loop for column in columns
-              for tail on columns
-              for index from 0
-              collect
-              (etaf-ui--table-header-cell
-               column (zerop index) (cdr tail)
-               (plist-get theme :ui-table-border))))))
+     (if fixed-text
+         (list (etaf-node 'text nil (list fixed-text)))
+       (cl-loop for column in columns
+                for tail on columns
+                for index from 0
+                collect
+                (etaf-ui--table-header-cell
+                 column (zerop index) (cdr tail)
+                 (plist-get theme :ui-table-border)))))))
 
 (defun etaf-ui--table-cell (row column first-p gap-p border-color)
   "Return one Label cell for ROW and COLUMN using GAP-P."
diff --git a/tests/etaf-ui-tests.el b/tests/etaf-ui-tests.el
index 1bb9ad4..030fb7e 100644
--- a/tests/etaf-ui-tests.el
+++ b/tests/etaf-ui-tests.el
@@ -823,6 +823,14 @@
   (should-not
    (etaf-ui--table-fixed-row-text
     '(:name "Ada" :kind "Essay")
+    '((:key :name :width 5) (:key :kind))))
+  (should
+   (equal "Name  Kind   "
+          (etaf-ui--table-fixed-header-text
+           '((:key :name :label "Name" :width 5)
+             (:key :kind :label "Kind" :width 7)))))
+  (should-not
+   (etaf-ui--table-fixed-header-text
     '((:key :name :width 5) (:key :kind)))))
 
 (ert-deftest etaf-ui-data-grid-noninteractive-rows-have-no-focus-contract ()