Replace platform-dependent info glyph in AI prefs model card with cairo-drawn icon

src/CMakeLists.txt

@@ -137,6 +137,7 @@ FILE(GLOB SOURCE_FILES
   "dtgtk/gradientslider.c"
   "dtgtk/icon.c"
   "dtgtk/paint.c"
+  "dtgtk/paint_cell.c"
   "dtgtk/range.c"
   "dtgtk/resetlabel.c"
   "dtgtk/sidepanel.c"

src/dtgtk/paint.c

@@ -2140,6 +2140,32 @@ void dtgtk_cairo_paint_help(cairo_t *cr, const gint x, const gint y, const gint
   FINISH
 }
 
+void dtgtk_cairo_paint_info(cairo_t *cr, const gint x, const gint y, const gint w, const gint h, gint flags, void *data)
+{
+  PREAMBLE(0.95, 1, 0, 0)
+
+  // dot (filled so it reads as a tittle, not a tiny ring)
+  cairo_arc(cr, 0.5, 0.22, 0.05, 0.0, 2.0 * M_PI);
+  cairo_fill(cr);
+
+  // stem
+  cairo_move_to(cr, 0.5,  0.40);
+  cairo_line_to(cr, 0.5,  0.72);
+  // top serif (asymmetric, ends at stem centreline)
+  cairo_move_to(cr, 0.35, 0.40);
+  cairo_line_to(cr, 0.50, 0.40);
+  // bottom serif
+  cairo_move_to(cr, 0.35, 0.72);
+  cairo_line_to(cr, 0.65, 0.72);
+  // outer circle
+  cairo_new_sub_path(cr);
+  cairo_arc(cr, 0.5, 0.5, 0.45, 0.0, 2.0 * M_PI);
+
+  cairo_stroke(cr);
+
+  FINISH
+}
+
 void dtgtk_cairo_paint_grouping(cairo_t *cr, const gint x, const gint y, const gint w, const gint h, const gint flags, void *data)
 {
   PREAMBLE(1, 1, 0, 0)

src/dtgtk/paint.h

@@ -159,6 +159,8 @@ void dtgtk_cairo_paint_messages(cairo_t *cr, gint x, gint y, gint w, gint h, gin
 void dtgtk_cairo_paint_styles(cairo_t *cr, gint x, gint y, gint w, gint h, gint flags, void *data);
 /** paint the ? help label */
 void dtgtk_cairo_paint_help(cairo_t *cr, gint x, gint y, gint w, gint h, gint flags, void *data);
+/** paint the i info label */
+void dtgtk_cairo_paint_info(cairo_t *cr, gint x, gint y, gint w, gint h, gint flags, void *data);
 /** paint the grouping icon. */
 void dtgtk_cairo_paint_grouping(cairo_t *cr, gint x, gint y, gint w, gint h, gint flags, void *data);
 /** paint the preferences wheel. */

src/dtgtk/paint_cell.c

@@ -0,0 +1,122 @@
+/*
+    This file is part of darktable,
+    Copyright (C) 2026 darktable developers.
+
+    darktable is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    darktable is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with darktable.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "dtgtk/paint_cell.h"
+#include "common/darktable.h"
+#include "gui/gtk.h"
+
+G_DEFINE_TYPE(GtkDarktablePaintCell, dtgtk_paint_cell, GTK_TYPE_CELL_RENDERER)
+
+// icon edge length, derived from the widget's line height
+static int _paint_cell_compute_size(GtkWidget *widget)
+{
+  int s = DT_PIXEL_APPLY_DPI(12);
+  if(widget)
+  {
+    PangoContext *pctx = gtk_widget_get_pango_context(widget);
+    const PangoFontDescription *fd = pango_context_get_font_description(pctx);
+    PangoFontMetrics *m = pango_context_get_metrics(pctx, fd, NULL);
+    const int line_h = (pango_font_metrics_get_ascent(m)
+                        + pango_font_metrics_get_descent(m)) / PANGO_SCALE;
+    pango_font_metrics_unref(m);
+    if(line_h > 0) s = line_h;
+  }
+  return s;
+}
+
+static void _paint_cell_get_preferred_width(GtkCellRenderer *r,
+                                            GtkWidget *widget,
+                                            gint *minimum_size,
+                                            gint *natural_size)
+{
+  (void)r;
+  const int s = _paint_cell_compute_size(widget);
+  if(minimum_size) *minimum_size = s;
+  if(natural_size) *natural_size = s;
+}
+
+static void _paint_cell_get_preferred_height(GtkCellRenderer *r,
+                                             GtkWidget *widget,
+                                             gint *minimum_size,
+                                             gint *natural_size)
+{
+  (void)r;
+  const int s = _paint_cell_compute_size(widget);
+  if(minimum_size) *minimum_size = s;
+  if(natural_size) *natural_size = s;
+}
+
+static void _paint_cell_render(GtkCellRenderer *r,
+                               cairo_t *cr,
+                               GtkWidget *widget,
+                               const GdkRectangle *bg_area,
+                               const GdkRectangle *cell_area,
+                               GtkCellRendererState flags)
+{
+  (void)bg_area; (void)flags;
+  GtkDarktablePaintCell *self = DTGTK_PAINT_CELL(r);
+  if(!self->paint) return;
+
+  GdkRGBA fg;
+  GtkStyleContext *ctx = gtk_widget_get_style_context(widget);
+  gtk_style_context_get_color(ctx, gtk_widget_get_state_flags(widget), &fg);
+
+  const int mx = cell_area->width  / 5;
+  const int my = cell_area->height / 5;
+
+  cairo_save(cr);
+  gdk_cairo_set_source_rgba(cr, &fg);
+  self->paint(cr,
+              cell_area->x + mx, cell_area->y + my,
+              cell_area->width  - 2 * mx,
+              cell_area->height - 2 * my,
+              self->paint_flags, self->paint_data);
+  cairo_restore(cr);
+}
+
+static void dtgtk_paint_cell_class_init(GtkDarktablePaintCellClass *klass)
+{
+  GtkCellRendererClass *cr_class = GTK_CELL_RENDERER_CLASS(klass);
+  cr_class->get_preferred_width  = _paint_cell_get_preferred_width;
+  cr_class->get_preferred_height = _paint_cell_get_preferred_height;
+  cr_class->render               = _paint_cell_render;
+}
+
+static void dtgtk_paint_cell_init(GtkDarktablePaintCell *self)
+{
+  self->paint = NULL;
+  self->paint_flags = 0;
+  self->paint_data = NULL;
+}
+
+GtkCellRenderer *dtgtk_paint_cell_new(DTGTKCairoPaintIconFunc paint,
+                                      gint paint_flags,
+                                      void *paint_data)
+{
+  GtkDarktablePaintCell *cell = g_object_new(dtgtk_paint_cell_get_type(), NULL);
+  cell->paint = paint;
+  cell->paint_flags = paint_flags;
+  cell->paint_data = paint_data;
+  return GTK_CELL_RENDERER(cell);
+}
+
+// clang-format off
+// modelines: These editor modelines have been set for all relevant files by tools/update_modelines.py
+// vim: shiftwidth=2 expandtab tabstop=2 cindent
+// kate: tab-indents: off; indent-width 2; replace-tabs on; indent-mode cstyle; remove-trailing-spaces modified;
+// clang-format on

src/dtgtk/paint_cell.h

@@ -0,0 +1,56 @@
+/*
+    This file is part of darktable,
+    Copyright (C) 2026 darktable developers.
+
+    darktable is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    darktable is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with darktable.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+#include "paint.h"
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+#define DTGTK_TYPE_PAINT_CELL dtgtk_paint_cell_get_type()
+G_DECLARE_FINAL_TYPE(GtkDarktablePaintCell, dtgtk_paint_cell,
+                     DTGTK, PAINT_CELL, GtkCellRenderer)
+
+struct _GtkDarktablePaintCell
+{
+  GtkCellRenderer parent;
+  DTGTKCairoPaintIconFunc paint;
+  gint paint_flags;
+  void *paint_data;
+};
+
+/** Cell renderer that draws a dtgtk cairo paint function directly
+ *  into the tree view's cairo context — the same approach
+ *  dtgtk_button uses for its icon. avoids the GtkCellRendererPixbuf
+ *  intermediate, which softens edges at icon sizes.
+ *
+ *  Visibility is controlled via the standard GtkCellRenderer "visible"
+ *  property, typically bound to a model column via
+ *  gtk_tree_view_column_new_with_attributes(..., "visible", COL, NULL). */
+GtkCellRenderer *dtgtk_paint_cell_new(DTGTKCairoPaintIconFunc paint,
+                                      gint paint_flags,
+                                      void *paint_data);
+
+G_END_DECLS
+
+// clang-format off
+// modelines: These editor modelines have been set for all relevant files by tools/update_modelines.py
+// vim: shiftwidth=2 expandtab tabstop=2 cindent
+// kate: tab-indents: off; indent-width 2; replace-tabs on; indent-mode cstyle; remove-trailing-spaces modified;
+// clang-format on

src/gui/preferences_ai.c

@@ -20,6 +20,7 @@
 #include "bauhaus/bauhaus.h"
 #include "dtgtk/button.h"
 #include "dtgtk/paint.h"
+#include "dtgtk/paint_cell.h"
 #include "ai/backend.h"
 #include "common/ai_models.h"
 #include "common/darktable.h"
@@ -69,7 +70,7 @@ enum
 {
   COL_SELECTED,
   COL_NAME,
-  COL_INFO,     // info icon column (static "ⓘ" text)
+  COL_INFO,     // info icon visibility flag (TRUE on downloaded rows)
   COL_VERSION,
   COL_TASK,
   COL_ENABLED,
@@ -257,8 +258,7 @@ static void _refresh_model_list(dt_prefs_ai_data_t *data)
         ? (model->version ? model->version : "0.0") : "–",
       COL_ID,
       model->id,
-      COL_INFO,
-      is_downloaded ? "\xe2\x93\x98" : "",  // U+24D8 CIRCLED LATIN SMALL LETTER I
+      COL_INFO, is_downloaded,
       -1);
     dt_ai_model_free(model);
   }
@@ -1220,12 +1220,9 @@ static gboolean _info_active_at_bin(dt_prefs_ai_data_t *data,
      && column == data->info_col)
   {
     GtkTreeIter iter;
-    gchar *info = NULL;
     if(gtk_tree_model_get_iter(GTK_TREE_MODEL(data->model_store), &iter, path))
       gtk_tree_model_get(GTK_TREE_MODEL(data->model_store),
-                         &iter, COL_INFO, &info, -1);
-    active = (info && info[0]);
-    g_free(info);
+                         &iter, COL_INFO, &active, -1);
   }
   if(path) gtk_tree_path_free(path);
   return active;
@@ -1309,13 +1306,12 @@ static gboolean _on_info_button_press(GtkWidget *widget,
   if(gtk_tree_model_get_iter(GTK_TREE_MODEL(data->model_store), &iter, path))
   {
     gchar *model_id = NULL;
-    gchar *info = NULL;
+    gboolean has_info = FALSE;
     gtk_tree_model_get(GTK_TREE_MODEL(data->model_store),
-                       &iter, COL_ID, &model_id, COL_INFO, &info, -1);
-    if(model_id && info && info[0])
+                       &iter, COL_ID, &model_id, COL_INFO, &has_info, -1);
+    if(model_id && has_info)
       _show_model_card(data, model_id);
     g_free(model_id);
-    g_free(info);
   }
   gtk_tree_path_free(path);
   return TRUE;
@@ -1713,7 +1709,7 @@ void init_tab_ai(GtkWidget *dialog, GtkWidget *stack)
     NUM_COLS,
     G_TYPE_BOOLEAN, // selected
     G_TYPE_STRING,  // name
-    G_TYPE_STRING,  // info icon
+    G_TYPE_BOOLEAN, // info icon visible
     G_TYPE_STRING,  // version
     G_TYPE_STRING,  // task
     G_TYPE_BOOLEAN, // enabled
@@ -1782,11 +1778,12 @@ void init_tab_ai(GtkWidget *dialog, GtkWidget *stack)
   gtk_tree_view_append_column(GTK_TREE_VIEW(data->model_list), name_col);
 
   // info icon column — click opens model card
-  GtkCellRenderer *info_renderer = gtk_cell_renderer_text_new();
+  GtkCellRenderer *info_renderer
+    = dtgtk_paint_cell_new(dtgtk_cairo_paint_info, 0, NULL);
   data->info_col = gtk_tree_view_column_new_with_attributes(
     "",
     info_renderer,
-    "text",
+    "visible",
     COL_INFO,
     NULL);
   gtk_tree_view_column_set_clickable(data->info_col, FALSE);