[gtk+] fontchooser: Set a fixed size on the preview cell

[Benjamin Otte <otte src gnome org>]

commit 1892c64accc3a5b8ef91b139597b076ea52515fc
Author: Benjamin Otte <otte redhat com>
Date:   Thu Sep 22 18:00:37 2011 +0200

    fontchooser: Set a fixed size on the preview cell
    
    This way, all rows have the same height. It has 3 advantages:
    1) No actual computation is necessary to compute the size of the cell.
       This speeds up the list tremendously (filling out the list goes from
       25s to 3s).
    2) Buggy fonts don't mess up the list anymore with their weird sizes.
       Instead, they are clipped / empty space is added.
    3) Buggy fonts look more buggy. So their use is hopefully discouraged.

 gtk/gtkfontchooserwidget.c |   55 +++++++++++++++++++++++++++++++++++++------
 1 files changed, 47 insertions(+), 8 deletions(-)
---
diff --git a/gtk/gtkfontchooserwidget.c b/gtk/gtkfontchooserwidget.c
index ef0f525..d7c3acc 100644
--- a/gtk/gtkfontchooserwidget.c
+++ b/gtk/gtkfontchooserwidget.c
@@ -78,6 +78,7 @@ struct _GtkFontChooserWidgetPrivate
 {
   GtkWidget    *search_entry;
   GtkWidget    *family_face_list;
+  GtkCellRenderer *family_face_cell;
   GtkWidget    *list_scrolled_window;
   GtkWidget    *empty_list;
   GtkWidget    *list_notebook;
@@ -826,9 +827,12 @@ gtk_font_chooser_widget_get_preview_attributes (GtkFontChooserWidget       *font
   attribute->end_index = first_line_len;
   pango_attr_list_insert (attrs, attribute);
 
-  attribute = pango_attr_font_desc_new (font_desc);
-  attribute->start_index = first_line_len;
-  pango_attr_list_insert (attrs, attribute);
+  if (font_desc)
+    {
+      attribute = pango_attr_font_desc_new (font_desc);
+      attribute->start_index = first_line_len;
+      pango_attr_list_insert (attrs, attribute);
+    }
 
   attribute = pango_attr_size_new_absolute (gtk_font_chooser_widget_get_preview_text_height (fontchooser));
   attribute->start_index = first_line_len;
@@ -873,13 +877,46 @@ gtk_font_chooser_widget_cell_data_func (GtkTreeViewColumn *column,
 }
 
 static void
+gtk_font_chooser_widget_set_cell_size (GtkFontChooserWidget *fontchooser)
+{
+  GtkFontChooserWidgetPrivate *priv = fontchooser->priv;
+  PangoAttrList *attrs;
+  GtkRequisition size;
+
+  gtk_cell_renderer_set_fixed_size (priv->family_face_cell, -1, -1);
+
+  attrs = gtk_font_chooser_widget_get_preview_attributes (fontchooser, 
+                                                          NULL,
+                                                          1);
+  
+  g_object_set (priv->family_face_cell,
+                "attributes", attrs,
+                "text", "x\nx",
+                NULL);
+
+  pango_attr_list_unref (attrs);
+
+  gtk_cell_renderer_get_preferred_size (priv->family_face_cell,
+                                        priv->family_face_list,
+                                        &size,
+                                        NULL);
+  gtk_cell_renderer_set_fixed_size (priv->family_face_cell, size.width, size.height);
+}
+
+static void
 gtk_font_chooser_widget_bootstrap_fontlist (GtkFontChooserWidget *fontchooser)
 {
   GtkFontChooserWidgetPrivate *priv = fontchooser->priv;
   GtkTreeView *treeview = GTK_TREE_VIEW (priv->family_face_list);
-  GtkCellRenderer *cell;
   GtkTreeViewColumn *col;
 
+  g_signal_connect_data (priv->family_face_list,
+                         "style-updated",
+                         G_CALLBACK (gtk_font_chooser_widget_set_cell_size),
+                         fontchooser,
+                         NULL,
+                         G_CONNECT_AFTER | G_CONNECT_SWAPPED);
+
   priv->model = GTK_TREE_MODEL (gtk_list_store_new (4,
                                                     PANGO_TYPE_FONT_FAMILY,
                                                     PANGO_TYPE_FONT_FACE,
@@ -898,14 +935,14 @@ gtk_font_chooser_widget_bootstrap_fontlist (GtkFontChooserWidget *fontchooser)
   gtk_tree_view_set_rules_hint      (treeview, TRUE);
   gtk_tree_view_set_headers_visible (treeview, FALSE);
 
-  cell = gtk_cell_renderer_text_new ();
-  g_object_set (cell, "ellipsize", PANGO_ELLIPSIZE_END, NULL);
+  priv->family_face_cell = gtk_cell_renderer_text_new ();
+  g_object_set (priv->family_face_cell, "ellipsize", PANGO_ELLIPSIZE_END, NULL);
 
   col = gtk_tree_view_column_new ();
   gtk_tree_view_column_set_title (col, _("Font Family"));
-  gtk_tree_view_column_pack_start (col, cell, TRUE);
+  gtk_tree_view_column_pack_start (col, priv->family_face_cell, TRUE);
   gtk_tree_view_column_set_cell_data_func (col,
-                                           cell,
+                                           priv->family_face_cell,
                                            gtk_font_chooser_widget_cell_data_func,
                                            fontchooser,
                                            NULL);
@@ -913,6 +950,8 @@ gtk_font_chooser_widget_bootstrap_fontlist (GtkFontChooserWidget *fontchooser)
   gtk_tree_view_append_column (treeview, col);
 
   gtk_font_chooser_widget_load_fonts (fontchooser);
+
+  gtk_font_chooser_widget_set_cell_size (fontchooser);
 }
 
 static void