[gtk/text-fixes: 1/8] textview: Invalidate Pango contexts

[Matthias Clasen <matthiasc src gnome org>]

commit 4fee70935130bf40dd26c70afcddfbabeb3614ae
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Sep 4 14:46:32 2021 -0400

    textview: Invalidate Pango contexts
    
    We need to invalidate the Pango contexts when
    font settings change.

 gtk/gtktextview.c | 46 ++++++++++++++++++++++++++++++++++++----------
 1 file changed, 36 insertions(+), 10 deletions(-)
---
diff --git a/gtk/gtktextview.c b/gtk/gtktextview.c
index 3a66926e98..39398bdd92 100644
--- a/gtk/gtktextview.c
+++ b/gtk/gtktextview.c
@@ -397,6 +397,8 @@ static void gtk_text_view_css_changed          (GtkWidget           *widget,
                                                 GtkCssStyleChange   *change);
 static void gtk_text_view_direction_changed    (GtkWidget        *widget,
                                                 GtkTextDirection  previous_direction);
+static void gtk_text_view_system_setting_changed (GtkWidget           *widget,
+                                                  GtkSystemSetting     setting);
 static void gtk_text_view_state_flags_changed  (GtkWidget        *widget,
                                                GtkStateFlags     previous_state);
 
@@ -819,6 +821,7 @@ gtk_text_view_class_init (GtkTextViewClass *klass)
   widget_class->map = gtk_text_view_map;
   widget_class->css_changed = gtk_text_view_css_changed;
   widget_class->direction_changed = gtk_text_view_direction_changed;
+  widget_class->system_setting_changed = gtk_text_view_system_setting_changed;
   widget_class->state_flags_changed = gtk_text_view_state_flags_changed;
   widget_class->measure = gtk_text_view_measure;
   widget_class->size_allocate = gtk_text_view_size_allocate;
@@ -5028,6 +5031,38 @@ gtk_text_view_direction_changed (GtkWidget        *widget,
     }
 }
 
+static void
+gtk_text_view_update_pango_contexts (GtkTextView *text_view)
+{
+  GtkTextViewPrivate *priv = text_view->priv;
+  PangoContext *ltr_context, *rtl_context;
+
+  if (!priv->layout)
+    return;
+
+  ltr_context = gtk_widget_create_pango_context (GTK_WIDGET (text_view));
+  pango_context_set_base_dir (ltr_context, PANGO_DIRECTION_LTR);
+  rtl_context = gtk_widget_create_pango_context (GTK_WIDGET (text_view));
+  pango_context_set_base_dir (rtl_context, PANGO_DIRECTION_RTL);
+
+  gtk_text_layout_set_contexts (priv->layout, ltr_context, rtl_context);
+
+  g_object_unref (ltr_context);
+  g_object_unref (rtl_context);
+}
+
+static void
+gtk_text_view_system_setting_changed (GtkWidget        *widget,
+                                      GtkSystemSetting  setting)
+{
+  if (setting == GTK_SYSTEM_SETTING_DPI ||
+      setting == GTK_SYSTEM_SETTING_FONT_NAME ||
+      setting == GTK_SYSTEM_SETTING_FONT_CONFIG)
+    {
+      gtk_text_view_update_pango_contexts (GTK_TEXT_VIEW (widget));
+    }
+}
+
 static void
 gtk_text_view_state_flags_changed (GtkWidget     *widget,
                                    GtkStateFlags  previous_state)
@@ -7809,7 +7844,6 @@ gtk_text_view_ensure_layout (GtkTextView *text_view)
   if (priv->layout == NULL)
     {
       GtkTextAttributes *style;
-      PangoContext *ltr_context, *rtl_context;
       const GList *iter;
 
       DV(g_print(G_STRLOC"\n"));
@@ -7842,15 +7876,7 @@ gtk_text_view_ensure_layout (GtkTextView *text_view)
       gtk_text_layout_set_overwrite_mode (priv->layout,
                                          priv->overwrite_mode && priv->editable);
 
-      ltr_context = gtk_widget_create_pango_context (GTK_WIDGET (text_view));
-      pango_context_set_base_dir (ltr_context, PANGO_DIRECTION_LTR);
-      rtl_context = gtk_widget_create_pango_context (GTK_WIDGET (text_view));
-      pango_context_set_base_dir (rtl_context, PANGO_DIRECTION_RTL);
-
-      gtk_text_layout_set_contexts (priv->layout, ltr_context, rtl_context);
-
-      g_object_unref (ltr_context);
-      g_object_unref (rtl_context);
+      gtk_text_view_update_pango_contexts (text_view);
 
       gtk_text_view_check_keymap_direction (text_view);