[gtk+] GtkLabel: Rely on the new pango support for context change tracking

[Alexander Larsson <alexl src gnome org>]

commit bf35c2f044296bfc4d016010adde4bf09a1a311d
Author: Alexander Larsson <alexl redhat com>
Date:   Wed Dec 5 14:51:23 2012 +0100

    GtkLabel: Rely on the new pango support for context change tracking
    
    Now that Pango tracks changes to the context automatically there is
    no need to do it manually in e.g. style-updated or direction-changed,
    in fact the only case we have to care about is when we re-create
    the PangoContext due to a screen change, so we only have to clear
    the layouts in GtkLabel in screen-changed.
    
    This means we're not clearing all the layouts whenever the state changes,
    which happens to every widget when the window is unfocused, which helps
    performance a lot.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=340066

 gtk/gtklabel.c  |   35 +++--------------------------------
 gtk/gtkwidget.c |   17 ++++++-----------
 2 files changed, 9 insertions(+), 43 deletions(-)
---
diff --git a/gtk/gtklabel.c b/gtk/gtklabel.c
index 6fbd712..942c093 100644
--- a/gtk/gtklabel.c
+++ b/gtk/gtklabel.c
@@ -384,9 +384,6 @@ static void gtk_label_size_allocate     (GtkWidget        *widget,
                                          GtkAllocation    *allocation);
 static void gtk_label_state_flags_changed   (GtkWidget        *widget,
                                              GtkStateFlags     prev_state);
-static void gtk_label_style_updated     (GtkWidget        *widget);
-static void gtk_label_direction_changed (GtkWidget        *widget,
-					 GtkTextDirection  previous_dir);
 static gint gtk_label_draw              (GtkWidget        *widget,
                                          cairo_t          *cr);
 static gboolean gtk_label_focus         (GtkWidget         *widget,
@@ -566,9 +563,7 @@ gtk_label_class_init (GtkLabelClass *class)
   widget_class->destroy = gtk_label_destroy;
   widget_class->size_allocate = gtk_label_size_allocate;
   widget_class->state_flags_changed = gtk_label_state_flags_changed;
-  widget_class->style_updated = gtk_label_style_updated;
   widget_class->query_tooltip = gtk_label_query_tooltip;
-  widget_class->direction_changed = gtk_label_direction_changed;
   widget_class->draw = gtk_label_draw;
   widget_class->realize = gtk_label_realize;
   widget_class->unrealize = gtk_label_unrealize;
@@ -1852,6 +1847,9 @@ gtk_label_screen_changed (GtkWidget *widget,
   GtkSettings *settings;
   gboolean shortcuts_connected;
 
+  /* The PangoContext is replaced when the screen changes, so clear the layouts */
+  gtk_label_clear_layout (GTK_LABEL (widget));
+
   if (!gtk_widget_has_screen (widget))
     return;
 
@@ -3811,38 +3809,11 @@ gtk_label_state_flags_changed (GtkWidget     *widget,
       gtk_label_update_cursor (label);
     }
 
-  /* We have to clear the layout, fonts etc. may have changed */
-  gtk_label_clear_layout (label);
-
   if (GTK_WIDGET_CLASS (gtk_label_parent_class)->state_flags_changed)
     GTK_WIDGET_CLASS (gtk_label_parent_class)->state_flags_changed (widget, prev_state);
 }
 
 static void
-gtk_label_style_updated (GtkWidget *widget)
-{
-  GtkLabel *label = GTK_LABEL (widget);
-
-  GTK_WIDGET_CLASS (gtk_label_parent_class)->style_updated (widget);
-
-  /* We have to clear the layout, fonts etc. may have changed */
-  gtk_label_clear_layout (label);
-}
-
-static void 
-gtk_label_direction_changed (GtkWidget        *widget,
-			     GtkTextDirection previous_dir)
-{
-  GtkLabel *label = GTK_LABEL (widget);
-  GtkLabelPrivate *priv = label->priv;
-
-  if (priv->layout)
-    pango_layout_context_changed (priv->layout);
-
-  GTK_WIDGET_CLASS (gtk_label_parent_class)->direction_changed (widget, previous_dir);
-}
-
-static void
 get_layout_location (GtkLabel  *label,
                      gint      *xp,
                      gint      *yp)
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 53c791a..a82e62b 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -8705,12 +8705,8 @@ gtk_widget_peek_pango_context (GtkWidget *widget)
  * by gtk_widget_create_pango_context(), this context is owned by
  * the widget (it can be used until the screen for the widget changes
  * or the widget is removed from its toplevel), and will be updated to
- * match any changes to the widget's attributes.
- *
- * If you create and keep a #PangoLayout using this context, you must
- * deal with changes to the context by calling pango_layout_context_changed()
- * on the layout in response to the #GtkWidget::style-updated and
- * #GtkWidget::direction-changed signals for the widget.
+ * match any changes to the widget's attributes. This can be tracked
+ * by using the #GtkWidget::screen-changed signal on the widget.
  *
  * Return value: (transfer none): the #PangoContext for the widget.
  **/
@@ -8821,11 +8817,10 @@ gtk_widget_create_pango_context (GtkWidget *widget)
  * font description, and base direction for drawing text for
  * this widget.
  *
- * If you keep a #PangoLayout created in this way around, in order to
- * notify the layout of changes to the base direction or font of this
- * widget, you must call pango_layout_context_changed() in response to
- * the #GtkWidget::style-updated and #GtkWidget::direction-changed signals
- * for the widget.
+ * If you keep a #PangoLayout created in this way around, you need
+ * to re-create it when the widget #PangoContext is replaced.
+ * This can be tracked by using the #GtkWidget::screen-changed signal
+ * on the widget.
  *
  * Return value: (transfer full): the new #PangoLayout
  **/