stylecontext: Remove long outdated docs

The part about transition animations doesn't apply since 3.8.

diff --git a/gtk/gtkstylecontext.c b/gtk/gtkstylecontext.c
index bc87b1352c82cc005061c48ccc4637bbb92f82a9..80c176ea12bea9279b4d1c20b1817ab12c33b1bf 100644 (file)
--- a/gtk/gtkstylecontext.c
+++ b/gtk/gtkstylecontext.c
@@ -79,103 +79,6 @@
  * #GtkSettings:gtk-theme-name setting or a hierarchy change in the rendered
  * widget.
  *
- * # Transition Animations
- *
- * #GtkStyleContext has built-in support for state change transitions.
- * Note that these animations respect the #GtkSettings:gtk-enable-animations
- * setting.
- *
- * For simple widgets where state changes affect the whole widget area,
- * calling gtk_style_context_notify_state_change() with a %NULL region
- * is sufficient to trigger the transition animation. And GTK+ already
- * does that when gtk_widget_set_state() or gtk_widget_set_state_flags()
- * are called.
- *
- * If a widget needs to declare several animatable regions (i.e. not
- * affecting the whole widget area), its #GtkWidget::draw signal handler
- * needs to wrap the render operations for the different regions with
- * calls to gtk_style_context_push_animatable_region() and
- * gtk_style_context_pop_animatable_region(). These functions take an
- * identifier for the region which must be unique within the style context.
- * For simple widgets with a fixed set of animatable regions, using an
- * enumeration works well:
- *
- * An example for Using an enumeration to identify animatable regions:
- *
- * |[<!-- language="C" -->
- * enum {
- *   REGION_ENTRY,
- *   REGION_BUTTON_UP,
- *   REGION_BUTTON_DOWN
- * };
- *
- * ...
- *
- * gboolean
- * spin_button_draw (GtkWidget *widget,
- *                   cairo_t   *cr)
- * {
- *   GtkStyleContext *context;
- *
- *   context = gtk_widget_get_style_context (widget);
- *
- *   gtk_style_context_push_animatable_region (context,
- *                                             GUINT_TO_POINTER (REGION_ENTRY));
- *
- *   gtk_render_background (cr, 0, 0, 100, 30);
- *   gtk_render_frame (cr, 0, 0, 100, 30);
- *
- *   gtk_style_context_pop_animatable_region (context);
- *
- *   ...
- * }
- * ]|
- *
- * For complex widgets with an arbitrary number of animatable regions, it
- * is up to the implementation to come up with a way to uniquely identify
- * each animatable region. Using pointers to internal structs is one way
- * to achieve this:
- *
- * An example for using struct pointers to identify animatable regions:
- * |[<!-- language="C" -->
- * void
- * notebook_draw_tab (GtkWidget    *widget,
- *                    NotebookPage *page,
- *                    cairo_t      *cr)
- * {
- *   gtk_style_context_push_animatable_region (context, page);
- *   gtk_render_extension (cr, page->x, page->y, page->width, page->height);
- *   gtk_style_context_pop_animatable_region (context);
- * }
- * ]|
- *
- * The widget also needs to notify the style context about a state change
- * for a given animatable region so the animation is triggered.
- *
- * An example for triggering a state change animation on a region:
- * |[<!-- language="C" -->
- * gboolean
- * notebook_motion_notify (GtkWidget      *widget,
- *                         GdkEventMotion *event)
- * {
- *   GtkStyleContext *context;
- *   NotebookPage *page;
- *
- *   context = gtk_widget_get_style_context (widget);
- *   page = find_page_under_pointer (widget, event);
- *   gtk_style_context_notify_state_change (context,
- *                                          gtk_widget_get_window (widget),
- *                                          page,
- *                                          GTK_STATE_PRELIGHT,
- *                                          TRUE);
- *   ...
- * }
- * ]|
- *
- * gtk_style_context_notify_state_change() accepts %NULL region IDs as a
- * special value, in this case, the whole widget area will be updated
- * by the animation.
- *
  * # Style Classes and Regions # {#gtkstylecontext-classes}
  *
  * Widgets can add style classes to their context, which can be used