[evince] ev-view-accessible: Add a method to determine if a given doc rect is showing

[Joanmarie Diggs <joanied src gnome org>]

commit 5c2ce4e9d82ebf579296ab64330d4364f5ae83de
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Mon Jun 23 08:54:56 2014 -0400

    ev-view-accessible: Add a method to determine if a given doc rect is showing
    
    The Accessibility code needs to know this to set and update ATK_STATE_SHOWING.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=728475

 libview/ev-view-accessible.c |   26 ++++++++++++++++++++++++++
 libview/ev-view-accessible.h |    3 +++
 2 files changed, 29 insertions(+), 0 deletions(-)
---
diff --git a/libview/ev-view-accessible.c b/libview/ev-view-accessible.c
index 7bb0774..1d9c320 100644
--- a/libview/ev-view-accessible.c
+++ b/libview/ev-view-accessible.c
@@ -540,6 +540,32 @@ _transform_doc_rect_to_atk_rect (EvViewAccessible *accessible,
        atk_rect->y2 = view_rect.y + view_rect.height;
 }
 
+gboolean
+ev_view_accessible_is_doc_rect_showing (EvViewAccessible *accessible,
+                                       gint              page,
+                                       EvRectangle      *doc_rect)
+{
+       EvView *view;
+       GdkRectangle view_rect;
+       GtkAllocation allocation;
+       gint x, y;
+       gboolean hidden;
+
+       view = EV_VIEW (gtk_accessible_get_widget (GTK_ACCESSIBLE (accessible)));
+       if (page < view->start_page || page > view->end_page)
+               return FALSE;
+
+       gtk_widget_get_allocation (GTK_WIDGET (view), &allocation);
+       x = gtk_adjustment_get_value (view->hadjustment);
+       y = gtk_adjustment_get_value (view->vadjustment);
+
+       _ev_view_transform_doc_rect_to_view_rect (view, page, doc_rect, &view_rect);
+       hidden = view_rect.x + view_rect.width < x || view_rect.x > x + allocation.width ||
+               view_rect.y + view_rect.height < y || view_rect.y > y + allocation.height;
+
+       return !hidden;
+}
+
 void
 ev_view_accessible_set_page_range (EvViewAccessible *accessible,
                                   gint start,
diff --git a/libview/ev-view-accessible.h b/libview/ev-view-accessible.h
index 1ff5e20..bb10d10 100644
--- a/libview/ev-view-accessible.h
+++ b/libview/ev-view-accessible.h
@@ -62,6 +62,9 @@ void       _transform_doc_rect_to_atk_rect (EvViewAccessible *accessible,
                                            EvRectangle      *doc_rect,
                                            EvRectangle      *atk_rect,
                                            AtkCoordType      coord_type);
+gboolean  ev_view_accessible_is_doc_rect_showing (EvViewAccessible *accessible,
+                                                 gint              page,
+                                                 EvRectangle      *doc_rect);
 
 #endif  /* __EV_VIEW_ACCESSIBLE_H__ */