[gtkmm-documentation] Adapt to changed cairomm enums.

[Murray Cumming <murrayc src gnome org>]

commit 095e5839bfffc55e28f0dd821222a76788973885
Author: Murray Cumming <murrayc murrayc com>
Date:   Wed Apr 19 13:48:52 2017 +0200

    Adapt to changed cairomm enums.

 examples/book/drawingarea/clock/clock.cc  |    4 ++--
 examples/book/drawingarea/joins/myarea.cc |    6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/examples/book/drawingarea/clock/clock.cc b/examples/book/drawingarea/clock/clock.cc
index 198d29d..46b7e5a 100644
--- a/examples/book/drawingarea/clock/clock.cc
+++ b/examples/book/drawingarea/clock/clock.cc
@@ -59,7 +59,7 @@ void Clock::on_draw(const Cairo::RefPtr<Cairo::Context>& cr, int width, int heig
     double inset = 0.05;
 
     cr->save();
-    cr->set_line_cap(Cairo::LINE_CAP_ROUND);
+    cr->set_line_cap(Cairo::Context::LineCap::ROUND);
 
     if(i % 3 != 0)
     {
@@ -88,7 +88,7 @@ void Clock::on_draw(const Cairo::RefPtr<Cairo::Context>& cr, int width, int heig
   double seconds= timeinfo->tm_sec * M_PI / 30;
 
   cr->save();
-  cr->set_line_cap(Cairo::LINE_CAP_ROUND);
+  cr->set_line_cap(Cairo::Context::LineCap::ROUND);
 
   // draw the seconds hand
   cr->save();
diff --git a/examples/book/drawingarea/joins/myarea.cc b/examples/book/drawingarea/joins/myarea.cc
index d4a2cad..1910ec8 100644
--- a/examples/book/drawingarea/joins/myarea.cc
+++ b/examples/book/drawingarea/joins/myarea.cc
@@ -44,17 +44,17 @@ void MyArea::on_draw(const Cairo::RefPtr<Cairo::Context>& cr, int width, int hei
     cr->move_to(0.3, 0.3);
     cr->rel_line_to(0.2, -0.2);
     cr->rel_line_to(0.2, 0.2);
-    cr->set_line_join(Cairo::LINE_JOIN_MITER); /* default */
+    cr->set_line_join(Cairo::Context::LineJoin::MITER); /* default */
     cr->stroke();
     cr->move_to(0.3, 0.6);
     cr->rel_line_to(0.2, -0.2);
     cr->rel_line_to(0.2, 0.2);
-    cr->set_line_join(Cairo::LINE_JOIN_BEVEL);
+    cr->set_line_join(Cairo::Context::LineJoin::BEVEL);
     cr->stroke();
     cr->move_to(0.3, 0.9);
     cr->rel_line_to(0.2, -0.2);
     cr->rel_line_to(0.2, 0.2);
-    cr->set_line_join(Cairo::LINE_JOIN_ROUND);
+    cr->set_line_join(Cairo::Context::LineJoin::ROUND);
     cr->stroke();
   }
 }