Fix broken logic and possible NULL pointer dereference for Bundle XML.

[ardour.git] / libs / canvas / ruler.cc

diff --git a/libs/canvas/ruler.cc b/libs/canvas/ruler.cc
index 120ba845a5550d7a8d94a5e2c79ffddaefdcd98f..b11793cb7fa1d1a524049cfc1ea1f5d3375bdf9e 100644 (file)
--- a/libs/canvas/ruler.cc
+++ b/libs/canvas/ruler.cc
@@ -33,7 +33,7 @@ using namespace ArdourCanvas;
 
 Ruler::Ruler (Canvas* c, const Metric& m)
        : Rectangle (c)
-       , _metric (m)
+       , _metric (&m)
        , _lower (0)
        , _upper (0)
        , _need_marks (true)
@@ -42,7 +42,7 @@ Ruler::Ruler (Canvas* c, const Metric& m)
 
 Ruler::Ruler (Canvas* c, const Metric& m, Rect const& r)
        : Rectangle (c, r)
-       , _metric (m)
+       , _metric (&m)
        , _lower (0)
        , _upper (0)
        , _need_marks (true)
@@ -51,7 +51,7 @@ Ruler::Ruler (Canvas* c, const Metric& m, Rect const& r)
 
 Ruler::Ruler (Item* parent, const Metric& m)
        : Rectangle (parent)
-       , _metric (m)
+       , _metric (&m)
        , _lower (0)
        , _upper (0)
        , _need_marks (true)
@@ -60,7 +60,7 @@ Ruler::Ruler (Item* parent, const Metric& m)
 
 Ruler::Ruler (Item* parent, const Metric& m, Rect const& r)
        : Rectangle (parent, r)
-       , _metric (m)
+       , _metric (&m)
        , _lower (0)
        , _upper (0)
        , _need_marks (true)
@@ -106,7 +106,7 @@ Ruler::render (Rect const & area, Cairo::RefPtr<Cairo::Context> cr) const
 
        if (_need_marks) {
                marks.clear ();
-               _metric.get_marks (marks, _lower, _upper, 50);
+               _metric->get_marks (marks, _lower, _upper, 50);
                _need_marks = false;
        }
 
@@ -142,7 +142,7 @@ Ruler::render (Rect const & area, Cairo::RefPtr<Cairo::Context> cr) const
        for (vector<Mark>::const_iterator m = marks.begin(); m != marks.end(); ++m) {
                Duple pos;
 
-               pos.x = floor ((m->position - _lower) / _metric.units_per_pixel);
+               pos.x = floor ((m->position - _lower) / _metric->units_per_pixel);
                pos.y = self.y1; /* bottom edge */
 
                if (_outline_width == 1.0) {
@@ -180,3 +180,11 @@ Ruler::render (Rect const & area, Cairo::RefPtr<Cairo::Context> cr) const
 
        /* done! */
 }
+
+void
+Ruler::set_metric (const Metric& m)
+{
+        _metric = &m;
+        _need_marks = true;
+        redraw ();
+}