X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fcanvas%2Farrow.cc;h=1f8f5b44ec19ea2a66e36f6abd68121e8baa775d;hb=860ffed6d17c6eaa3d947b905c1c1118fb147924;hp=2e9557e1796ec1038dd963a3c8003f94ff6e19a2;hpb=f17b84ad10eef7249c49a0e9d94b259ddbb87345;p=ardour.git

diff --git a/libs/canvas/arrow.cc b/libs/canvas/arrow.cc
index 2e9557e179..1f8f5b44ec 100644
--- a/libs/canvas/arrow.cc
+++ b/libs/canvas/arrow.cc
@@ -34,11 +34,21 @@ using namespace ArdourCanvas;
 /** Construct an Arrow.
  *  @param parent Parent canvas group.
  */
-Arrow::Arrow (Group* parent)
-	: Group (parent)
+Arrow::Arrow (Canvas* c)
+	: Container (c)
 {
-	assert (parent);
+	setup ();
+}
+
+Arrow::Arrow (Item* parent)
+	: Container (parent)
+{
+	setup ();
+}
 
+void
+Arrow::setup ()
+{
 	/* set up default arrow heads at each end */
 	for (int i = 0; i < 2; ++i) {
 		_heads[i].polygon = new Polygon (this);
@@ -48,11 +58,29 @@ Arrow::Arrow (Group* parent)
 		setup_polygon (i);
 		CANVAS_DEBUG_NAME (_heads[i].polygon, string_compose ("arrow head %1", i));
 	}
-	
+
 	_line = new Line (this);
 	CANVAS_DEBUG_NAME (_line, "arrow line");
 }
 
+void
+Arrow::compute_bounding_box () const
+{
+	/* Compute our bounding box manually rather than using the default
+	   container algorithm, since having the bounding box with origin other
+	   than zero causes strange problems for mysterious reasons. */
+
+	const double outline_pad = 0.5 + (_line->outline_width() / 2.0);
+	const double head_width  = std::max(_heads[0].width, _heads[1].width);
+
+	_bounding_box = Rect(0,
+	                     0,
+	                     _line->x1() + (head_width / 2.0) + outline_pad,
+	                     _line->y1());
+
+	_bounding_box_dirty = false;
+}
+
 /** Set whether to show an arrow head at one end or other
  *  of the line.
  *  @param which 0 or 1 to specify the arrow head to set up.
@@ -62,9 +90,9 @@ void
 Arrow::set_show_head (int which, bool show)
 {
 	assert (which == 0 || which == 1);
-	
+
 	begin_change ();
-	
+
 	if (!show) {
 		delete _heads[which].polygon;
 		_heads[which].polygon = 0;
@@ -86,7 +114,7 @@ void
 Arrow::set_head_outward (int which, bool outward)
 {
 	assert (which == 0 || which == 1);
-	
+
 	begin_change ();
 
 	_heads[which].outward = outward;
@@ -104,9 +132,9 @@ void
 Arrow::set_head_height (int which, Distance height)
 {
 	assert (which == 0 || which == 1);
-	
+
 	begin_change ();
-	
+
 	_heads[which].height = height;
 
 	setup_polygon (which);
@@ -122,9 +150,9 @@ void
 Arrow::set_head_width (int which, Distance width)
 {
 	assert (which == 0 || which == 1);
-	
+
 	begin_change ();
-	
+
 	_heads[which].width = width;
 
 	setup_polygon (which);
@@ -145,6 +173,7 @@ Arrow::set_outline_width (Distance width)
 	if (_heads[1].polygon) {
 		_heads[1].polygon->set_outline_width (width);
 	}
+	_bounding_box_dirty = true;
 }
 
 /** Set the x position of our line.
@@ -160,7 +189,7 @@ Arrow::set_x (Coord x)
 			_heads[i].polygon->set_x_position (x - _heads[i].width / 2);
 		}
 	}
-		
+	_bounding_box_dirty = true;
 }
 
 /** Set the y position of end 0 of our line.
@@ -173,6 +202,7 @@ Arrow::set_y0 (Coord y0)
 	if (_heads[0].polygon) {
 		_heads[0].polygon->set_y_position (y0);
 	}
+	_bounding_box_dirty = true;
 }
 
 /** Set the y position of end 1 of our line.
@@ -185,6 +215,7 @@ Arrow::set_y1 (Coord y1)
 	if (_heads[1].polygon) {
 		_heads[1].polygon->set_y_position (y1 - _heads[1].height);
 	}
+	_bounding_box_dirty = true;
 }
 
 /** @return x position of our line in pixels (in our coordinate system) */
@@ -208,7 +239,7 @@ void
 Arrow::setup_polygon (int which)
 {
 	assert (which == 0 || which == 1);
-	
+
 	Points points;
 
 	if ((which == 0 && _heads[which].outward) || (which == 1 && !_heads[which].outward)) {