# HG changeset patch
# User Justin Bronn <jbronn@geodjango.org>
# Date 1237486130 18000
# Node ID 87b34dce202d71ac0463f28ce316a1cf41ae21b0
# Parent  be2975906c897f2b0ce60aec5c850276e5eac83a
Added `merged` property to LineString & MultiLineString, which returns the output of the GEOS line merging operation.

--- a/django/contrib/gis/geos/collections.py	Thu Mar 19 12:33:18 2009 -0500
+++ b/django/contrib/gis/geos/collections.py	Thu Mar 19 13:08:50 2009 -0500
@@ -103,6 +103,14 @@
     _allowed = (LineString, LinearRing)
     _typeid = 5
 
+    @property
+    def merged(self):
+        """ 
+        Returns a LineString representing the line merge of this 
+        MultiLineString.
+        """ 
+        return self._topology(capi.geos_linemerge(self.ptr))         
+
 class MultiPolygon(GeometryCollection):
     _allowed = Polygon
     _typeid = 6
--- a/django/contrib/gis/geos/linestring.py	Thu Mar 19 12:33:18 2009 -0500
+++ b/django/contrib/gis/geos/linestring.py	Thu Mar 19 13:08:50 2009 -0500
@@ -126,6 +126,11 @@
         return self._listarr(self._cs.__getitem__)
 
     @property
+    def merged(self):
+        "Returns the line merge of this LineString."
+        return self._topology(capi.geos_linemerge(self.ptr))   
+
+    @property
     def x(self):
         "Returns a list or numpy array of the X variable."
         return self._listarr(self._cs.getX)
--- a/django/contrib/gis/geos/prototypes/topology.py	Thu Mar 19 12:33:18 2009 -0500
+++ b/django/contrib/gis/geos/prototypes/topology.py	Thu Mar 19 13:08:50 2009 -0500
@@ -3,9 +3,9 @@
  topological operations on geometries.
 """
 __all__ = ['geos_boundary', 'geos_buffer', 'geos_centroid', 'geos_convexhull',
-           'geos_difference', 'geos_envelope', 'geos_intersection',
-           'geos_pointonsurface', 'geos_preservesimplify', 'geos_simplify',
-           'geos_symdifference', 'geos_union', 'geos_relate']
+           'geos_difference', 'geos_envelope', 'geos_intersection', 
+           'geos_linemerge', 'geos_pointonsurface', 'geos_preservesimplify',
+           'geos_simplify', 'geos_symdifference', 'geos_union', 'geos_relate']
 
 from ctypes import c_char_p, c_double, c_int
 from django.contrib.gis.geos.libgeos import lgeos, GEOM_PTR, GEOS_PREPARE
@@ -28,6 +28,7 @@
 geos_difference = topology(lgeos.GEOSDifference, GEOM_PTR)
 geos_envelope = topology(lgeos.GEOSEnvelope)
 geos_intersection = topology(lgeos.GEOSIntersection, GEOM_PTR)
+geos_linemerge = topology(lgeos.GEOSLineMerge)
 geos_pointonsurface = topology(lgeos.GEOSPointOnSurface)
 geos_preservesimplify = topology(lgeos.GEOSTopologyPreserveSimplify, c_double)
 geos_simplify = topology(lgeos.GEOSSimplify, c_double)
--- a/django/contrib/gis/geos/tests/test_geos.py	Thu Mar 19 12:33:18 2009 -0500
+++ b/django/contrib/gis/geos/tests/test_geos.py	Thu Mar 19 13:08:50 2009 -0500
@@ -824,6 +824,17 @@
             self.assertEqual(mpoly.intersects(pnt), prep.intersects(pnt))
             self.assertEqual(c, prep.covers(pnt))
 
+    def test26_line_merge(self): 
+        "Testing line merge support"
+        ref_geoms = (fromstr('LINESTRING(1 1, 1 1, 3 3)'),
+                     fromstr('MULTILINESTRING((1 1, 3 3), (3 3, 4 2))'),
+                     )
+        ref_merged = (fromstr('LINESTRING(1 1, 3 3)'),
+                      fromstr('LINESTRING (1 1, 3 3, 4 2)'),
+                      )
+        for geom, merged in zip(ref_geoms, ref_merged):
+            self.assertEqual(merged, geom.merged)
+
 def suite():
     s = unittest.TestSuite()
     s.addTest(unittest.makeSuite(GEOSTest))