Allow removing existing transforms from context

qgis · Dec 15, 2017 · 2e2e124 · 2e2e124
1 parent 8a0bd08
commit 2e2e124
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diff --git a/python/core/qgscoordinatetransformcontext.sip b/python/core/qgscoordinatetransformcontext.sip
@@ -52,6 +52,8 @@ class QgsCoordinateTransformContext
  Adds a new ``transform`` to use when projecting coordinates from the specified source
  ``crs``.
 
+ If ``transform`` is -1, then any existing source transform for the ``crs`` will be removed.
+
  Returns true if the new transform was added successfully.
 
  \warning Transforms set using this method may be overridden by specific source/destination
@@ -81,6 +83,8 @@ class QgsCoordinateTransformContext
  Adds a new ``transform`` to use when projecting coordinates to the specified destination
  ``crs``.
 
+ If ``transform`` is -1, then any existing destination transform for the ``crs`` will be removed.
+
  Returns true if the new transform was added successfully.
 
  \warning Transforms set using this method may be overridden by specific source/destination
@@ -112,6 +116,9 @@ class QgsCoordinateTransformContext
  Adds a new ``sourceTransform`` and ``destinationTransform`` to use when projecting coordinates
  from the the specified ``sourceCrs`` to the specified ``destinationCrs``.
 
+ If either ``sourceTransform`` or ``destinationTransform`` is -1, then any existing source to destination
+ transform for the crs pair will be removed.
+
  Returns true if the new transform pair was added successfully.
 
 .. note::

diff --git a/src/core/qgscoordinatetransformcontext.cpp b/src/core/qgscoordinatetransformcontext.cpp
@@ -34,6 +34,12 @@ bool QgsCoordinateTransformContext::addSourceDatumTransform( const QgsCoordinate
   if ( !crs.isValid() )
     return false;
 
+  if ( transform == -1 )
+  {
+    mSourceDatumTransforms.remove( crs.authid() );
+    return true;
+  }
+
   mSourceDatumTransforms.insert( crs.authid(), transform );
   return true;
 }
@@ -48,6 +54,12 @@ bool QgsCoordinateTransformContext::addDestinationDatumTransform( const QgsCoord
   if ( !crs.isValid() )
     return false;
 
+  if ( transform == -1 )
+  {
+    mDestDatumTransforms.remove( crs.authid() );
+    return true;
+  }
+
   mDestDatumTransforms.insert( crs.authid(), transform );
   return true;
 }
@@ -62,6 +74,12 @@ bool QgsCoordinateTransformContext::addSourceDestinationDatumTransform( const Qg
   if ( !sourceCrs.isValid() || !destinationCrs.isValid() )
     return false;
 
+  if ( sourceTransform == -1 || destinationTransform == -1 )
+  {
+    mSourceDestDatumTransforms.remove( qMakePair( sourceCrs.authid(), destinationCrs.authid() ) );
+    return true;
+  }
+
   mSourceDestDatumTransforms.insert( qMakePair( sourceCrs.authid(), destinationCrs.authid() ), qMakePair( sourceTransform, destinationTransform ) );
   return true;
 }

diff --git a/src/core/qgscoordinatetransformcontext.h b/src/core/qgscoordinatetransformcontext.h
@@ -61,6 +61,8 @@ class CORE_EXPORT QgsCoordinateTransformContext
      * Adds a new \a transform to use when projecting coordinates from the specified source
      * \a crs.
      *
+     * If \a transform is -1, then any existing source transform for the \a crs will be removed.
+     *
      * Returns true if the new transform was added successfully.
      *
      * \warning Transforms set using this method may be overridden by specific source/destination
@@ -88,6 +90,8 @@ class CORE_EXPORT QgsCoordinateTransformContext
      * Adds a new \a transform to use when projecting coordinates to the specified destination
      * \a crs.
      *
+     * If \a transform is -1, then any existing destination transform for the \a crs will be removed.
+     *
      * Returns true if the new transform was added successfully.
      *
      * \warning Transforms set using this method may be overridden by specific source/destination
@@ -114,6 +118,9 @@ class CORE_EXPORT QgsCoordinateTransformContext
      * Adds a new \a sourceTransform and \a destinationTransform to use when projecting coordinates
      * from the the specified \a sourceCrs to the specified \a destinationCrs.
      *
+     * If either \a sourceTransform or \a destinationTransform is -1, then any existing source to destination
+     * transform for the crs pair will be removed.
+     *
      * Returns true if the new transform pair was added successfully.
      *
      * \note Transforms set using this method will override any specific source or destination

diff --git a/tests/src/python/test_qgscoordinatetransformcontext.py b/tests/src/python/test_qgscoordinatetransformcontext.py
@@ -39,6 +39,14 @@ def testSourceDatumTransforms(self):
         self.assertFalse(context.addSourceDatumTransform(QgsCoordinateReferenceSystem(), 4))
         self.assertEqual(context.sourceDatumTransforms(), {'EPSG:3111': 1, 'EPSG:28356': 3})
 
+        # removing non-existing
+        self.assertTrue(context.addSourceDatumTransform(QgsCoordinateReferenceSystem(28357), -1))
+        self.assertEqual(context.sourceDatumTransforms(), {'EPSG:3111': 1, 'EPSG:28356': 3})
+
+        # remove existing
+        self.assertTrue(context.addSourceDatumTransform(QgsCoordinateReferenceSystem(28356), -1))
+        self.assertEqual(context.sourceDatumTransforms(), {'EPSG:3111': 1})
+
         context.clear()
         self.assertEqual(context.sourceDatumTransforms(), {})
 
@@ -58,6 +66,14 @@ def testDestDatumTransforms(self):
         self.assertFalse(context.addDestinationDatumTransform(QgsCoordinateReferenceSystem(), 4))
         self.assertEqual(context.destinationDatumTransforms(), {'EPSG:3111': 1, 'EPSG:28356': 3})
 
+        # removing non-existing
+        self.assertTrue(context.addDestinationDatumTransform(QgsCoordinateReferenceSystem(28357), -1))
+        self.assertEqual(context.destinationDatumTransforms(), {'EPSG:3111': 1, 'EPSG:28356': 3})
+
+        # remove existing
+        self.assertTrue(context.addDestinationDatumTransform(QgsCoordinateReferenceSystem(28356), -1))
+        self.assertEqual(context.destinationDatumTransforms(), {'EPSG:3111': 1})
+
         context.clear()
         self.assertEqual(context.destinationDatumTransforms(), {})
 
@@ -94,6 +110,27 @@ def testSourceDestinationDatumTransforms(self):
                                                                       ('EPSG:28356', 'EPSG:4283'): (3, 4),
                                                                       ('EPSG:28356', 'EPSG:28357'): (9, 11)})
 
+        # removing non-existing
+        self.assertTrue(context.addSourceDestinationDatumTransform(QgsCoordinateReferenceSystem(28357),
+                                                                   QgsCoordinateReferenceSystem(28356), -1, -1))
+        self.assertEqual(context.sourceDestinationDatumTransforms(), {('EPSG:3111', 'EPSG:4283'): (1, 2),
+                                                                      ('EPSG:28356', 'EPSG:4283'): (3, 4),
+                                                                      ('EPSG:28356', 'EPSG:28357'): (9, 11)})
+        self.assertTrue(context.addSourceDestinationDatumTransform(QgsCoordinateReferenceSystem(3111),
+                                                                   QgsCoordinateReferenceSystem(28356), -1, -1))
+        self.assertEqual(context.sourceDestinationDatumTransforms(), {('EPSG:3111', 'EPSG:4283'): (1, 2),
+                                                                      ('EPSG:28356', 'EPSG:4283'): (3, 4),
+                                                                      ('EPSG:28356', 'EPSG:28357'): (9, 11)})
+
+        # remove existing
+        self.assertTrue(context.addSourceDestinationDatumTransform(QgsCoordinateReferenceSystem(3111),
+                                                                   QgsCoordinateReferenceSystem(4283), -1, 3))
+        self.assertEqual(context.sourceDestinationDatumTransforms(), {('EPSG:28356', 'EPSG:4283'): (3, 4),
+                                                                      ('EPSG:28356', 'EPSG:28357'): (9, 11)})
+        self.assertTrue(context.addSourceDestinationDatumTransform(QgsCoordinateReferenceSystem(28356),
+                                                                   QgsCoordinateReferenceSystem(28357), 1, -1))
+        self.assertEqual(context.sourceDestinationDatumTransforms(), {('EPSG:28356', 'EPSG:4283'): (3, 4)})
+
         context.clear()
         self.assertEqual(context.sourceDestinationDatumTransforms(), {})