def get_transformed_layers(self):
transformed_layers = []
for background_layer in self.layers_to_transform:
_t = QgsWkbTypes.displayString(background_layer.wkbType())
result_layer = QgsVectorLayer(
"{}?crs={}".format(_t,
background_layer.crs().authid()),
"result_cartogram", "memory")
features_to_add = []
result_layer.setCrs(background_layer.crs())
pr_result_layer = result_layer.dataProvider()
pr_result_layer.addAttributes(background_layer.fields().toList())
result_layer.updateFields()
for ix, ft in enumerate(background_layer.getFeatures()):
ref_geom = ft.geometry()
ref_coords = ref_geom.__geo_interface__['coordinates']
if ref_geom.__geo_interface__['type'] == 'LineString':
new_geom = QgsGeometry.fromPolyLineXY([
QgsPointXY(*self.g._interp_point(
*ref_coords[ix_coords]))
for ix_coords in range(len(ref_coords))
])
elif ref_geom.__geo_interface__['type'] == 'MultiLineString':
lines = []
for ix_line in range(len(ref_coords)):
lines.append([
QgsPointXY(*self.g._interp_point(
*ref_coords[ix_line][ix_coords]))
for ix_coords in range(len(ref_coords[ix_line]))
])
new_geom = QgsGeometry.fromMultiPolylineXY(lines)
elif ref_geom.__geo_interface__['type'] == 'Polygon':
rings = []
for ix_ring in range(len(ref_coords)):
rings.append([
QgsPointXY(*self.g._interp_point(
*ref_coords[ix_ring][ix_coords]))
for ix_coords in range(len(ref_coords[ix_ring]))
])
new_geom = QgsGeometry.fromPolygonXY(rings)
elif ref_geom.__geo_interface__['type'] == 'MultiPolygon':
polys = []
for ix_poly in range(len(ref_coords)):
rings = []
for ix_ring in range(len(ref_coords[ix_poly])):
rings.append([
QgsPointXY(*self.g._interp_point(
*ref_coords[ix_poly][ix_ring][ix_coords]))
for ix_coords in range(
len(ref_coords[ix_poly][ix_ring]))
])
polys.append(rings)
new_geom = QgsGeometry.fromMultiPolygonXY(polys)
else:
self.status.emit('Geometry type error')
continue
feature = QgsFeature()
feature.setGeometry(new_geom)
feature.setAttributes(ft.attributes())
features_to_add.append(feature)
self.progress.emit(1)
pr_result_layer.addFeatures(features_to_add)
result_layer.updateExtents()
transformed_layers.append(result_layer)
return transformed_layers
