def create_memory_layer(self, layer):
"""Create an in-memory copy of an existing vector layer."""
data_provider = layer.dataProvider()
# create the layer path defining geometry type and reference system
geometry_type = QGis.vectorGeometryType(layer.geometryType())
crs_id = layer.crs().authid()
path = geometry_type + '?crs=' + crs_id + '&index=yes'
# create the memory layer and get a reference to the data provider
memory_layer = QgsVectorLayer(path, 'Cartogram', 'memory')
memory_layer_data_provider = memory_layer.dataProvider()
# copy all attributes from the source layer to the memory layer
memory_layer.startEditing()
memory_layer_data_provider.addAttributes(
data_provider.fields().toList())
memory_layer.commitChanges()
# copy all features from the source layer to the memory layer
for feature in data_provider.getFeatures():
memory_layer_data_provider.addFeatures([feature])
return memory_layer
def action_triggered(self, *args):
action = self.actiongroup.checkedAction()
layer = self.activelayercombo.currentLayer()
self.clear_line()
if not action:
return
if not action == self.measureaction and (
not layer or not layer.type() == QgsMapLayer.VectorLayer):
return
color = self.current_action_color
actiondata = {}
if action == self.measureaction:
self.measuredialog.show()
actiondata['mode'] = self.mode
geomtype = None
layerid = None
else:
self.measuredialog.hide()
geomtype = QGis.vectorGeometryType(layer.geometryType())
layerid = layer.id()
data = dict(action=action.objectName(),
layer=layerid,
geom=geomtype,
actiondata=actiondata,
color=color)
self.earthmine.updateAction(data)
def load_layer_features(self, point=None, layers=None):
# TODO Move this logic into the viewer and let it track it's position
if point is None and self.marker.map_pos is None:
return
if point is None:
point = self.marker.map_pos
area, units = self.distancearea()
rect = search_area(units, area, point)
if layers is None:
layers = self.visible_layers()
for layer in layers:
transform = self.coordinatetransform(layer)
# Transform the rect
source = self.canvas.mapRenderer().destinationCrs()
dest = layer.crs()
recttransform = QgsCoordinateTransform(source, dest)
rect = recttransform.transformBoundingBox(rect)
features = list(get_features_in_area(layer, rect, transform, self.canvas.mapSettings()))
geomtype = layer.geometryType()
layerdata = dict(id=layer.id(), geomtype=QGis.vectorGeometryType(geomtype))
self.viewer.load_features(layerdata, features)
def action_triggered(self, *args):
action = self.actiongroup.checkedAction()
layer = self.activelayercombo.currentLayer()
self.clear_line()
if not action:
return
if not action == self.measureaction and (not layer or not layer.type() == QgsMapLayer.VectorLayer):
return
color = self.current_action_color
actiondata = {}
if action == self.measureaction:
self.measuredialog.show()
actiondata['mode'] = self.mode
geomtype = None
layerid = None
else:
self.measuredialog.hide()
geomtype = QGis.vectorGeometryType(layer.geometryType())
layerid = layer.id()
data = dict(action=action.objectName(),
layer=layerid,
geom=geomtype,
actiondata=actiondata,
color=color)
self.earthmine.updateAction(data)
def load_layer_features(self, point=None, layers=None):
# TODO Move this logic into the viewer and let it track it's position
if point is None and self.marker.map_pos is None:
return
if point is None:
point = self.marker.map_pos
area, units = self.distancearea()
rect = search_area(units, area, point)
if layers is None:
layers = self.visible_layers()
for layer in layers:
transform = self.coordinatetransform(layer)
# Transform the rect
source = self.canvas.mapRenderer().destinationCrs()
dest = layer.crs()
recttransform = QgsCoordinateTransform(source, dest)
rect = recttransform.transformBoundingBox(rect)
features = list(
get_features_in_area(layer, rect, transform,
self.canvas.mapSettings()))
geomtype = layer.geometryType()
layerdata = dict(id=layer.id(),
geomtype=QGis.vectorGeometryType(geomtype))
self.viewer.load_features(layerdata, features)
def layer_feature_added(self, layer, featureid):
if not self.viewer:
return
feature = layer.getFeatures(QgsFeatureRequest(featureid)).next()
renderer = layer.rendererV2()
transform = self.coordinatetransform(layer)
featuredata = to_feature_data(layer.id(), feature, renderer, transform)
geomtype = layer.geometryType()
layerdata = dict(id=layer.id(), geomtype=QGis.vectorGeometryType(geomtype))
self.viewer.load_features(layerdata, featuredata)
def layer_feature_added(self, layer, featureid):
if not self.viewer:
return
feature = layer.getFeatures(QgsFeatureRequest(featureid)).next()
renderer = layer.rendererV2()
transform = self.coordinatetransform(layer)
featuredata = to_feature_data(layer.id(), feature, renderer, transform)
geomtype = layer.geometryType()
layerdata = dict(id=layer.id(),
geomtype=QGis.vectorGeometryType(geomtype))
self.viewer.load_features(layerdata, featuredata)
def to_feature_data(layerid, feature, renderer, transform):
"""
Transform the feature into the data for the viewer to use.
:param feature: QgsFeature
:param renderer:
:param transform:
:return:
"""
def polylinenodes(polyline):
nodes = []
for point in polyline:
point = transform.transform(
point, QgsCoordinateTransform.ReverseTransform)
location = dict(lat=point.y(), lng=point.x())
nodes.append(location)
return nodes
geom = feature.geometry()
geomtype = geom.type()
featuredata = []
data = dict(id=feature.id(),
layerid=layerid,
color=get_color(renderer, feature),
geomtype=QGis.vectorGeometryType(geomtype))
if geomtype == QGis.Point:
geom = geom.asPoint()
point = transform.transform(geom,
QgsCoordinateTransform.ReverseTransform)
try:
z = feature['Z']
if not z:
z = 0
except KeyError:
z = 0
location = dict(lat=point.y(), lng=point.x(), z=z)
data['nodes'] = [location]
featuredata.append(data)
elif geomtype == QGis.Line:
if geom.isMultipart():
# Copy the data for each polyline
for polyline in geom.asMultiPolyline():
newdata = copy.copy(data)
newdata['nodes'] = polylinenodes(polyline)
featuredata.append(newdata)
else:
data['nodes'] = polylinenodes(geom.asPolyline())
featuredata.append(data)
return featuredata
def to_feature_data(layerid, feature, renderer, transform):
"""
Transform the feature into the data for the viewer to use.
:param feature: QgsFeature
:param renderer:
:param transform:
:return:
"""
def polylinenodes(polyline):
nodes = []
for point in polyline:
point = transform.transform(point, QgsCoordinateTransform.ReverseTransform)
location = dict(lat=point.y(), lng=point.x())
nodes.append(location)
return nodes
geom = feature.geometry()
geomtype = geom.type()
featuredata = []
data = dict(
id=feature.id(), layerid=layerid, color=get_color(renderer, feature), geomtype=QGis.vectorGeometryType(geomtype)
)
if geomtype == QGis.Point:
geom = geom.asPoint()
point = transform.transform(geom, QgsCoordinateTransform.ReverseTransform)
try:
z = feature["Z"]
if not z:
z = 0
except KeyError:
z = 0
location = dict(lat=point.y(), lng=point.x(), z=z)
data["nodes"] = [location]
featuredata.append(data)
elif geomtype == QGis.Line:
if geom.isMultipart():
# Copy the data for each polyline
for polyline in geom.asMultiPolyline():
newdata = copy.copy(data)
newdata["nodes"] = polylinenodes(polyline)
featuredata.append(newdata)
else:
data["nodes"] = polylinenodes(geom.asPolyline())
featuredata.append(data)
return featuredata
