def fetch_and_apply_style(layer: QgsMapLayer,
url: str,
style_attr: str = '') -> Optional[str]:
"""
Fetches a QML style from the specified URL, and applies it to a layer.
@param layer: target layer to apply style to
@param url: URL for QML content
@param style_attr: optional str specifying name of existing field in layer to automatically
update classified references to
@return: Returns a str if an error occurred, or None if the fetch and apply was successful
"""
request = QgsBlockingNetworkRequest()
if request.get(QNetworkRequest(
QUrl(url))) != QgsBlockingNetworkRequest.NoError:
return 'Error while fetching QML style: {}'.format(
request.errorMessage())
reply = request.reply().content()
tmp_file = QTemporaryFile('{}/XXXXXX.qml'.format(QDir.tempPath()))
tmp_file.open()
tmp_file_name = tmp_file.fileName()
tmp_file.close()
with open(tmp_file_name, 'wt', encoding='utf8') as f:
f.write(reply.data().decode())
layer.loadNamedStyle(tmp_file_name)
if style_attr:
StyleUtils.update_class_attribute(layer, style_attr)
layer.triggerRepaint()
return None
def _set_output_layer_style(layerName: str, layer: QgsMapLayer,
alg: QgsProcessingAlgorithm,
details: 'QgsProcessingContext::LayerDetails',
context: QgsProcessingContext, parameters) -> None:
""" Set layer style
Original code is from python/plugins/processing/gui/Postprocessing.py
"""
'''If running a model, the execution will arrive here when an algorithm that is part of
that model is executed. We check if its output is a final otuput of the model, and
adapt the output name accordingly'''
outputName = details.outputName
if parameters:
expcontext = QgsExpressionContext()
scope = QgsExpressionContextScope()
expcontext.appendScope(scope)
for out in alg.outputDefinitions():
if out.name() not in parameters:
continue
outValue = parameters[out.name()]
if hasattr(outValue, "sink"):
outValue = outValue.sink.valueAsString(expcontext)[0]
else:
outValue = str(outValue)
if outValue == layerName:
outputName = out.name()
break
style = None
if outputName:
# If a style with the same name as the outputName exists
# in workdir then use it
style = os.path.join(context.workdir, outputName + '.qml')
if not os.path.exists(style):
style = RenderingStyles.getStyle(alg.id(), outputName)
LOGGER.debug("Getting style for %s: %s <%s>", alg.id(), outputName,
style)
# Get defaults styles
if style is None:
if layer.type() == QgsMapLayer.RasterLayer:
style = ProcessingConfig.getSetting(ProcessingConfig.RASTER_STYLE)
else:
if layer.geometryType() == QgsWkbTypes.PointGeometry:
style = ProcessingConfig.getSetting(
ProcessingConfig.VECTOR_POINT_STYLE)
elif layer.geometryType() == QgsWkbTypes.LineGeometry:
style = ProcessingConfig.getSetting(
ProcessingConfig.VECTOR_LINE_STYLE)
else:
style = ProcessingConfig.getSetting(
ProcessingConfig.VECTOR_POLYGON_STYLE)
if style:
LOGGER.debug("Adding style '%s' to layer %s (outputName %s)", style,
details.name, outputName)
layer.loadNamedStyle(style)
LOGGER.debug("Layer name set to %s <details name: %s>", layer.name(),
details.name)
def update_symbology(layer: QgsMapLayer,
color: typing.Tuple[int, int, int] = None,
size: float = None,
file: str = None) -> None:
assert layer, 'Layer is not defined'
if file:
assert isinstance(file, str)
(msg, noError) = layer.loadNamedStyle(file)
if not noError:
raise Exception(msg)
renderer = layer.renderer()
symbol = None
if isinstance(renderer, QgsSingleSymbolRenderer):
symbol = renderer.symbol()
elif isinstance(renderer, QgsGraduatedSymbolRenderer):
symbol = renderer.sourceSymbol()
else:
raise Exception('Unknown renderer!')
if color:
assert isinstance(
color, collections.abc.Sequence
), 'Color should be a iteratable of three numbers for Red, Green, Blue; Each of them between 0 and 255'
assert len(color) in (
3, 4
), 'There should be three numbers passed for Red, Green, Blue; Each of them between 0 and 255'
symbol.setColor(QColor.fromRgb(*color))
if size:
# For lines
if type(symbol) == QgsLineSymbol:
symbol.setWidth(size)
# For points
if type(symbol) == QgsMarkerSymbol:
symbol.setSize(size)
layer.triggerRepaint()
iface.layerTreeView().refreshLayerSymbology(layer.id())
def _load_qml_style(map_layer: qgc.QgsMapLayer, style_path: Path) -> None:
msg, status = map_layer.loadNamedStyle(str(style_path))
if not status:
raise RuntimeError(f"Problem loading '{style_path}': '{msg}'")
