def __init__(self, iface):
"""Constructor.
:param iface: An interface instance that will be passed to this class
which provides the hook by which you can manipulate the QGIS
application at run time.
:type iface: QgsInterface
"""
# Save reference to the QGIS interface
self.iface = iface
# initialize plugin directory
self.plugin_dir = os.path.dirname(__file__)
# initialize locale
locale = QSettings().value('locale/userLocale')[0:2]
locale_path = os.path.join(
self.plugin_dir,
'i18n',
'MultiRingBuffer_{}.qm'.format(locale))
if os.path.exists(locale_path):
self.translator = QTranslator()
self.translator.load(locale_path)
if qVersion() > '4.3.3':
QCoreApplication.installTranslator(self.translator)
# Create the dialog (after translation) and keep reference
self.dlg = MultiRingBufferDialog()
# Declare instance attributes
self.actions = []
self.menu = self.tr(u'&Multi Ring Buffer')
# TODO: We are going to let the user set this up in a future iteration
self.toolbar = self.iface.addToolBar(u'MultiRingBuffer')
self.toolbar.setObjectName(u'MultiRingBuffer')
class MultiRingBuffer:
"""QGIS Plugin Implementation."""
def __init__(self, iface):
"""Constructor.
:param iface: An interface instance that will be passed to this class
which provides the hook by which you can manipulate the QGIS
application at run time.
:type iface: QgsInterface
"""
# Save reference to the QGIS interface
self.iface = iface
# initialize plugin directory
self.plugin_dir = os.path.dirname(__file__)
# initialize locale
locale = QSettings().value('locale/userLocale')[0:2]
locale_path = os.path.join(
self.plugin_dir,
'i18n',
'MultiRingBuffer_{}.qm'.format(locale))
if os.path.exists(locale_path):
self.translator = QTranslator()
self.translator.load(locale_path)
if qVersion() > '4.3.3':
QCoreApplication.installTranslator(self.translator)
# Create the dialog (after translation) and keep reference
self.dlg = MultiRingBufferDialog()
# Declare instance attributes
self.actions = []
self.menu = self.tr(u'&Multi Ring Buffer')
# TODO: We are going to let the user set this up in a future iteration
self.toolbar = self.iface.addToolBar(u'MultiRingBuffer')
self.toolbar.setObjectName(u'MultiRingBuffer')
# noinspection PyMethodMayBeStatic
def tr(self, message):
"""Get the translation for a string using Qt translation API.
We implement this ourselves since we do not inherit QObject.
:param message: String for translation.
:type message: str, QString
:returns: Translated version of message.
:rtype: QString
"""
# noinspection PyTypeChecker,PyArgumentList,PyCallByClass
return QCoreApplication.translate('MultiRingBuffer', message)
def add_action(self, icon_path, text, callback, enabled_flag=True, add_to_menu=True, add_to_toolbar=True, status_tip=None, whats_this=None, parent=None):
icon = QIcon(icon_path)
action = QAction(icon, text, parent)
action.triggered.connect(callback)
action.setEnabled(enabled_flag)
if status_tip is not None:
action.setStatusTip(status_tip)
if whats_this is not None:
action.setWhatsThis(whats_this)
if add_to_toolbar:
self.toolbar.addAction(action)
if add_to_menu:
self.iface.addPluginToVectorMenu(
self.menu,
action)
self.actions.append(action)
return action
def initGui(self):
"""Create the menu entries and toolbar icons inside the QGIS GUI."""
icon_path = ':/plugins/Multi_Ring_Buffer/icon.svg'
self.add_action(icon_path, text=self.tr(u'Multi Ring Buffer'), callback=self.run, parent=self.iface.mainWindow())
def unload(self):
"""Removes the plugin menu item and icon from QGIS GUI."""
for action in self.actions:
self.iface.removePluginVectorMenu(self.tr(u'&Multi Ring Buffer'), action)
self.iface.removeToolBarIcon(action)
def dissolve(self, input_feats):
# Function to dissolve input features to allow for buffering of multiple features
feats = []
# Create and empty list of features and add all features to it.
# We use feature 0 later and this ensures it exits.
for each_feat in input_feats:
feats.append(each_feat)
# Do not run if geometry is empty, produce an error instead.
if len(feats) > 0:
# Need to create empty geometry to hold the dissolved features, we use the first feature to seed it.
# Combine require a non-empty geometry to work (I could not get it to work).
feat = feats[0]
dissolved_geom = QgsGeometry()
dissolved_geom = feat.geometry()
# Progress bar for dissolving
progressMessageBar = self.iface.messageBar().createMessage("Dissolving...")
progress = QProgressBar()
progress.setAlignment(Qt.AlignLeft|Qt.AlignVCenter)
progressMessageBar.layout().addWidget(progress)
self.iface.messageBar().pushWidget(progressMessageBar, self.iface.messageBar().INFO)
maximum_progress = len(feats)
progress.setMaximum(maximum_progress)
i = 0
# Run through the features and dissolve them all.
for each_feat in feats:
geom = each_feat.geometry()
dissolved_geom = geom.combine(dissolved_geom)
i = i + 1
progress.setValue(i + 1)
return_f = QgsFeature()
return_f.setGeometry(dissolved_geom)
self.iface.messageBar().clearWidgets()
return return_f
else:
QMessageBox.warning(self.iface.mainWindow(), "Warning",
"No features to dissolve.", QMessageBox.Ok)
return input_feats
def run(self):
# Plugin uses selected layer, hope to add layer selection later.
active_vl = self.iface.activeLayer()
# We check for selected features to auto-populate the "use selected feature" box in the dialog.
sel_feats = ''
if active_vl is not None:
sel_feats = active_vl.selectedFeatures()
result = 0
"""Run method that performs all the real work"""
# Logic if to run the dialog
if active_vl is None:
sel_feats = ''
QMessageBox.warning(self.iface.mainWindow(), "Warning",
"No layer selected.", QMessageBox.Ok)
result = 0
elif active_vl.type() == QgsMapLayer.RasterLayer:
sel_feats = ''
QMessageBox.warning(self.iface.mainWindow(), "Warning",
"Raster layer selected.", QMessageBox.Ok)
result = 0
elif active_vl.type() == QgsMapLayer.PluginLayer:
sel_feats = ''
QMessageBox.warning(self.iface.mainWindow(), "Warning",
"Plugin layer selected, please save as a regular layer and try again.", QMessageBox.Ok)
result = 0
elif active_vl is not None:
self.dlg.populatedialogue(active_vl.name())
if len(sel_feats) == 0:
# If selected layer has selected features populate the box.
# If not make it impossible to populate the box.
self.dlg.selectedfeats(0)
else:
self.dlg.selectedfeats(1)
self.dlg.show()
result = self.dlg.exec_()
else:
sel_feats = ''
QMessageBox.warning(self.iface.mainWindow(), "Warning",
"Could not process layer.", QMessageBox.Ok)
result = 0
# If ok was clicked in the dialog, continue:
if result == 1:
buffer_crs_object = self.iface.activeLayer().crs()
# Check the current CRS of the layer
buffer_crs = buffer_crs_object.authid()
# Apply that to the created layer if recognised
buffer_input_crs = "Polygon?crs=%s" % buffer_crs
# Create empty memory vector layer for buffers
layer_name = active_vl.name()
vl = QgsVectorLayer(buffer_input_crs, "%s_MultiRingBuffer" % layer_name, "memory")
vl_pr = vl.dataProvider()
# Distance feature for buffer distance
vl_pr.addAttributes([QgsField("distance", QVariant.String)])
vl.updateFields()
# Switch between sequential and central buffer styles.
# A toggle was added, but it seems too complex of a question for most users.
buffer_style = "sequential"
#if self.dlg.ui.central.isChecked():
# buffer_style = "central"
#else:
# buffer_style = "sequential"
# Inputs from the dialog:
dissolve_test = self.dlg.ui.dissovle_button_2.isChecked()
if dissolve_test == 0:
dissolve_bool = 0
else:
dissolve_bool = 1
segments_to_approximate = self.dlg.ui.segmentsToApproximate.value()
num_of_rings = self.dlg.ui.numberOfRings.value()
buffer_distance = self.dlg.ui.bufferDistance.value()
use_sel_feats_test = self.dlg.ui.selectedfeats.isChecked()
if use_sel_feats_test == 0:
use_sel_feats = 0
else:
use_sel_feats = 1
# We use "sel_feats" to populate a box in the dialog, but if all features wanted, we need to re-populate it
# with all the features in the layer.
if use_sel_feats == 0:
iterate = active_vl.getFeatures()
sel_feats = []
for feature in iterate:
sel_feats.append(feature)
# Dissolve the features if selected.
if dissolve_bool == 1:
sel2feats = []
add_feat = self.dissolve(sel_feats)
# Our buffer loops require a list (as sel_feats originally is), so we append the features to a list.
sel2feats.append(add_feat)
else:
sel2feats = sel_feats
# Progress bar.
progressMessageBar = self.iface.messageBar().createMessage("Buffering...")
progress = QProgressBar()
progress.setAlignment(Qt.AlignLeft|Qt.AlignVCenter)
progressMessageBar.layout().addWidget(progress)
self.iface.messageBar().pushWidget(progressMessageBar, self.iface.messageBar().INFO)
maximum_progress = len(sel2feats) * num_of_rings
progress.setMaximum(maximum_progress)
i = 0
# Run if there are features in the layer
if len(sel_feats) > 0:
# Buffer a feature then buffer the buffer (used)
if buffer_style == "sequential":
new_buff_feats = []
distance = buffer_distance
while num_of_rings > 0:
to_buffer = []
for each_feat in sel2feats:
geom = each_feat.geometry()
buff = geom.buffer(buffer_distance, segments_to_approximate)
new_f = QgsFeature()
new_f.setGeometry(buff)
to_buffer.append(new_f)
new_f_geom = new_f.geometry()
new_f_clipped = new_f_geom.difference(geom)
new_f2 = QgsFeature()
new_f2.setGeometry(new_f_clipped)
new_f2.setAttributes([distance])
new_buff_feats.append(new_f2)
i = i + 1
progress.setValue(i + 1)
sel2feats = to_buffer
num_of_rings = num_of_rings - 1
distance = distance + buffer_distance
vl_pr.addFeatures(new_buff_feats)
QgsMapLayerRegistry.instance().addMapLayer(vl)
# Sequential buffers of the original feature with larger buffers
if buffer_style == "central":
orig_buffer_distance = buffer_distance
buffered = []
for each_feat in sel2feats:
num_to_buffer = num_of_rings
to_clip = each_feat.geometry()
buffer_distance = orig_buffer_distance
while num_to_buffer > 0:
geom = each_feat.geometry()
buff = geom.buffer(buffer_distance, segments_to_approximate)
new_f = QgsFeature()
new_f_clipped = buff.difference(to_clip)
new_f.setGeometry(new_f_clipped)
new_f.setAttributes([buffer_distance])
buffered.append(new_f)
buffer_distance = buffer_distance + orig_buffer_distance
num_to_buffer = num_to_buffer - 1
to_clip = to_clip.combine(buff)
i = i + 1
progress.setValue(i + 1)
vl_pr.addFeatures(buffered)
QgsMapLayerRegistry.instance().addMapLayer(vl)
self.iface.messageBar().clearWidgets()
