Nyall Dawson bd7d913379 Refine QgsFeature geometry getters/setters
All pointer based methods have been removed.

Now we have only:

  void setGeometry( const QgsGeometry& geom )

and

  QgsGeometry geometry() const

Benefits include avoiding a whole lot of tricky pointer lifetime
issues, potential memory leaks, and finally closing #777, which
has survived for over 9 years!...

Impacts on PyQGIS code:
- no more need for the messy
  g = QgsGeometry( feature.geometry() )
  workaround, just use g = feature.geometry() instead
- IMPORTANT: you can no longer test whether a feature has geometry
 using `if f.geometry():`, since QgsFeature::geometry() will
 *always* return an object. Instead, use
 `if not f.geometry().isEmpty():`, or preferably the new method
 `if not f.hasGeometry():`

Fix #777
2016-08-01 16:25:46 +10:00

103 lines
3.6 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
Buffer.py
---------------------
Date : August 2012
Copyright : (C) 2012 by Victor Olaya
Email : volayaf at gmail dot com
***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************
"""
__author__ = 'Victor Olaya'
__date__ = 'August 2012'
__copyright__ = '(C) 2012, Victor Olaya'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
from qgis.core import QgsFeature, QgsGeometry
from processing.core.ProcessingLog import ProcessingLog
from processing.tools import vector
def buffering(progress, writer, distance, field, useField, layer, dissolve,
segments):
if useField:
field = layer.fieldNameIndex(field)
outFeat = QgsFeature()
inFeat = QgsFeature()
inGeom = QgsGeometry()
outGeom = QgsGeometry()
current = 0
features = vector.features(layer)
total = 100.0 / float(len(features))
# With dissolve
if dissolve:
first = True
for inFeat in features:
attrs = inFeat.attributes()
if useField:
value = attrs[field]
else:
value = distance
inGeom = inFeat.geometry()
if inGeom.isEmpty() or inGeom.isGeosEmpty():
ProcessingLog.addToLog(ProcessingLog.LOG_WARNING, 'Feature {} has empty geometry. Skipping...'.format(inFeat.id()))
continue
if not inGeom.isGeosValid():
ProcessingLog.addToLog(ProcessingLog.LOG_WARNING, 'Feature {} has invalid geometry. Skipping...'.format(inFeat.id()))
continue
outGeom = inGeom.buffer(float(value), segments)
if first:
tempGeom = QgsGeometry(outGeom)
first = False
else:
tempGeom = tempGeom.combine(outGeom)
current += 1
progress.setPercentage(int(current * total))
outFeat.setGeometry(tempGeom)
outFeat.setAttributes(attrs)
writer.addFeature(outFeat)
else:
# Without dissolve
for inFeat in features:
attrs = inFeat.attributes()
if useField:
value = attrs[field]
else:
value = distance
inGeom = inFeat.geometry()
if inGeom.isEmpty() or inGeom.isGeosEmpty():
ProcessingLog.addToLog(ProcessingLog.LOG_WARNING, 'Feature {} has empty geometry. Skipping...'.format(inFeat.id()))
continue
if not inGeom.isGeosValid():
ProcessingLog.addToLog(ProcessingLog.LOG_WARNING, 'Feature {} has invalid geometry. Skipping...'.format(inFeat.id()))
continue
outGeom = inGeom.buffer(float(value), segments)
outFeat.setGeometry(outGeom)
outFeat.setAttributes(attrs)
writer.addFeature(outFeat)
current += 1
progress.setPercentage(int(current * total))
del writer