def syntheticFeatureSelection(self, startPoint: QgsPointXY,
endPoint: QgsPointXY,
modifiers: Qt.KeyboardModifiers) -> None:
if startPoint is None or endPoint is None:
raise Exception(
'Something went very bad, unable to create selection without start or end point'
)
assert self.simplifiedSegmentsLayer
if self.selectionMode != SelectionModes.LINES:
self.simplifiedSegmentsLayer.removeSelection()
# check the Shift and Control modifiers to reproduce the navive selection
if modifiers & Qt.ShiftModifier:
selectBehaviour = QgsVectorLayer.AddToSelection
elif modifiers & Qt.ControlModifier:
selectBehaviour = QgsVectorLayer.RemoveFromSelection
else:
selectBehaviour = QgsVectorLayer.SetSelection
if startPoint.x() == endPoint.x() and startPoint.y() == endPoint.y():
tolerance = QgsTolerance.defaultTolerance(iface.activeLayer(),
QgsMapSettings())
tolerance = tolerance * self.canvas.mapUnitsPerPixel()
startPoint = QgsPointXY(startPoint.x() - tolerance,
startPoint.y() - tolerance)
endPoint = QgsPointXY(endPoint.x() + tolerance,
endPoint.y() + tolerance)
lines = None
rect = QgsRectangle(startPoint, endPoint)
if self.selectionMode == SelectionModes.ENCLOSING:
lines = self.getLinesSelectionModeEnclosing(selectBehaviour, rect)
elif self.selectionMode == SelectionModes.LINES:
lines = self.getLinesSelectionModeLines(selectBehaviour, rect)
elif self.selectionMode == SelectionModes.NODES:
lines = self.getLinesSelectionModeVertices(selectBehaviour, rect)
if lines is None:
return
else:
raise Exception(
'Wrong selection mode selected, should never be the case')
if not len(lines):
show_info(__('No results found!'))
self.deleteAllCandidates()
return
if not self.addCandidates(lines):
show_info(__('Unable to add candidates'))
return
def layer_tolerance(map_canvas, layer):
"""Functions finds out default tolerance from qgis settings.
Required value (of qgis settings) is returned by QgsTolerance.defaultTolerance(...) calling.
If returned value equals 0.0, we ignore it and calculate our own tolerance from current extent width.
@return default tolerance
"""
qgis_tolerance = QgsTolerance.defaultTolerance(
layer, map_canvas.mapRenderer())
if qgis_tolerance == 0.0:
extent = map_canvas.extent()
w = extent.xMaximum() - extent.xMinimum()
return w / 220
return qgis_tolerance
