def set_vector_graduated_style(vector_layer, style):
"""Set graduated QGIS vector style based on InaSAFE style dictionary.
For **opaque** a value of **0** can be used. For **fully transparent**, a
value of **100** can be used. The calling function should take care to
scale the transparency level to between 0 and 100.
:param vector_layer: A QGIS vector layer that will be styled.
:type vector_layer: QgsVectorLayer, QgsMapLayer
:param style: Dictionary of the form as in the example below
:type style: dict
:returns: None - Sets and saves style for vector_layer
Example style::
{'target_field': 'DMGLEVEL',
'style_classes':
[{'transparency': 1, 'max': 1.5, 'colour': '#fecc5c',
'min': 0.5, 'label': '[0.5 - 1.5] Low damage', 'size' : 1},
{'transparency': 55, 'max': 2.5, 'colour': '#fd8d3c',
'min': 1.5, 'label': '[1.5 - 2.5] Medium damage', 'size' : 1},
{'transparency': 80, 'max': 3.5, 'colour': '#f31a1c',
'min': 2.5, 'label': '[2.5 - 3.5] High damage', 'size' : 1}]}
.. note:: The transparency and size keys are optional. Size applies
to points only.
.. note:: you can optionally pass border_color also, if not color will be
used
.. note:: you can optionally pass data_defined also, this has to be a
dictionary of property: expressions like
{'color': 'color_hsv(%s, "pop"/%s*100, %s)' % (hue, max, val)}
"""
target_field = style['target_field']
style_classes = style['style_classes']
geometry_type = vector_layer.geometryType()
range_list = []
for style_class in style_classes:
# Transparency 100: transparent
# Transparency 0: opaque
size = 2 # mm
if 'size' in style_class:
size = style_class['size']
transparency_percent = 0
if 'transparency' in style_class:
transparency_percent = style_class['transparency']
if 'min' not in style_class:
raise StyleError('Style info should provide a "min" entry')
if 'max' not in style_class:
raise StyleError('Style info should provide a "max" entry')
try:
min_val = float(style_class['min'])
except TypeError:
raise StyleError('Class break lower bound should be a number.'
'I got %s' % style_class['min'])
try:
max_val = float(style_class['max'])
except TypeError:
raise StyleError('Class break upper bound should be a number.'
'I got %s' % style_class['max'])
color = style_class['colour']
label = style_class['label']
color = QtGui.QColor(color)
# noinspection PyArgumentList
symbol = QgsSymbolV2.defaultSymbol(geometry_type)
# We need to create a custom symbol layer as
# the border colour of a symbol can not be set otherwise
# noinspection PyArgumentList
try:
value = style_class['border_color']
border_color = QtGui.QColor(value)
except KeyError:
border_color = color
if geometry_type == QGis.Point:
symbol_layer = QgsSimpleMarkerSymbolLayerV2()
symbol_layer.setBorderColor(border_color)
symbol_layer.setSize(size)
symbol.changeSymbolLayer(0, symbol_layer)
elif geometry_type == QGis.Polygon:
symbol_layer = QgsSimpleFillSymbolLayerV2()
symbol_layer.setBorderColor(border_color)
symbol.changeSymbolLayer(0, symbol_layer)
else:
# for lines we do nothing special as the property setting
# below should give us what we require.
pass
try:
value = style_class['border_wdth']
symbol_layer.setBorderWidth(value)
except (NameError, KeyError):
# use QGIS default border size
# NameError is when symbol_layer is not defined (lines for example)
# KeyError is when borderWidth is not defined
if hasattr(symbol_layer, 'setBorderWidth') and \
geometry_type == QGis.Polygon:
symbol_layer.setBorderWidth(0)
# set data defined properties
try:
for prop, expr in style_class['data_defined'].iteritems():
symbol_layer.setDataDefinedProperty(prop, expr)
except (NameError, KeyError):
# NameError is when symbol_layer is not defined (lines for example)
# KeyError is when data_defined is not defined
pass
symbol.setColor(color)
# .. todo:: Check that vectors use alpha as % otherwise scale TS
# Convert transparency % to opacity
# alpha = 0: transparent
# alpha = 1: opaque
alpha = 1 - transparency_percent / 100.0
symbol.setAlpha(alpha)
range_renderer = QgsRendererRangeV2(min_val, max_val, symbol, label)
range_list.append(range_renderer)
renderer = QgsGraduatedSymbolRendererV2('', range_list)
renderer.setMode(QgsGraduatedSymbolRendererV2.EqualInterval)
renderer.setClassAttribute(target_field)
vector_layer.setRendererV2(renderer)
vector_layer.saveDefaultStyle()
def set_vector_categorized_style(vector_layer, style):
"""Set categorized QGIS vector style based on InaSAFE style dictionary.
For **opaque** a value of **0** can be used. For **fully transparent**, a
value of **100** can be used. The calling function should take care to
scale the transparency level to between 0 and 100.
:param vector_layer: A QGIS vector layer that will be styled.
:type vector_layer: QgsVectorLayer
:param style: Dictionary of the form as in the example below.
:type style: dict
:returns: None - Sets and saves style for vector_layer
Example::
{'target_field': 'DMGLEVEL',
'style_classes':
[{'transparency': 1, 'value': 1, 'colour': '#fecc5c',
'label': 'Low damage', 'size' : 1},
{'transparency': 55, 'value': 2, 'colour': '#fd8d3c',
'label': 'Medium damage', 'size' : 1},
{'transparency': 80, 'value': 3, 'colour': '#f31a1c',
'label': 'High damage', 'size' : 1}]}
.. note:: The transparency and size keys are optional. Size applies
to points only.
.. note:: We should change 'value' in style classes to something more
meaningful e.g. discriminant value
.. note:: you can optionally pass border_color also, if not color will be
used
.. note:: you can optionally pass border_width also, if not QGIS defaults
will be used
.. note:: you can optionally pass data_defined also, this has to be a
dictionary of property: expressions like
{'color': 'color_hsv(%s, "pop"/%s*100, %s)' % (hue, max, val)}
"""
target_field = style['target_field']
style_classes = style['style_classes']
geometry_type = vector_layer.geometryType()
category_list = []
for style_class in style_classes:
# Transparency 100: transparent
# Transparency 0: opaque
size = 2 # mm
if 'size' in style_class:
size = style_class['size']
transparency_percent = 0
if 'transparency' in style_class:
transparency_percent = style_class['transparency']
if 'value' not in style_class:
raise StyleError('Style info should provide a "value" entry')
value = style_class['value']
colour = style_class['colour']
label = style_class['label']
colour = QtGui.QColor(colour)
try:
border_color = QtGui.QColor(style_class['border_color'])
except KeyError:
border_color = colour
# noinspection PyArgumentList
symbol = QgsSymbolV2.defaultSymbol(geometry_type)
# We need to create a custom symbol layer as
# the border colour of a symbol can not be set otherwise
# noinspection PyArgumentList
if geometry_type == QGis.Point:
symbol_layer = QgsSimpleMarkerSymbolLayerV2()
symbol_layer.setBorderColor(border_color)
symbol_layer.setSize(size)
symbol.changeSymbolLayer(0, symbol_layer)
elif geometry_type == QGis.Polygon:
symbol_layer = QgsSimpleFillSymbolLayerV2()
symbol_layer.setBorderColor(border_color)
symbol.changeSymbolLayer(0, symbol_layer)
else:
# for lines we do nothing special as the property setting
# below should give us what we require.
symbol_layer = None
try:
symbol_layer.setBorderWidth(style_class['border_width'])
except (NameError, KeyError, AttributeError):
# use QGIS default border size
# NameError is when symbol_layer is not defined (lines for example)
# KeyError is when border_width is not defined
# AttributeError is when setBorderWidth is not defined
# (QgsSimpleMarkerSymbolLayerV2)
if hasattr(symbol_layer, 'setBorderWidth') and \
geometry_type == QGis.Polygon:
symbol_layer.setBorderWidth(0)
# set data defined properties
try:
for prop, expr in style_class['data_defined'].iteritems():
symbol_layer.setDataDefinedProperty(prop, expr)
except (NameError, KeyError):
# NameError is when symbol_layer is not defined (lines for example)
# KeyError is when data_defined is not defined
pass
symbol.setColor(colour)
# .. todo:: Check that vectors use alpha as % otherwise scale TS
# Convert transparency % to opacity
# alpha = 0: transparent
# alpha = 1: opaque
alpha = 1 - transparency_percent / 100.0
symbol.setAlpha(alpha)
category = QgsRendererCategoryV2(value, symbol, label)
category_list.append(category)
renderer = QgsCategorizedSymbolRendererV2('', category_list)
renderer.setClassAttribute(target_field)
vector_layer.setRendererV2(renderer)
vector_layer.saveDefaultStyle()