def PresetColorRamp_to_QgsColorRamp(ramp: PresetColorRamp):
"""
Converts a PresetColorRamp to a QgsColorRamp
"""
colors = [symbol_color_to_qcolor(c) for c in ramp.colors]
out = QgsPresetSchemeColorRamp(colors)
return out
def get_quantile_ramp_item_list(layer):
"""
Returns the quantile ramp item list and overrides the ramp items
labels with our custom categories.
We use a dummy shader function to help us with the quantile
classification
"""
stats = layer.dataProvider().bandStatistics(
1, QgsRasterBandStats.All)
min_val = stats.minimumValue
max_value = stats.maximumValue
colors = [
QColor('#4c724b'),
QColor('#89a167'),
QColor('#d9d98d'),
QColor('#b08d64'),
QColor('#8a514a')
]
dummy_shader = QgsColorRampShader(
minimumValue=min_val,
maximumValue=max_val,
colorRamp=QgsPresetSchemeColorRamp(colors=colors),
type=QgsColorRampShader.Discrete,
classificationMode=QgsColorRampShader.Quantile)
dummy_shader.classifyColorRamp(classes=5,
band=1,
input=layer.dataProvider())
labels = ['Very low', 'Low', 'Moderate', 'High', 'Very high']
ramp_items = []
for i, ramp_item in enumerate(dummy_shader.colorRampItemList()):
ramp_item.label = labels[i]
ramp_items.append(ramp_item)
return ramp_items
def testQgsPresetSchemeColorRamp(self):
# test preset color ramp
r = QgsPresetSchemeColorRamp()
self.assertEqual(r.type(), 'preset')
# should be forced to have at least one color
self.assertEqual(r.count(), 1)
# test getter/setter
r = QgsPresetSchemeColorRamp([QColor(255, 0, 0), QColor(0, 255, 0), QColor(0, 0, 255), QColor(0, 0, 0)])
self.assertEqual(r.colors(), [QColor(255, 0, 0), QColor(0, 255, 0), QColor(0, 0, 255), QColor(0, 0, 0)])
r.setColors([(QColor(255, 0, 0), '1'), (QColor(0, 255, 0), '2')])
self.assertEqual(r.colors(), [QColor(255, 0, 0), QColor(0, 255, 0)])
self.assertEqual(r.fetchColors(), [(QColor(255, 0, 0), '1'), (QColor(0, 255, 0), '2')])
# test value
r = QgsPresetSchemeColorRamp([QColor(255, 0, 0), QColor(0, 255, 0), QColor(0, 0, 255), QColor(0, 0, 0), QColor(255, 255, 255)])
self.assertEqual(r.value(0), 0)
self.assertEqual(r.value(1), 0.25)
self.assertEqual(r.value(2), 0.5)
self.assertEqual(r.value(3), 0.75)
self.assertEqual(r.value(4), 1)
self.assertTrue(not r.color(-1).isValid())
self.assertTrue(not r.color(5).isValid())
# test generated colors
for i in range(5):
self.assertEqual(r.color(r.value(i)), r.colors()[i])
# test creating from properties
r.setColors([(QColor(255, 0, 0), '1'), (QColor(0, 255, 0), '2')])
props = r.properties()
fromProps = QgsPresetSchemeColorRamp.create(props)
self.assertEqual(fromProps.count(), 2)
self.assertEqual(fromProps.fetchColors(), r.fetchColors())
# test cloning ramp
cloned = r.clone()
self.assertEqual(cloned.count(), 2)
self.assertEqual(cloned.fetchColors(), r.fetchColors())
# test invert function
r.invert()
self.assertEqual(r.color(0), QColor(0, 255, 0))
self.assertEqual(r.color(1), QColor(255, 0, 0))
def getPresetGnYlRd():
colors = [redCol, yellowCol, greenCol]
colorRamp = QgsPresetSchemeColorRamp(colors=colors)
return colorRamp
def rat_classify(raster_layer, band, rat, criteria, ramp=None, feedback=QgsRasterBlockFeedback()) -> list:
"""Classify a raster.
Note: cannot use a custom shader function QgsColorRampShader subclass because it's lost in
the clone stage of the renderer.
:param raster_layer: the raster layer to classify
:type raster_layer: QgsRasterLayer
:param band: band number (1-based)
:type band: int
:param rat: the RAT data
:type rat: dict
:param criteria: key of the RAT to be used for labels
:type criteria: str
:param ramp: optional color ramp, defaults to QgsRandomColorRamp()
:type ramp: QgsColorRamp, optional
:param feedback: QGIS feedback object, defaults to QgsRasterBlockFeedback()
:type feedback: QgsRasterBlockFeedback, optional
:return: unique row indexes for legend items (1-based)
:rtype: list
"""
has_color = rat.has_color
labels = rat.data[criteria]
label_colors = {}
unique_indexes = []
# QGIS >= 3.18 for first element label
if Qgis.QGIS_VERSION_INT >= 31800:
base_legend_row_index = 1
else:
base_legend_row_index = 0
if rat.thematic_type == gdal.GRTT_THEMATIC:
# Use paletted
rat_log('Using paletted renderer')
value_column_name = rat.field_name(gdal.GFU_MinMax)
values = rat.data[value_column_name]
is_integer = isinstance(values[0], int)
if ramp is None:
ramp = QgsRandomColorRamp()
classes = QgsPalettedRasterRenderer.classDataFromRaster(
raster_layer.dataProvider(), band, ramp, feedback)
row_index = base_legend_row_index
for klass in classes:
value = int(klass.value) if is_integer else klass.value
try:
index = values.index(value)
except ValueError: # NODATA
rat_log(
f'Value {value} not found in RAT, assuming NODATA', Qgis.Warning)
data_provider = raster_layer.dataProvider()
if not data_provider.userNoDataValuesContains(band, value):
nodata = data_provider.userNoDataValues(band)
nodata_value = QgsRasterRange(value, value)
nodata.append(nodata_value)
data_provider.setUserNoDataValue(band, nodata)
continue
klass.label = str(labels[index])
if klass.label not in label_colors:
unique_indexes.append(row_index)
if has_color:
label_colors[klass.label] = rat.data[RAT_COLOR_HEADER_NAME][index]
else:
label_colors[klass.label] = klass.color
klass.color = label_colors[klass.label]
row_index += 1
renderer = QgsPalettedRasterRenderer(
raster_layer.dataProvider(), band, classes)
else: # ranges
rat_log('Using singleband pseudocolor renderer')
min_value_column = rat.field_name(gdal.GFU_Min)
max_value_column = rat.field_name(gdal.GFU_Max)
# Collect unique values and colors from criteria
row_index = base_legend_row_index
unique_labels = []
for index in range(len(labels)):
label = labels[index]
if label not in unique_labels:
unique_labels.append(label)
unique_indexes.append(row_index)
# Collect color
if has_color:
label_colors[label] = rat.data[RAT_COLOR_HEADER_NAME][index]
row_index += 1
# Assign colors from random ramp
if not has_color:
ramp = QgsRandomColorRamp()
ramp.setTotalColorCount(len(unique_labels))
i = 0
for index in unique_indexes:
label_colors[labels[index]] = ramp.color(ramp.value(i))
i += 1
# Create values for the ramp
# Collect colors for all classes
colors = []
for label in labels:
colors.append(label_colors[label])
ramp = QgsPresetSchemeColorRamp(colors)
minValue = min(rat.data[min_value_column])
maxValue = max(rat.data[max_value_column])
assert minValue < maxValue, "Min Value must be lower than Max Value"
shader = QgsRasterShader(minValue, maxValue)
colorRampShaderFcn = QgsColorRampShader(
minValue, maxValue, ramp)
colorRampShaderFcn.setClip(True)
colorRampShaderFcn.setColorRampType(QgsColorRampShader.Discrete)
items = []
row = 0
for label in labels:
items.append(QgsColorRampShader.ColorRampItem(
rat.data[max_value_column][row], label_colors[label], label))
row += 1
colorRampShaderFcn.setColorRampItemList(items)
try: # for older QGIS
colorRampShaderFcn.legendSettings().setUseContinuousLegend(False)
except AttributeError:
rat_log(
'QgsColorRampShader.legendSettings().setUseContinuousLegend() is not supported on ths QGIS version.', Qgis.Warning)
shader.setRasterShaderFunction(colorRampShaderFcn)
renderer = QgsSingleBandPseudoColorRenderer(
raster_layer.dataProvider(), band, shader)
raster_layer.setRenderer(renderer)
raster_layer.triggerRepaint()
return unique_indexes
