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#!/usr/bin/env python
import mapnik
import sys
import os.path
from compare import compare, summary
dirname = os.path.dirname(__file__)
class MyText(mapnik.FormattingNode):
def __init__(self):
mapnik.FormattingNode.__init__(self)
self.expr = mapnik.Expression("[name]")
self.expr_nr = mapnik.Expression("[nr]")
def apply(self, properties, feature, output):
colors = [mapnik.Color('red'),
mapnik.Color('green'),
mapnik.Color('blue')]
text = self.expr.evaluate(feature)
if int(feature['nr']) > 5:
i = 0
my_properties = mapnik.CharProperties(properties)
for char in text:
my_properties.fill = colors[i % len(colors)]
output.append(my_properties, char)
i += 1
else:
output.append(properties, text)
def add_expressions(self, output):
output.insert(self.expr)
output.insert(self.expr_nr)
class IfElse(mapnik.FormattingNode):
def __init__(self, condition, if_node, else_node):
mapnik.FormattingNode.__init__(self)
self.condition = mapnik.Expression(condition)
self.if_node = if_node
self.else_node = else_node
def apply(self, properties, feature, output):
c = self.condition.evaluate(feature)
if c:
self.if_node.apply(properties, feature, output)
else:
self.else_node.apply(properties, feature, output)
def add_expressions(self, output):
output.insert(self.condition)
self.if_node.add_expressions(output)
self.else_node.add_expressions(output)
m = mapnik.Map(600, 100)
m.background = mapnik.Color('white')
text = mapnik.TextSymbolizer()
text.placements.defaults.displacement = (0, 5)
text.placements.defaults.format.face_name = 'DejaVu Sans Book'
point = mapnik.PointSymbolizer()
rule = mapnik.Rule()
rule.symbols.append(text)
rule.symbols.append(point)
style = mapnik.Style()
style.rules.append(rule)
m.append_style('Style', style)
layer = mapnik.Layer('Layer')
layer.datasource = mapnik.Datasource(**{file=os.path.join(dirname,"data/points.csv"))
layer.styles.append('Style')
m.layers.append(layer)
bbox = mapnik.Box2d(-0.05, -0.01, 0.95, 0.01)
m.zoom_to_box(bbox)
formatnode = mapnik.FormattingFormat()
formatnode.child = mapnik.FormattingText("[name]")
formatnode.fill = mapnik.Color("green")
format_trees = [
('TextNode', mapnik.FormattingText("[name]")),
('MyText', MyText()),
('IfElse', IfElse("[nr] != 5",
mapnik.FormattingText("[name]"),
mapnik.FormattingText("'SPECIAL!'"))),
('Format', formatnode),
('List', mapnik.FormattingList([
mapnik.FormattingText("[name]+'\n'"),
MyText()
])
)
]
for format_tree in format_trees:
text.placements.defaults.format_tree = format_tree[1]
mapnik.render_to_file(m, os.path.join(dirname,"images", 'python-%s.png' % format_tree[0]), 'png')
compare(os.path.join(dirname,"images", 'python-%s.png' % format_tree[0]),
os.path.join(dirname,"images", 'python-%s-reference.png' % format_tree[0])
)
summary()
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