Adicionar Interatividade ao Histograma
Em seguida, adicionaremos interatividade ao histograma modificando o código SVG usando ECMAScript (JavaScript). Adicionaremos atributos aos objetos patch e texto usando o método set(). Também criaremos uma variável global container que armazena os IDs dos patches pertencentes a cada histograma. Finalmente, criaremos uma função toggle_hist() que define o atributo de visibilidade de todos os patches de cada histograma e a opacidade do próprio marcador.
from io import BytesIO
import json
import xml.etree.ElementTree as ET
plt.rcParams['svg.fonttype'] = 'none'
## Save SVG in a fake file object
f = BytesIO()
plt.savefig(f, format="svg")
## Create XML tree from the SVG file
tree, xmlid = ET.XMLID(f.getvalue())
## Add attributes to the patch objects
for i, t in enumerate(leg.get_patches()):
el = xmlid[f'leg_patch_{i}']
el.set('cursor', 'pointer')
el.set('onclick', "toggle_hist(this)")
## Add attributes to the text objects
for i, t in enumerate(leg.get_texts()):
el = xmlid[f'leg_text_{i}']
el.set('cursor', 'pointer')
el.set('onclick', "toggle_hist(this)")
## Create script defining the function `toggle_hist`
script = """
<script type="text/ecmascript">
<![CDATA[
var container = %s
function toggle(oid, attribute, values) {
/* Toggle the style attribute of an object between two values.
Parameters
----------
oid : str
Object identifier.
attribute : str
Name of style attribute.
values : [on state, off state]
The two values that are switched between.
*/
var obj = document.getElementById(oid);
var a = obj.style[attribute];
a = (a == values[0] || a == "") ? values[1] : values[0];
obj.style[attribute] = a;
}
function toggle_hist(obj) {
var num = obj.id.slice(-1);
toggle('leg_patch_' + num, 'opacity', [1, 0.3]);
toggle('leg_text_' + num, 'opacity', [1, 0.5]);
var names = container['hist_'+num]
for (var i=0; i < names.length; i++) {
toggle(names[i], 'opacity', [1, 0])
};
}
]]>
</script>
""" % json.dumps(hist_patches)
## Add a transition effect
css = tree.find('.//{http://www.w3.org/2000/svg}style')
css.text = css.text + "g {-webkit-transition:opacity 0.4s ease-out;" + \
"-moz-transition:opacity 0.4s ease-out;}"
## Insert the script and save to file
tree.insert(0, ET.XML(script))
ET.ElementTree(tree).write("svg_histogram.svg")
