Merge pull request #634 from ocefpaf/png_repr

PNG repr

Author: ocefpaf

.travis.yml

@@ -33,7 +33,7 @@ before_install:
     - export PATH="$HOME/miniconda/bin:$PATH"
     - conda update --yes --all
     - conda config --add channels conda-forge --force
-    - conda create --yes -n TEST python=$TRAVIS_PYTHON_VERSION --file requirements.txt --file requirements-dev.txt
+    - conda create --yes -n TEST python=$TRAVIS_PYTHON_VERSION phantomjs --file requirements.txt --file requirements-dev.txt
     - source activate TEST
 
     - if [[ "$TRAVIS_PYTHON_VERSION" == "2.7" ]]; then

examples/Features.ipynb

@@ -10,6 +10,10 @@
 
 from __future__ import unicode_literals
 
+import os
+import tempfile
+import time
+
 import json
 from collections import OrderedDict
 
@@ -153,10 +157,13 @@ def __init__(self, location=None, width='100%', height='100%',
                  min_lon=-180, max_lon=180, max_bounds=True,
                  detect_retina=False, crs='EPSG3857', control_scale=False,
                  prefer_canvas=False, no_touch=False, disable_3d=False,
-                 subdomains='abc'):
+                 subdomains='abc', png_enabled=False):
         super(LegacyMap, self).__init__()
         self._name = 'Map'
         self._env = ENV
+        # Undocumented for now b/c this will be subject to a re-factor soon.
+        self._png_image = None
+        self.png_enabled = png_enabled
 
         if not location:
             # If location is not passed we center and ignore zoom.
@@ -236,8 +243,7 @@ def __init__(self, location=None, width='100%', height='100%',
         """)  # noqa
 
     def _repr_html_(self, **kwargs):
-        """Displays the Map in a Jupyter notebook.
-        """
+        """Displays the HTML Map in a Jupyter notebook."""
         if self._parent is None:
             self.add_to(Figure())
             out = self._parent._repr_html_(**kwargs)
@@ -246,6 +252,35 @@ def _repr_html_(self, **kwargs):
             out = self._parent._repr_html_(**kwargs)
         return out
 
+    def _to_png(self):
+        """Export the HTML to byte representation of a PNG image."""
+        if self._png_image is None:
+            import selenium.webdriver
+
+            with tempfile.NamedTemporaryFile(suffix=".html") as f:
+                fname = f.name
+                self.save(fname)
+                driver = selenium.webdriver.PhantomJS(service_log_path=os.path.devnull)
+                driver.get('file://{}'.format(fname))
+                driver.maximize_window()
+                # Ignore user map size.
+                driver.execute_script("document.body.style.width = '100%';")
+                # We should probably monitor if some element is present,
+                # but this is OK for now.
+                time.sleep(3)
+                png = driver.get_screenshot_as_png()
+                driver.quit()
+                self._png_image = png
+        return self._png_image
+
+    def _repr_png_(self):
+        """Displays the PNG Map in a Jupyter notebook."""
+        # The notebook calls all _repr_*_ by default.
+        # We don't want that here b/c this one is quite slow.
+        if not self.png_enabled:
+            return None
+        return self._to_png()
+
     def add_tile_layer(self, tiles='OpenStreetMap', name=None,
                        API_key=None, max_zoom=18, min_zoom=1,
                        continuous_world=False, attr=None, active=False,

folium/map.py

@@ -1,11 +1,12 @@
-pycodestyle
-pytest
-nbconvert
-jupyter_client
-ipykernel
-vincent
-geopandas
 cartopy
-gpxpy
 geographiclib
+geopandas
+gpxpy
+ipykernel
+jupyter_client
 mplleaflet
+nbconvert
+pycodestyle
+pytest
+selenium
+vincent

requirements-dev.txt

@@ -1,4 +1,4 @@
-Jinja2
 branca
-six
+jinja2
 requests
+six

requirements.txt

@@ -0,0 +1,53 @@
+# -*- coding: utf-8 -*-
+""""
+Folium _repr_*_ Tests
+---------------------
+
+"""
+
+import io
+
+import folium
+
+import pytest
+
+import PIL.Image
+
+
+@pytest.fixture
+def make_map(png_enabled=False):
+    m = folium.Map(png_enabled=png_enabled)
+    return m
+
+
+def test__repr_html_is_str():
+    html = make_map()._repr_html_()
+    assert isinstance(html, str)
+
+
+def test_valid_html():
+    html = make_map()._repr_html_()
+    parts = html.split('><')
+    assert len(parts) == 6
+    assert parts[0].lstrip('<div ') == 'style="width:100%;"'
+    assert parts[1].lstrip('<div ') == 'style="position:relative;width:100%;height:0;padding-bottom:60%;"'  # noqa
+    assert parts[2].startswith('iframe')
+    assert parts[3] == '/iframe'
+    assert parts[4] == '/div'
+    assert parts[5] == '/div>'
+
+
+def test__repr_png_no_image():
+    png = make_map(png_enabled=False)._repr_png_()
+    assert png is None
+
+
+def test__repr_png_is_bytes():
+    png = make_map(png_enabled=True)._repr_png_()
+    assert isinstance(png, bytes)
+
+
+def test_valid_png():
+    png = make_map(png_enabled=True)._repr_png_()
+    img = PIL.Image.open(io.BytesIO(png))
+    isinstance(img, PIL.PngImagePlugin.PngImageFile)