Docs: create cytoscape example

docs/examples/ipycytoscape_example.rst

@@ -0,0 +1,140 @@
+====================
+IPyCytoscape Example
+====================
+
+Thebe can display output from ipycytoscape_, which could visualize graphs using Cytoscape.js_.
+
+.. _ipycytoscape: https://github.com/QuantStack/ipycytoscape 
+.. _Cytoscape.js: https://js.cytoscape.org/ 
+
+Setup
+=====
+
+Be sure to load require.js before any of your thebe activation code so that the
+Cytoscape visualizations can function:
+
+.. code-block:: html
+
+   <script src="https://cdnjs.cloudflare.com/ajax/libs/require.js/2.3.4/require.min.js"></script>
+
+
+Configure thebe and load it:
+
+.. code-block:: html
+
+   <script type="text/x-thebe-config">
+     {
+       requestKernel: true,
+       binderOptions: {
+         repo: "QuantStack/ipycytoscape",
+         ref: "1.0.4",
+         repoProvider: "github",
+       },
+     }
+   </script>
+   <script src="https://unpkg.com/thebelab@latest/lib/index.js"></script>
+
+Create a button to activate thebe:
+
+.. code-block:: html
+
+   <button id="activateButton" style="width: 120px; height: 40px; font-size: 1.5em;">
+     Activate
+   </button>
+   <script>
+   var bootstrapThebe = function() {
+       thebelab.bootstrap();
+   }
+   document.querySelector("#activateButton").addEventListener('click', bootstrapThebe)
+   </script>
+
+Now add code cells between these HTML tags:
+
+.. code-block:: html
+
+   <pre data-executable="true" data-language="python"></pre>
+
+Example
+=======
+
+Using Cytoscape, you can display a graph with several nodes. This example_ is 
+from the ipycytoscape repository and is licensed under the BSD 3-Clause License.
+
+.._example: https://github.com/QuantStack/ipycytoscape/blob/master/examples/Text%20on%20node.ipynb
+
+Press the "Activate" button below to connect to a Jupyter server:
+
+.. raw:: html
+
+   <script src="https://cdnjs.cloudflare.com/ajax/libs/require.js/2.3.4/require.min.js"></script>
+
+   <button id="activateButton" style="width: 120px; height: 40px; font-size: 1.5em;">
+     Activate
+   </button>
+   <script>
+   var bootstrapThebe = function() {
+       thebelab.bootstrap();
+   }
+   document.querySelector("#activateButton").addEventListener('click', bootstrapThebe)
+   </script>
+
+.. raw:: html
+
+   <script type="text/x-thebe-config">
+     {
+       requestKernel: true,
+       binderOptions: {
+         repo: "QuantStack/ipycytoscape",
+         ref: "1.0.4",
+         repoProvider: "github",
+       },
+     }
+   </script>
+   <script src="https://unpkg.com/thebelab@latest/lib/index.js"></script>
+
+
+.. raw:: html
+
+   <pre data-executable="true" data-language="python">
+   import ipycytoscape
+   data = {
+     'nodes': [
+         { 'data': { 'id': 'desktop', 'name': 'Cytoscape', 'href': 'http://cytoscape.org' } },
+         { 'data': { 'id': 'a', 'name': 'Grid', 'href': 'http://cytoscape.org' } },
+         { 'data': { 'id': 'b', 'name': 'Cola', 'href': 'http://cytoscape.org' } },
+         { 'data': { 'id': 'c', 'name': 'Popper', 'href': 'http://cytoscape.org' } },
+         { 'data': { 'id': 'js', 'name': 'Cytoscape.js', 'href': 'http://js.cytoscape.org' } }
+     ],
+     'edges': [
+         {'data': { 'source': 'desktop', 'target': 'js' }},
+         {'data': { 'source': 'a', 'target': 'b' }},
+         {'data': { 'source': 'a', 'target': 'c' }},
+         {'data': { 'source': 'b', 'target': 'c' }},
+         {'data': { 'source': 'js', 'target': 'b' }}
+     ]
+   }
+   cytoscapeobj = ipycytoscape.CytoscapeWidget()
+   cytoscapeobj.graph.add_graph_from_json(data)
+   cytoscapeobj.set_style([{
+     'selector': 'node',
+     'css': {
+         'content': 'data(name)',
+         'text-valign': 'center',
+         'color': 'white',
+         'text-outline-width': 2,
+         'text-outline-color': 'green',
+         'background-color': 'green'
+     }
+     },
+     {
+     'selector': ':selected',
+     'css': {
+         'background-color': 'black',
+         'line-color': 'black',
+         'target-arrow-color': 'black',
+         'source-arrow-color': 'black',
+         'text-outline-color': 'black'
+     }}
+     ])
+   cytoscapeobj
+   </pre>

docs/index.rst

@@ -88,6 +88,7 @@ see how Thebe is used.
    examples/minimal_example
    examples/ipyleaflet_example
    examples/plotly-example
+   examples/ipycytoscape_example
 
 * `Making use of Jupyter interactive widgets <_static/widgets.html>`_
 * `Status field and styling <_static/status_field.html>`_