Add examples to README, add dependencies for video, bump version to 1.2

DESCRIPTION.rst

···
-Most common SVG tags are supported and others can easily be added by
-writing a small subclass of ``DrawableBasicElement`` or
-``DrawableParentElement``.
-
-Install
-=======
-
-drawSvg is available on PyPI:
-
-::
-
-    $ pip3 install drawSvg
-
-Examples
-========
-
-Basic drawing elements
-~~~~~~~~~~~~~~~~~~~~~~
-
-.. code:: python
-
-    d = draw.Drawing(200, 100, origin='center')
-
-    d.append(draw.Lines(-80, -45,
-                        70, -49,
-                        95, 49,
-                        -90, 40,
-                        close=False,
-                fill='#eeee00',
-                stroke='black'))
-
-    d.append(draw.Rectangle(0,0,40,50, fill='#1248ff'))
-    d.append(draw.Circle(-40, -10, 30,
-                fill='red', stroke_width=2, stroke='black'))
-
-    p = draw.Path(stroke_width=2, stroke='green',
-                  fill='black', fill_opacity=0.5)
-    p.M(-30,5)  # Start path at point (-30, 5)
-    p.l(60,30)  # Draw line to (60, 30)
-    p.h(-70)    # Draw horizontal line to x=-70
-    p.Z()       # Draw line to start
-    d.append(p)
-
-    d.append(draw.ArcLine(60,-20,20,60,270,
-                stroke='red', stroke_width=5, fill='red', fill_opacity=0.2))
-    d.append(draw.Arc(60,-20,20,60,270,cw=False,
-                stroke='green', stroke_width=3, fill='none'))
-    d.append(draw.Arc(60,-20,20,270,60,cw=True,
-                stroke='blue', stroke_width=1, fill='black', fill_opacity=0.3))
-
-    d.setPixelScale(2)  # Set number of pixels per geometry unit
-    #d.setRenderSize(400,200)  # Alternative to setPixelScale
-    d.saveSvg('example.svg')
-    d.savePng('example.png')
-
-    # Display in iPython notebook
-    d.rasterize()  # Display as PNG
-    d  # Display as SVG
-
-.. image:: https://github.com/cduck/drawSvg/raw/master/example1.png
-   :alt: Example output image
-
-Gradients
-~~~~~~~~~
-
-.. code:: python
-
-    d = draw.Drawing(1.5, 0.8, origin='center')
-
-    d.draw(draw.Rectangle(-0.75,-0.5,1.5,1, fill='#ddd'))
-
-    # Create gradient
-    gradient = draw.RadialGradient(0,-0.35,0.7*10)
-    gradient.addStop(0.5/0.7/10, 'green', 1)
-    gradient.addStop(1/10, 'red', 0)
-
-    # Draw a shape to fill with the gradient
-    p = draw.Path(fill=gradient, stroke='black', stroke_width=0.002)
-    p.arc(0,-0.35,0.7,30,120)
-    p.arc(0,-0.35,0.5,120,30,cw=True, includeL=True)
-    p.Z()
-    d.append(p)
-
-    # Draw another shape to fill with the same gradient
-    p = draw.Path(fill=gradient, stroke='red', stroke_width=0.002)
-    p.arc(0,-0.35,0.75,130,160)
-    p.arc(0,-0.35,0,160,130,cw=True, includeL=True)
-    p.Z()
-    d.append(p)
-
-    # Another gradient
-    gradient2 = draw.LinearGradient(0.1,-0.35,0.1+0.6,-0.35+0.2)
-    gradient2.addStop(0, 'green', 1)
-    gradient2.addStop(1, 'red', 0)
-    d.append(draw.Rectangle(0.1,-0.35,0.6,0.2,
-                            stroke='black', stroke_width=0.002,
-                            fill=gradient2))
-
-    # Display
-    d.setRenderSize(w=600)
-    d
-
-.. image:: https://github.com/cduck/drawSvg/raw/master/example2.png
-   :alt: Example output image
-
-Duplicate geometry and clip paths
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-.. code:: python
-
-    d = draw.Drawing(1.4, 1.4, origin='center')
-
-    # Define clip path
-    clip = draw.ClipPath()
-    clip.append(draw.Rectangle(-.25,.25-1,1,1))
-
-    # Draw a cropped circle
-    c = draw.Circle(0,0,0.5, stroke_width='0.01', stroke='black',
-                             fill_opacity=0.3, clip_path=clip,
-                             id='circle')
-    d.append(c)
-
-    # Make a transparent copy, cropped again
-    g = draw.Group(opacity=0.5, clip_path=clip)
-    g.append(draw.Use('circle', 0.25,0.1))
-    d.append(g)
-
-    # Display
-    d.setRenderSize(400)
-    d.rasterize()
-
-.. image:: https://github.com/cduck/drawSvg/raw/master/example3.png
-   :alt: Example output image
-
-Implementing other SVG tags
-~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-.. code:: python
-
-    # Subclass DrawingBasicElement if it cannot have child nodes
-    # Subclass DrawingParentElement otherwise
-    # Subclass DrawingDef if it must go between <def></def> tags in an SVG
-    class Hyperlink(draw.DrawingParentElement):
-        TAG_NAME = 'a'
-        def __init__(self, href, target=None, **kwargs):
-            # Other init logic...
-            # Keyword arguments to super().__init__() correspond to SVG node
-            # arguments: stroke_width=5 -> stroke-width="5"
-            super().__init__(href=href, target=target, **kwargs)
-
-    d = draw.Drawing(1, 1.2, origin='center')
-
-    # Create hyperlink
-    hlink = Hyperlink('https://www.python.org', target='_blank',
-                      transform='skewY(-30)')
-    # Add child elements
-    hlink.append(draw.Circle(0,0,0.5, fill='green'))
-    hlink.append(draw.Text('Hyperlink',0.2, 0,0, center=0.6, fill='white'))
-
-    # Draw and display
-    d.append(hlink)
-    d.setRenderSize(200)
-    d
-
-.. image:: https://github.com/cduck/drawSvg/raw/master/example4.png
-   :alt: Example output image
-

README.md

···
 # drawSvg
 
-This is a Python 3 library for programmatically generating SVG images (vector drawings) and rendering them or displaying them in an iPython notebook.
+A Python 3 library for programmatically generating SVG images (vector drawings) and rendering them or displaying them in an iPython notebook.
 
 Most common SVG tags are supported and others can easily be added by writing a small subclass of `DrawableBasicElement` or `DrawableParentElement`.
+
+An interactive Jupyter widget, `drawSvg.widgets.DrawingWidget`, is included that can update drawings based on mouse events.
 
 # Install
 drawSvg is available on PyPI:
···
 d  # Display as SVG
 ```
 
-![Example output image](https://github.com/cduck/drawSvg/raw/master/example1.png)
+![Example output image](https://raw.githubusercontent.com/cduck/drawSvg/master/examples/example1.png)
 
 ### Gradients
 ```python
···
 d
 ```
 
-![Example output image](https://github.com/cduck/drawSvg/raw/master/example2.png)
+![Example output image](https://raw.githubusercontent.com/cduck/drawSvg/master/examples/example2.png)
 
 ### Duplicate geometry and clip paths
 ```python
···
 d.rasterize()
 ```
 
-![Example output image](https://github.com/cduck/drawSvg/raw/master/example3.png)
+![Example output image](https://raw.githubusercontent.com/cduck/drawSvg/master/examples/example3.png)
 
 ### Implementing other SVG tags
 ```python
···
 d
 ```
 
-![Example output image](https://github.com/cduck/drawSvg/blob/master/example4.svg)
+![Example output image](https://github.com/cduck/drawSvg/blob/master/examples/example4.svg)
+
+### Interactive Widget
+```python
+import drawSvg as draw
+from drawSvg.widgets import DrawingWidget
+import hyperbolic.poincare.shapes as hyper  # pip3 install hyperbolic
+
+# Create drawing
+d = draw.Drawing(2, 2, origin='center')
+d.setRenderSize(500)
+d.append(draw.Circle(0, 0, 1, fill='orange'))
+group = draw.Group()
+d.append(group)
+
+# Update the drawing based on user input
+click_list = []
+def redraw(points):
+    group.children.clear()
+    for x1, y1 in points:
+        for x2, y2 in points:
+            if (x1, y1) == (x2, y2): continue
+            p1 = hyper.Point.fromEuclid(x1, y1)
+            p2 = hyper.Point.fromEuclid(x2, y2)
+            if p1.distanceTo(p2) <= 2:
+                line = hyper.Line.fromPoints(*p1, *p2, segment=True)
+                group.draw(line, hwidth=0.2, fill='white')
+    for x, y in points:
+        p = hyper.Point.fromEuclid(x, y)
+        group.draw(hyper.Circle.fromCenterRadius(p, 0.1),
+                   fill='green')
+redraw(click_list)
+
+# Create interactive widget and register mouse events
+widget = DrawingWidget(d)
[e-mail]
+def mousedown(widget, x, y, info):
+    if (x**2 + y**2) ** 0.5 + 1e-5 < 1:
+        click_list.append((x, y))
+    redraw(click_list)
+    widget.refresh()
[e-mail]
+def mousemove(widget, x, y, info):
+    if (x**2 + y**2) ** 0.5 + 1e-5 < 1:
+        redraw(click_list + [(x, y)])
+    widget.refresh()
+widget
+```
+
+![Example output image](https://raw.githubusercontent.com/cduck/drawSvg/master/examples/example5.gif)
+
+### Animation
+```python
+import drawSvg as draw
+
+# Draw a frame of the animation
+def draw_frame(t):
+    d = draw.Drawing(2, 6.05, origin=(-1,-1.05))
+    d.setRenderSize(h=300)
+    d.append(draw.Rectangle(-2, -2, 4, 8, fill='white'))
+    d.append(draw.Rectangle(-1, -1.05, 2, 0.05, fill='brown'))
+    t = (t + 1) % 2 - 1
+    y = 4 - t**2 * 4
+    d.append(draw.Circle(0, y, 1, fill='lime'))
+    return d
+
+with draw.animate_jupyter(draw_frame, delay=0.05) as anim:
+# Or:
+#with draw.animate_video('example6.gif', draw_frame, duration=0.05
+#                       ) as anim:
+    # Add each frame to the animation
+    for i in range(20):
+        anim.draw_frame(i/10)
+    for i in range(20):
+        anim.draw_frame(i/10)
+    for i in range(20):
+        anim.draw_frame(i/10)
+```
+
+![Example output image](https://raw.githubusercontent.com/cduck/drawSvg/master/examples/example6.gif)
 

setup.py

···
 from setuptools import setup, find_packages
+import logging
+logger = logging.getLogger(__name__)
 
-version = '1.1.0'
+version = '1.2.0'
 
 try:
-    with open('DESCRIPTION.rst', 'r') as f:
-        longDesc = f.read()
+    with open('README.md', 'r') as f:
+        long_desc = f.read()
 except:
-    print('Warning: Could not open DESCRIPTION.rst.  long_description will be set to None.')
-    longDesc = None
+    logger.warning('Could not open README.md.  long_description will be set to None.')
+    long_desc = None
 
 setup(
     name = 'drawSvg',
     packages = find_packages(),
     version = version,
-    description = 'This is a Python 3 library for programmatically generating SVG images (vector drawings) and rendering them or displaying them in an iPython notebook.',
-    long_description = longDesc,
+    description = 'A Python 3 library for programmatically generating SVG images (vector drawings) and rendering them or displaying them in an iPython notebook.',
+    long_description = long_desc,
+    long_description_content_type = 'text/markdown',
     author = 'Casey Duckering',
     #author_email = '',
     url = 'https://github.com/cduck/drawSvg',
     download_url = 'https://github.com/cduck/drawSvg/archive/{}.tar.gz'.format(version),
-    keywords = ['SVG', 'draw', 'graphics', 'iPython', 'Jupyter'],
+    keywords = ['SVG', 'draw', 'graphics', 'iPython', 'Jupyter', 'widget'],
     classifiers = [
         'License :: OSI Approved :: MIT License',
         'Programming Language :: Python :: 3',
···
     ],
     install_requires = [
         'cairoSVG',
+        'numpy',
+        'imageio',
     ],
 )