René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Unnecessary drawing with NbAgg","articleBody":"I am running into performance issues when using the NbAgg backend, some of which I think is avoidable. Essentially, when clicking on an NbAgg plot, with no tool active, the backend re-draws the data, which can cause the kernel to hang if the plot is complex. Here is a demonstration - note the kernel activity in the circle in the top right. Every time I click on the plot, it is redrawn:\r\n\r\n![Screen-Recording-2019-04-16-at-11 13 08](https://user-images.githubusercontent.com/314716/56201666-3af44480-6039-11e9-9b11-dfc0d612f1a5.gif)\r\n\r\nJust to be clear, I totally expect plotting to be slow the first time the plot is shown, and if e.g. panning/zooming, but drawing when no tool is active doesn't seem right. This is causing issues for me because I am developing tools that respond to a click event in the plot and try and be nice by doing ``draw_idle`` to keep the UI responsive, but every mouse action also results in a full ``draw`` which slows things down a lot.\r\n\r\n**Matplotlib version**\r\n\r\n  * Operating system: MacOS X 10.14.2\r\n  * Matplotlib version: latest dev (557cdfaef1836a7e39d93e41c93810876c715016)\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): NbAgg\r\n  * Python version: 3.7.1\r\n  * Jupyter version (if applicable): 4.4.0\r\n\r\n","author":{"url":"https://github.com/astrofrog","@type":"Person","name":"astrofrog"},"datePublished":"2019-04-16T10:20:59.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":20},"url":"https://github.com/13971/matplotlib/issues/13971"}