Matplotlib Tkagg Backend Performance

I have a tkinter application that can plot a large number of data, where I have noticed poor pan and zoom performance when there is a large number of data on the canvas. Looking in

Solution 1:

When refering to "being idle" it is not the user or his mouse activity that is meant, but rather the GUI mainloop. The canvas should only be redrawn if the mainloop is not currently busy. Here, of course self._idle only refers to the matplotlib part of the GUI and what this structure inside draw_idle is supposed to do is to prevent the canvas from being drawn while it is being drawn.

This could easily happen when panning or zooming. The mouse moves to a new location, causing a readraw. While this redraw is happening, the mouse has already moved further and caused the next redraw. At that point in time the first redraw may not yet have finished, such that it would queue up. And so forth, such that at some point the GUI might become unresponsive. To prevent that, a new draw is only initialized once the previous one has finished and this behaviour is steered by self._idle being true or false.