[Matplotlib-users] Problem : Combining mouse button events with pick events in a scatter plot

[Thomas Caswell]

The issue unrelated to the pick events, it is due to clicking without
moving the mouse (and can be reproduced with all of the pick logic removed).

In your `onpress` you lock the widget and then in the `callback` you pass
to lasso widget you release it, however if you start the lasso, but do not
move the mouse no move_events are generated, then the callback is never
called.

You probably should handle the unlocking in a 'button_release_event'.

Tom

On Fri, Oct 9, 2015 at 7:19 AM joh <johtoldr at yahoo.gr> wrote:

> Hello everybody,
>
>
> I am trying to combine mouse button events with a pick event in scatter
> plot. Different functionalities take place, based on the mouse button
> pressed each time. I want each functionality to be triggered with a
> combination of mouse buttons events and/or key press events. When the left
> mouse button is pressed matplotlib's Lasso widget is called and with the
> included points functionality 1 takes place. When Shift+LMB are pressed a
> Lasso is drawn and functionality 2 takes place with the included points.
> When Alt+LMB are pressed a Lasso is drawn and with the included points
> functionality 3 takes place. Last, but not least, when I press the RMB a
> pick event is triggered and the index of the selected point in the scatter
> plot is given.
>
> Since I added the pick event, the aforementioned functionalities work
> correctly until a pick event is triggered. When it is triggered it seems
> that the canvas gets locked and I can not use any other functionality. I
> don't get the index of the selected points and I do not get any errors.
>
>
> ----------------Code-------------------------
>
> import logging
> import matplotlib
> from matplotlib.widgets import Lasso
> from matplotlib.colors import colorConverter
> from matplotlib.collections import RegularPolyCollection
> from matplotlib import path
> import numpy as np
> import matplotlib.pyplot as plt
> from numpy.random import rand
>
> logger = logging.getLogger()
> logger.setLevel(logging.DEBUG)
>
>
> class Datum(object):
>       colorin = colorConverter.to_rgba('red')
>       colorShift = colorConverter.to_rgba('cyan')
>       colorCtrl = colorConverter.to_rgba('pink')
>       colorout = colorConverter.to_rgba('blue')
>
>       def __init__(self, x, y, include=False):
>          self.x = x
>          self.y = y
>          if include:
>             self.color = self.colorin
>          else:
>             self.color = self.colorout
>
>
> class LassoManager(object):
>       def __init__(self, ax, data):
>          self.axes = ax
>          self.canvas = ax.figure.canvas
>          self.data = data
>
>          self.Nxy = len(data)
>
>          facecolors = [d.color for d in data]
>          self.xys = [(d.x, d.y) for d in data]
>          fig = ax.figure
>          self.collection = RegularPolyCollection(fig.dpi, 6,
> sizes=(100,),facecolors=facecolors, offsets = self.xys, transOffset =
> ax.transData)
>
>          ax.add_collection(self.collection)
>
>          self.pick=self.canvas.mpl_connect('pick_event', self.onpick)
>          self.cid = self.canvas.mpl_connect('button_press_event',
> self.onpress)
>          self.keyPress = self.canvas.mpl_connect('key_press_event',
> self.onKeyPress)
>          self.keyRelease = self.canvas.mpl_connect('key_release_event',
> self.onKeyRelease)
>          self.lasso = None
>          self.shiftKey = False
>          self.ctrlKey = False
>
>       def callback(self, verts):
>           logging.debug('in LassoManager.callback(). Shift: %s, Ctrl: %s' %
> (self.shiftKey, self.ctrlKey))
>           facecolors = self.collection.get_facecolors()
>           p = path.Path(verts)
>           ind = p.contains_points(self.xys)
>           for i in range(len(self.xys)):
>               if ind[i]:
>                  if self.shiftKey:
>                     facecolors[i] = Datum.colorShift
>                  elif self.ctrlKey:
>                     facecolors[i] = Datum.colorCtrl
>                  else:
>                     facecolors[i] = Datum.colorin
>                     print self.xys[i]
>               else:
>                    facecolors[i] = Datum.colorout
>
>           self.canvas.draw_idle()
>           self.canvas.widgetlock.release(self.lasso)
>           del self.lasso
>
>       def onpress(self, event):
>            if self.canvas.widgetlock.locked(): return
>            if event.inaxes is None:    return
>            self.lasso = Lasso(event.inaxes, (event.xdata, event.ydata),
> self.callback)
>            # acquire a lock on the widget drawing
>            self.canvas.widgetlock(self.lasso)
>
>       def onKeyPress(self, event):
>           logging.debug('in LassoManager.onKeyPress(). Event received: %s
> (key: %s)' % (event, event.key))
>           if event.key == 'alt':
>              self.ctrlKey = True
>           if event.key == 'shift':
>              self.shiftKey = True
>
>       def onKeyRelease(self, event):
>           logging.debug('in LassoManager.onKeyRelease(). Event received: %s
> (key: %s)' % (event, event.key))
>           if event.key == 'alt':
>              self.ctrlKey = False
>           if event.key == 'shift':
>              self.shiftKey = False
>
>
>       def onpick(self,event):
>
>           if event.mouseevent.button == 3:
>
>              index = event.ind
>              print('onpick3 scatter:', index)
>
>       if __name__ == '__main__':
>
>          data = [Datum(*xy) for xy in rand(100, 2)]
>
>          ax = plt.axes(xlim=(0,1), ylim=(0,1), autoscale_on=False)
>          lman = LassoManager(ax, data)
>
>          plt.show()
>
> ------------------End of Code-----------------------------
>
> Any suggestions on what might be causing this malfunction? What am I doing
> wrong?
>
>
>
> --
> View this message in context:
> http://matplotlib.1069221.n5.nabble.com/Problem-Combining-mouse-button-events-with-pick-events-in-a-scatter-plot-tp46109.html
> Sent from the matplotlib - users mailing list archive at Nabble.com.
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