[FIXED] Using clicks and keys for different events on Matplotlib

Issue

I want to use the mouse clicks to draw lines, while a letter button on the keyboard to draw a point on a Matplotlib figure. This is the code I have so far.

def onclick(event):
    global current_coords
    if event.inaxes:
        current_coords.append((event.xdata, event.ydata))
        if len(current_coords) == 2:
            ax.plot([current_coords[0][0], current_coords[1][0]],
                    [current_coords[0][1], current_coords[1][1]], 'ro-')
            coords.append([current_coords[0], current_coords[1]])
            current_coords[:] = []

        fig.canvas.draw()
        
def onkey(event):
    global current_coords1
    
    if keyboard.is_pressed('p'):
        current_coords1.append((event.xdata, event.ydata))
        if len(current_coords1) == 1:
            ax.plot([current_coords1[0][0], current_coords1[1][0]], 'bo-')
            coords1.append([current_coords1[0], current_coords1[1]])
            current_coords1[:] = []

        fig.canvas.draw()

cid = fig.canvas.mpl_connect('button_press_event', onclick)
cid1 = fig.canvas.mpl_connect('button_press_event', onkey)
plt.show()

   

The first function should create a line when you click twice on the figure. The second should just create a dot when you press "P" on the figure. Any help would be greatly appreciated.

Thanks in advance.

Solution

Note that I changed the key form p to x for drawing points as p is also the shortcut to pan the graph.

import matplotlib.pyplot as plt

# %matplotlib widget  # for jupyter notebooks (pip install ipympl)

fig, ax = plt.subplots()
ax.set_xlim(0, 10)
ax.set_ylim(0, 10)

global current_coords
current_coords = []

def onclick(event):
    global current_coords
    if event.inaxes:
        current_coords.append((event.xdata, event.ydata))
        if len(current_coords) == 2:
            ax.plot([current_coords[0][0], current_coords[1][0]],
                    [current_coords[0][1], current_coords[1][1]], 'ro-')
            current_coords[:] = []
    fig.canvas.draw()

def onkey(event):
    print(event.key)
    if event.key == 'x':
        if event.xdata is not None and event.ydata is not None:
            ax.plot(event.xdata, event.ydata, 'bo-')
            fig.canvas.draw()


cid1 = fig.canvas.mpl_connect('button_press_event', onclick)
cid2 = fig.canvas.mpl_connect('key_press_event', onkey)

Answered By - scleronomic