You can attach an event binding to a widget using the bind method. The following example binds some mouse events to a Frame instance:
import tkinter as tk
class App(tk.Tk):
def __init__(self):
super().__init__()
frame = tk.Frame(self, bg="green",
height=100, width=100)
frame.bind("<Button-1>", self.print_event)
frame.bind("<Double-Button-1>", self.print_event)
frame.bind("<ButtonRelease-1>", self.print_event)
frame.bind("<B1-Motion>", self.print_event)
frame.bind("<Enter>", self.print_event)
frame.bind("<Leave>", self.print_event)
frame.pack(padx=50, pady=50)
def print_event(self, event):
position = "(x={}, y={})".format(event.x, event.y)
print(event.type, "event", position)
if __name__ == "__main__":
app = App()
app.mainloop()
All events are handled by the print_event() method of our class, which prints the type of event and the position of the mouse in the console. You can try it out by clicking on the green frame with the mouse, and moving it around while it starts printing the event messages.
The following example contains an Entry widget with a couple of bindings; one for the event that gets triggered when the entry gets the focus, and another for all the key press events:
import tkinter as tk
class App(tk.Tk):
def __init__(self):
super().__init__()
entry = tk.Entry(self)
entry.bind("<FocusIn>", self.print_type)
entry.bind("<Key>", self.print_key)
entry.pack(padx=20, pady=20)
def print_type(self, event):
print(event.type)
def print_key(self, event):
args = event.keysym, event.keycode, event.char
print("Symbol: {}, Code: {}, Char: {}".format(*args))
if __name__ == "__main__":
app = App()
app.mainloop()
The first message this program will output is the FocusIn event when you set the focus on the Entry widget. If you try it out, you will see that it will also show the events of keys that do not correspond to non-printable characters, such as arrow keys or the return key.
