I'm using the code shown by MonsterBat Doppelgänger in Move and zoom a tkinter canvas with mouse
It works great! But when I add a self.canvas.bind("<Button-2>",self.find_nearest), the right button click is ignored completely.
Here is the code as modified:
#!/usr/bin/python2.7
"""
https://stackoverflow.com/questions/25787523/move-and-zoom-a-tkinter-canvas-with-mouse
by MonsterBat Doppelganger
"""
import Tkinter as tk
import random
class Example(tk.Frame):
def __init__(self, root):
tk.Frame.__init__(self, root)
self.canvas = tk.Canvas(self, width=400, height=400, background="bisque")
self.xsb = tk.Scrollbar(self, orient="horizontal", command=self.canvas.xview)
self.ysb = tk.Scrollbar(self, orient="vertical", command=self.canvas.yview)
self.canvas.configure(yscrollcommand=self.ysb.set, xscrollcommand=self.xsb.set)
self.canvas.configure(scrollregion=(0,0,1000,1000))
self.xsb.grid(row=1, column=0, sticky="ew")
self.ysb.grid(row=0, column=1, sticky="ns")
self.canvas.grid(row=0, column=0, sticky="nsew")
self.grid_rowconfigure(0, weight=1)
self.grid_columnconfigure(0, weight=1)
#Plot some rectangles
for n in range(50):
x0 = random.randint(0, 900)
y0 = random.randint(50, 900)
x1 = x0 + random.randint(50, 100)
y1 = y0 + random.randint(50,100)
color = ("red", "orange", "yellow", "green", "blue")[random.randint(0,4)]
self.canvas.create_rectangle(x0,y0,x1,y1, outline="black", fill=color, activefill="black", tags=n)
self.canvas.create_text(50,10, anchor="nw", text="Click and drag to move the canvas\nScroll to zoom.")
# This is what enables using the mouse:
self.canvas.bind("<ButtonPress-1>", self.move_start)
self.canvas.bind("<B1-Motion>", self.move_move)
#linux scroll
self.canvas.bind("<Button-4>", self.zoomerP)
self.canvas.bind("<Button-5>", self.zoomerM)
#windows scroll
self.canvas.bind("<MouseWheel>",self.zoomer)
""" My add """
# find my position
self.canvas.bind("<Button-2>", self.find_nearest)
#move
def move_start(self, event):
self.canvas.scan_mark(event.x, event.y)
def move_move(self, event):
self.canvas.scan_dragto(event.x, event.y, gain=1)
#windows zoom
def zoomer(self,event):
if (event.delta > 0):
self.canvas.scale("all", event.x, event.y, 1.1, 1.1)
elif (event.delta < 0):
self.canvas.scale("all", event.x, event.y, 0.9, 0.9)
self.canvas.configure(scrollregion = self.canvas.bbox("all"))
#linux zoom
def zoomerP(self,event):
self.canvas.scale("all", event.x, event.y, 1.1, 1.1)
self.canvas.configure(scrollregion = self.canvas.bbox("all"))
def zoomerM(self,event):
self.canvas.scale("all", event.x, event.y, 0.9, 0.9)
self.canvas.configure(scrollregion = self.canvas.bbox("all"))
""" The rest of the story """
def find_nearest(self,event):
print 'nearest to %d,%d' % (event.x, event.y)
closest = self.canvas.find_closest(event.x,event.y)
if len(closest) == 0:
print 'Nothing near'
else:
print 'Id %s' % closest
if __name__ == "__main__":
root = tk.Tk()
Example(root).pack(fill="both", expand=True)
root.mainloop()
I'm not even getting to the print in find_nearest. Everything runs as in the original. The canvas scrolls and zooms. No exceptions are raised.
