Demo/tkinter/matt/rubber-band-box-demo-1.py

   1 from Tkinter import *
   2
   3 class Test(Frame):
   4     def printit(self):
   5         print "hi"
   6
   7     def createWidgets(self):
   8         self.QUIT = Button(self, text='QUIT',
   9                                   background='red',
  10                                   foreground='white',
  11                                   height=3,
  12                                   command=self.quit)
  13         self.QUIT.pack(side=BOTTOM, fill=BOTH)
  14
  15         self.canvasObject = Canvas(self, width="5i", height="5i")
  16         self.canvasObject.pack(side=LEFT)
  17
  18     def mouseDown(self, event):
  19         # canvas x and y take the screen coords from the event and translate
  20         # them into the coordinate system of the canvas object
  21         self.startx = self.canvasObject.canvasx(event.x)
  22         self.starty = self.canvasObject.canvasy(event.y)
  23
  24     def mouseMotion(self, event):
  25         # canvas x and y take the screen coords from the event and translate
  26         # them into the coordinate system of the canvas object
  27         x = self.canvasObject.canvasx(event.x)
  28         y = self.canvasObject.canvasy(event.y)
  29
  30         if (self.startx != event.x)  and (self.starty != event.y) :
  31             self.canvasObject.delete(self.rubberbandBox)
  32             self.rubberbandBox = self.canvasObject.create_rectangle(
  33                 self.startx, self.starty, x, y)
  34             # this flushes the output, making sure that
  35             # the rectangle makes it to the screen
  36             # before the next event is handled
  37             self.update_idletasks()
  38
  39     def mouseUp(self, event):
  40         self.canvasObject.delete(self.rubberbandBox)
  41
  42     def __init__(self, master=None):
  43         Frame.__init__(self, master)
  44         Pack.config(self)
  45         self.createWidgets()
  46
  47         # this is a "tagOrId" for the rectangle we draw on the canvas
  48         self.rubberbandBox = None
  49
  50         # and the bindings that make it work..
  51         Widget.bind(self.canvasObject, "<Button-1>", self.mouseDown)
  52         Widget.bind(self.canvasObject, "<Button1-Motion>", self.mouseMotion)
  53         Widget.bind(self.canvasObject, "<Button1-ButtonRelease>", self.mouseUp)
  54
  55
  56 test = Test()
  57
  58 test.mainloop()