Mega Code Archive

 

Categories / Python / GUI Tk

 

Animation with threads

#/* #Python and Tkinter Programming #John E. Grayson #ISBN: 1884777813 #Publisher: Manning #*/ from Tkinter import * import thread, time trace = 0  class CanvasEventsDemo:      def __init__(self, parent=None):         canvas = Canvas(width=300, height=300, bg='beige')          canvas.pack()         canvas.bind('<ButtonPress-1>', self.onStart)      # click         canvas.bind('<B1-Motion>',     self.onGrow)       # and drag         canvas.bind('<Double-1>',      self.onClear)      # delete all         canvas.bind('<ButtonPress-3>', self.onMove)       # move latest         self.canvas = canvas         self.drawn  = None         self.kinds = [canvas.create_oval, canvas.create_rectangle]     def onStart(self, event):         self.shape = self.kinds[0]         self.kinds = self.kinds[1:] + self.kinds[:1]      # start dragout         self.start = event         self.drawn = None     def onGrow(self, event):                              # delete and redraw         canvas = event.widget         if self.drawn: canvas.delete(self.drawn)         objectId = self.shape(self.start.x, self.start.y, event.x, event.y)         if trace: print objectId         self.drawn = objectId     def onClear(self, event):         event.widget.delete('all')                        # use tag all     def onMove(self, event):         if self.drawn:                                    # move to click spot             if trace: print self.drawn             canvas = event.widget             diffX, diffY = (event.x - self.start.x), (event.y - self.start.y)             canvas.move(self.drawn, diffX, diffY)             self.start = event class CanvasEventsDemoTags(CanvasEventsDemo):     def __init__(self, parent=None):         CanvasEventsDemo.__init__(self, parent)         self.canvas.create_text(75, 8, text='Press o and r to move shapes')         self.canvas.master.bind('<KeyPress-o>', self.onMoveOvals)             self.canvas.master.bind('<KeyPress-r>', self.onMoveRectangles)           self.kinds = self.create_oval_tagged, self.create_rectangle_tagged     def create_oval_tagged(self, x1, y1, x2, y2):         objectId = self.canvas.create_oval(x1, y1, x2, y2)         self.canvas.itemconfig(objectId, tag='ovals', fill='blue')         return objectId     def create_rectangle_tagged(self, x1, y1, x2, y2):         objectId = self.canvas.create_rectangle(x1, y1, x2, y2)         self.canvas.itemconfig(objectId, tag='rectangles', fill='red')         return objectId     def onMoveOvals(self, event):         print 'moving ovals'         self.moveInSquares(tag='ovals')           # move all tagged ovals     def onMoveRectangles(self, event):         print 'moving rectangles'         self.moveInSquares(tag='rectangles')     def moveInSquares(self, tag):                 # 5 reps of 4 times per sec         for i in range(5):             for (diffx, diffy) in [(+20, 0), (0, +20), (-20, 0), (0, -20)]:                 self.canvas.move(tag, diffx, diffy)                 self.canvas.update()              # force screen redraw/update                 time.sleep(0.25)                  # pause, but don't block gui class CanvasEventsDemoThread(CanvasEventsDemoTags):     def moveEm(self, tag):         for i in range(5):             for (diffx, diffy) in [(+20, 0), (0, +20), (-20, 0), (0, -20)]:                 self.canvas.move(tag, diffx, diffy)                 time.sleep(0.25)                      # pause this thread only     def moveInSquares(self, tag):         thread.start_new_thread(self.moveEm, (tag,)) if __name__ == '__main__':     CanvasEventsDemoThread()     mainloop()