from Tkinter import * import 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) canvas.bind('<B1-Motion>', self.onGrow) canvas.bind('<Double-1>', self.onClear) canvas.bind('<ButtonPress-3>', self.onMove) 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] self.start = event self.drawn = None def onGrow(self, event): 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') def onMove(self, event): if self.drawn: 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') def onMoveRectangles(self, event): print 'moving rectangles' self.moveInSquares(tag='rectangles') def moveInSquares(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) self.canvas.update() time.sleep(0.25)
if __name__ == '__main__': CanvasEventsDemoTags() mainloop()
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