Right click not working on MacOS

[callzhang]

Also drag with right button is not working. Using Python 3.8 and tcl-tk 8.6.11_1 installed from brew

[callzhang]

Found the reason: MacOS uses Button-2 for right button. We should update the code in canvas.py as:

        # Bind events to the Canvas
        self.canvas.bind('<Configure>', lambda event: self.__size_changed())  # canvas is resized
        self.canvas.bind('<Button-1>', self.__left_mouse_button)  # remember canvas position
        self.canvas.bind('<ButtonPress-3>', self.__right_mouse_button_pressed)  # remember canvas position
        self.canvas.bind('<ButtonPress-2>', self.__right_mouse_button_pressed)  # remember canvas position
        self.canvas.bind('<ButtonRelease-3>', self.__right_mouse_button_released)  # remember canvas position
        self.canvas.bind('<ButtonRelease-2>', self.__right_mouse_button_released)  # remember canvas position
        self.canvas.bind('<B3-Motion>', self.__right_mouse_button_motion)  # move canvas to the new position
        self.canvas.bind('<B2-Motion>', self.__right_mouse_button_motion)  # move canvas to the new position
        self.canvas.bind('<MouseWheel>', self.__wheel)  # zoom for Windows and MacOS, but not Linux
        self.canvas.bind('<Button-5>', self.__wheel)  # zoom for Linux, wheel scroll down
        self.canvas.bind('<Button-4>', self.__wheel)  # zoom for Linux, wheel scroll up

[callzhang]

Also, for mouse wheel event to be compatible with MacOS, modify as follows:

    def __wheel(self, event):
        """ Zoom with mouse wheel """
        x = self.canvas.canvasx(event.x)  # get coordinates of the event on the canvas
        y = self.canvas.canvasy(event.y)
        if self.outside(x, y): return  # zoom only inside image area

        scale = 1.0
        # Respond to Linux (event.num) or Windows (event.delta) wheel event
        if event.num == 5 or event.delta == -120 or event.delta == 1:  # scroll down, zoom out, smaller
            scale /= self.__delta
        if event.num == 4 or event.delta == 120 or event.delta == -1:  # scroll up, zoom in, bigger
            scale *= self.__delta

        self._change_canvas_scale(scale, x, y)
        self.__show_image()

It works for the Mac mouse. Hope it helps.

[ptrvilya]

@callzhang Thanks for your help, I've updated the code to support MacOS.

[dpolikarpov-works]

@callzhang could you tell how you installed this amazing lib on mac? I always face errors so I guess I did smth wrong