def change_shift_influence(self, shift_pressed):
        """Perform setups according to state of shift key.

        Parameters
        ==========
        shift_pressed (boolean)
            indicates whether the shift key is pressed,
            and thus whether to enable or not the influence
            of the shift button in how the mouse dragging
            affects the incrementation of the value displayed
            in the widget.
        """
        ### define the value of the increment used
        ### to increment/decrement the value displayed
        ### in the widget

        self.increment = (
            self.preciser_drag_increment
            if shift_pressed
            else self.normal_drag_increment
        )

        ### assign the current value displayed as the
        ### base value which will be the target of the
        ### incrementation/decrementation performed
        ### whenever the mouse moves
        self.base_value = self.evaluate_string(self.cursor.get())

        ### set the origin of the mouse dragging movement
        ### to the center of the screen
        self.dragging_origin_x = SCREEN_RECT.centerx
Perform setups according to state of shift key.

        Parameters
        ==========
        shift_pressed (boolean)
            indicates whether the shift key is pressed,
            and thus whether to enable or not the influence
            of the shift button in how the mouse dragging
            affects the incrementation of the value displayed
            in the widget.
        
nodezator/widget/intfloatentry/modes.py