module tool;

import icanvas;

interface IToolStack {
    void push(Tool tool);
    void pop();
    void replace(Tool tool);
}

abstract class Tool : ICanvasEventHandler {
    /*
    abstract bool is_sticky();
    abstract bool is_replaceable();
    */

    abstract void start(IToolStack tool_stack);
    abstract void stop(IToolStack tool_stack);
}