class Actions {
    owner: Object
    state: Object
    function complete(self: Actions): Unit { self.state.increment() }
    function schedule(self: Actions, event: Event): Unit {
        ui.after(self.owner, "load", 1500, self.complete)
    }
}
state = ui.state(0)
hidden = TextBlock("这个 Block 没有挂载，也能拥有任务")
page = Page()
page.title = "任务生命周期"
pageActions = Actions(page, state)
blockActions = Actions(hidden, state)
appActions = Actions(ui, state)
pageButton = Button("Page 任务：关闭 Tab 会取消")
blockButton = Button("隐藏 Block 任务：关闭 Tab 仍继续")
appButton = Button("应用任务：关闭 Tab 仍继续")
pageConnection = pageButton.on("click", pageActions.schedule)
blockConnection = blockButton.on("click", blockActions.schedule)
appConnection = appButton.on("click", appActions.schedule)
page.render(Column(24, 16, TextBlock("1.5 秒后更新同一个状态对象；重复点击只保留最新任务"), ui.textOf(state, "value"), pageButton, blockButton, appButton))
initial = ui.after(ui, "initial", 500, appActions.complete)
ui.window().setTitle("Owned Tasks")