wxpython如何给panel控件获得焦点时增加阴影特效

如图，panel或控件获得焦点时，增加阴影边框和背景变黑，过两秒再变回来，如此往复

改变Panel的边框有点困难，改变背景倒是简单。下面的代码生成了两个panel，获得焦点后就会变色，2秒钟后复原。

import wx

class MainFrame(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None, -1)
        
        self.SetTitle('Panel焦点事件')
        self.SetBackgroundColour((224, 224, 224))
        self.SetSize((300, 100))
        self.Center()
        
        p1 = wx.Panel(self, -1, style=wx.SUNKEN_BORDER)
        p1.SetBackgroundColour((224, 224, 224))
        
        p2 = wx.Panel(self, -1, style=wx.RAISED_BORDER)
        p2.SetBackgroundColour((224, 224, 224))
        
        bs = wx.BoxSizer()
        bs.Add(p1, 1, wx.EXPAND|wx.ALL, 5)
        bs.Add(p2, 1, wx.EXPAND|wx.ALL, 5)
        
        self.SetSizer(bs)
        self.Layout()
        
        self.currut_panel = None
        self.timer = wx.Timer()
        self.timer.Bind(wx.EVT_TIMER, self.on_timer)
        
        p1.Bind(wx.EVT_SET_FOCUS, self.on_focus)
        p2.Bind(wx.EVT_SET_FOCUS, self.on_focus)
    
    def on_focus(self, evt):
        self.currut_panel = evt.GetEventObject()
        self.currut_panel.SetBackgroundColour((255, 224, 224))
        self.Refresh()
        self.timer.StartOnce(2000)
    
    def on_timer(self, evt):
        self.currut_panel.SetBackgroundColour((224, 224, 224))
        self.Refresh()

if __name__ == '__main__':
    app = wx.App()
    frame = MainFrame()
    frame.Show()
    app.MainLoop()