KiCAD minimal pcbnew plugin example

#!/usr/bin/env python
import pcbnew
import wx

class DialogExamplePlugin(pcbnew.ActionPlugin):
    def defaults(self):
        self.name = "Show dialog example"
        self.category = "A descriptive category name"
        self.description = "A description of the plugin and what it does"
        self.show_toolbar_button = False # Optional, defaults to False

    def Run(self):
        dlg = wx.MessageDialog(None, "Please select one or multiple footprints!\n...or use Ctrl+A to select everything.", "No footprints selected", wx.OK | wx.ICON_ERROR)
        dlg.ShowModal()
        dlg.Destroy()

DialogExamplePlugin().register() # Instantiate and register to Pcbnew