"""

a couple of classes for implementing partial tabbed-page like behaviour

"""

from Tkinter import *

class InvalidTabPage(Exception): pass

class AlreadyExists(Exception): pass

class PageTab(Frame):

    """

    a 'page tab' like framed button

    """

    def __init__(self,parent):

        Frame.__init__(self, parent,borderwidth=2,relief=RIDGE)

        self.button=Radiobutton(self,padx=5,pady=5,takefocus=FALSE,

                indicatoron=FALSE,highlightthickness=0,

                borderwidth=0,selectcolor=self.cget('bg'))

        self.button.pack()

class TabPageSet(Frame):

    """

    a set of 'pages' with TabButtons for controlling their display

    """

    def __init__(self,parent,pageNames=[],**kw):

        """

        pageNames - a list of strings, each string will be the dictionary key

        to a page's data, and the name displayed on the page's tab. Should be

        specified in desired page order. The first page will be the default

        and first active page.

        """

        Frame.__init__(self, parent, kw)

        self.grid_location(0,0)

        self.columnconfigure(0,weight=1)

        self.rowconfigure(1,weight=1)

        self.tabBar=Frame(self)

        self.tabBar.grid(row=0,column=0,sticky=EW)

        self.activePage=StringVar(self)

        self.defaultPage=''

        self.pages={}

        for name in pageNames:

            self.AddPage(name)

    def ChangePage(self,pageName=None):

        if pageName:

            if pageName in self.pages.keys():

                self.activePage.set(pageName)

            else:

                raise InvalidTabPage, 'Invalid TabPage Name'

        ## pop up the active 'tab' only

        for page in self.pages.keys():

            self.pages[page]['tab'].config(relief=RIDGE)

        self.pages[self.GetActivePage()]['tab'].config(relief=RAISED)

        ## switch page

        self.pages[self.GetActivePage()]['page'].lift()

    def GetActivePage(self):

        return self.activePage.get()

    def AddPage(self,pageName):

        if pageName in self.pages.keys():

            raise AlreadyExists, 'TabPage Name Already Exists'

        self.pages[pageName]={'tab':PageTab(self.tabBar),

                'page':Frame(self,borderwidth=2,relief=RAISED)}

        self.pages[pageName]['tab'].button.config(text=pageName,

                command=self.ChangePage,variable=self.activePage,

                value=pageName)

        self.pages[pageName]['tab'].pack(side=LEFT)

        self.pages[pageName]['page'].grid(row=1,column=0,sticky=NSEW)

        if len(self.pages)==1: # adding first page

            self.defaultPage=pageName

            self.activePage.set(self.defaultPage)

            self.ChangePage()

    def RemovePage(self,pageName):

        if not pageName in self.pages.keys():

            raise InvalidTabPage, 'Invalid TabPage Name'

        self.pages[pageName]['tab'].pack_forget()

        self.pages[pageName]['page'].grid_forget()

        self.pages[pageName]['tab'].destroy()

        self.pages[pageName]['page'].destroy()

        del(self.pages[pageName])

        # handle removing last remaining, or default, or active page

        if not self.pages: # removed last remaining page

            self.defaultPage=''

            return

        if pageName==self.defaultPage: # set a new default page

            self.defaultPage=\

                self.tabBar.winfo_children()[0].button.cget('text')

        if pageName==self.GetActivePage(): # set a new active page

            self.activePage.set(self.defaultPage)

        self.ChangePage()

if __name__ == '__main__':

    #test dialog

    root=Tk()

    tabPage=TabPageSet(root,pageNames=['Foobar','Baz'])

    tabPage.pack(expand=TRUE,fill=BOTH)

    Label(tabPage.pages['Foobar']['page'],text='Foo',pady=20).pack()

    Label(tabPage.pages['Foobar']['page'],text='Bar',pady=20).pack()

    Label(tabPage.pages['Baz']['page'],text='Baz').pack()

    entryPgName=Entry(root)

    buttonAdd=Button(root,text='Add Page',

            command=lambda:tabPage.AddPage(entryPgName.get()))

    buttonRemove=Button(root,text='Remove Page',

            command=lambda:tabPage.RemovePage(entryPgName.get()))

    labelPgName=Label(root,text='name of page to add/remove:')

    buttonAdd.pack(padx=5,pady=5)

    buttonRemove.pack(padx=5,pady=5)

    labelPgName.pack(padx=5)

    entryPgName.pack(padx=5)

    tabPage.ChangePage()

    root.mainloop()