"""
Dialog that allows user to specify a new config file section name.
Used to get new highlight theme and keybinding set names.
"""
from tkinter import *
import tkinter.messagebox as tkMessageBox

class GetCfgSectionNameDialog(Toplevel):
    def __init__(self,parent,title,message,usedNames):
        """
        message - string, informational message to display
        usedNames - list, list of names already in use for validity check
        """
        Toplevel.__init__(self, parent)
        self.configure(borderwidth=5)
        self.resizable(height=FALSE, width=FALSE)
        self.title(title)
        self.transient(parent)
        self.grab_set()
        self.protocol("WM_DELETE_WINDOW", self.Cancel)
        self.parent = parent
        self.message=message
        self.usedNames=usedNames
        self.result = ''
        self.CreateWidgets()
        self.withdraw()  #hide while setting geometry
        self.update_idletasks()
        #needs to be done here so that the winfo_reqwidth is valid
        self.messageInfo.config(width=self.frameMain.winfo_reqwidth())
        self.geometry(
                "+%d+%d" % (
                parent.winfo_rootx() +
                (parent.winfo_width()/2 - self.winfo_reqwidth()/2),
                parent.winfo_rooty() +
                (parent.winfo_height()/2 - self.winfo_reqheight()/2)
                ) )  #centre dialog over parent
        self.deiconify()  #geometry set, unhide
        self.wait_window()

    def CreateWidgets(self):
        self.name = StringVar(self)
        self.fontSize = StringVar(self)
        self.frameMain = Frame(self,borderwidth=2,relief=SUNKEN)
        self.frameMain.pack(side=TOP, expand=TRUE, fill=BOTH)
        self.messageInfo = Message(self.frameMain, anchor=W, justify=LEFT,
                    padx=5, pady=5, text=self.message) #,aspect=200)
        entryName = Entry(self.frameMain, textvariable=self.name, width=30)
        entryName.focus_set()
        self.messageInfo.pack(padx=5, pady=5) #,expand=TRUE,fill=BOTH)
        entryName.pack(padx=5, pady=5)

        frameButtons = Frame(self, pady=2)
        frameButtons.pack(side=BOTTOM)
        self.buttonOk = Button(frameButtons,text='Ok',
                width=8, command=self.Ok)
        self.buttonOk.pack(side=LEFT, padx=5)
        self.buttonCancel = Button(frameButtons,text='Cancel',
                width=8, command=self.Cancel)
        self.buttonCancel.pack(side=RIGHT, padx=5)

    def NameOk(self):
        ''' After stripping entered name, check that it is a  sensible
        ConfigParser file section name. Return it if it is, '' if not.
        '''
        name = self.name.get().strip()
        if not name: #no name specified
            tkMessageBox.showerror(title='Name Error',
                    message='No name specified.', parent=self)
        elif len(name)>30: #name too long
            tkMessageBox.showerror(title='Name Error',
                    message='Name too long. It should be no more than '+
                    '30 characters.', parent=self)
            name = ''
        elif name in self.usedNames:
            tkMessageBox.showerror(title='Name Error',
                    message='This name is already in use.', parent=self)
            name = ''
        return name

    def Ok(self, event=None):
        name = self.NameOk()
        if name:
            self.result = name
            self.destroy()

    def Cancel(self, event=None):
        self.result = ''
        self.destroy()

if __name__ == '__main__':
    #test the dialog
    root=Tk()
    def run():
        dlg=GetCfgSectionNameDialog(root,'Get Name',
                "After the text entered with [Ok] is stripped, <nothing>, "
                "'abc', or more that 30 chars are errors. "
                "Close with a valid entry (printed), [Cancel], or [X]",
                ['abc'])
        print(dlg.result)
    Message(root, text='').pack()  # will be needed for oher dialog tests
    Button(root, text='Click to begin dialog test', command=run).pack()
    root.mainloop()