"""Simple text browser for IDLE

"""
from tkinter import *
from tkinter.ttk import Scrollbar
from tkinter.messagebox import showerror


class TextViewer(Toplevel):
    "A simple text viewer dialog for IDLE."

    def __init__(self, parent, title, text, modal=True,
                 _htest=False, _utest=False):
        """Show the given text in a scrollable window with a 'close' button.

        If modal is left True, users cannot interact with other windows
        until the textview window is closed.

        _htest - bool; change box location when running htest.
        _utest - bool; don't wait_window when running unittest.
        """
        Toplevel.__init__(self, parent)
        self.configure(borderwidth=5)
        # Place dialog below parent if running htest.
        self.geometry("=%dx%d+%d+%d" % (750, 500,
                           parent.winfo_rootx() + 10,
                           parent.winfo_rooty() + (10 if not _htest else 100)))
        # TODO: get fg/bg from theme.
        self.bg = '#ffffff'
        self.fg = '#000000'

        self.CreateWidgets()
        self.title(title)
        self.protocol("WM_DELETE_WINDOW", self.Ok)
        self.parent = parent
        self.textView.focus_set()
        # Bind keys for closing this dialog.
        self.bind('<Return>',self.Ok)
        self.bind('<Escape>',self.Ok)
        self.textView.insert(0.0, text)
        self.textView.config(state=DISABLED)

        if modal:
            self.transient(parent)
            self.grab_set()
            if not _utest:
                self.wait_window()

    def CreateWidgets(self):
        "Create Frame with Text (with vertical Scrollbar) and Button."
        frameText = Frame(self, relief=SUNKEN, height=700)
        frameButtons = Frame(self)
        self.buttonOk = Button(frameButtons, text='Close',
                               command=self.Ok, takefocus=FALSE)
        self.scrollbarView = Scrollbar(frameText, orient=VERTICAL,
                                       takefocus=FALSE)
        self.textView = Text(frameText, wrap=WORD, highlightthickness=0,
                             fg=self.fg, bg=self.bg)
        self.scrollbarView.config(command=self.textView.yview)
        self.textView.config(yscrollcommand=self.scrollbarView.set)
        self.buttonOk.pack()
        self.scrollbarView.pack(side=RIGHT,fill=Y)
        self.textView.pack(side=LEFT,expand=TRUE,fill=BOTH)
        frameButtons.pack(side=BOTTOM,fill=X)
        frameText.pack(side=TOP,expand=TRUE,fill=BOTH)

    def Ok(self, event=None):
        self.destroy()


def view_text(parent, title, text, modal=True, _utest=False):
    "Display text in a TextViewer."
    return TextViewer(parent, title, text, modal, _utest=_utest)

def view_file(parent, title, filename, encoding=None, modal=True, _utest=False):
    "Display file in a TextViever or show error message."
    try:
        with open(filename, 'r', encoding=encoding) as file:
            contents = file.read()
    except OSError:
        showerror(title='File Load Error',
                  message='Unable to load file %r .' % filename,
                  parent=parent)
    except UnicodeDecodeError as err:
        showerror(title='Unicode Decode Error',
                  message=str(err),
                  parent=parent)
    else:
        return view_text(parent, title, contents, modal, _utest=_utest)
    return None


if __name__ == '__main__':
    import unittest
    unittest.main('idlelib.idle_test.test_textview', verbosity=2, exit=False)
    from idlelib.idle_test.htest import run
    run(TextViewer)