"""
This demonstrates using the Traits file dialog with a file dialog extension,
in this case, the <b>FileInfo</b> extension, which displays information about
the currently selected file, such as:

 - File size.
 - Date and time last accessed.
 - Date and time last modified.
 - Date and time last created.

For more information about why you would want to use the Traits file dialog
over the standard OS file dialog, select the <b>File Open</b> demo. For a
demonstration of writing a custom file dialog extension, select the
<b>File Open with Custom Extension</b> demo.
"""

#-- Imports --------------------------------------------------------------

from traits.api \
    import HasTraits, File, Button

from traitsui.api \
    import View, HGroup, Item

from traitsui.file_dialog  \
    import open_file, FileInfo

#-- FileDialogDemo Class -------------------------------------------------

# Demo specific file dialig id:
demo_id = 'traitsui.demo.standard_editors.file_dialog.file_info'


class FileDialogDemo(HasTraits):

    # The name of the selected file:
    file_name = File()

    # The button used to display the file dialog:
    open = Button('Open...')

    #-- Traits View Definitions ----------------------------------------------

    view = View(
        HGroup(
            Item('open', show_label=False),
            '_',
            Item('file_name', style='readonly', springy=True)
        ),
        width=0.5
    )

    #-- Traits Event Handlers ------------------------------------------------

    def _open_changed(self):
        """ Handles the user clicking the 'Open...' button.
        """
        file_name = open_file(extensions=FileInfo(), id=demo_id)
        if file_name != '':
            self.file_name = file_name

# Create the demo:
demo = FileDialogDemo()

# Run the demo (if invoked from the command line):
if __name__ == '__main__':
    demo.configure_traits()
