#------------------------------------------------------------------------------
# Copyright (c) 2005, Enthought, Inc.
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in enthought/LICENSE.txt and may be redistributed only
# under the conditions described in the aforementioned license.  The license
# is also available online at http://www.enthought.com/licenses/BSD.txt
# Thanks for using Enthought open source!
#
# Author: Enthought, Inc.
# Description: <Enthought util package component>
#------------------------------------------------------------------------------
#-------------------------------------------------------------------------------
#
#  Provides a simple object for interacting with the system clipboard.
#
#  Written by: David C. Morrill
#
#  Date: 01/11/2005
#
#  (c) Copyright 2005 by Enthought, Inc.
#
#-------------------------------------------------------------------------------

#-------------------------------------------------------------------------------
#  Imports:
#-------------------------------------------------------------------------------

import wx

from cStringIO \
    import StringIO

from cPickle \
    import dumps, load, loads

from enthought.traits.api \
    import HasStrictTraits, Property

#-------------------------------------------------------------------------------
#  Constants:
#-------------------------------------------------------------------------------

# Data formats:
PythonObjectFormat = wx.CustomDataFormat( 'PythonObject' )
TextFormat         = wx.DataFormat( wx.DF_TEXT )
FileFormat         = wx.DataFormat( wx.DF_FILENAME )

# Shortcuts:
cb           = wx.TheClipboard
is_supported = cb.IsSupported

# Standard sequence types:
SequenceTypes = ( list, tuple )

#-------------------------------------------------------------------------------
#  'Clipboard' class:
#-------------------------------------------------------------------------------

class Clipboard ( HasStrictTraits ):

    #---------------------------------------------------------------------------
    #  Trait definitions:
    #---------------------------------------------------------------------------

    data_type       = Property  # The type of data in the clipboard (string)
    data            = Property  # Arbitrary Python data
    has_data        = Property  # Arbitrary Python data is available

    object_type     = Property  # Name of the class of object in the clipboard
    object_data     = Property  # Python object data
    has_object_data = Property  # Python object data is available

    text_data       = Property  # Text data
    has_text_data   = Property  # Text data is available

    file_data       = Property  # File name data
    has_file_data   = Property  # File name data is available

    #---------------------------------------------------------------------------
    #  'data' property methods:
    #---------------------------------------------------------------------------

    def _get_data ( self ):
        if self.has_text_data:
            return self.text_data
        if self.has_file_data:
            return self.file_data
        if self.has_object_data:
            return self.object_data
        return None

    def _set_data ( self, data ):
        if isinstance(data, basestring):
            self.text_data = data
        elif type( data ) in SequenceTypes:
            self.file_data = data
        else:
            self.object_data = data

    def _get_has_data ( self ):
        result = False
        if cb.Open():
            result = (is_supported( TextFormat ) or
                      is_supported( FileFormat ) or
                      is_supported( PythonObjectFormat ))
            cb.Close()
        return result

    def _get_data_type ( self ):
        if self.has_text_data:
            return 'str'
        if self.has_file_data:
            return 'file'
        if self.has_object_data:
            return self.object_type
        return ''

    #---------------------------------------------------------------------------
    #  'object_data' property methods:
    #---------------------------------------------------------------------------

    def _get_object_data ( self ):
        result = None
        if cb.Open():
            try:
                if is_supported( PythonObjectFormat ):
                    cdo = wx.CustomDataObject( PythonObjectFormat )
                    if cb.GetData( cdo ):
                        file   = StringIO( cdo.GetData() )
                        klass  = load( file )
                        result = load( file )
            finally:
                cb.Close()
        return result

    def _set_object_data ( self, data ):
        if cb.Open():
            try:
                cdo = wx.CustomDataObject( PythonObjectFormat )
                cdo.SetData( dumps( data.__class__ ) + dumps( data ) )
                # fixme: There seem to be cases where the '-1' value creates
                # pickles that can't be unpickled (e.g. some TraitDictObject's)
                #cdo.SetData( dumps( data, -1 ) )
                cb.SetData( cdo )
            finally:
                cb.Close()
                cb.Flush()

    def _get_has_object_data ( self ):
        return self._has_this_data( PythonObjectFormat )

    def _get_object_type ( self ):
        result = ''
        if cb.Open():
            try:
                if is_supported( PythonObjectFormat ):
                    cdo = wx.CustomDataObject( PythonObjectFormat )
                    if cb.GetData( cdo ):
                        try:
                            # We may not be able to load the required class:
                            result = loads( cdo.GetData() )
                        except:
                            pass
            finally:
                cb.Close()
        return result

    #---------------------------------------------------------------------------
    #  'text_data' property methods:
    #---------------------------------------------------------------------------

    def _get_text_data ( self ):
        result = ''
        if cb.Open():
            if is_supported( TextFormat ):
                tdo = wx.TextDataObject()
                if cb.GetData( tdo ):
                    result = tdo.GetText()
            cb.Close()
        return result

    def _set_text_data ( self, data ):
        if cb.Open():
            cb.SetData( wx.TextDataObject( str( data ) ) )
            cb.Close()
            cb.Flush()

    def _get_has_text_data ( self ):
        return self._has_this_data( TextFormat )

    #---------------------------------------------------------------------------
    #  'file_data' property methods:
    #---------------------------------------------------------------------------

    def _get_file_data ( self ):
        result = []
        if cb.Open():
            if is_supported( FileFormat ):
                tfo = wx.FileDataObject()
                if cb.GetData( tfo ):
                    result = tfo.GetFilenames()
            cb.Close()
        return result

    def _set__file_data ( self, data ):
        if cb.Open():
            tfo = wx.FileDataObject()
            if isinstance(data, basestring):
                tfo.AddFile( data )
            else:
                for filename in data:
                    tfo.AddFile( filename )
            cb.SetData( tfo )
            cb.Close()
            cb.Flush()

    def _get_has_file_data ( self ):
        return self._has_this_data( FileFormat )

    #---------------------------------------------------------------------------
    #  Private helper methods:
    #---------------------------------------------------------------------------

    def _has_this_data ( self, format ):
        result = False
        if cb.Open():
            result = is_supported( format )
            cb.Close()
        return result

#-------------------------------------------------------------------------------
#  Create a singleton instance for quick reference:
#-------------------------------------------------------------------------------

clipboard = Clipboard()