#------------------------------------------------------------------------------
# Copyright (c) 2007, Riverbank Computing Limited
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD license.
# However, when used with the GPL version of PyQt the additional terms described in the PyQt GPL exception also apply

#
# Author: Riverbank Computing Limited
#------------------------------------------------------------------------------

""" Defines the various text editors for the PyQt user interface toolkit.
"""

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

from pyface.qt import QtCore, QtGui

from traits.api \
    import TraitError

# FIXME: ToolkitEditorFactory is a proxy class defined here just for backward
# compatibility. The class has been moved to the
# traitsui.editors.text_editor file.
from traitsui.editors.text_editor \
    import evaluate_trait, ToolkitEditorFactory

from .editor \
    import Editor

from .editor_factory \
    import ReadonlyEditor as BaseReadonlyEditor

from .constants \
    import OKColor

#-------------------------------------------------------------------------------
#  'SimpleEditor' class:
#-------------------------------------------------------------------------------

class SimpleEditor ( Editor ):
    """ Simple style text editor, which displays a text field.
    """

    # Flag for window styles:
    base_style = QtGui.QLineEdit

    # Background color when input is OK:
    ok_color = OKColor

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

    # Function used to evaluate textual user input:
    evaluate = evaluate_trait

    #---------------------------------------------------------------------------
    #  Finishes initializing the editor by creating the underlying toolkit
    #  widget:
    #---------------------------------------------------------------------------

    def init ( self, parent ):
        """ Finishes initializing the editor by creating the underlying toolkit
            widget.
        """
        factory = self.factory
        wtype = self.base_style
        self.evaluate = factory.evaluate
        self.sync_value(factory.evaluate_name, 'evaluate', 'from')

        if not factory.multi_line or factory.is_grid_cell or factory.password:
            wtype = QtGui.QLineEdit

        multi_line = (wtype is not QtGui.QLineEdit)
        if multi_line:
            self.scrollable = True

        control = wtype(self.str_value)

        if factory.read_only:
            control.setReadOnly(True)

        if factory.password:
            control.setEchoMode(QtGui.QLineEdit.Password)

        if factory.auto_set and not factory.is_grid_cell:
            if wtype == QtGui.QTextEdit:
                QtCore.QObject.connect(control,
                    QtCore.SIGNAL('textChanged()'), self.update_object)
            else:
                QtCore.QObject.connect(control,
                    QtCore.SIGNAL('textEdited(QString)'), self.update_object)

        else:
            # Assume enter_set is set, otherwise the value will never get
            # updated.
            QtCore.QObject.connect(control, QtCore.SIGNAL('editingFinished()'),
                    self.update_object)

        self.control = control
        # default horizontal policy is Expand, set this to Minimum
        if not (self.item.resizable == True) and not self.item.springy:
            policy = self.control.sizePolicy()
            policy.setHorizontalPolicy(QtGui.QSizePolicy.Minimum)
            self.control.setSizePolicy(policy)
        self.set_error_state( False )
        self.set_tooltip()

    #---------------------------------------------------------------------------
    #  Handles the user entering input data in the edit control:
    #---------------------------------------------------------------------------

    def update_object ( self ):
        """ Handles the user entering input data in the edit control.
        """
        if (not self._no_update) and (self.control is not None):
            try:
                self.value = self._get_user_value()

                if self._error is not None:
                    self._error = None
                    self.ui.errors -= 1

                self.set_error_state( False )

            except TraitError as excp:
                pass

    #---------------------------------------------------------------------------
    #  Updates the editor when the object trait changes external to the editor:
    #---------------------------------------------------------------------------

    def update_editor ( self ):
        """ Updates the editor when the object trait changes externally to the
            editor.
        """
        user_value = self._get_user_value()
        try:
            unequal = bool(user_value != self.value)
        except ValueError:
            # This might be a numpy array.
            unequal = True

        if unequal:
            self._no_update = True
            self.control.setText(self.str_value)
            self._no_update = False

        if self._error is not None:
            self._error = None
            self.ui.errors -= 1
            self.set_error_state( False )

    #---------------------------------------------------------------------------
    #  Gets the actual value corresponding to what the user typed:
    #---------------------------------------------------------------------------

    def _get_user_value ( self ):
        """ Gets the actual value corresponding to what the user typed.
        """
        try:
            value = self.control.text()
        except AttributeError:
            value = self.control.toPlainText()

        value = str(value)

        try:
            value = self.evaluate( value )
        except:
            pass

        try:
            ret = self.factory.mapping.get(value, value)
        except TypeError:
            # The value is probably not hashable.
            ret = value

        return ret

    #---------------------------------------------------------------------------
    #  Handles an error that occurs while setting the object's trait value:
    #---------------------------------------------------------------------------

    def error ( self, excp ):
        """ Handles an error that occurs while setting the object's trait value.
        """
        if self._error is None:
            self._error = True
            self.ui.errors += 1

        self.set_error_state( True )

    #---------------------------------------------------------------------------
    #  Returns whether or not the editor is in an error state:
    #---------------------------------------------------------------------------

    def in_error_state ( self ):
        """ Returns whether or not the editor is in an error state.
        """
        return (self.invalid or self._error)

#-------------------------------------------------------------------------------
#  'CustomEditor' class:
#-------------------------------------------------------------------------------

class CustomEditor ( SimpleEditor ):
    """ Custom style of text editor, which displays a multi-line text field.
    """

    # FIXME: The wx version exposes a wx constant.
    # Flag for window style. This value overrides the default.
    base_style = QtGui.QTextEdit

#-------------------------------------------------------------------------------
#  'ReadonlyEditor' class:
#-------------------------------------------------------------------------------

class ReadonlyEditor ( BaseReadonlyEditor ):
    """ Read-only style of text editor, which displays a read-only text field.
    """

    def init(self, parent):
        super(ReadonlyEditor, self).init(parent)

        if self.factory.readonly_allow_selection:
            flags = (self.control.textInteractionFlags() |
                QtCore.Qt.TextSelectableByMouse)
            self.control.setTextInteractionFlags(flags)

    #---------------------------------------------------------------------------
    #  Updates the editor when the object trait changes external to the editor:
    #---------------------------------------------------------------------------

    def update_editor ( self ):
        """ Updates the editor when the object trait changes externally to the
            editor.
        """
        new_value = self.str_value

        if self.factory.password:
            new_value = '*' * len(new_value)

        self.control.setText(new_value)
