#------------------------------------------------------------------------------
# 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 color editors for the PyQt user interface toolkit.
"""



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

from pyface.qt import QtCore, QtGui

from traitsui.editors.color_editor \
    import ToolkitEditorFactory as BaseToolkitEditorFactory

from .editor_factory \
    import SimpleEditor as BaseSimpleEditor, \
    TextEditor as BaseTextEditor, \
    ReadonlyEditor as BaseReadonlyEditor

from .editor \
    import Editor

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

# Standard color samples:
color_samples = []

#---------------------------------------------------------------------------
#  The PyQt ToolkitEditorFactory class.
#---------------------------------------------------------------------------

## We need to add qt4-specific methods to the editor factory (since all editors
## will be accessing these functions. Making these functions global functions
## in this file does not work quite well, since we want custom editors to
## override these methods easily.


class ToolkitEditorFactory(BaseToolkitEditorFactory):
    """ PyQt editor factory for color editors.
    """

    #-------------------------------------------------------------------------
    #  Gets the PyQt color equivalent of the object trait:
    #-------------------------------------------------------------------------

    def to_qt4_color(self, editor):
        """ Gets the PyQt color equivalent of the object trait.
        """
        if self.mapped:
            return getattr(editor.object, editor.name + '_')

        return getattr(editor.object, editor.name)

    #-------------------------------------------------------------------------
    #  Gets the application equivalent of a PyQt value:
    #-------------------------------------------------------------------------

    def from_qt4_color(self, color):
        """ Gets the application equivalent of a PyQt value.
        """
        return color

    #-------------------------------------------------------------------------
    #  Returns the text representation of a specified color value:
    #-------------------------------------------------------------------------

    def str_color(self, color):
        """ Returns the text representation of a specified color value.
        """
        if isinstance(color, QtGui.QColor):
            alpha = color.alpha()
            if alpha == 255:
                return "(%d,%d,%d)" % (
                    color.red(), color.green(), color.blue())

            return "(%d,%d,%d,%d)" % (
                color.red(), color.green(), color.blue(), alpha)

        return color

#-------------------------------------------------------------------------
#  'SimpleColorEditor' class:
#-------------------------------------------------------------------------


class SimpleColorEditor(BaseSimpleEditor):
    """ Simple style of color editor, which displays a text field whose
    background color is the color value. Selecting the text field displays
    a dialog box for selecting a new color value.
    """

    #-------------------------------------------------------------------------
    #  Invokes the pop-up editor for an object trait:
    #-------------------------------------------------------------------------

    def popup_editor(self):
        """ Invokes the pop-up editor for an object trait.
        """
        color = self.factory.to_qt4_color(self)
        options = QtGui.QColorDialog.ShowAlphaChannel
        if not self.factory.use_native_dialog:
            options |= QtGui.QColorDialog.DontUseNativeDialog
        color = QtGui.QColorDialog.getColor(
            color,
            self.control,
            'Select Color',
            options,
        )

        if color.isValid():
            self.value = self.factory.from_qt4_color(color)
            self.update_editor()

    #-------------------------------------------------------------------------
    #  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.
        """
        super(SimpleColorEditor, self).update_editor()
        set_color(self)

    #-------------------------------------------------------------------------
    #  Returns the text representation of a specified color value:
    #-------------------------------------------------------------------------

    def string_value(self, color):
        """ Returns the text representation of a specified color value.
        """
        return self.factory.str_color(color)

#-------------------------------------------------------------------------
#  'CustomColorEditor' class:
#-------------------------------------------------------------------------


class CustomColorEditor(Editor):
    """ Custom style of color editor, which displays a color editor panel.
    """

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

    def init(self, parent):
        """ Finishes initializing the editor by creating the underlying toolkit
            widget.
        """
        self.control, self._simple_field = color_editor_for(self, parent)

    #-------------------------------------------------------------------------
    #  Disposes of the contents of an editor:
    #-------------------------------------------------------------------------

    def dispose(self):
        """ Disposes of the contents of an editor.
        """
        if getattr(self, '_simple_field', None) is not None:
            self._simple_field.dispose()
            self._simple_field = None
        super(CustomColorEditor, self).dispose()

    #-------------------------------------------------------------------------
    #  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.
        """
        self._simple_field.update_editor()

    #-------------------------------------------------------------------------
    #  Updates the object trait when a color swatch is clicked:
    #-------------------------------------------------------------------------

    def update_object_from_swatch(self, color_text):
        """ Updates the object trait when a color swatch is clicked.
        """
        color = QtGui.QColor(*[int(part) for part in color_text.split(',')])
        self.value = self.factory.from_qt4_color(color)
        self.update_editor()

    #-------------------------------------------------------------------------
    #  Returns the text representation of a specified color value:
    #-------------------------------------------------------------------------

    def string_value(self, color):
        """ Returns the text representation of a specified color value.
        """
        return self.factory.str_color(color)

#-------------------------------------------------------------------------
#  'TextColorEditor' class:
#-------------------------------------------------------------------------


class TextColorEditor(BaseTextEditor):
    """ Text style of color editor, which displays a text field whose
    background color is the color value.
    """

    #-------------------------------------------------------------------------
    #  Handles the user changing the contents of the edit control:
    #-------------------------------------------------------------------------

    def update_object(self):
        """ Handles the user changing the contents of the edit control.
        """
        self.value = str(self.control.text())
        set_color(self)

    #-------------------------------------------------------------------------
    #  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.
        """
        super(TextColorEditor, self).update_editor()
        set_color(self)

    #-------------------------------------------------------------------------
    #  Returns the text representation of a specified color value:
    #-------------------------------------------------------------------------

    def string_value(self, color):
        """ Returns the text representation of a specified color value.
        """
        return self.factory.str_color(color)

#-------------------------------------------------------------------------
#  'ReadonlyColorEditor' class:
#-------------------------------------------------------------------------


class ReadonlyColorEditor(BaseReadonlyEditor):
    """ Read-only style of color editor, which displays a read-only text field
    whose background color is the color value.
    """

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

    def init(self, parent):
        """ Finishes initializing the editor by creating the underlying toolkit
            widget.
        """
        self.control = QtGui.QLineEdit()
        self.control.setReadOnly(True)

    #-------------------------------------------------------------------------
    #  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.
        """
        super(ReadonlyColorEditor, self).update_editor()
        set_color(self)

    #-------------------------------------------------------------------------
    #  Returns the text representation of a specified color value:
    #-------------------------------------------------------------------------

    def string_value(self, color):
        """ Returns the text representation of a specified color value.
        """
        return self.factory.str_color(color)

#-------------------------------------------------------------------------
#   Sets the color of the specified editor's color control:
#-------------------------------------------------------------------------


def set_color(editor):
    """  Sets the color of the specified color control.
    """
    color = editor.factory.to_qt4_color(editor)
    pal = QtGui.QPalette(editor.control.palette())

    pal.setColor(QtGui.QPalette.Base, color)

    if (color.red() > 192 or color.blue() > 192 or color.green() > 192):
        pal.setColor(QtGui.QPalette.Text, QtCore.Qt.black)
    else:
        pal.setColor(QtGui.QPalette.Text, QtCore.Qt.white)

    editor.control.setPalette(pal)

#----------------------------------------------------------------------------
#  Creates a custom color editor panel for a specified editor:
#----------------------------------------------------------------------------


class FixedButton(QtGui.QPushButton):
    """ Override to work around a bug in Qt 4.7 on Macs.

    https://bugreports.qt-project.org/browse/QTBUG-15936
    """

    def hitButton(self, pos):
        return QtGui.QAbstractButton.hitButton(self, pos)


def color_editor_for(editor, parent):
    """ Creates a custom color editor panel for a specified editor.
    """
    # Create the colour samples if it hasn't already been done.
    if len(color_samples) == 0:
        color_choices = (0, 128, 192, 255)
        for r in color_choices:
            for g in color_choices:
                for b in (0, 128, 255):
                    color_samples.append(QtGui.QColor(r, g, b))

    root = QtGui.QWidget()
    panel = QtGui.QHBoxLayout(root)
    panel.setContentsMargins(0, 0, 0, 0)

    swatch_editor = editor.factory.simple_editor(
        editor.ui, editor.object, editor.name, editor.description, None)
    swatch_editor.prepare(parent)
    panel.addWidget(swatch_editor.control)

    # Add all of the color choice buttons:
    grid = QtGui.QGridLayout()
    grid.setSpacing(0)

    mapper = QtCore.QSignalMapper(panel)

    rows = 4
    cols = len(color_samples) // rows
    i = 0

    sheet_template = """
    QPushButton {
        min-height: 18px;
        max-height: 18px;
        min-width: 18px;
        max-width: 18px;
        background-color: rgb(%s);
    }
    """

    for r in range(rows):
        for c in range(cols):
            control = FixedButton()
            color = color_samples[r * cols + c]
            color_text = '%d,%d,%d,%d' % color.getRgb()
            control.setStyleSheet(sheet_template % color_text)
            control.setAttribute(QtCore.Qt.WA_LayoutUsesWidgetRect, True)

            control.clicked.connect(mapper.map)
            mapper.setMapping(control, color_text)

            grid.addWidget(control, r, c)
            editor.set_tooltip(control)

            i += 1

    mapper.mapped[str].connect(editor.update_object_from_swatch)

    panel.addLayout(grid)

    return root, swatch_editor


# Define the SimpleEditor, CustomEditor, etc. classes which are used by the
# editor factory for the color editor.
SimpleEditor = SimpleColorEditor
CustomEditor = CustomColorEditor
TextEditor = TextColorEditor
ReadonlyEditor = ReadonlyColorEditor
