# Copyright (C) 2007, Red Hat, Inc.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.

"""
All the constants are expressed in pixels. They are defined for the XO screen
and are usually adapted to different resolution by applying a zoom factor. The
factor for traditional 96 dpi screen is currently 0.72 which is the inverse
of the one we are using to adapt web pages to the XO screen. It should be
considered a reference value rather then a scale constant which has to be
automatically applied and always respected.
"""

import os

import gtk
import pango

_XO_DPI = 200.0

_FOCUS_LINE_WIDTH = 2
_TAB_CURVATURE = 1

def _get_screen_dpi():
    xft_dpi = gtk.settings_get_default().get_property('gtk-xft-dpi')
    return float(xft_dpi / 1024)

def _compute_zoom_factor():
    if _get_screen_dpi() == 96.0:
        if not os.environ.has_key('SUGAR_XO_STYLE') or \
           not os.environ['SUGAR_XO_STYLE'] == 'yes':
            return 0.72

    return 1.0

def _compute_font_height(font):
    widget = gtk.Label('')

    context = widget.get_pango_context()
    pango_font = context.load_font(font.get_pango_desc())
    metrics = pango_font.get_metrics()
    
    return pango.PIXELS(metrics.get_ascent() + metrics.get_descent())

class Font(object):
    def __init__(self, desc):
        self._desc = desc

    def __str__(self):
        return self._desc

    def get_pango_desc(self):
        return pango.FontDescription(self._desc)

class Color(object):
    def __init__(self, color, alpha=1.0):
        self._r, self._g, self._b = self._html_to_rgb(color)
        self._a = alpha

    def get_rgba(self):
        return (self._r, self._g, self._b, self._a)

    def get_int(self):
        return int(self._a * 255) + (int(self._b * 255) << 8) + \
                (int(self._g * 255) << 16) + (int(self._r * 255) << 24)

    def get_gdk_color(self):
        return gtk.gdk.Color(int(self._r * 65535), int(self._g * 65535),
                             int(self._b * 65535))

    def get_html(self):
        return '#%02x%02x%02x' % (self._r * 255, self._g * 255, self._b * 255)

    def _html_to_rgb(self, html_color):
        """ #RRGGBB -> (r, g, b) tuple (in float format) """

        html_color = html_color.strip()
        if html_color[0] == '#':
            html_color = html_color[1:]
        if len(html_color) != 6:
            raise ValueError, "input #%s is not in #RRGGBB format" % html_color

        r, g, b = html_color[:2], html_color[2:4], html_color[4:]
        r, g, b = [int(n, 16) for n in (r, g, b)]
        r, g, b = (r / 255.0, g / 255.0, b / 255.0)

        return (r, g, b)

    def get_svg(self):
        if self._a == 0.0:
            return 'none'
        else:
            return self.get_html()

def zoom(units):
    return int(ZOOM_FACTOR * units)

ZOOM_FACTOR = _compute_zoom_factor()

DEFAULT_SPACING = zoom(8)
DEFAULT_PADDING = zoom(6)
GRID_CELL_SIZE = zoom(75)
LINE_WIDTH = zoom(2)

STANDARD_ICON_SIZE = zoom(55)
SMALL_ICON_SIZE = zoom(55 * 0.5)
MEDIUM_ICON_SIZE = zoom(55 * 1.5)
LARGE_ICON_SIZE = zoom(55 * 2.0)
XLARGE_ICON_SIZE = zoom(55 * 2.75)

FONT_SIZE = zoom(7 * _XO_DPI / _get_screen_dpi())
FONT_NORMAL = Font('Bitstream Vera Sans %d' % FONT_SIZE)
FONT_BOLD = Font('Bitstream Vera Sans bold %d' % FONT_SIZE)
FONT_NORMAL_H = _compute_font_height(FONT_NORMAL)
FONT_BOLD_H = _compute_font_height(FONT_BOLD)

TOOLBOX_SEPARATOR_HEIGHT = zoom(9)
TOOLBOX_HORIZONTAL_PADDING = zoom(75)
TOOLBOX_TAB_VBORDER = int((zoom(36) - FONT_NORMAL_H - _FOCUS_LINE_WIDTH) / 2)
TOOLBOX_TAB_HBORDER = zoom(15) - _FOCUS_LINE_WIDTH - _TAB_CURVATURE
TOOLBOX_TAB_LABEL_WIDTH = zoom(150 - 15 * 2)

COLOR_BLACK = Color('#000000')
COLOR_WHITE = Color('#FFFFFF')
COLOR_TRANSPARENT = Color('#FFFFFF', alpha=0.0)
COLOR_PANEL_GREY = Color('#C0C0C0')
COLOR_SELECTION_GREY = Color('#A6A6A6')
COLOR_TOOLBAR_GREY = Color('#404040')
COLOR_BUTTON_GREY = Color('#808080')
COLOR_INACTIVE_FILL = Color('#9D9FA1')
COLOR_INACTIVE_STROKE = Color('#757575')
COLOR_TEXT_FIELD_GREY = Color('#E5E5E5')

PALETTE_CURSOR_DISTANCE = zoom(10)