"""
Copyright 2007, 2008, 2009 Free Software Foundation, Inc.
This file is part of GNU Radio

GNU Radio Companion is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

GNU Radio Companion 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
"""

from Constants import LINE_SELECT_SENSITIVITY
from Constants import POSSIBLE_ROTATIONS

import gtk


class Element(object):
    """
    GraphicalElement is the base class for all graphical elements.
    It contains an X,Y coordinate, a list of rectangular areas that the element occupies,
    and methods to detect selection of those areas.
    """

    def __init__(self):
        """
        Make a new list of rectangular areas and lines, and set the coordinate and the rotation.
        """
        self.set_rotation(POSSIBLE_ROTATIONS[0])
        self.set_coordinate((0, 0))
        self.clear()
        self.set_highlighted(False)
        self.line_attributes = [
            0, gtk.gdk.LINE_SOLID, gtk.gdk.CAP_BUTT, gtk.gdk.JOIN_MITER
        ]

    def is_horizontal(self, rotation=None):
        """
        Is this element horizontal?
        If rotation is None, use this element's rotation.

        Args:
            rotation: the optional rotation

        Returns:
            true if rotation is horizontal
        """
        rotation = rotation or self.get_rotation()
        return rotation in (0, 180)

    def is_vertical(self, rotation=None):
        """
        Is this element vertical?
        If rotation is None, use this element's rotation.

        Args:
            rotation: the optional rotation

        Returns:
            true if rotation is vertical
        """
        rotation = rotation or self.get_rotation()
        return rotation in (90, 270)

    def create_labels(self):
        """
        Create labels (if applicable) and call on all children.
        Call this base method before creating labels in the element.
        """
        for child in self.get_children():child.create_labels()

    def create_shapes(self):
        """
        Create shapes (if applicable) and call on all children.
        Call this base method before creating shapes in the element.
        """
        self.clear()
        for child in self.get_children(): child.create_shapes()

    def draw(self, gc, window, border_color, bg_color):
        """
        Draw in the given window.

        Args:
            gc: the graphics context
            window: the gtk window to draw on
            border_color: the color for lines and rectangle borders
            bg_color: the color for the inside of the rectangle
        """
        X, Y = self.get_coordinate()
        gc.set_line_attributes(*self.line_attributes)
        for (rX, rY), (W, H) in self._areas_list:
            aX = X + rX
            aY = Y + rY
            gc.set_foreground(bg_color)
            window.draw_rectangle(gc, True, aX, aY, W, H)
            gc.set_foreground(border_color)
            window.draw_rectangle(gc, False, aX, aY, W, H)
        for (x1, y1), (x2, y2) in self._lines_list:
            gc.set_foreground(border_color)
            gc.set_background(bg_color)
            window.draw_line(gc, X+x1, Y+y1, X+x2, Y+y2)

    def rotate(self, rotation):
        """
        Rotate all of the areas by 90 degrees.

        Args:
            rotation: multiple of 90 degrees
        """
        self.set_rotation((self.get_rotation() + rotation)%360)

    def clear(self):
        """Empty the lines and areas."""
        self._areas_list = list()
        self._lines_list = list()

    def set_coordinate(self, coor):
        """
        Set the reference coordinate.

        Args:
            coor: the coordinate tuple (x,y)
        """
        self.coor = coor

    def get_parent(self):
        """
        Get the parent of this element.

        Returns:
            the parent
        """
        return self.parent

    def set_highlighted(self, highlighted):
        """
        Set the highlight status.

        Args:
            highlighted: true to enable highlighting
        """
        self.highlighted = highlighted

    def is_highlighted(self):
        """
        Get the highlight status.

        Returns:
            true if highlighted
        """
        return self.highlighted

    def get_coordinate(self):
        """Get the coordinate.

        Returns:
            the coordinate tuple (x,y)
        """
        return self.coor

    def move(self, delta_coor):
        """
        Move the element by adding the delta_coor to the current coordinate.

        Args:
            delta_coor: (delta_x,delta_y) tuple
        """
        deltaX, deltaY = delta_coor
        X, Y = self.get_coordinate()
        self.set_coordinate((X+deltaX, Y+deltaY))

    def add_area(self, rel_coor, area):
        """
        Add an area to the area list.
        An area is actually a coordinate relative to the main coordinate
        with a width/height pair relative to the area coordinate.
        A positive width is to the right of the coordinate.
        A positive height is above the coordinate.
        The area is associated with a rotation.

        Args:
            rel_coor: (x,y) offset from this element's coordinate
            area: (width,height) tuple
        """
        self._areas_list.append((rel_coor, area))

    def add_line(self, rel_coor1, rel_coor2):
        """
        Add a line to the line list.
        A line is defined by 2 relative coordinates.
        Lines must be horizontal or vertical.
        The line is associated with a rotation.

        Args:
            rel_coor1: relative (x1,y1) tuple
            rel_coor2: relative (x2,y2) tuple
        """
        self._lines_list.append((rel_coor1, rel_coor2))

    def what_is_selected(self, coor, coor_m=None):
        """
        One coordinate specified:
            Is this element selected at given coordinate?
            ie: is the coordinate encompassed by one of the areas or lines?
        Both coordinates specified:
            Is this element within the rectangular region defined by both coordinates?
            ie: do any area corners or line endpoints fall within the region?

        Args:
            coor: the selection coordinate, tuple x, y
            coor_m: an additional selection coordinate.

        Returns:
            self if one of the areas/lines encompasses coor, else None.
        """
        #function to test if p is between a and b (inclusive)
        in_between = lambda p, a, b: p >= min(a, b) and p <= max(a, b)
        #relative coordinate
        x, y = [a-b for a,b in zip(coor, self.get_coordinate())]
        if coor_m:
            x_m, y_m = [a-b for a,b in zip(coor_m, self.get_coordinate())]
            #handle rectangular areas
            for (x1,y1), (w,h) in self._areas_list:
                if in_between(x1, x, x_m) and in_between(y1, y, y_m) or \
                    in_between(x1+w, x, x_m) and in_between(y1, y, y_m) or \
                    in_between(x1, x, x_m) and in_between(y1+h, y, y_m) or \
                    in_between(x1+w, x, x_m) and in_between(y1+h, y, y_m):
                    return self
            #handle horizontal or vertical lines
            for (x1, y1), (x2, y2) in self._lines_list:
                if in_between(x1, x, x_m) and in_between(y1, y, y_m) or \
                    in_between(x2, x, x_m) and in_between(y2, y, y_m):
                    return self
            return None
        else:
            #handle rectangular areas
            for (x1,y1), (w,h) in self._areas_list:
                if in_between(x, x1, x1+w) and in_between(y, y1, y1+h): return self
            #handle horizontal or vertical lines
            for (x1, y1), (x2, y2) in self._lines_list:
                if x1 == x2: x1, x2 = x1-LINE_SELECT_SENSITIVITY, x2+LINE_SELECT_SENSITIVITY
                if y1 == y2: y1, y2 = y1-LINE_SELECT_SENSITIVITY, y2+LINE_SELECT_SENSITIVITY
                if in_between(x, x1, x2) and in_between(y, y1, y2): return self
            return None

    def get_rotation(self):
        """
        Get the rotation in degrees.

        Returns:
            the rotation
        """
        return self.rotation

    def set_rotation(self, rotation):
        """
        Set the rotation in degrees.

        Args:
            rotation: the rotation"""
        if rotation not in POSSIBLE_ROTATIONS:
            raise Exception('"%s" is not one of the possible rotations: (%s)'%(rotation, POSSIBLE_ROTATIONS))
        self.rotation = rotation

    def mouse_over(self):
        pass

    def mouse_out(self):
        pass
