# Copyright 2008 by Peter Moxhay and Wade Brainerd.  
# This file is part of Math.
#
# Math 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 3 of the License, or
# (at your option) any later version.
# 
# Math 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 Math.  If not, see <http://www.gnu.org/licenses/>.
from objectarea import Object
from vector import Vector

import gtk, math, rsvg

STEM_SVG = rsvg.Handle('balance_stem.svg')
ARM_SVG = rsvg.Handle('balance_arm.svg')
PAN_SVG = rsvg.Handle('balance_pan.svg')
OVAL_SVG = rsvg.Handle('oval.svg')
MIDDLE_SVG = rsvg.Handle('balance_middle.svg')
LEFT_SVG = rsvg.Handle('balance_left.svg')
RIGHT_SVG = rsvg.Handle('balance_right.svg')

# Class containing various standard colors.  Each color is a 3 element tuple.
class Color:
    BLUE = (0.25, 0.25, 0.75)
    GREEN = (0.25, 0.75, 0.25)
    RED = (0.75, 0.25, 0.25)


class BalanceObject(Object):
    """Balance scale for comparing masses."""

    def __init__(self, pos, container):
        Object.__init__(self)

        self.pos = pos
        self.size = Vector (200, 200)
        
        self.selectable = False
        self.rotatable = False
        
        self.container = container
        
        self.amount_scale = 1.0
        
        self.state = 'middle'
        
        self.left_pan_full = False
        self.right_pan_full = False
        
        self.pan1_position = Vector(200, 500)
        self.pan2_position = Vector(725, 500)
        
    def draw(self, cr):
        cr.scale(self.amount_scale, self.amount_scale)
            
        #if self.state == 'left':
        #    self.draw_pan(cr, Vector (self.pos.x + self.amount_scale * 20, self.pos.y + self.amount_scale * (255 + 68)))
        #    self.draw_pan(cr, Vector (self.pos.x + self.amount_scale * 539, self.pos.y + self.amount_scale * (255 - 72)))
        #elif self.state == 'right':
        #    self.draw_pan(cr, Vector (self.pos.x + self.amount_scale * 20, self.pos.y + self.amount_scale * (255 - 72)))
        #    self.draw_pan(cr, Vector (self.pos.x + self.amount_scale * 539, self.pos.y + self.amount_scale * (255 + 68)))
        #else:
        #    self.draw_pan(cr, Vector (self.pos.x + self.amount_scale * 20, self.pos.y + self.amount_scale * 255))
        #    self.draw_pan(cr, Vector (self.pos.x + self.amount_scale * 539, self.pos.y + self.amount_scale * 255))
        #    
        #self.draw_arm(cr, Vector (self.pos.x + self.amount_scale * 177, self.pos.y + self.amount_scale * 210))
        
        if self.state == 'left':
            self.draw_left(cr, Vector (self.pos.x, self.pos.y))
        elif self.state == 'right':
            self.draw_right(cr, Vector (self.pos.x, self.pos.y))
        else:
            self.draw_middle(cr, Vector (self.pos.x, self.pos.y))
    
    def adjust_balance_state(self):
        #print "BalanceObject: adjust_balance_state called, self.state =", self.state
        if self.state == 'left':
            self.pan1_position = Vector(200, 500 + 68)
            self.pan2_position = Vector(725, 500 - 72)
        elif self.state == 'right':
            self.pan1_position = Vector(200, 500 - 72)
            self.pan2_position = Vector(725, 500 + 68)
        else:
            self.pan1_position = Vector(200, 500)
            self.pan2_position = Vector(725, 500)
            
        self.queue_draw()

    def draw_circle(self, cr, pos, color):   
        cr.save()
        # Draw the fill.
        #cr.set_source_rgb(color[0], color[1], color[2])
        
        if self.selected:
            cr.set_source_rgb(color[0]*1.6, color[1]*1.6, color[2]*1.6)
        else:
            cr.set_source_rgb(color[0], color[1], color[2])
            
        cr.arc(self.pos.x + pos.x, self.pos.y + pos.y, 35, 0.0, 2.0 * math.pi)
        cr.fill()
            
        # Draw the outline.
        #cr.set_source_rgb(color[0]*0.75, color[1]*0.75, color[2]*0.75)
        
        if self.selected:
            cr.set_dash((10, 10), 0)
        cr.set_source_rgb(color[0]*0.75, color[1]*0.75, color[2]*0.75)
            
        cr.set_line_width(4.0)
        cr.arc(self.pos.x + pos.x, self.pos.y + pos.y, 35, 0.0, 2.0 * math.pi)
        cr.stroke()
        cr.restore()
        
    def draw_stem(self, cr, pos):    
        cr.save()
        cr.translate(pos.x, pos.y)
        cr.scale(3.0, 3.0)
        STEM_SVG.render_cairo(cr)
        cr.restore()
        
    def draw_left(self, cr, pos):    
        cr.save()
        cr.translate(pos.x, pos.y)
        cr.scale(3.0, 3.0)
        LEFT_SVG.render_cairo(cr)
        cr.restore()
        
    def draw_right(self, cr, pos):    
        cr.save()
        cr.translate(pos.x, pos.y)
        cr.scale(3.0, 3.0)
        RIGHT_SVG.render_cairo(cr)
        cr.restore()
        
    def draw_middle(self, cr, pos):    
        cr.save()
        cr.translate(pos.x, pos.y)
        cr.scale(3.0, 3.0)
        MIDDLE_SVG.render_cairo(cr)
        cr.restore()


    def draw_arm(self, cr, pos):    
        cr.save()
        if self.state == 'left':
            cr.rotate(-15.0 * math.pi/180.0)
            cr.translate(pos.x - 150 + 68, pos.y + 113)
        elif self.state == 'right':
            cr.rotate(15.0 * math.pi/180.0)
            cr.translate(pos.x - 150 + 168 + 32, pos.y - 90 -40)
        else:
            cr.translate(pos.x, pos.y)
            
        cr.scale(3.0, 3.0)
        ARM_SVG.render_cairo(cr)
        cr.restore()

    def draw_pan(self, cr, pos):    
        cr.save()
        cr.translate(pos.x, pos.y)
        cr.scale(3.0, 3.0)
        PAN_SVG.render_cairo(cr)
        cr.restore()