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# 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 draggableobject import DraggableObject
from vector import Vector
import gtk
# The global grid unit size, in pixels. Objects will snap to multiples of this value.
GRID_SIZE = 50
# Width and height of region within which we can drag objects.
DRAGGING_RECT_WIDTH = 24*GRID_SIZE
DRAGGING_RECT_HEIGHT = 16*GRID_SIZE
class SymbolObject(DraggableObject):
"""Draggable symbol object."""
def __init__(self, pos, symbol, drop_targets, container, size=50):
DraggableObject.__init__(self)
self.pos = pos
self.symbol = symbol
self.size = size
self.symbol_visible = True
self.width = 0
self.height = 0
self.selectable = True
self.rotatable = False
self.use_minimum_width_and_height = False
self.drop_target = None
self.drop_targets = drop_targets
self.container = container
def draw(self, cr):
text = self.symbol
if self.dragged:
# The line segment gets transparent when dragged.
cr.set_source_rgba(0, 0, 0, 0.5)
else:
# Otherwise, it's black.
cr.set_source_rgb(0, 0, 0)
cr.set_font_size(self.size)
x_bearing, y_bearing, width, height = cr.text_extents(text)[:4]
if self.use_minimum_width_and_height:
letter_width = width
letter_height = height
width = 75
height = 75
cr.move_to(self.pos.x - x_bearing - width/2 + width/2 - letter_width/2, self.pos.y - y_bearing - height/2 + height/2 - letter_height/2)
if self.symbol_visible:
cr.show_text(text)
else:
cr.move_to(self.pos.x - x_bearing - width/2, self.pos.y - y_bearing - height/2)
if self.symbol_visible:
cr.show_text(text)
if self.selected:
if self.use_minimum_width_and_height:
self.width = 75
self.height = 75
cr.rectangle(self.pos.x - 5 - width/2, self.pos.y - 5 - height/2, self.width + 10, self.height + 10)
cr.set_line_width(1.0)
# Draw a different dashed outline if the object is not only selected but dragged.
if self.dragged:
cr.set_dash((2, 2, 0))
else:
cr.set_dash((10, 10), 0)
cr.set_source_rgb(0, 0, 0)
cr.stroke()
self.width = width
self.height = height
def is_in_container(self):
bounds_inner, bounds_outer = self.get_bounds()
if bounds_inner.x < -2 or bounds_outer.x > DRAGGING_RECT_WIDTH + 2 \
or bounds_inner.y < -1 or bounds_outer.y > DRAGGING_RECT_HEIGHT:
return False
return True
def move(self, pos):
self.queue_draw()
# Tentatively place in the object in the new position
last_pos = self.pos
self.pos = pos
# If any point is out of bounds, move object back to last position.
if not self.is_in_container():
self.pos = last_pos
self.queue_draw()
def get_bounds(self):
hsz = Vector(self.width/2, self.height/2)
return self.pos - hsz, self.pos + hsz
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