sugar-toolkit-gtk3/sugar/graphics/spreadbox.py
Marco Pesenti Gritti ac4338e3c0 Add an ItemInfo object associated with each item.
Remove weight from the grid when removing items.
2007-05-10 10:42:56 +02:00

190 lines
5.5 KiB
Python

# Copyright (C) 2006, 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.
from array import array
from random import random
import gobject
import hippo
_X_TILES = 120
_NUM_TRIALS = 20
_MAX_WEIGHT = 255
class _Grid(object):
def __init__(self, x_tiles, y_tiles, cell_size):
self._array = array('B')
self.x_tiles = x_tiles
self.y_tiles = y_tiles
self.cell_size = cell_size
for i in range(self.y_tiles * self.x_tiles):
self._array.append(0)
def __getitem__(self, (row, col)):
return self._array[col + row * self.x_tiles]
def __setitem__(self, (row, col), value):
self._array[col + row * self.x_tiles] = value
def compute_weight_at(self, x, y, width, height):
weight = 0
for i in range(x, x + width):
for j in range(y, y + height):
weight += self[j, i]
return weight
def add_weight_at(self, x, y, width, height):
for i in range(x, x + width):
for j in range(y, y + height):
self[j, i] += 1
def remove_weight_at(self, x, y, width, height):
for i in range(x, x + width):
for j in range(y, y + height):
self[j, i] -= 1
def from_canvas(self, dim):
return dim / self.cell_size
def to_canvas(self, dim):
return dim * self.cell_size
class _ItemInfo(gobject.GObject):
def __init__(self):
gobject.GObject.__init__(self)
self.x = -1
self.y = -1
self.width = -1
self.height = -1
def add_weight(self, grid):
grid.add_weight_at(self.x, self.y, self.width, self.height)
def remove_weight(self, grid):
grid.remove_weight_at(self.x, self.y, self.width, self.height)
def compute_weight(self, grid, x=-1, y=-1):
if x < 0:
x = self.x
if y < 0:
y = self.y
grid.compute_weight_at(x, y, self.width, self.height)
class SpreadBox(hippo.CanvasBox, hippo.CanvasItem):
__gtype_name__ = 'SugarSpreadBox'
def __init__(self, **kwargs):
hippo.CanvasBox.__init__(self, **kwargs)
self._grid = None
self._center = None
self._width = -1
self._height = -1
def set_center_item(self, item):
if self._center:
self.remove(self._center)
self.append(item, hippo.PACK_FIXED)
self._center = item
self._layout_center()
def add_item(self, item):
item.set_data('item-info', _ItemInfo())
self.append(item, hippo.PACK_FIXED)
self._layout_item(item)
def remove_item(self, item):
info = item.get_data('item-info')
info.remove_weigth(self._grid)
self.remove(item)
def _place_item(self, item, x, y):
info = item.get_data('item-info')
info.x = x
info.y = y
info.add_weight(self._grid)
self.set_position(item, self._grid.to_canvas(x),
self._grid.to_canvas(y))
def _layout_item(self, item):
if not self._grid:
return
info = item.get_data('item-info')
[width, height] = item.get_allocation()
info.width = self._grid.from_canvas(width)
info.height = self._grid.from_canvas(height)
trials = _NUM_TRIALS
placed = False
best_weight = _MAX_WEIGHT
while trials > 0 and not placed:
x = int(random() * (self._grid.x_tiles - info.width))
y = int(random() * (self._grid.y_tiles - info.height))
weight = info.compute_weight(self._grid, x, y)
if weight == 0:
self._place_item(item, x, y)
placed = True
elif weight < best_weight:
best_x = x
best_y = y
trials -= 1
if not placed:
self._place_item(item, best_x, best_y)
def _layout(self):
for item in self.get_children():
if item != self._center:
self._layout_item(item)
def _layout_center(self):
if not self._center or not self._grid:
return
[width, height] = self._center.get_allocation()
x = (self._width - width) / 2
y = (self._height - height) / 2
self.set_position(self._center, x, y)
def do_allocate(self, width, height, origin_changed):
hippo.CanvasBox.do_allocate(self, width, height, origin_changed)
if width != self._width or height != self._height:
cell_size = width / _X_TILES
y_tiles = height / cell_size
self._grid = _Grid(_X_TILES, y_tiles, cell_size)
self._width = width
self._height = height
self._layout()
self._layout_center()