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Diffstat (limited to 'src/jarabe/desktop/grid.py')
| -rw-r--r-- | src/jarabe/desktop/grid.py | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/src/jarabe/desktop/grid.py b/src/jarabe/desktop/grid.py new file mode 100644 index 0000000..eab4033 --- /dev/null +++ b/src/jarabe/desktop/grid.py @@ -0,0 +1,204 @@ +# Copyright (C) 2007 Red Hat, Inc. +# Copyright (C) 2008 One Laptop Per Child +# +# This program 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. +# +# This program 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 St, Fifth Floor, Boston, MA 02110-1301 USA + +import random + +import gobject +import gtk + +from sugar import _sugarext + + +_PLACE_TRIALS = 20 +_MAX_WEIGHT = 255 +_REFRESH_RATE = 200 +_MAX_COLLISIONS_PER_REFRESH = 20 + + +class Grid(_sugarext.Grid): + __gsignals__ = { + 'child-changed': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE, + ([gobject.TYPE_PYOBJECT])), + } + + def __init__(self, width, height): + gobject.GObject.__init__(self) + + self.width = width + self.height = height + self._children = [] + self._child_rects = {} + self._locked_children = set() + self._collisions = [] + self._collisions_sid = 0 + + self.setup(self.width, self.height) + + def add(self, child, width, height, x=None, y=None, locked=False): + if x is not None and y is not None: + rect = gtk.gdk.Rectangle(x, y, width, height) + weight = self.compute_weight(rect) + else: + trials = _PLACE_TRIALS + weight = _MAX_WEIGHT + while trials > 0 and weight: + x = int(random.random() * (self.width - width)) + y = int(random.random() * (self.height - height)) + + rect = gtk.gdk.Rectangle(x, y, width, height) + new_weight = self.compute_weight(rect) + if weight > new_weight: + weight = new_weight + + trials -= 1 + + self._child_rects[child] = rect + self._children.append(child) + self.add_weight(self._child_rects[child]) + if locked: + self._locked_children.add(child) + + if weight > 0: + self._detect_collisions(child) + + def remove(self, child): + self._children.remove(child) + self.remove_weight(self._child_rects[child]) + self._locked_children.discard(child) + del self._child_rects[child] + + if child in self._collisions: + self._collisions.remove(child) + + def move(self, child, x, y, locked=False): + self.remove_weight(self._child_rects[child]) + + rect = self._child_rects[child] + rect.x = x + rect.y = y + + weight = self.compute_weight(rect) + self.add_weight(self._child_rects[child]) + + if locked: + self._locked_children.add(child) + else: + self._locked_children.discard(child) + + if weight > 0: + self._detect_collisions(child) + + def _shift_child(self, child, weight): + rect = self._child_rects[child] + + new_rects = [] + + # Get rects right, left, bottom and top + if (rect.x + rect.width < self.width - 1): + new_rects.append(gtk.gdk.Rectangle(rect.x + 1, rect.y, + rect.width, rect.height)) + + if (rect.x - 1 > 0): + new_rects.append(gtk.gdk.Rectangle(rect.x - 1, rect.y, + rect.width, rect.height)) + + if (rect.y + rect.height < self.height - 1): + new_rects.append(gtk.gdk.Rectangle(rect.x, rect.y + 1, + rect.width, rect.height)) + + if (rect.y - 1 > 0): + new_rects.append(gtk.gdk.Rectangle(rect.x, rect.y - 1, + rect.width, rect.height)) + + # Get diagonal rects + if rect.x + rect.width < self.width - 1 and \ + rect.y + rect.height < self.height - 1: + new_rects.append(gtk.gdk.Rectangle(rect.x + 1, rect.y + 1, + rect.width, rect.height)) + + if rect.x - 1 > 0 and rect.y + rect.height < self.height - 1: + new_rects.append(gtk.gdk.Rectangle(rect.x - 1, rect.y + 1, + rect.width, rect.height)) + + if rect.x + rect.width < self.width - 1 and rect.y - 1 > 0: + new_rects.append(gtk.gdk.Rectangle(rect.x + 1, rect.y - 1, + rect.width, rect.height)) + + if rect.x - 1 > 0 and rect.y - 1 > 0: + new_rects.append(gtk.gdk.Rectangle(rect.x - 1, rect.y - 1, + rect.width, rect.height)) + + random.shuffle(new_rects) + + best_rect = None + for new_rect in new_rects: + new_weight = self.compute_weight(new_rect) + if new_weight < weight: + best_rect = new_rect + weight = new_weight + + if best_rect: + self._child_rects[child] = best_rect + weight = self._shift_child(child, weight) + + return weight + + def __solve_collisions_cb(self): + for i_ in range(_MAX_COLLISIONS_PER_REFRESH): + collision = self._collisions.pop(0) + + old_rect = self._child_rects[collision] + self.remove_weight(old_rect) + weight = self.compute_weight(old_rect) + weight = self._shift_child(collision, weight) + self.add_weight(self._child_rects[collision]) + + # TODO: we shouldn't give up the first time we failed to find a + # better position. + if old_rect != self._child_rects[collision]: + self._detect_collisions(collision) + self.emit('child-changed', collision) + if weight > 0: + self._collisions.append(collision) + + if not self._collisions: + self._collisions_sid = 0 + return False + + return True + + def _detect_collisions(self, child): + collision_found = False + child_rect = self._child_rects[child] + for c in self._children: + intersection = child_rect.intersect(self._child_rects[c]) + if c != child and intersection.width > 0: + if (c not in self._locked_children and + c not in self._collisions): + collision_found = True + self._collisions.append(c) + + if collision_found: + if child not in self._collisions: + self._collisions.append(child) + + if self._collisions and not self._collisions_sid: + self._collisions_sid = gobject.timeout_add(_REFRESH_RATE, + self.__solve_collisions_cb, priority=gobject.PRIORITY_LOW) + + def get_child_rect(self, child): + return self._child_rects[child] |