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# Copyright (C) 2009, Tomeu Vizoso
#
# 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 logging
import gobject
import gtk
from sugar import dispatch
class Canvas(gtk.DrawingArea):
__gtype_name__ = 'MindMapCanvas'
def __init__(self):
self._elements = []
self._pressed_button = None
self._press_start_x = None
self._press_start_y = None
self._last_clicked_element = None
self._dragging = False
gobject.GObject.__init__(self)
self.dragging_started = dispatch.Signal()
self.dragging_finished = dispatch.Signal()
self.add_events(gtk.gdk.BUTTON_PRESS_MASK |
gtk.gdk.BUTTON_RELEASE_MASK |
gtk.gdk.POINTER_MOTION_MASK |
gtk.gdk.POINTER_MOTION_HINT_MASK)
self.connect('expose-event', self.__expose_event_cb)
self.connect('button-press-event', self.__button_press_event_cb)
self.connect('button-release-event', self.__button_release_event_cb)
self.connect('motion-notify-event', self.__motion_notify_event_cb)
def __expose_event_cb(self, widget, event):
context = self.window.cairo_create()
rect = self.get_allocation()
rect.x = 0
rect.y = 0
context.rectangle(event.area.x, event.area.y,
event.area.width, event.area.height)
context.clip()
context.set_source_rgb(1.0, 1.0, 1.0)
context.paint()
for element in self._elements:
rect = element.get_rect()
if rect.intersect(event.area):
context.save()
context.rectangle(rect.x, rect.y, rect.width, rect.height)
context.clip()
element.draw(context)
context.restore()
return False
def get_element_at(self, x, y):
for element in self._elements:
rect = element.get_rect()
if (x >= rect.x and x <= rect.x + rect.width) and \
(y >= rect.y and y <= rect.y + rect.height):
return element
return None
def _invalidate(self, x, y, width, height):
if self.window is None:
return
rect = gtk.gdk.Rectangle(x, y, width, height)
self.window.invalidate_rect(rect, True)
self.window.process_updates(True)
def add_element(self, element):
element.invalidated.connect(self.__element_invalidated_cb)
self._elements.append(element)
rect = element.get_rect()
self._invalidate(rect.x, rect.y, rect.width, rect.height)
def remove_all_elements(self):
rect = gtk.gdk.Rectangle(0, 0, 0, 0)
for element in self._elements:
rect.union(element.get_rect())
self._invalidate(rect.x, rect.y, rect.width, rect.height)
self._elements = []
def __element_invalidated_cb(self, **kwargs):
element = kwargs['sender']
rect = element.previous_rect
self._invalidate(rect.x, rect.y, rect.width, rect.height)
rect = element.get_rect()
self._invalidate(rect.x, rect.y, rect.width, rect.height)
def __button_press_event_cb(self, widget, event):
logging.debug('button_press_event_cb')
if event.button == 1 and event.type == gtk.gdk.BUTTON_PRESS:
self._last_clicked_element = self.get_element_at(event.x, event.y)
logging.debug('button_press_event_cb %r' % self._last_clicked_element)
if self._last_clicked_element is not None:
self._pressed_button = event.button
self._press_start_x = event.x
self._press_start_y = event.y
return False
def __button_release_event_cb(self, widget, event):
logging.debug('button_release_event_cb')
if self._dragging:
self.dragging_finished.send(self, position=(event.x, event.y),
element=self._last_clicked_element)
self._cleanup_drag()
return False
def _cleanup_drag(self):
self._last_clicked_element = None
self._pressed_button = None
self._press_start_x = None
self._press_start_y = None
self._dragging = False
def __motion_notify_event_cb(self, widget, event):
if self._dragging or self._last_clicked_element is None:
return True
# if the mouse button is not pressed, no drag should occurr
if not event.state & gtk.gdk.BUTTON1_MASK:
self._cleanup_drag()
return True
logging.debug('motion_notify_event_cb')
if event.is_hint:
x, y, state_ = event.window.get_pointer()
else:
x = event.x
y = event.y
if self.drag_check_threshold(int(self._press_start_x),
int(self._press_start_y),
int(x),
int(y)):
self._dragging = True
self.dragging_started.send(self, position=(x, y),
element=self._last_clicked_element)
return True
class CanvasElement(object):
def __init__(self):
self.invalidated = dispatch.Signal()
self.previous_rect = (0, 0, 0, 0)
def draw(self, context):
self.previous_rect = self.get_rect()
def invalidate(self):
self.invalidated.send(self)
def get_rect(self):
pass
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