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# coding: UTF-8
# Copyright 2009 Thomas Jourdan
#
# 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 3 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 os.path
import base64
import sys
import gtk.gdk
import cairo
from sugar.datastore import datastore
import ka_debug
import ka_task
_THUMB_SIZE = 100
class PngExporter(object):
"""
"""
def __init__(self, protozoon, init_activity_root):
"""
inv: self._protozoon is not None
inv: self._activity_root is not None
"""
self._protozoon = protozoon
self._activity_root = init_activity_root
self._export_surface = None
self._thumb_surface = None
def export(self, width, height):
"""
pre: width > 0
pre: height > 0
pre: width == height
"""
task = ka_task.GeneratorTask(self.task_render,
self.on_render_completed,
'export_png'+self._protozoon.get_unique_id())
task.start(self._protozoon, -1, width, height)
ka_debug.info('export: start_calculation %ux%u for %s' %
(width, height, self._protozoon.get_unique_id()))
def task_render(self, task, *args, **kwargs):
"""Render bitmap for exporting protozoon.
pre: len(args) == 4
"""
protozoon, dummy, width, height = \
args[0], args[1], args[2], args[3]
ka_debug.info('export: task_render entry: ')
self._export_surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
ctx = cairo.Context(self._export_surface)
protozoon.render(task, ctx, width, height)
self._thumb_surface = cairo.ImageSurface(cairo.FORMAT_ARGB32,
_THUMB_SIZE, _THUMB_SIZE)
ctx = cairo.Context(self._thumb_surface)
protozoon.render(task, ctx, _THUMB_SIZE, _THUMB_SIZE)
ka_debug.info('export: task_render exit: ')
def on_render_completed(self, *args):
"""Rendering protozoon is completed.
pre: self._export_surface is not None
pre: self._thumb_surface is not None
"""
ka_debug.info('export: on_render_completed: ' + str(args[0]))
unique_id = 'kandidimage' + self._protozoon.get_unique_id()
export_filename = unique_id + '.png'
export_path = os.path.join(self._activity_root, 'instance', export_filename)
# Create a datastore object
file_dsobject = datastore.create()
# Write any metadata (here we specifically set the title of the file
# and specify that this is a portable network graphics file).
file_dsobject.metadata['title'] = 'Kandid Image ' + \
self._protozoon.get_unique_id()[1:]
file_dsobject.metadata['mime_type'] = 'image/png'
#Write the actual file to the data directory of this activity's root.
try:
self._export_surface.write_to_png(export_path)
except:
ka_debug.err('export: failed exporting to [%s] [%s] [%s]' % \
(export_path, sys.exc_info()[0], sys.exc_info()[1]))
#insert thumbnail image into metadata
thumb_filename = unique_id + '.thumb.png'
thumb_path = os.path.join(self._activity_root, 'instance', thumb_filename)
try:
self._thumb_surface.write_to_png(thumb_path)
thumb_in = open(thumb_path, 'rb')
file_dsobject.metadata['preview'] = \
base64.b64encode(thumb_in.read())
thumb_in.close()
os.unlink(thumb_path)
except:
ka_debug.err('export: failed creating preview image [%s] [%s] [%s]' % \
(thumb_path, sys.exc_info()[0], sys.exc_info()[1]))
#Set the file_path in the datastore.
file_dsobject.set_file_path(export_path)
datastore.write(file_dsobject)
file_dsobject.destroy()
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