code/train/Python/0004037_yaybeesee.py

#!/usr/bin/env python
# Copyright 2008 by Ben Whley Sittler and Wade Brainerd.  
# This file is part of YayBeeSee.
#
# YayBeeSee 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.
# 
# YayBeeSee 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 YayBeeSee.  If not, see <http://www.gnu.org/licenses/>.
"""YayBeeSee - Simple letter game."""

# Import standard Python modules.
import logging, os, json, locale, random, gc
from gettext import gettext as _

# Import PyGTK.
import gobject, pygtk, gtk, pango, cairo

# Import Sugar UI modules.
import sugar.activity.activity
from sugar.graphics import *

# Initialize logging.
log = logging.getLogger('YayBeeSee')
log.setLevel(logging.DEBUG)
logging.basicConfig()

class YayBeeSee(sugar.activity.activity.Activity):
    def __init__ (self, handle):
        sugar.activity.activity.Activity.__init__(self, handle)
        self.set_title(_("Yay! Bee See"))
        
        # Create the drawing area.
        self.area = gtk.DrawingArea()
        self.area.connect('expose-event', self.expose_cb)
        
        self.area.modify_bg(gtk.STATE_NORMAL, self.get_colormap().alloc_color('#808080'))
        
        self.key = None
        self.key_info = None
        self.all_loaded = False
        self.pixbuf = None
        
        # Create the toolbar.
        tbox = sugar.activity.activity.ActivityToolbox(self)
        self.set_toolbox(tbox)
        
        fullscreenbtn = sugar.graphics.toolbutton.ToolButton('view-fullscreen')
        fullscreenbtn.set_tooltip(_("Fullscreen"))
        fullscreenbtn.connect('clicked', self.fullscreen_cb)

        activity_toolbar = tbox.get_activity_toolbar()
        share_idx = activity_toolbar.get_item_index(activity_toolbar.share) 
        activity_toolbar.insert(fullscreenbtn, share_idx)

        # Load the image index for the current locale.
        bundle = sugar.activity.activity.get_bundle_path()
        code = locale.getlocale(locale.LC_ALL)[0]
        fd = open(bundle + '/images/INDEX.'+code, 'r')
        self.index = json.read(fd.read())

        # This has to happen last, because it calls the read_file method when restoring from the Journal.
        self.set_canvas(self.area)
        self.show_all()
        
        # Hide the sharing button from the activity toolbar since we don't support it (yet). 
        activity_toolbar.share.props.visible = False
        
        # Set up key events.
        self.add_events(gtk.gdk.KEY_PRESS_MASK)
        self.connect('key-press-event', self.key_press_cb)

        # Set up the 'Ken Burns' effect.
        self.reset_zoom()

        # Default to fullscreen mode.
        self.fullscreen()

        # Set up the idle timer.
        gobject.idle_add(self.idle_cb)

    def idle_cb(self):
        # Apply the 'Ken Burns' effect (disabled due to Cairo performance).
        #self.play_zoom()

        # Make progress on loading.
        all_loaded = True 
        for key in self.index:
            key_info = self.index[key]

            if not key_info.has_key('data'): 
                bundle = sugar.activity.activity.get_bundle_path()
                filename = os.path.join(bundle, key_info['file'])

                print 'Loading ' + filename

                fd = open(filename, 'r')
                key_info['data'] = fd.read()

                self.area.queue_draw()

                all_loaded = False
                break

        if all_loaded:
            self.all_loaded = True

        # Keep tracking idle events until all images are loaded.
        return not self.all_loaded 
    
    def fullscreen_cb(self, widget):
        self.fullscreen()

    def key_press_cb(self, widget, event):
        # Ignore keypresses until the images are loaded. 
        if not self.all_loaded:
            return True

        # Get the letter corresponding to the keypress.
        key = event.string.lower()
        
        # Load the picture.
        if self.index.has_key(key):
            self.key = key
            self.key_info = self.index[self.key]
            
            # Decompress the JPEG data in-memory.
            loader = gtk.gdk.PixbufLoader()
            loader.write(self.key_info['data'])
            loader.close()

            self.pixbuf = loader.get_pixbuf()

            loader = None
            gc.collect()

            self.reset_zoom()

        self.area.queue_draw()
        
        return True

    def reset_zoom(self):
        self.zoom = 1.0
        self.px = 0.0
        self.py = 0.0
        self.vx = random.random() * 0.02 - 0.01
        self.vy = random.random() * 0.02 - 0.01

    def play_zoom(self):
        self.zoom += 0.001
        self.px += self.vx
        self.py += self.vy
        self.area.queue_draw()
        
    def expose_cb(self, widget, event):
        cr = widget.window.cairo_create()
        cr.rectangle(event.area.x, event.area.y, event.area.width, event.area.height)
        cr.clip()
        
        bounds = widget.get_allocation()
        
        if self.key_info:
            # Draw the background image.
            cr.save()
            
            # Scale the image such that it fills the screen while preserving the aspect ratio.
            # Using 'min' here shows the entire image, 'max' fills the screen.
            # It might be nice to be able to choose 'fill' or 'fit' mode per-image.
            ratio = min(
                float(bounds.width) / float(self.pixbuf.get_width()),
                float(bounds.height) / float(self.pixbuf.get_height()))

            ratio = ratio * self.zoom

            cr.translate(
                self.px + (bounds.width - self.pixbuf.get_width()*ratio) / 2,
                self.py + (bounds.height - self.pixbuf.get_height()*ratio) / 2)
            
            cr.scale(ratio, ratio)
            
            cr.set_source_pixbuf(self.pixbuf, 0, 0)
            cr.paint()
            
            cr.restore()
            
            # Draw the letter.
            if self.key.upper() != self.key.lower():
                text = self.key.upper() + self.key.lower()
            else:
                text = self.key
            
            color = self.key_info['color']
            cr.set_source_rgb(color[0]/255.0, color[1]/255.0, color[2]/255.0)
            
            cr.set_font_size(500)
            x_bearing, y_bearing, width, height = cr.text_extents(text)[:4]
            
            cr.move_to(bounds.width - width - 30 - x_bearing, 30 - y_bearing)
            cr.show_text(text)

            # Draw the attribution.
            text = _('Source: "%(description)s" by %(author)s') % self.key_info
            
            cr.set_font_size(20)
            
            x_bearing, y_bearing, width, height = cr.text_extents(text)[:4]

            cr.rectangle(30, bounds.height-60, width+20, height+20)
            cr.set_source_rgba(0.3, 0.3, 0.3, 0.7)
            cr.fill_preserve()
            cr.set_source_rgba(1, 1, 1, 0.7)
            cr.stroke()
            
            cr.set_source_rgb(0.7, 0.7, 0.7)
            cr.move_to(40, bounds.height-50 - y_bearing)
            cr.show_text(text)

        else:

            loaded_count = 0
            total_count = 0
            for key in self.index: 
                if self.index[key].has_key('data'):
                    loaded_count += 1
                total_count += 1

            loaded_ratio = float(loaded_count) / float(total_count)

            # Draw loading bar.
            cr.rectangle(bounds.width-30, bounds.height-60, -int((bounds.width-140) * loaded_ratio), 40)
            cr.set_source_rgb(0.4, 0.4, 0.8)
            cr.fill_preserve()
            cr.set_source_rgb(0.6, 0.6, 0.9)
            cr.stroke()

            # Draw help text.
            text = _('Welcome! Press any letter or number.')
              
            help_alpha = max(0, min(1, (loaded_ratio-0.8)/0.2))
            cr.set_source_rgba(1, 1, 1, help_alpha)
            
            cr.set_font_size(20)
            x_bearing, y_bearing, width, height = cr.text_extents(text)[:4]
            
            cr.move_to(bounds.width-40 - width - x_bearing, bounds.height-50 - y_bearing)
            cr.show_text(text)