def addedToWorld(self, world):
     """The screen was added to the world"""
     super(HelpScreen, self).addedToWorld(world)
     #
     # Logo
     L = theme.getTheme('help-screen').getProperty
     logo = serge.blocks.utils.addSpriteActorToWorld(world, 'logo', 'logo', 'icon', 'ui', 
         center_position=L('logo-position'))
     #
     # Background
     bh = serge.blocks.utils.addSpriteActorToWorld(world, 'bg', 'bg', L('screen-background-sprite'), 'background', 
         center_position=L('screen-background-position'))
     #
     # Help text
     text = serge.blocks.utils.addSpriteActorToWorld(world, 'text', 'text', 'help-text', 'ui', 
         center_position=L('text-position'))
     #
     # Back link
     back = serge.blocks.utils.addVisualActorToWorld(world, 'button', 'back', 
         serge.visual.Text('Back', L('back-colour'), font_size=L('back-font-size')),
         'ui', 
         center_position=L('help-position'))
     back.linkEvent(serge.events.E_LEFT_CLICK, serge.blocks.utils.backToPreviousWorld('click'))
     #
     # Trees
     tree.addTrees(L, world)
 def addedToWorld(self, world):
     """The screen was added to the world"""
     super(CreditsScreen, self).addedToWorld(world)
     #
     # Logo
     the_theme = theme.getTheme('credits-screen')
     L = the_theme.getProperty
     logo = serge.blocks.utils.addSpriteActorToWorld(world, 'logo', 'logo', 'icon', 'ui', 
         center_position=L('logo-position'))
     #
     # Background
     bh = serge.blocks.utils.addSpriteActorToWorld(world, 'bg', 'bg', L('screen-background-sprite'), 'background', 
         center_position=L('screen-background-position'))
     #
     # Text on the page
     serge.blocks.utils.addTextItemsToWorld(world, [
                 ('Game concept, design and coding', 'author-title'),
                 (AUTHOR, 'author'),
                 (URL, 'url', self.launchURL),
                 ('Music', 'music-title1'),
                 ('from the FreeMusicArchive.org', 'music-title2'),
                 ('Sound', 'sound-title1'),
                 ('From FreeSound.org', 'sound-title2'),
                 ('Built using', 'built-title'),
                 (BUILT_USING, 'built'),
                 ('Game engine', 'engine-title'),
                 (GAME_ENGINE, 'engine'),  
                 ('Fonts', 'font-title1'),
                 ('from the cooltext.com', 'font-title2'), 
                 ('Back', 'back', serge.blocks.utils.backToPreviousWorld('click')),                 
             ],
             the_theme, 'ui')
     #
     x, y = L('music-position')
     for idx, track in enumerate(MUSIC):
         serge.blocks.utils.addVisualActorToWorld(world, 'title', 'music-item', 
             serge.visual.Text(track, L('music-colour'), 
             font_size=L('music-font-size')), 'ui', 
             center_position=(x, y+idx*20))
     #
     x, y = L('font-position')
     for idx, font in enumerate(FONTS):
         serge.blocks.utils.addVisualActorToWorld(world, 'title', 'font-item', 
             serge.visual.Text(font, L('font-colour'), 
             font_size=L('font-font-size')), 'ui', 
             center_position=(x, y+idx*20))
     #
     # Trees
     tree.addTrees(L, world)
 def addedToWorld(self, world):
     """The start screen was added to the world"""
     super(CollectionScreen, self).addedToWorld(world)
     #
     self.manager = world.findActorByName('behaviours')
     self.history = self.globals.history
     #
     # Logo
     the_theme = theme.getTheme('collection-screen')
     self.L = L = the_theme.getProperty
     logo = serge.blocks.utils.addSpriteActorToWorld(world, 'logo', 'logo', 'icon', 'ui', 
         center_position=L('logo-position'))
     #
     # Background
     bh = serge.blocks.utils.addSpriteActorToWorld(world, 'bg', 'bg', L('screen-background-sprite'), 'background', 
         center_position=L('screen-background-position'))
     #
     serge.blocks.utils.addTextItemsToWorld(world, [
                 ('Your collection of named crystals', 'title'),
                 ('Next Page', 'next', self.nextPage),
                 ('Previous Page', 'previous', self.previousPage),
                 ('Page ...', 'page'),
                 ('Back', 'back', serge.blocks.utils.backToPreviousWorld('click')),
     ], the_theme, 'ui')
     #
     self.page = world.findActorByName('page')
     #
     # The grid
     self.grid = grid = serge.blocks.utils.addActorToWorld(world,
         serge.blocks.layout.Grid('grid', 'grid', size=L('grid-size'), width=L('grid-width'),
             height=L('grid-height'), background_colour=L('background-colour')),
         center_position=L('grid-position'), layer_name='ui-back')
     #
     # Populate with slots
     w, h = L('grid-size')
     for x in range(w):
         for y in range(h):
             #
             # Layout of the labels
             slot = serge.blocks.layout.VerticalBar('slot', 'vbar', width=L('slot-width'), height=L('slot-height'),
                 background_colour=L('slot-background-colour'), background_layer='ui-back')
             grid.addActor((x, y), slot, 'ui')
             #
             # Text labels
             t1 = serge.blocks.actors.StringText(
                 'label', 'text', 'Title', colour=L('t1-colour'), font_size=L('t1-font-size'))
             t2 = serge.blocks.actors.StringText(
                 'label', 'text', 'Details', colour=L('t2-colour'), font_size=L('t2-font-size'))
             slot.addActor(t1)
             slot.addActor(t2)
             t1.setLayerName('ui')
             t2.setLayerName('ui')
             slot.long_description = ''
     #
     self.selected_slot = None
     #
     # Extra detail window
     self.detail = serge.blocks.utils.addVisualActorToWorld(world, 'text', 'detail',
         serge.blocks.visualblocks.RectangleText('Details', L('detail-colour'), 
             (L('detail-width'), L('detail-height')), L('detail-backcolour'), L('detail-font-size')),
             layer_name='overlay')
     self.detail.visible = False
     #
     # Trees
     tree.addTrees(L, world)
     #
     self.current_page = 0
     self.page_size = w*h
     self.page_width = w
     self.page_height = h
     self.populateCurrentPage()
     #
     self.world.linkEvent(serge.events.E_ACTIVATE_WORLD, self.resetCamera)