lib/python/Screens/Screen.py

   1 from Components.HTMLSkin import HTMLSkin
   2 from Components.GUISkin import GUISkin
   3 from Components.Sources.Source import Source
   4 from Components.GUIComponent import GUIComponent
   5
   6 class Screen(dict, HTMLSkin, GUISkin):
   7
   8         ALLOW_SUSPEND = False
   9
  10         global_screen = None
  11
  12         def __init__(self, session, parent = None):
  13                 self.skinName = self.__class__.__name__
  14                 self.session = session
  15                 self.parent = parent
  16                 GUISkin.__init__(self)
  17
  18                 self.onClose = [ ]
  19                 self.onFirstExecBegin = [ ]
  20                 self.onExecBegin = [ ]
  21                 self.onShown = [ ]
  22
  23                 self.onShow = [ ]
  24                 self.onHide = [ ]
  25
  26                 self.execing = False
  27
  28                 self.shown = True
  29                 # already shown is false until the screen is really shown (after creation)
  30                 self.already_shown = False
  31
  32                 self.renderer = [ ]
  33
  34                 # in order to support screens *without* a help,
  35                 # we need the list in every screen. how ironic.
  36                 self.helpList = [ ]
  37
  38                 self.close_on_next_exec = None
  39
  40                 self.in_close = False
  41
  42                 # stand alone screens (for example web screens)
  43                 # don't care about having or not having focus.
  44                 self.stand_alone = False
  45
  46         def execBegin(self):
  47                 self.active_components = [ ]
  48                 if self.close_on_next_exec is not None:
  49                         tmp = self.close_on_next_exec
  50                         self.close_on_next_exec = None
  51                         self.execing = True
  52                         self.close(*tmp)
  53                 else:
  54                         single = self.onFirstExecBegin
  55                         self.onFirstExecBegin = []
  56                         for x in self.onExecBegin + single:
  57                                 x()
  58                                 if not self.stand_alone and self.session.current_dialog != self:
  59                                         return
  60
  61 #                       assert self.session == None, "a screen can only exec once per time"
  62 #                       self.session = session
  63
  64                         for val in self.values() + self.renderer:
  65                                 val.execBegin()
  66                                 if not self.stand_alone and self.session.current_dialog != self:
  67                                         return
  68                                 self.active_components.append(val)
  69
  70                         self.execing = True
  71
  72                         for x in self.onShown:
  73                                 x()
  74
  75         def execEnd(self):
  76 #               for (name, val) in self.items():
  77                 for val in self.active_components:
  78                         val.execEnd()
  79                 del self.active_components
  80 #               assert self.session != None, "execEnd on non-execing screen!"
  81 #               self.session = None
  82                 self.execing = False
  83
  84         # never call this directly - it will be called from the session!
  85         def doClose(self):
  86                 self.hide()
  87                 for x in self.onClose:
  88                         x()
  89
  90                 # fixup circular references
  91                 del self.helpList
  92                 GUISkin.close(self)
  93
  94                 # first disconnect all render from their sources.
  95                 # we might split this out into a "unskin"-call,
  96                 # but currently we destroy the screen afterwards
  97                 # anyway.
  98                 for val in self.renderer:
  99                         val.disconnectAll()  # disconnected converter/sources and probably destroy them
 100
 101                 del self.session
 102                 for (name, val) in self.items():
 103                         val.destroy()
 104                         del self[name]
 105
 106                 for val in self.renderer:
 107                         val.destroy()
 108
 109                 self.renderer = [ ]
 110
 111                 # really delete all elements now
 112                 self.__dict__.clear()
 113
 114         def close(self, *retval):
 115                 if not self.in_close:
 116                         if not self.execing:
 117                                 self.close_on_next_exec = retval
 118                         else:
 119                                 self.in_close = True
 120                                 self.session.close(self, *retval)
 121
 122         def setFocus(self, o):
 123                 self.instance.setFocus(o.instance)
 124
 125         def show(self):
 126                 if (self.shown and self.already_shown) or not self.instance:
 127                         return
 128                 self.shown = True
 129                 self.already_shown = True
 130                 self.instance.show()
 131                 for x in self.onShow:
 132                         x()
 133                 for val in self.values() + self.renderer:
 134                         if isinstance(val, GUIComponent) or isinstance(val, Source):
 135                                 val.onShow()
 136
 137         def hide(self):
 138                 if not self.shown or not self.instance:
 139                         return
 140                 self.shown = False
 141                 self.instance.hide()
 142                 for x in self.onHide:
 143                         x()
 144                 for val in self.values() + self.renderer:
 145                         if isinstance(val, GUIComponent) or isinstance(val, Source):
 146                                 val.onHide()
 147
 148         def __repr__(self):
 149                 return str(type(self))
 150
 151         def getRelatedScreen(self, name):
 152                 if name == "session":
 153                         return self.session.screen
 154                 elif name == "parent":
 155                         return self.parent
 156                 elif name == "global":
 157                         return self.global_screen
 158                 else:
 159                         return None