1 """gmRegetMixin - GNUmed data change callback mixin.
2
3 Widget code can mix in this class as a base class and
4 thus gain the infrastructure to update it's display
5 when data changes. If the widget is not visible it will
6 only schedule refetching data from the business layer.
7 If it *is* visible it will immediately fetch and redisplay.
8
9 You must call cRegetOnPaintMixin.__init__() in your own
10 __init__() after calling __init__() on the appropriate
11 wx.Widgets class your widget inherits from.
12
13 You must then make sure to call _schedule_data_reget()
14 whenever you learn of backend data changes. This will
15 in most cases happen after you receive a gmDispatcher
16 signal indicating a change in the backend.
17
18 The _populate_with_data(self) method must be overriden in the
19 including class and must return True if the UI was successfully
20 repopulated with content.
21
22 @copyright: authors
23
24 Template for users:
25
26 #-----------------------------------------------------
27 # reget-on-paint mixin API
28 #-----------------------------------------------------
29 # remember to call
30 # self._schedule_data_reget()
31 # whenever you learn of data changes from database listener
32 # threads, dispatcher signals etc.
33 def _populate_with_data(self):
34 # fill the UI with data
35 print "need to implement _populate_with_data"
36 return False
37 return True
38 #-----------------------------------------------------
39 """
40
41 __author__ = "K.Hilbert <Karsten.Hilbert@gmx.net>"
42 __license__ = 'GPL v2 or later (details at http://www.gnu.org)'
43
44 import wx
45
46
48 """Mixin to add redisplay_data-on-wx.EVT_PAINT aspect.
49
50 Any code mixing in this class will gain the mechanism
51 to reget data on wxPaint events. The code must be an
52 instance of a wx.Window and must implement a
53 _populate_with_data() method. It must also call
54 _schedule_data_reget() at appropriate times.
55 """
57 self._data_stale = True
58 try:
59 wx.EVT_PAINT(self, self.__on_paint_event)
60 except:
61 print 'you likely need to call "cRegetOnPaintMixin.__init__(self)" later in %s__init__()' % self.__class__.__name__
62 raise
63
65 """Called just before the widget is repainted.
66
67 Checks whether data needs to be refetched.
68 """
69 self.__repopulate_ui()
70 event.Skip()
71
73 """Checks whether data must be refetched and does so
74
75 Called on different occasions such as "notebook page
76 raised" or "paint event received".
77 """
78 if not self._data_stale:
79 return True
80 repopulated = self._populate_with_data()
81 self._data_stale = (repopulated is False)
82 return repopulated
83
84
85
87 """Actually fills the UI with data.
88
89 This must be overridden in child classes !
90
91 Must return True/False.
92 """
93 raise NotImplementedError, "[%s] _populate_with_data() not implemented" % self.__class__.__name__
94
96 """Flag data as stale and schedule refetch/redisplay.
97
98 - if not visible schedules refetch only
99 - if visible redisplays immediately (virtue of Refresh()
100 calling __on_paint_event() if visible) thereby invoking
101 the actual data refetch
102
103 Called by the child class whenever it learns of data changes
104 such as from database listener threads, dispatcher signals etc.
105 """
106 self._data_stale = True
107
108
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118
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126 self.Refresh()
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134
135
136 return True
137
138
139
141 """Just a glue method to make this compatible with notebook plugins."""
142 self.__repopulate_ui()
143
144
145
146 if __name__ == '__main__':
147 print "no unit test available"
148