wxPython/demo/ListCtrl_virtual.py

   1
   2 import  wx
   3 import  images
   4
   5 #----------------------------------------------------------------------
   6
   7 class TestVirtualList(wx.ListCtrl):
   8     def __init__(self, parent, log):
   9         wx.ListCtrl.__init__(
  10             self, parent, -1,
  11             style=wx.LC_REPORT|wx.LC_VIRTUAL|wx.LC_HRULES|wx.LC_VRULES
  12             )
  13
  14         self.log = log
  15
  16         self.il = wx.ImageList(16, 16)
  17         self.idx1 = self.il.Add(images.getSmilesBitmap())
  18         self.SetImageList(self.il, wx.IMAGE_LIST_SMALL)
  19
  20
  21         self.InsertColumn(0, "First")
  22         self.InsertColumn(1, "Second")
  23         self.InsertColumn(2, "Third")
  24         self.SetColumnWidth(0, 175)
  25         self.SetColumnWidth(1, 175)
  26         self.SetColumnWidth(2, 175)
  27
  28         self.SetItemCount(1000000)
  29
  30         self.attr1 = wx.ListItemAttr()
  31         self.attr1.SetBackgroundColour("yellow")
  32
  33         self.attr2 = wx.ListItemAttr()
  34         self.attr2.SetBackgroundColour("light blue")
  35
  36         self.Bind(wx.EVT_LIST_ITEM_SELECTED, self.OnItemSelected)
  37         self.Bind(wx.EVT_LIST_ITEM_ACTIVATED, self.OnItemActivated)
  38         self.Bind(wx.EVT_LIST_ITEM_DESELECTED, self.OnItemDeselected)
  39
  40
  41     def OnItemSelected(self, event):
  42         self.currentItem = event.m_itemIndex
  43         self.log.WriteText('OnItemSelected: "%s", "%s", "%s", "%s"\n' %
  44                            (self.currentItem,
  45                             self.GetItemText(self.currentItem),
  46                             self.getColumnText(self.currentItem, 1),
  47                             self.getColumnText(self.currentItem, 2)))
  48
  49     def OnItemActivated(self, event):
  50         self.currentItem = event.m_itemIndex
  51         self.log.WriteText("OnItemActivated: %s\nTopItem: %s\n" %
  52                            (self.GetItemText(self.currentItem), self.GetTopItem()))
  53
  54     def getColumnText(self, index, col):
  55         item = self.GetItem(index, col)
  56         return item.GetText()
  57
  58     def OnItemDeselected(self, evt):
  59         self.log.WriteText("OnItemDeselected: %s" % evt.m_itemIndex)
  60
  61
  62     #---------------------------------------------------
  63     # These methods are callbacks for implementing the
  64     # "virtualness" of the list...  Normally you would
  65     # determine the text, attributes and/or image based
  66     # on values from some external data source, but for
  67     # this demo we'll just calculate them
  68     def OnGetItemText(self, item, col):
  69         return "Item %d, column %d" % (item, col)
  70
  71     def OnGetItemImage(self, item):
  72         if item % 3 == 0:
  73             return self.idx1
  74         else:
  75             return -1
  76
  77     def OnGetItemAttr(self, item):
  78         if item % 3 == 1:
  79             return self.attr1
  80         elif item % 3 == 2:
  81             return self.attr2
  82         else:
  83             return None
  84
  85
  86 class TestVirtualListPanel(wx.Panel):
  87     def __init__(self, parent, log):
  88         wx.Panel.__init__(self, parent, -1, style=wx.WANTS_CHARS)
  89
  90         self.log = log
  91         sizer = wx.BoxSizer(wx.VERTICAL)
  92
  93         if wx.Platform == "__WXMAC__" and \
  94                hasattr(wx.GetApp().GetTopWindow(), "LoadDemo"):
  95             self.useNative = wx.CheckBox(self, -1, "Use native listctrl")
  96             self.useNative.SetValue(
  97                 not wx.SystemOptions.GetOptionInt("mac.listctrl.always_use_generic") )
  98             self.Bind(wx.EVT_CHECKBOX, self.OnUseNative, self.useNative)
  99             sizer.Add(self.useNative, 0, wx.ALL | wx.ALIGN_RIGHT, 4)
 100
 101         self.list = TestVirtualList(self, self.log)
 102         sizer.Add(self.list, 1, wx.EXPAND)
 103
 104         self.SetSizer(sizer)
 105         self.SetAutoLayout(True)
 106
 107     def OnUseNative(self, event):
 108         wx.SystemOptions.SetOptionInt("mac.listctrl.always_use_generic", not event.IsChecked())
 109         wx.GetApp().GetTopWindow().LoadDemo("ListCtrl_virtual")
 110
 111 #----------------------------------------------------------------------
 112
 113 def runTest(frame, nb, log):
 114     win = TestVirtualListPanel(nb, log)
 115     return win
 116
 117 #----------------------------------------------------------------------
 118
 119
 120 overview = """\
 121 This example demonstrates the ListCtrl's Virtual List features. A Virtual list
 122 can contain any number of cells, but data is not loaded into the control itself.
 123 It is loaded on demand via virtual methods <code>OnGetItemText(), OnGetItemImage()</code>,
 124 and <code>OnGetItemAttr()</code>. This greatly reduces the amount of memory required
 125 without limiting what can be done with the list control itself.
 126 """
 127
 128
 129
 130 if __name__ == '__main__':
 131     import sys,os
 132     import run
 133     run.main(['', os.path.basename(sys.argv[0])] + sys.argv[1:])
 134