Added the sample code from wxPython In Action to the samples dir

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@42925 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

wxPython/samples/wxPIA_book/Chapter-15/tree_virtual.py

@@ -0,0 +1,92 @@
+import wx
+import data
+
+class TestFrame(wx.Frame):
+    def __init__(self):
+        wx.Frame.__init__(self, None, title="virtual tree with icons", size=(400,500))
+        il = wx.ImageList(16,16)
+        self.fldridx = il.Add(
+            wx.ArtProvider.GetBitmap(wx.ART_FOLDER, wx.ART_OTHER, (16,16)))
+        self.fldropenidx = il.Add(
+            wx.ArtProvider.GetBitmap(wx.ART_FILE_OPEN,   wx.ART_OTHER, (16,16)))
+        self.fileidx = il.Add(
+            wx.ArtProvider.GetBitmap(wx.ART_NORMAL_FILE, wx.ART_OTHER, (16,16)))
+        self.tree = wx.TreeCtrl(self)
+        self.tree.AssignImageList(il)
+        root = self.tree.AddRoot("wx.Object")
+        self.tree.SetItemImage(root, self.fldridx,
+                               wx.TreeItemIcon_Normal)
+        self.tree.SetItemImage(root, self.fldropenidx,
+                               wx.TreeItemIcon_Expanded)
+        
+        # Instead of adding nodes for the whole tree, just attach some
+        # data to the root node so that it can find and add its child
+        # nodes when it is expanded, and mark it as having children so
+        # it will be expandable.
+        self.tree.SetItemPyData(root, data.tree)
+        self.tree.SetItemHasChildren(root, True)
+        
+        # Bind some interesting events
+        self.Bind(wx.EVT_TREE_ITEM_EXPANDED, self.OnItemExpanded, self.tree)
+        self.Bind(wx.EVT_TREE_ITEM_COLLAPSED, self.OnItemCollapsed, self.tree)
+        self.Bind(wx.EVT_TREE_SEL_CHANGED, self.OnSelChanged, self.tree)
+        self.Bind(wx.EVT_TREE_ITEM_ACTIVATED, self.OnActivated, self.tree)
+
+        self.Bind(wx.EVT_TREE_ITEM_EXPANDING, self.OnItemExpanding, self.tree)
+        self.tree.Expand(root)
+        
+
+    def AddTreeNodes(self, parentItem):
+        """
+        Add nodes for just the children of the parentItem
+        """
+        items = self.tree.GetItemPyData(parentItem)
+        for item in items:
+            if type(item) == str:
+                # a leaf node
+                newItem = self.tree.AppendItem(parentItem, item)
+                self.tree.SetItemImage(newItem, self.fileidx,
+                                       wx.TreeItemIcon_Normal)
+            else:
+                # this item has children
+                newItem = self.tree.AppendItem(parentItem, item[0])
+                self.tree.SetItemImage(newItem, self.fldridx,
+                                       wx.TreeItemIcon_Normal)
+                self.tree.SetItemImage(newItem, self.fldropenidx,
+                                       wx.TreeItemIcon_Expanded)
+                self.tree.SetItemPyData(newItem, item[1])
+                self.tree.SetItemHasChildren(newItem, True)
+   
+                
+
+    def GetItemText(self, item):
+        if item:
+            return self.tree.GetItemText(item)
+        else:
+            return ""
+        
+    def OnItemExpanded(self, evt):
+        print "OnItemExpanded: ", self.GetItemText(evt.GetItem())
+
+    def OnItemExpanding(self, evt):
+        # When the item is about to be expanded add the first level of child nodes
+        print "OnItemExpanding:", self.GetItemText(evt.GetItem())
+        self.AddTreeNodes(evt.GetItem())
+        
+    def OnItemCollapsed(self, evt):
+        print "OnItemCollapsed:", self.GetItemText(evt.GetItem())
+        # And remove them when collapsed as we don't need them any longer
+        self.tree.DeleteChildren(evt.GetItem())
+
+    def OnSelChanged(self, evt):
+        print "OnSelChanged:   ", self.GetItemText(evt.GetItem())
+
+    def OnActivated(self, evt):
+        print "OnActivated:    ", self.GetItemText(evt.GetItem())
+
+
+app = wx.PySimpleApp(redirect=True)
+frame = TestFrame()
+frame.Show()
+app.MainLoop()
+