Files
wxWidgets/wxPython/wx/lib/mixins/treemixin.py
2007-03-19 16:02:51 +00:00

654 lines
28 KiB
Python

'''
treemixin.py
This module provides three mixin classes that can be used with tree
controls:
- VirtualTree is a class that, when mixed in with a tree control,
makes the tree control virtual, similar to a ListCtrl in virtual mode.
A virtual tree control builds the tree itself by means of callbacks,
so the programmer is freed from the burden of building the tree herself.
- DragAndDrop is a mixin class that helps with dragging and dropping of
items. The graphical part of dragging and dropping tree items is done by
this mixin class. You only need to implement the OnDrop method that is
called when the drop happens.
- ExpansionState is a mixin that can be queried for the expansion state of
all items in the tree to restore it later.
All mixin classes work with wx.TreeCtrl, wx.gizmos.TreeListCtrl,
and wx.lib.customtree.CustomTreeCtrl. They can be used together or
separately.
The VirtualTree and DragAndDrop mixins force the wx.TR_HIDE_ROOT style.
Author: Frank Niessink <frank@niessink.com>
License: wxWidgets license
Version: 0.8
Date: 13 March 2007
ExpansionState is based on code and ideas from Karsten Hilbert.
Andrea Gavana provided help with the CustomTreeCtrl integration.
'''
import wx, wx.lib.customtreectrl
class TreeAPIHarmonizer(object):
''' This class attempts to hide the differences in API between the
different tree controls that are part of wxPython. '''
def __init__(self, *args, **kwargs):
# CustomTreeCtrl uses a different keyword for the window style
# argument ('ctstyle'). To hide this, we replace the 'style' keyword
# by 'ctstyle' if we're mixed in with CustomTreeCtrl.
if isinstance(self, wx.lib.customtreectrl.CustomTreeCtrl):
kwargs['ctstyle'] = kwargs.pop('style', wx.TR_DEFAULT_STYLE)
super(TreeAPIHarmonizer, self).__init__(*args, **kwargs)
def __callSuper(self, methodName, default, *args, **kwargs):
# If our super class has a method called methodName, call it,
# otherwise return the default value.
superClass = super(TreeAPIHarmonizer, self)
if hasattr(superClass, methodName):
return getattr(superClass, methodName)(*args, **kwargs)
else:
return default
def GetColumnCount(self, *args, **kwargs):
# Only TreeListCtrl has columns, return 0 if we are mixed in
# with another tree control.
return self.__callSuper('GetColumnCount', 0, *args, **kwargs)
def GetItemType(self, *args, **kwargs):
# Only CustomTreeCtrl has different item types, return the
# default item type if we are mixed in with another tree control.
return self.__callSuper('GetItemType', 0, *args, **kwargs)
def SetItemType(self, item, newType):
# CustomTreeCtrl doesn't support changing the item type on the fly,
# so we create a new item and delete the old one. We currently only
# keep the item text, would be nicer to also retain other attributes.
text = self.GetItemText(item)
newItem = self.InsertItem(self.GetItemParent(item), item, text,
ct_type=newType)
self.Delete(item)
return newItem
def IsItemChecked(self, *args, **kwargs):
# Only CustomTreeCtrl supports checkable items, return False if
# we are mixed in with another tree control.
return self.__callSuper('IsItemChecked', False, *args, **kwargs)
def GetItemChecked(self, *args, **kwargs):
# For consistency's sake, provide a 'Get' and 'Set' method for
# checkable items.
return self.IsItemChecked(*args, **kwargs)
def SetItemChecked(self, *args, **kwargs):
# For consistency's sake, provide a 'Get' and 'Set' method for
# checkable items.
return self.CheckItem(*args, **kwargs)
def GetMainWindow(self, *args, **kwargs):
# Only TreeListCtrl has a separate main window, return self if we are
# mixed in with another tree control.
return self.__callSuper('GetMainWindow', self, *args, **kwargs)
def GetItemImage(self, item, which=wx.TreeItemIcon_Normal, column=-1):
# CustomTreeCtrl always wants the which argument, so provide it
# TreeListCtr.GetItemImage has a different order of arguments than
# the other tree controls. Hide the differenes.
if self.GetColumnCount():
args = (item, column, which)
else:
args = (item, which)
return super(TreeAPIHarmonizer, self).GetItemImage(*args)
def SetItemImage(self, item, imageIndex, which=wx.TreeItemIcon_Normal,
column=-1):
# The SetItemImage signature is different for TreeListCtrl and
# other tree controls. This adapter method hides the differences.
if self.GetColumnCount():
args = (item, imageIndex, column, which)
else:
args = (item, imageIndex, which)
super(TreeAPIHarmonizer, self).SetItemImage(*args)
def UnselectAll(self):
# Unselect all items, regardless of whether we are in multiple
# selection mode or not.
if self.HasFlag(wx.TR_MULTIPLE):
super(TreeAPIHarmonizer, self).UnselectAll()
else:
# CustomTreeCtrl Unselect() doesn't seem to work in all cases,
# also invoke UnselectAll just to be sure.
self.Unselect()
super(TreeAPIHarmonizer, self).UnselectAll()
def GetCount(self):
# TreeListCtrl correctly ignores the root item when it is hidden,
# but doesn't count the root item when it is visible
itemCount = super(TreeAPIHarmonizer, self).GetCount()
if self.GetColumnCount() and not self.HasFlag(wx.TR_HIDE_ROOT):
itemCount += 1
return itemCount
def GetSelections(self):
# Always return a list of selected items, regardless of whether
# we are in multiple selection mode or not.
if self.HasFlag(wx.TR_MULTIPLE):
selections = super(TreeAPIHarmonizer, self).GetSelections()
else:
selection = self.GetSelection()
if selection:
selections = [selection]
else:
selections = []
# If the root item is hidden, it should never be selected,
# unfortunately, CustomTreeCtrl allows it to be selected.
if self.HasFlag(wx.TR_HIDE_ROOT):
rootItem = self.GetRootItem()
if rootItem and rootItem in selections:
selections.remove(rootItem)
return selections
def SelectItem(self, item, *args, **kwargs):
# Prevent the hidden root from being selected, otherwise TreeCtrl
# crashes
if self.HasFlag(wx.TR_HIDE_ROOT) and item == self.GetRootItem():
return
else:
return super(TreeAPIHarmonizer, self).SelectItem(item, *args,
**kwargs)
def HitTest(self, *args, **kwargs):
''' HitTest returns a two-tuple (item, flags) for tree controls
without columns and a three-tuple (item, flags, column) for tree
controls with columns. Our caller can indicate this method to
always return a three-tuple no matter what tree control we're mixed
in with by specifying the optional argument 'alwaysReturnColumn'
to be True. '''
alwaysReturnColumn = kwargs.pop('alwaysReturnColumn', False)
hitTestResult = super(TreeAPIHarmonizer, self).HitTest(*args, **kwargs)
if len(hitTestResult) == 2 and alwaysReturnColumn:
hitTestResult += (0,)
return hitTestResult
def ExpandAll(self, item=None):
# TreeListCtrl wants an item as argument. That's an inconsistency with
# the TreeCtrl API.
try:
super(TreeAPIHarmonizer, self).ExpandAll()
except TypeError:
if item is None:
item = self.GetRootItem()
super(TreeAPIHarmonizer, self).ExpandAll(item)
class TreeHelper(object):
''' This class provides methods that are not part of the API of any
tree control, but are convenient to have available. '''
def GetItemChildren(self, item, recursively=False):
''' Return the children of item as a list. '''
children = []
child, cookie = self.GetFirstChild(item)
while child:
children.append(child)
if recursively:
children.extend(self.GetItemChildren(child, True))
child, cookie = self.GetNextChild(item, cookie)
return children
def ItemIndex(self, item, tupleIndex=True):
''' Return the index of item. If tupleIndex is True, return a
an tuple-based index else return an integer-based index for item. '''
if tupleIndex:
parent = self.GetItemParent(item)
if parent:
parentIndices = self.ItemIndex(parent)
ownIndex = self.GetItemChildren(parent).index(item)
return parentIndices + (ownIndex,)
else:
return ()
else:
rootItem = self.GetRootItem()
if self.HasFlag(wx.TR_HIDE_ROOT):
if item == rootItem:
return None
countRoot = 0
else:
if item == rootItem:
return 0
countRoot = 1
return self.GetItemChildren(rootItem,
recursively=True).index(item) + countRoot
class VirtualTree(TreeAPIHarmonizer, TreeHelper):
''' This is a mixin class that can be used to allow for virtual tree
controls. It can be mixed in with wx.TreeCtrl, wx.gizmos.TreeListCtrl,
wx.lib.customtree.CustomTreeCtrl.
To use it derive a new class from this class and one of the tree
controls, e.g.:
class MyTree(VirtualTree, wx.TreeCtrl):
...
VirtualTree uses several callbacks (such as OnGetItemText) to
retrieve information needed to construct the tree and render the
items. To specify what item the callback needs information about,
the callback passes an item index. VirtualTree supports two types of
indices: a tuple-based index (the default) and an integer based index.
See below for a more detailed explanation of the two index types.
Note that VirtualTree forces the wx.TR_HIDE_ROOT style.
In your subclass you *must* override OnGetItemText and either
OnGetChildrenCount if you use the tuple-based index or
OnGetChildrenIndices if you use the integer-based index. These
methods are the minimum needed to construct the tree and render
the item labels. If you want to add images, change fonts our colours,
etc., you need to override the appropriate OnGetXXX method as well.
About the index types: VirtualTree supports two types of indices that
are passed to the several callbacks to retrieve information about
items in the tree. The default index type is tuple-based, the second
type is integer-based.
If you use tuple-based indices, your callbacks are passed a tuple of
integers that identifies the item the VirtualTree wants information
about. An empty tuple, i.e. (), represents the hidden root item.
A tuple with one integer, e.g. (3,), represents a visible root item,
in this case the fourth one. A tuple with two integers, e.g. (3,0),
represents a child of a visible root item, in this case the first
child of the fourth root item. The tuple-based index is best suited
if your underlying data structure is organized as a tree and allows
for easy navigation to the right object in your tree data structure.
If you use integer-based indices, your callbacks are passed a simple
integer (or None) that identifies the item the VirtualTree wants
information about. None represents the hidden root item. Zero (0)
represents the first visible root item. If the first visible root
item has children 1 represents the first child of the first visible
root item. If that child has children 2 represents the first grand
child of the first visible root item. If the first child has no
children, 2 would represent the second child of the first visible
root item, etc. Basically, the integer is the row number of the item
(when the tree is completely expanded). Integer-based indices are
more convenient when your underlying data structure is organized as
a list that is in the same order as the tree items in the tree need
to be.
'''
def __init__(self, *args, **kwargs):
self._tupleIndex = kwargs.pop('tupleIndex', True)
kwargs['style'] = kwargs.get('style', wx.TR_DEFAULT_STYLE) | \
wx.TR_HIDE_ROOT
super(VirtualTree, self).__init__(*args, **kwargs)
self.Bind(wx.EVT_TREE_ITEM_EXPANDING, self.OnItemExpanding)
self.Bind(wx.EVT_TREE_ITEM_COLLAPSED, self.OnItemCollapsed)
def OnGetChildrenCount(self, tupleIndex):
''' This function must be overloaded in the derived class, if
you use the tuple-based indices. It should return the number
of child items of the item with the provided tupleIndex. If
tupleIndex == () it should return the number of root items. '''
raise NotImplementedError
def OnGetChildrenIndices(self, integerIndex=None):
''' This function must be overloaded in the derived class, if
you want to use the integer-based index. The overridden method
should return a list containing the (integer) indices of the
children of the specified item. '''
raise NotImplementedError
def OnGetItemText(self, index, column=0):
''' This function must be overloaded in the derived class. It
should return the string containing the text of the specified
item. '''
raise NotImplementedError
def OnGetItemFont(self, index):
''' This function may be overloaded in the derived class. It
should return the wx.Font to be used for the specified item. '''
return wx.NullFont
def OnGetItemTextColour(self, index):
''' This function may be overloaded in the derived class. It
should return the wx.Colour to be used as text colour for the
specified item. '''
return wx.NullColour
def OnGetItemBackgroundColour(self, index):
''' This function may be overloaded in the derived class. It
should return the wx.Colour to be used as background colour for
the specified item. '''
return wx.NullColour
def OnGetItemImage(self, index, which=wx.TreeItemIcon_Normal, column=0):
''' This function may be overloaded in the derived class. It
should return the index of the image to be used. Don't forget
to associate an ImageList with the tree control. '''
return -1
def OnGetItemType(self, index):
''' This function may be overloaded in the derived class, but
that only makes sense when this class is mixed in with a tree
control that supports checkable items, i.e. CustomTreeCtrl.
This method should return whether the item is to be normal (0,
the default), a checkbox (1) or a radiobutton (2).
Note that OnGetItemChecked needs to be implemented as well; it
should return whether the item is actually checked. '''
return 0
def OnGetItemChecked(self, index):
''' This function may be overloaded in the derived class, but
that only makes sense when this class is mixed in with a tree
control that supports checkable items, i.e. CustomTreeCtrl.
This method should return whether the item is to be checked.
Note that OnGetItemType should return 1 (checkbox) or 2
(radiobutton) for this item. '''
return False
def RefreshItems(self):
''' Redraws all visible items. '''
rootItem = self.GetRootItem()
if not rootItem:
rootItem = self.AddRoot('Hidden root')
self.RefreshChildrenRecursively(rootItem)
def RefreshChildrenRecursively(self, item, itemIndex=None):
''' Refresh the children of item, reusing as much of the
existing items in the tree as possible. '''
if itemIndex is None:
itemIndex = self.ItemIndex(item, tupleIndex=self._tupleIndex)
reusableChildren = self.GetItemChildren(item)
for childIndex in self.ChildIndices(itemIndex):
if reusableChildren:
child = reusableChildren.pop(0)
else:
child = self.AppendItem(item, '')
self.RefreshItemRecursively(child, childIndex)
for child in reusableChildren:
self.Delete(child)
def RefreshItemRecursively(self, item, itemIndex):
''' Refresh the item and its children recursively. '''
hasChildren = bool(self.ChildIndices(itemIndex))
self.RefreshItem(item, itemIndex, hasChildren)
# We need to refresh the children when the item is expanded and
# when the item has no children, because in the latter case we
# might have to delete old children from the tree:
if self.IsExpanded(item) or not hasChildren:
self.RefreshChildrenRecursively(item, itemIndex)
self.SetItemHasChildren(item, hasChildren)
def RefreshItem(self, item, index, hasChildren):
''' Refresh one item. '''
item = self.RefreshItemType(item, index)
self.RefreshItemText(item, index)
self.RefreshColumns(item, index)
self.RefreshItemFont(item, index)
self.RefreshTextColour(item, index)
self.RefreshBackgroundColour(item, index)
self.RefreshItemImage(item, index, hasChildren)
self.RefreshCheckedState(item, index)
def RefreshItemText(self, item, index):
self.__refreshAttribute(item, index, 'ItemText')
def RefreshColumns(self, item, index):
for columnIndex in range(1, self.GetColumnCount()):
self.__refreshAttribute(item, index, 'ItemText', columnIndex)
def RefreshItemFont(self, item, index):
self.__refreshAttribute(item, index, 'ItemFont')
def RefreshTextColour(self, item, index):
self.__refreshAttribute(item, index, 'ItemTextColour')
def RefreshBackgroundColour(self, item, index):
self.__refreshAttribute(item, index, 'ItemBackgroundColour')
def RefreshItemImage(self, item, index, hasChildren):
regularIcons = [wx.TreeItemIcon_Normal, wx.TreeItemIcon_Selected]
expandedIcons = [wx.TreeItemIcon_Expanded,
wx.TreeItemIcon_SelectedExpanded]
# Refresh images in first column:
for icon in regularIcons:
self.__refreshAttribute(item, index, 'ItemImage', icon)
for icon in expandedIcons:
if hasChildren:
imageIndex = self.OnGetItemImage(index, icon)
else:
imageIndex = -1
if self.GetItemImage(item, icon) != imageIndex or imageIndex == -1:
self.SetItemImage(item, imageIndex, icon)
# Refresh images in remaining columns, if any:
for columnIndex in range(1, self.GetColumnCount()):
for icon in regularIcons:
self.__refreshAttribute(item, index, 'ItemImage', icon,
columnIndex)
def RefreshItemType(self, item, index):
return self.__refreshAttribute(item, index, 'ItemType')
def RefreshCheckedState(self, item, index):
self.__refreshAttribute(item, index, 'ItemChecked')
def ChildIndices(self, itemIndex):
if self._tupleIndex:
childrenCount = self.OnGetChildrenCount(itemIndex)
return [itemIndex + (childNumber,) for childNumber \
in range(childrenCount)]
else:
return self.OnGetChildrenIndices(itemIndex)
def OnItemExpanding(self, event):
self.RefreshChildrenRecursively(event.GetItem())
event.Skip()
def OnItemCollapsed(self, event):
parent = self.GetItemParent(event.GetItem())
if not parent:
parent = self.GetRootItem()
self.RefreshChildrenRecursively(parent)
event.Skip()
def __refreshAttribute(self, item, index, attribute, *args):
''' Refresh the specified attribute if necessary. '''
value = getattr(self, 'OnGet%s'%attribute)(index, *args)
if getattr(self, 'Get%s'%attribute)(item, *args) != value:
return getattr(self, 'Set%s'%attribute)(item, value, *args)
else:
return item
class DragAndDrop(TreeAPIHarmonizer, TreeHelper):
''' This is a mixin class that can be used to easily implement
dragging and dropping of tree items. It can be mixed in with
wx.TreeCtrl, wx.gizmos.TreeListCtrl, or wx.lib.customtree.CustomTreeCtrl.
To use it derive a new class from this class and one of the tree
controls, e.g.:
class MyTree(DragAndDrop, wx.TreeCtrl):
...
You *must* implement OnDrop. OnDrop is called when the user has
dropped an item on top of another item. It's up to you to decide how
to handle the drop. If you are using this mixin together with the
VirtualTree mixin, it makes sense to rearrange your underlying data
and then call RefreshItems to let the virtual tree refresh itself. '''
def __init__(self, *args, **kwargs):
kwargs['style'] = kwargs.get('style', wx.TR_DEFAULT_STYLE) | \
wx.TR_HIDE_ROOT
super(DragAndDrop, self).__init__(*args, **kwargs)
self.Bind(wx.EVT_TREE_BEGIN_DRAG, self.OnBeginDrag)
def OnDrop(self, dropItem, dragItem):
''' This function must be overloaded in the derived class.
dragItem is the item being dragged by the user. dropItem is the
item dragItem is dropped upon. If the user doesn't drop dragItem
on another item, dropItem equals the (hidden) root item of the
tree control. '''
raise NotImplementedError
def OnBeginDrag(self, event):
# We allow only one item to be dragged at a time, to keep it simple
self._dragItem = event.GetItem()
if self._dragItem and self._dragItem != self.GetRootItem():
self.StartDragging()
event.Allow()
else:
event.Veto()
def OnEndDrag(self, event):
self.StopDragging()
dropTarget = event.GetItem()
if not dropTarget:
dropTarget = self.GetRootItem()
if self.IsValidDropTarget(dropTarget):
self.UnselectAll()
if dropTarget != self.GetRootItem():
self.SelectItem(dropTarget)
self.OnDrop(dropTarget, self._dragItem)
def OnDragging(self, event):
if not event.Dragging():
self.StopDragging()
return
item, flags, column = self.HitTest(wx.Point(event.GetX(), event.GetY()),
alwaysReturnColumn=True)
if not item:
item = self.GetRootItem()
if self.IsValidDropTarget(item):
self.SetCursorToDragging()
else:
self.SetCursorToDroppingImpossible()
if flags & wx.TREE_HITTEST_ONITEMBUTTON:
self.Expand(item)
if self.GetSelections() != [item]:
self.UnselectAll()
if item != self.GetRootItem():
self.SelectItem(item)
event.Skip()
def StartDragging(self):
self.GetMainWindow().Bind(wx.EVT_MOTION, self.OnDragging)
self.Bind(wx.EVT_TREE_END_DRAG, self.OnEndDrag)
self.SetCursorToDragging()
def StopDragging(self):
self.GetMainWindow().Unbind(wx.EVT_MOTION)
self.Unbind(wx.EVT_TREE_END_DRAG)
self.ResetCursor()
self.UnselectAll()
self.SelectItem(self._dragItem)
def SetCursorToDragging(self):
self.GetMainWindow().SetCursor(wx.StockCursor(wx.CURSOR_HAND))
def SetCursorToDroppingImpossible(self):
self.GetMainWindow().SetCursor(wx.StockCursor(wx.CURSOR_NO_ENTRY))
def ResetCursor(self):
self.GetMainWindow().SetCursor(wx.NullCursor)
def IsValidDropTarget(self, dropTarget):
if dropTarget:
allChildren = self.GetItemChildren(self._dragItem, recursively=True)
parent = self.GetItemParent(self._dragItem)
return dropTarget not in [self._dragItem, parent] + allChildren
else:
return True
class ExpansionState(TreeAPIHarmonizer, TreeHelper):
''' This is a mixin class that can be used to save and restore
the expansion state (i.e. which items are expanded and which items
are collapsed) of a tree. It can be mixed in with wx.TreeCtrl,
wx.gizmos.TreeListCtrl, or wx.lib.customtree.CustomTreeCtrl.
To use it derive a new class from this class and one of the tree
controls, e.g.:
class MyTree(ExpansionState, wx.TreeCtrl):
...
By default, ExpansionState uses the position of tree items in the tree
to keep track of which items are expanded. This should be sufficient
for the simple scenario where you save the expansion state of the tree
when the user closes the application or file so that you can restore
the expansion state when the user start the application or loads that
file for the next session.
If you need to add or remove items between the moments of saving and
restoring the expansion state (e.g. in case of a multi-user application)
you must override GetItemIdentity so that saving and loading of the
expansion doesn't depend on the position of items in the tree, but
rather on some more stable characteristic of the underlying domain
object, e.g. a social security number in case of persons or an isbn
number in case of books. '''
def GetItemIdentity(self, item):
''' Return a hashable object that represents the identity of the
item. By default this returns the position of the item in the
tree. You may want to override this to return the item label
(if you know that labels are unique and don't change), or return
something that represents the underlying domain object, e.g.
a database key. '''
return self.ItemIndex(item)
def GetExpansionState(self):
''' GetExpansionState() -> list of expanded items. Expanded items
are coded as determined by the result of GetItemIdentity(item). '''
root = self.GetRootItem()
if not root:
return []
if self.HasFlag(wx.TR_HIDE_ROOT):
return self.GetExpansionStateOfChildren(root)
else:
return self.GetExpansionStateOfItem(root)
def SetExpansionState(self, listOfExpandedItems):
''' SetExpansionState(listOfExpandedItems). Expands all tree items
whose identity, as determined by GetItemIdentity(item), is present
in the list and collapses all other tree items. '''
root = self.GetRootItem()
if not root:
return
if self.HasFlag(wx.TR_HIDE_ROOT):
self.SetExpansionStateOfChildren(listOfExpandedItems, root)
else:
self.SetExpansionStateOfItem(listOfExpandedItems, root)
ExpansionState = property(GetExpansionState, SetExpansionState)
def GetExpansionStateOfItem(self, item):
listOfExpandedItems = []
if self.IsExpanded(item):
listOfExpandedItems.append(self.GetItemIdentity(item))
listOfExpandedItems.extend(self.GetExpansionStateOfChildren(item))
return listOfExpandedItems
def GetExpansionStateOfChildren(self, item):
listOfExpandedItems = []
for child in self.GetItemChildren(item):
listOfExpandedItems.extend(self.GetExpansionStateOfItem(child))
return listOfExpandedItems
def SetExpansionStateOfItem(self, listOfExpandedItems, item):
if self.GetItemIdentity(item) in listOfExpandedItems:
self.Expand(item)
self.SetExpansionStateOfChildren(listOfExpandedItems, item)
else:
self.Collapse(item)
def SetExpansionStateOfChildren(self, listOfExpandedItems, item):
for child in self.GetItemChildren(item):
self.SetExpansionStateOfItem(listOfExpandedItems, child)