Bring in the listbox widget with drag.

You can drag items up and down to rearrange the list.

joy/gui/controllerlistbox.py

@@ -0,0 +1,127 @@
+'''
+    Copyright (C) 2004 - 2008 Simon Forman
+
+    This file is part of Xerblin.
+
+    Xerblin is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+'''
+from Tkinter import Listbox, SINGLE
+from Tkdnd import dnd_start
+
+
+class SourceWrapper:
+    '''
+    Helper object for drag and drop.
+    '''
+    def __init__(self, source, widget, index=None):
+        '''
+        source is the object being dragged, widget is the container thats
+        initialing the drag operation, and index s thu index of the item
+        in the widget's model object (which presumably is a ListModel
+        containing the source object.)
+        '''
+        self.source = source
+        self.widget = widget
+        self.index = index
+
+    def dnd_end(self, target, event):
+        try:
+            self.widget.clear()
+        except AttributeError:
+            pass
+
+
+class DraggyListbox(Listbox):
+
+    def __init__(self, master=None, **kw):
+
+        # Get our stack.
+        self.stack = kw.pop('items')
+
+        # Override any passed in selectmode.
+        kw['selectmode'] = SINGLE
+
+        Listbox.__init__(self, master, **kw)
+
+        self.bind('<Button-1>', self.startDrag)
+        self.bind('<ButtonRelease-1>', self.clear)
+
+    def clear(self, event=None):
+        i = self.curselection()
+        if i:
+            i = int(i[0])
+            self.selection_clear(i)
+
+    def startDrag(self, event):
+        i = self.nearest(event.y)
+        if i >= 0:
+            self.selection_set(i)
+            source = self.stack[i]
+            source = SourceWrapper(source, self, i)
+            event.num = 1 # Don't ask. (See Tkdnd.py)
+            dnd_start(source, event)
+        return "break"
+
+
+class ControllerListbox(DraggyListbox):
+
+    def __init__(self, master=None, **kw):
+        DraggyListbox.__init__(self, master, **kw)
+        self._dragIndex = -1
+
+    def dnd_accept(self, source, event):
+        self.focus_force()
+        return self
+
+    def dnd_enter(self, source, event):
+        pass
+
+    def dnd_motion(self, source, event):
+        I = self.nearest(event.y_root - self.winfo_rooty())
+        if self._dragIndex >= 0:
+            self.delete(self._dragIndex)
+        self._dragIndex = I
+        self.insert(I, '---')
+
+    def dnd_leave(self, source, event):
+        if self._dragIndex >= 0:
+            self.delete(self._dragIndex)
+            self._dragIndex = -1
+
+    def dnd_commit(self, source, event):
+        i = self._dragIndex
+
+        if i >= 0:
+            self.delete(i)
+            self._dragIndex = -1
+
+        try:
+            if self is source.widget:
+
+                # Don't duplicate something by dropping it on itself.
+                if i == source.index:
+                    return
+
+                # Instead, move it by removing it before the pending append.
+                del self.stack[source.index]
+                if i > source.index:
+                    i -= 1
+
+            self.stack.insert(i, source.source)
+
+        finally:
+            self.clear()
+