Fix contact editing.

This fixes some bugs in contact editing:

- a changed address is now checked for validity. Shows
  error if invalid and restores prior value
- the changes are saved, before they were dropped
- adding a new contact switches to the contacts tab,
  it used to switch to the address tab

As an enhancement, the contact name, as well as its address,
can be edited and updated.

Finally, the platform edit key can also be used to edit,
in adition to double-clicking.  This is typically the F2 key.

gui/qt/util.py

@@ -289,13 +289,10 @@ class EditableItem(QTreeWidgetItem):
         self.setFlags(self.flags() | Qt.ItemIsEditable)
 
 class EditableItemDelegate(QStyledItemDelegate):
-    def __init__(self, parent, editable_columns):
-        QStyledItemDelegate.__init__(self, parent)
-        self.editable_columns = editable_columns
-
     def createEditor(self, parent, option, index):
-        if index.column() not in self.editable_columns:
+        if index.column() not in self.parent().editable_columns:
             return None
+        self.parent().prior_text = unicode(index.data().toString())
         return QStyledItemDelegate.createEditor(self, parent, option, index)
 
 class MyTreeWidget(QTreeWidget):
@@ -317,10 +314,11 @@ class MyTreeWidget(QTreeWidget):
         # Control which columns are editable
         if editable_columns is None:
             editable_columns = [stretch_column]
+        self.editable_columns = editable_columns
         self.setEditTriggers(QAbstractItemView.DoubleClicked |
                              QAbstractItemView.EditKeyPressed)
-        self.setItemDelegate(EditableItemDelegate(self, editable_columns))
-        self.itemChanged.connect(self.item_edited)
+        self.setItemDelegate(EditableItemDelegate(self))
+        self.itemChanged.connect(self.item_changed)
 
         # stretch
         for i in range(len(headers)):
@@ -340,6 +338,10 @@ class MyTreeWidget(QTreeWidget):
                 break
         self.emit(SIGNAL('customContextMenuRequested(const QPoint&)'), QPoint(50, i*5 + j - 1))
 
+    def item_changed(self, item, column):
+        '''Called only when the text actually changes'''
+        self.item_edited(item, column, self.prior_text)
+
     def item_edited(self, item, column, prior):
         '''Called only when the text actually changes'''
         key = str(item.data(0, Qt.UserRole).toString())