[PATCH] Make KJanusWidget consistent

Ravikiran Rajagopal ravi at ee.eng.ohio-state.edu
Tue Feb 18 19:42:54 GMT 2003

Hash: SHA1

  KJanusWidget has a consistency problem. The function showPage(int) is 
virtual but it is not used by slotShowPage() to show actual pages. Hence, if 
we want to do some processing in a derived class after showing a page, we 
cannot do so. For example, somthing like the following does not work (MyClass 
is derived from KJanusWidget):

bool MyClass::showPage(int index)
  boot ret = KJanusWidget::showPage(index);
  return ret;

Thus, the whole point of KJanusWidget::showPage(int) being virtual is 
defeated! The following patch makes showPage(int) overrides usable:

- --- kjanuswidget.cpp.orig       2003-02-18 14:18:27.000000000 -0500
+++ kjanuswidget.cpp    2003-02-18 14:19:47.000000000 -0500
@@ -540,14 +540,14 @@
     if( node == 0 ) { return( false ); }

     QWidget *stackItem = mTreeListToPageStack[node];
- -    return showPage(stackItem);
+    return showPage(pageIndex(stackItem));
   else if( mFace == IconList )
     QListBoxItem *node = mIconList->item( mIconList->currentItem() );
     if( node == 0 ) { return( false ); }
     QWidget *stackItem = mIconListToPageStack[node];
- -    return showPage(stackItem);
+    return showPage(pageIndex(stackItem));

   return( false );

Note that we should NOT make showPage(QWidget *) virtual because it would be 
BIC and, more importantly, it does not perform sanity checks. Actual usage 
instance: give the newly shown page widget the focus (like in KControl). This 
can be done only after the widget is already shown, and hence we cannot 
connect to the aboutToShowPage() signal.

I am surprised that no one has noticed this sooner as KJanusWidget is such an 
important base class. Please cc me on any replies as I am not subscribed to 
this list.

Thank you for your attention,
Version: GnuPG v1.0.7 (GNU/Linux)


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