Copyright 2006-2007 Nanorex, Inc.  See LICENSE file for details. 

This is an overview of the changes in the code that were necessary for
the port to Qt 4. As of this writing (27 Dec 2006) the Qt 4 code is on
the CVS branch "wware_qt4_20060919". For most files, the diffs can be
seen by going to
http://mirror2.cvsdude.com/~polosims/vcvs/cgi/viewcvs.cgi/cad/src/?pathrev=wware_qt4_20060919
and clicking the filename in the left column, then clicking the diff
"to branch point" for the most recent revision. For files with big
changes, the diff may be too confusing to be useful.

There are several relevant pages on the public wiki.

* "Transition to Qt 4"
	This page is primarily about installing Qt 4 on your platform.

* "Current Issues: NE1 on Qt4"
	This has been a bug list that Ninad and Will have worked from
	as the Qt 4 port has started to become useable.

* "Qt 4 mysteries"
	This page is a laundry list of random issues that Will ran
	into in the early stages of the Qt 4 port. There is probably
	very little here of practical value, except perhaps to Ninad
	as he might run into similar issues in the future. Also, there
	may be enough breadcrumbs here to help assemble this overview
	of the significant changes in the code.

* "Qt 4 C/C object deleted"
	This page describes an error message that comes up
	periodically while one works on Qt 4. Initially it was very
	confusing to us, but now we think we understand it better and
	we have some diagnostic tools for helping to figure out any
	future incidents of this error.

One big thing is that we have moved away from using Qt Designer. There
are still *.ui files in the Qt 4 branch, but they are long obsolete
and should really be removed to avoid confusion.

There are really big changes in MWsemantics.py and MainWindowUI.py.
They are probably barely recognizable from their Qt 3 counterparts.

The hierarchy of classes used to support the model tree has seen lots
of very big changes too. TreeWidget.py and TreeView.py are no longer
used and have been replaced by modelTreeGui.py. The work on the model
tree was prototyped in modelTreePrototype.py, which is not used in
the main program but shows some of the model tree design thinking in
its original form before it was merged with the rest of NE-1.

The DirView class becomes much simpler in Qt 4, so the DirView.py
file is no longer relevant and can be removed. The DirView class now
lives in MMKit.py, currently at line 596. This was possible because
Qt 4 provides a more useful set of classes than Qt 3 did, and stuff
we needed to do ourselves in Qt 3 is available as part of Qt 4.

There have been a lot of changes to MMKit.py. Some have to do with
bringing in connect statements from MMKitDialog.py, as it appears that
the convention with Qt 4 is that connect statements go in the
user-written code rather than the qt-designer-generated code. That's
not bad, as we are no longer using Qt Designer to generate code
anyway.