PySide Tree Tutorial: Introduction

I think that I shall never see
A poem lovely as a tree.                       -Joyce Kilmer

I've written an annotated companion to the simpletreemodel example that comes with PySide/PyQt. The code builds and displays a hierarchically organized data structure (i.e., a tree) using a model subclassed from QAbstractItemModel. I spread it out over multiple posts (see Table of Contents below). When finished, I'll put the entire series of posts into a single PDF and put a link to it in this post.

In Part I we will briefly review the model/view framework, focusing on details relevant for implementing our example. In sections II and III, we will study simpletreemodel. Part IV includes suggestions for future study. Part V shows how you can use other tools (QTreeWidget and QStandardItemModel) to construct a similar tree.

Table of Contents

0. Introduction

I:Models and Views

            A. The big picture

            B. The mighty index

II: Building the data structure
            A. An introduction to simpletreemodel

            B. From TreeItem to tree structure

            C. Cross-examining simpletreemodel

            D. Adding helper methods to TreeItem

III: Making the tree model

            A. Introducing the TreeModel class

            B. QAbstractItemModel's API

            C. Index and parent
            D. Creating the tree with setupModelData()

IV: What next?

V: Building trees with QTreeWidget andQStandardItemModel

Acknowledgments

This started as a direct translation of the online Qt documentation on model-view programming. The main sources used were:

http://qt-project.org/doc/qt-4.8/itemviews-simpletreemodel.html

http://qt-project.org/doc/qt-4.8/itemviews-editabletreemodel.html

http://qt-project.org/doc/qt-4.8/model-view-programming.html

http://qt-project.org/doc/qt-4.8/modelview.html

Also, thanks also to the folks at stackoverflow and qtcentre.org for answering my many questions. Thanks also to Tim Doty, Anna Stenwick, and Mark Summerfield for comments on previous drafts. Feel free to post questions/suggestions/comments in the comments of the relevant posts, or email them to me: thomson.eric at gmail.

References

Summerfield, M (2008) Rapid Gui Programming with Python and Qt. Prentice Hall.
Summerfield, M (2010) Advanced Qt Programming. Prentice Hall.