The Model acts as the interface between the data store and the ViewController. Importantly, the distinction between the data and how it is presented is preserved.

Rather than agonize over where to draw the line, in Qt-speak the View and Controller are instead merged together creating a Model/ViewController architecture - called 'Model View' for simplicity sake. However, widgets also handle presentation of the current state to the user, putting them squarely in the View. Qt accepts input events from the user (via the OS) and delegates these to the widgets (Controller) to handle. It Qt land the distinction between the View & Controller gets a little murky. Controller accepts input from the user, transforming it into commands to for the model or view.Multiple views of the same data model are allowed. View is any representation of information as shown to the user, whether graphical or tables.Model holds the data structure which the app is working with.The MVC design pattern decouples three major components. This separates the internal representation of data from how information is presented to and accepted from the user. Model–View–Controller (MVC) is an architectural pattern used for developing user interfaces which divides an application into three interconnected parts. This tutorial introduces the key aspects of Qt's ModelView architecture and uses it to build simple desktop Todo application in PyQt5. This isolates your data, allowing it to be kept in any structure you like, while the view takes care of presentation and updates.

ModelViews are a powerful alternative to the standard display widgets, which use a regular model interface to interact with data sources - from simple data structures to external databases. Thankfully Qt has a solution for this - ModelViews. This can get ugly quickly, and results in a lot of boilerplate just for fiddling the data. The default solution to this is to keep an external data representation in Python, and then either duplicate updates to the both the data and the widget, or simply rewrite the whole widget from the data. a simple QListWidget) is not readily available to manipulate from Python - changes require you to get an item, get the data, and then set it back. As you start to build more complex applications with PyQt5 you'll likely come across issues keeping widgets in sync with your data.ĭata stored in widgets (e.g.

Simple todo app for windows