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Editorial Team
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Asked: 2026-05-19T02:49:05+00:00

I’m building a desktop app in QT (although that may be irrelevant) and I’m

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I’m building a desktop app in QT (although that may be irrelevant) and I’m having a hard time working through the class structure and layout. The data model is fairly simple with a root container with a number of containers of items. Consider the following representation:

Root
+ Parent
  + Child

The UI is fairly simple and follows that data model with a main window with a scrollable area (root), widgets that contain layouts (parents) of custom widgets (children) with some labels and buttons.

My trouble is with handling events that need to go up the chain and then back down like moving a child from one parent to another, moving elements, or updating child meta-data that impacts several to many other widgets.

I’m currently splitting UI widgets and model objects but having each widget and corresponding model object pointing to and from each other feels cumbersome and I think it is leading to too much maintenance.

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1 Answer

  1. Editorial Team

    I’d suggest following a standard MVC pattern and ensure there are no dependencies from the model to the view; in your case this would mean that while there is a widget for every model item, the model items do not reference their corresponding widgets.

    While the MVC pattern has many flavours, one way to accomplish this would be to have a view class that monitors the model for any changes and updates the view accordingly (this can be accomplished by connecting a slot in the view class to a signal emitted from the model class). Any changes the user initiates through the view can then be:

    1) handled directly by the model
    through a simple signal/slot
    connection
    2) handled
    by a controller class which can
    direct the model to update accordingly

    Either of these would then cause the model to emit an update signal which would cause your view to update. The benefit of this is the ability to change your view (or add additional views) without having to update your model.

    I’d recommend reading Qt’s Model/View Programming Guide to better understand how MVC works in Qt and to see if there’s an existing class or interface (e.g. QAbstractItemModel) that you could use instead of baking your own.

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