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Tweak QListView Behavior on Click in PyQt5

Discover how to modify the default selection behavior of `QListView` in PyQt5 to maintain current selections while updating the current index without deselecting. --- This video is based on the question https://stackoverflow.com/q/65488667/ asked by the user 'mike rodent' ( https://stackoverflow.com/u/595305/ ) and on the answer https://stackoverflow.com/a/65496979/ provided by the user 'mike rodent' ( https://stackoverflow.com/u/595305/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Tweak QListView behaviour on click? Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l... The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Tweak QListView Behavior on Click in PyQt5 When working with PyQt5, a commonly encountered widget is the QListView. By default, the behavior when clicking on an item is to deselect any currently selected items and select the clicked item as the "current item". However, there are situations where you might want to change this behavior—specifically, you may want an item to remain in the selection but still update the current item based on what was clicked. In this guide, we'll explore how to alter the default click behavior of QListView, enabling it to update the current item without affecting the existing selections. This solution is both elegant and practical, making it a valuable enhancement for any PyQt5 application that utilizes a QListView for displaying lists of items. Understanding the Default Behavior Before we dive into the solution, let's clarify the default behavior of the QListView when an item is clicked: Deselection: Clicking on an item will clear any existing selections. Selection: The item that was clicked becomes the new selected item. Current Item Update: The clicked item is also set as the "current index". The Problem While this behavior can be useful in some contexts, it may not always be desired. For instance, if a user wants to keep their selections intact and merely indicate which item is currently being interacted with, the default behavior can be disruptive. In summary, the goal is to have the QListView exhibit the following behavior: Maintain existing selections. Set the clicked item as the current index without deselecting items. The Solution The approach to modifying the QListView behavior involves overriding the mousePressEvent method. Let's break down the implementation step-by-step. Step-by-step Implementation Override mousePressEvent: The first step is to create a new method that overrides the existing mousePressEvent. This method will contain the logic to handle mouse clicks specifically. Check Modifiers: By checking whether the event modifiers are set to NoModifier, we can ensure that our customization applies specifically to ordinary clicks. Get Click Position and Index: Use the event.pos() method to retrieve the clicked position and convert it to an index using indexAt(pos). Set Current Index: If the clicked index is valid, we update the current index using the setCurrentIndex method of the selection model, thereby ensuring that the current item is updated without affecting the selection state. Call the Super Class Method: Lastly, it’s good practice to call the superclass’s mousePressEvent method, allowing any default behavior for other types of clicks (like Ctrl-click or Shift-click) to remain intact. Here’s the complete code: [[See Video to Reveal this Text or Code Snippet]] Advantages of This Approach Using this method offers several advantages: Preservation of Selection: This solution allows users to maintain their selections, improving the user experience. Compatibility: It keeps the existing functionality for multi-selection methods (like Ctrl-click and Shift-click). Clarity: The code is straightforward and easy to understand, making maintenance and further development simpler. Conclusion Modifying the QListView click behavior in PyQt5 offers greater flexibility and enhances user experience in applications that utilize lists extensively. By implementing the steps outlined above, you can ensure that your list view behaves according to the specific needs of your users. If you're building a PyQt5 application, consider tweaking QListView behavior to provide a more intuitive interface. Experiment with different modifications to further enhance your UI—happy coding!