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Votes

0

Found in

2020.3.32f1

2021.2.19f1

2021.3.0f1

2022.1.0b15

2022.2.0a10

Issue ID

UUM-3464

Regression

No

PointerUpEvent doesn't work when using left-click on a dragger of the Slider

--

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Reproduction steps:
1. Open users attached project
2. Open Assets > Scenes > SampleScene.unity
3. Enter Play Mode
4. In the Game View left-click and release the dragger of the Slider
5. Observe the Console window

Expected result: "down" and "up" messages are printed in the Console
Actual result: Only the "down" message is printed is in the Console

Reproducible with: 1.0.0-preview.15, 1.0.0-preview.18 (2020.3.32f1), Built-in (2021.2.19f1, 2021.3.0f1, 2022.1.0b15, 2022.2.0a10)
Couldn't test with: 2019.4.38f1 (UI Toolkit not supported)

Note: PointerUpEvent works when using right-click

See: https://unity.slack.com/archives/C3414V4UV/p1656015671717799

  1. Resolution Note:

    This is not necessarily a bug as much as it's a possibly controversial design decision, to make pointer event callbacks only triggered on the capturing element itself and not its parents (even composite root parents) when there's a pointer capture. Exclusive processing by capturing element has been part of UI Toolkit for more than 5 years.

    Moreover, there's a relatively easy workaround. You can use
    ```
    slider.Q<VisualElement>("unity-drag-container").RegisterCallback<PointerUpEvent>(e => Debug.Log("Slider dragger PointerUp"));
    ```
    to react to the PointerUpEvent in this situation. You can discover what exact element was receiving the PointerUpEvent by using the UI Toolkit Event Debugger window, in Project Settings -> UI Toolkit -> Enable Event Debugger, then Window -> UI Toolkit -> Event Debugger.

    Note that we are changing how pointer events are propagated as part of an event dispatch simplification effort in 2023.2, which include getting rid of the exclusive processing by capturing element, but we don't want to change it in earlier versions such as 2021.3 or 2022.2, or even 2023.1.

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