Flutter should support capturing the mouse pointer

Is there an existing issue for this?

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Use case

I'm trying to implement a "zoom" feature in my app and i really find the one in Ableton Live to have the best feel/UX.

0913.mov

Notice that the mouse cursor disappears on what would be the Flutter Listener's onPointerDown equivalent, and then I can move the mouse as much as I have space on my desk upwards, while normally the cursor would quickly hit the top of my screen.

This is how it looks like in my app. The Listener's onPointerMove is limited by the screen's real estate.

0913.1.mov

Proposal

Any ideas on how I could "hide" the cursor in flutter and count the mouse travelled distance pixels in a virtually infinite space?

This would be implementing "mouse cursor capture" on supported desktop platforms. Through some new API I guess. Similar to how a FPS game might want to capture the mouse. No way at all to do it at the moment, let's keep this issue open to track such a feature.

This is functionality is implemented in JUCE (a C++ framework for audio apps).

documentation:
https://docs.juce.com/master/classMouseInputSource.html#ad0065b78d89d7dafdcd183fcafccf852
code:
https://github.com/juce-framework/JUCE/blob/HEAD/modules/juce_gui_basics/detail/juce_MouseInputSourceImpl.h#L444

I didn't carefully check the code but it looks doable

For reference to anyone interested in working on it

I guess Flutter API would look something like

GestureBinding.instance.capturePointer(int deviceId)
GestureBinding.instance.releasePointer(int deviceId, {bool restoreOriginalPosition = true})

Sounds legit. I wonder how mouse events are reported natively when captured? IIRC currently Flutter computes position delta by subtracting positions, so I assume either the position will be unbounded or the position delta will be explicitly given?

1st of all, I'm wondering why ShowCursor(0)/ShowCursor(1) (Windows) work when calling them through your plugin, and don't work when calling them from my plugin. Do you have any guess at why that might happen? This is just for my curiosity.

Not sure, I didn't inspect your code. But one possibility is that it's related to repeated calling. If I understand the Win32 API docs correctly, calling ShowCursor(0) / ShowCursor(1) multiple times will decrement/increment a counter. Windows will show the cursor only if the counter is >= 0. This can also happen with my current implementation if not used correctly. I think will introduce a flag that prevents from calling ShowCursor(0) or ShowCursor(1) again if it already has been called.

2nd, I'm going to need a few more functions in the API, if I am to completely use your implementation. I need a set of functions to get & set the raw cursor position, because I want to reveal the cursor position based on some custom application logic.

I have already implemented these partially, so I could make a PR, or just share my code with you. It's pretty much a matter of calling native functions SetCursorPos (Windows) / CGWarpMouseCursorPosition (macOS) and converting from Flutter global coordinate space to native coordinate space.

Sounds good. Looking forward to the PR.

I also realized that the pointer locking implementation on Windows has room for improvement. I implemented a knob with it (also for an audio application) and it's way too sensitive.

alright! thanks for the response, that makes sense. I'm glad to hear I'm not the only one building a desktop audio app with Flutter. I'd be curious to see what you're working on :D

I'll keep you posted about the PR

The triaged-desktop label is irrelevant if there is no team-desktop label or fyi-desktop label.

@alexvoina

@alexvoina I gave https://github.com/helgoboss/pointer_lock a revamp. It now supports a free mode in which any event can lock or unlock the pointer (see new README). There are a few other improvements as well, such as Linux support (X11), a smaller API surface and a dedicated widget for implementing the popular "lock while drag" use case.

@helgoboss

@helgoboss that's cool! I'll have a look and try to update. Your package still powers my app to this day, making real users happy so thank you for your work!

Hi,
On the windows side it already captures the mouse button if its primary.
I'm making a contribution to also allow other mouse buttons to be captured on windows: #188394.

Add the mouse_capture plugin: relative pointer deltas on macOS

[web] Capture pointers to the Flutter view so drags survive platform …

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Flutter should support capturing the mouse pointer #134652

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Flutter should support capturing the mouse pointer #134652

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Is there an existing issue for this?

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moffatman commented on Sep 13, 2023

alexvoina commented on Sep 13, 2023

moffatman commented on Sep 13, 2023

dkwingsmt commented on Sep 14, 2023

16 remaining items

helgoboss commented on Nov 10, 2023

alexvoina commented on Nov 13, 2023

flutter-triage-bot commented on Jun 7, 2024

helgoboss commented on Jan 12, 2025

alexvoina commented on Jan 13, 2025

CodeDoctorDE commented on Jun 26, 2026

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