Touchpad tap to click not captured when io.ConfigInputTrickleEventQueue is false

[kyle-sylvestre]

Version/Branch of Dear ImGui:

Version 1.91.1 WIP, Branch: master

Back-ends:

imgui_impl_metal.cpp + imgui_impl_osx.cpp

Compiler, OS:

macOS + Clang 15

Full config/build information:

No response

Details:

Tapping to click with a laptop touchpad fails when io.ConfigInputTrickleEventQueue is false. I have replicated this problem on a Windows 10 laptop and a Macbook M3 Air.

Screenshots/Video:

No response

Minimal, Complete and Verifiable Example code:

// Here's some code anyone can copy and paste to reproduce your issue
ImGui::GetIO().ConfigInputTrickleEventQueue = false;
ImGui::Begin("Touchpad Example");
static bool b;
ImGui::Checkbox("Untappable", &b);
ImGui::End();

[ocornut]

Yes that’s the point of this feature, it must not be disabled on a touchpad.

[ocornut]

I am curious about why you tried to disable it?
I will try to amend comments to clarify its purpose.

[kyle-sylvestre]

Turning trickle off lets me display characters in an InputText() as soon as possible. Ideally I'd only want the mouse down/up trickle since these touchpad taps are not getting captured.

[ocornut]

Turning trickle off lets me display characters in an InputText() as fast as possible.

You are correct that in the current version, there is a 1 frame delay processing characters because of this code.
This is caused by fa2b318
I am surprised that I didn't comment further on this when pushing this. I was eager to "fix" the issue outside of InputText() that I didn't fix this well enough, and it may feel different depending on whether your backend submits characters or keys first.

With

[03322] [io] Processed: Key "H" Down
[03322] [io] Remaining: Text: h (U+00000068)
[03323] [io] Processed: Text: h (U+00000068) <-- processed by `InputText()`

Without

[05931] [io] Processed: Key "H" Down
[05931] [io] Processed: Text: h (U+00000068) <-- processed by `InputText()`

I believe an issue should be open for this, ideally we could aim to find a way to disable some of the trickling better for text input. I don't have the solution yet but I can investigate.

[kyle-sylvestre]

I agree, I'll make a new issue referencing this one.