i.MX 8M PLUS - Qt5 5.2.15 app does not receive touchscreen Qt::PinchGesture event

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i.MX 8M PLUS - Qt5 5.2.15 app does not receive touchscreen Qt::PinchGesture event

Contributor I


I am new to NXP, the i.MX family, Qt5, and touchscreens.  Please bear with me

Executive Summary: we are porting a fairly mature Qt5 application from Android to (Yocto) Linux on the i.MX 8M PLUS.  The Android touchscreen solution works fine with regard to Qt::PanGesture events and Qt::PinchGesture events.  The Linux touchscreen solution works fine with regard to Qt::PanGesture events but not with Qt::PinchGesture events.  The only Linux solution gesture events we are receiving are for Qt::PanGesture events, even when using a two-finger pinch gesture.

Some Details:

* wayland 1.19.0

* weston

* Yotco Hardknott

* Qt5 5.15.2

 We have set the C++ class (of interest):


In case this looks familiar to any reader, another dev found it necessary to set the QT_PAN_TOUCHPOINTS QT envvar in the C++ main function in order to receive gesture events with the Android implementation:

qputenv("QT_PAN_TOUCHPOINTS", "1");

We definitely need this for the Linux implementation as well:  without it, we receive only mouse events rather than gesture events.

Any ideas about our problematic build and/or configuration issue?

Thank you for your time.  Let me know if additional details are required.

Meanwhile, I intend to compile and link an open-source Qt5 touchscreen gesture demo as a sanity-check.


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3 Replies

Contributor I

FYI - I see the same behavior when using the latest (I think) NXP-provided Yocto configuration for the i.MX 8M Plus

re: fsl-imx-wayland/5.15-kirkstone (sysroots/armv8a-poky-linux and x86_64-pokysdk-linux)

I don't have an NXP evaluation baseboard.  I have been unable to find a vendor who can provide these units at this time.

So I modified the as-delivered boot folder, adding the Device Tree Blobs that are required for the evaluation baseboard, SOM, and touch screen that I do have access to.

NOTE - I very much appreciate that NXP has provided a Docker image for this version of the Yocto environment.  That is hugely helpful.

After making a few changes to the gestures/imagegestures example app, I confirmed the same two-finger gesture behavior that is reported above.

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NXP TechSupport
NXP TechSupport

Hello abdodson,

Which BSP are you using? the new BSP use the QT6.0 you can download it from:





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Contributor I

Thank you.

We are using a proprietary BSP.

Thank you for the information; I will circle-back with the vendor and discuss this with my lead engineer.

Best regards,


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