[BUG] Mouse stops working after using projecteur

[giampierosalvi]

Description
After using the virtual laser (either by using a Logitech Spotlight or "Show test..." and a normal mouse) mouse clicks have no effects. In order to resume the normal function, I need to kill projecteur from a terminal.

To Reproduce
Start the application and activate the virtual pointer on the Logitech Spotlight (or with "Show test..." if using the normal mouse). After stopping the virtual pointer, I can still move the mouse pointer around. However, from that moment mouse clicks have no effect. The only way I can continue working with my session is to use Alt+Tab to change to the terminal and kill projecteur from there. The same behavior is observed if running QT_QPA_PLATFORM=wayland projecteur.

Expected behavior
The normal mouse functionality should resume when stopping the virtual pointer.

Desktop/Linux Environment (please complete the following information):

• Linux Distribution and Version: Ubuntu 26.04
• Desktop/Window Manager and Version GNOME 50
• Did you built Projecteur yourself?: n
• What is the output of projecteur -f ?:

Projecteur 0.10
  git-branch: tag: v0.10, master
  git-hash: a7b2649296f5f8b6793e0c38cdee93d36831404b
  compiler: GNU 15.2.0
  build-type: Debian
  qt-version: (build: 5.15.18, runtime: 5.15.18)
  device-scan: (errors: 0, devices: 0 [readable: 0, writable: 0])

• What is the output of projecteur -d ?: ...

Projecteur 0.10; device scan

 * Found 1 supported devices. (1 readable, 1 writable)

 +++ name:     'Logitech USB Receiver'
     userName: 'Logitech Spotlight (USB)'
     vendorId:  046d
     productId: c53e
     phys:      usb-0000:00:14.0-11
     busType:   BusType::Usb
     devices:   /dev/input/event3, /dev/input/event7, /dev/input/event19, /dev/input/event5, /dev/hidraw6
     readable:  true
     writable:  true

Screenshots
This is the output I can see on the terminal during the events described above (I start projecteur from the terminal to see these debug outputs):

This is using the Logitech Spotlight:

[2026-06-29T16:15:50.204][wrn][default] QSocketNotifier: Can only be used with threads started with QThread
[2026-06-29T16:15:50.277][inf][projecteur.virtualdevice] Created uinput device: Projecteur_virtual_mouse; /sys/devices/virtual/input/input40
[2026-06-29T16:15:50.277][inf][projecteur.virtualdevice] Created uinput device: Projecteur_virtual_keyboard; /sys/devices/virtual/input/input41
[2026-06-29T16:15:50.397][inf][projecteur.device] Connected device: Logitech Spotlight (USB) (046d:c53e)
[2026-06-29T16:15:50.409][inf][projecteur.HID] HID++ device '/dev/hidraw6' went offline.
[2026-06-29T16:16:00.391][inf][projecteur.HID] HID++ device '/dev/hidraw6' came online.
[2026-06-29T16:16:00.785][wrn][qt.qpa.wayland] Wayland does not support QWindow::requestActivate()
[2026-06-29T16:16:07.528][wrn][qt.qpa.wayland] Wayland does not support QWindow::requestActivate()
^C...
[2026-06-29T16:16:21.499][wrn][default] qrc:/main.qml:12: TypeError: Cannot read property 'currentSpotScreen' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:30: TypeError: Cannot read property 'overlayVisible' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:111: TypeError: Cannot read property 'showSpotShade' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:96: TypeError: Cannot read property 'shadeColor' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:91: TypeError: Cannot read property 'shadeOpacity' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:169: TypeError: Cannot read property 'dotSize' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:171: TypeError: Cannot read property 'dotColor' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:172: TypeError: Cannot read property 'showCenterDot' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:173: TypeError: Cannot read property 'dotOpacity' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:155: TypeError: Cannot read property 'showBorder' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:156: TypeError: Cannot read property 'borderOpacity' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:89: TypeError: Cannot read property 'spotSize' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:143: TypeError: Cannot read property 'borderSize' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:106: TypeError: Cannot read property 'spotShape' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:66: TypeError: Cannot read property 'multiScreenOverlayEnabled' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:72: TypeError: Cannot read property 'cursor' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:53: TypeError: Cannot read property 'zoomEnabled' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:28: TypeError: Cannot read property 'spotRotationAllowed' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:37: TypeError: Cannot read property 'zoomFactor' of null
[2026-06-29T16:16:21.500][wrn][default] qrc:/main.qml:129: TypeError: Cannot read property 'borderColor' of null

This is using the normal mouse and clicking on "Show test..."

[2026-06-29T16:04:31.816][wrn][default] QSocketNotifier: Can only be used with threads started with QThread
[2026-06-29T16:04:31.888][inf][projecteur.virtualdevice] Created uinput device: Projecteur_virtual_mouse; /sys/devices/virtual/input/input33
[2026-06-29T16:04:31.889][inf][projecteur.virtualdevice] Created uinput device: Projecteur_virtual_keyboard; /sys/devices/virtual/input/input34
[2026-06-29T16:05:18.867][wrn][qt.qpa.wayland] Wayland does not support QWindow::requestActivate()
[2026-06-29T16:05:23.770][wrn][qt.qpa.wayland] Wayland does not support QWindow::requestActivate()
^C...
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:12: TypeError: Cannot read property 'currentSpotScreen' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:30: TypeError: Cannot read property 'overlayVisible' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:111: TypeError: Cannot read property 'showSpotShade' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:96: TypeError: Cannot read property 'shadeColor' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:91: TypeError: Cannot read property 'shadeOpacity' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:169: TypeError: Cannot read property 'dotSize' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:171: TypeError: Cannot read property 'dotColor' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:172: TypeError: Cannot read property 'showCenterDot' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:173: TypeError: Cannot read property 'dotOpacity' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:155: TypeError: Cannot read property 'showBorder' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:156: TypeError: Cannot read property 'borderOpacity' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:89: TypeError: Cannot read property 'spotSize' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:143: TypeError: Cannot read property 'borderSize' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:106: TypeError: Cannot read property 'spotShape' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:66: TypeError: Cannot read property 'multiScreenOverlayEnabled' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:72: TypeError: Cannot read property 'cursor' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:53: TypeError: Cannot read property 'zoomEnabled' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:28: TypeError: Cannot read property 'spotRotationAllowed' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:37: TypeError: Cannot read property 'zoomFactor' of null
[2026-06-29T16:05:37.771][wrn][default] qrc:/main.qml:129: TypeError: Cannot read property 'borderColor' of null

[giampierosalvi]

Update:
Using QT_QPA_PLATFORM=xcb projecteur seems to solve the problem. However, when the virtual pointer is deactivated, for example by releasing the pointer button on the Logitech Spotlight, the projecteur settings window becomes in focus and it is no longer possible to advance the slides unless a keyboard or mouse is used to regain focus on the presentation. This new problem can be solved by starting projecteur and closing the settings window before starting the presentation.