Projecteur

develop: master:

Linux/X11 application for the Logitech Spotlight device.

Copyright 2018-2019 Jahn Fuchs

Motivation

I saw the Logitech Spotlight device in action at a conference and liked it immediately. Unfortenately as in a lot of cases software is only provided for Windows and Mac. The device itself works just fine on Linux, but the cool spot feature is done by additional software.

So here it is: a Linux application for the Logitech Spotlight.

Features

• Configurable desktop spotlight. Configure color, opacity, cursor, center dot.
• Multiple screen support

Supported Environments

The application was tested on Ubuntu 18.04 (GNOME) and OpenSuse 42.3 and 15 (GNOME) but should work on almost any Linux/X11 Desktop. Make sure you have the correct udev rules installed (see Installation Pre-requisites).

How it works

Basically the USB Dongle Receiver of the Logitech Spotlight device will end up being detected as one mouse input device and one keyboard input device. The mouse input device sends relative cursor coordinates and left button presses. The keyboard device basically just sends left and right arrow key events when forward or back on the device is pressed.

The dectected mouse input device is what we are interested in. Since it's already detected as a mouse input device and able to move the cursor, we will simply detect if it is the Spotlight device which is sending mouse events. If it is sending mouse events, we will 'turn on' the desktop spot.

For more details: Have a look at the source code ;)

Building

Requirements

• C++11 compiler
• CMake 3.6 or later
• Qt 5.6 and later

Build Example

Note: You can ommit setting the QTDIR variable, CMake will then usually find the Qt version that comes with the distribution's packacke management.

  > git clone https://github.com/jahnf/projecteur
  > cd projecteur
  > mkdir build && cd build
  > QTDIR=/opt/Qt/5.9.6/gcc_64 cmake ..
  > make

Installation/Running

Pre-requisites

The input devices detected from the Spotlight device must be readable to the user running the application. To make this easier there is a udev rule template file in this repository: 55-spotlight.rules

• Copy this file to /etc/udev/rules.d/55-spotlight.rules and update the 'plugdev' group in the file to a group you are a member in
• Run sudo udevadm control --reload-rules and sudo udevadm trigger to load the rules without a reboot.
• After that the two input devices from the Logitech USB Receiver in /dev/input should have the group 'plugdev', i.e. the group you configure in the rules file.
• When building against the Qt version that comes with your distribution's packages you might need to install some additional QML module packages. For example this is the case for Ubuntu, where you need to install the packages qml-module-qtgraphicaleffrects, qml-module-qtquick-window2 and qml-modules-qtquick2 to satisfy the application's runtime dependencies.

Application Menu

The application menu is accessable via the system tray icon. There you will find the preferences and the menu entry to exit the application.