Custom-Touchpad-Gesture

This project demonstrates a simple application to recognize multi-touch gestures and simulate key presses (such as "Ctrl + Page Down" or "Ctrl + Page Up") based on those gestures. It uses Linux input events (ABS_MT events) to track the movement of touch points and the uinput subsystem to send key events.

Description

This software is intended for users running GNOME on Wayland. It allows you to recognize multi-touch gestures on the touchpad and perform corresponding actions, such as key presses (e.g. Ctrl + PageDown to scroll down) using the specified gestures. This software supports settings for various gestures, which allows you to improve interaction with the device for users who actively work with Wayland-based graphical interfaces.

Who is this software for?

• GNOME Developers: If you are developing or configuring the GNOME environment on Wayland, this solution will allow you to integrate multi-touch gestures into your workflow.
• GNOME Users on Wayland: If you are using GNOME on Wayland, this software will help you to facilitate navigation using gestures, replacing the usual key presses.
• Integrators and Tech Enthusiasts: If you want to customize and integrate new touchpad functionality into GNOME, this software allows you to configure various settings for user convenience.

License

This project is available under dual licensing:

• GNU GPLv3 (for open source projects)
• Commercial License (for commercial use)

💡 If you would like to use this project in a commercial product, please contact.

1. Project Overview

This program reads touch events from an input device (like a touchscreen) and processes gestures to simulate specific keypresses. It tracks touch slots (fingers) and moves based on the gestures. When a specific gesture (e.g., swipe up or down) is detected, the program simulates pressing certain keys, such as "Ctrl + PgDown" for a forward movement or "Ctrl + PgUp" for backward movement.

2. Prerequisites

Before running the program, ensure the following:

• A Linux system with uinput support enabled.
• A touchscreen or touchpad that generates ABS_MT events.
• The input.h header file and uinput.h should be available. Make sure that the required permissions are set for accessing /dev/uinput and /dev/input/eventX files (where X is the event number of the input device).

3. How the Code Works

The program operates in the following key steps:

1. Setting up the uinput device: The function setup_uinput_device() configures a virtual input device using the uinput subsystem. This device is used to simulate key events (such as pressing "Ctrl + Page Down" or "Ctrl + Page Up").

   • IOCTL calls set up event types (EV_KEY for key events).

   • uinput_setup struct sets the properties of the virtual device.

2. Reading touch input events: The program opens the input device (e.g., /dev/input/event10) to read ABS_MT events. These events contain information about touch position and touch slot.

   • The handle_abs_event() function processes the events, updating the touch slot coordinates (ABS_MT_POSITION_X, ABS_MT_POSITION_Y) based on the active slot.

3. Processing gestures: The function process_gesture() monitors the position of the third touch slot (SLOT_TO_TRACK = 2). The program calculates the movement from the previous base point.

   • If a large enough movement is detected (greater than the THRESHOLD), the program simulates a key press using the simulate_keypress() function.

   • For forward gestures, "Ctrl + Page Down" is simulated.

   • For forward gestures, "Ctrl + Page Down" is simulated.

4. Simulating key presses: The function simulate_keypress() is responsible for sending the actual key press and release events for the virtual keyboard:

   • EV_KEY is used to send key down and key up events.
   • EV_SYN is used to indicate the end of the key event sequence.

5. Cleaning up resources: The cleanup() function closes the input device and destroys the uinput device.

4. Using the Program

To build and run the program:

1. Compile the code: Run make to compile the code:

   make

2. Run the program: Run the compiled program with sudo (necessary for accessing /dev/uinput and input devices):

   sudo ./custom-touchpad-gesture

   The program will start reading touch events from the input device and simulate key presses based on the detected gestures.

5. Program Configuration

• SLOT_TO_TRACK: Defines the slot to track for gesture recognition. In this case, slot 2 (the third touch point) is tracked.

• THRESHOLD: The threshold value that determines when a movement is considered significant enough to trigger a key event.

• MAX_SLOTS: The maximum number of slots (fingers) supported for touch tracking.

6. Troubleshooting

• Permission Issues: If you encounter permission issues accessing /dev/uinput or /dev/input/eventX, make sure your user has the correct permissions. You may need to add your user to the input group or adjust device permissions manually.
• No Input Device Found: Ensure the input device path (/dev/input/eventX) is correct. You can find the appropriate event device using the ls /dev/input/ command.
• No Gesture Detected: Check if the touch input device supports multitouch and that the input events are being generated. Use evtest or libinput debug-events to verify the events.