blender_accessibility

A lightweight Qt-based control panel application for sending keyboard events to specific windows, with special optimization for Blender 3D.

Status: Working | Qt6 | Platform: Linux

Features

• Window Targeting: Select specific application windows to control with robust multi-method detection
• Raw Input Events: Send keyboard events directly to target applications
• Blender Optimized: Special focus handling for Blender's 3D viewport
• Smart Mouse Positioning: Remembers your work area and moves mouse intelligently
• Lockable Modifiers: Three-state Shift, Ctrl, Alt with visual feedback (Off -> Green -> Red Locked)
• Expandable Numpad: Full numeric keypad with operators that extends from the main panel
• Comprehensive Key Set: G, E, S, X, Y, Z, F, B, Tab, Del for common Blender operations
• Position Memory: Remembers window position between sessions
• Always on Top: Stays visible above other windows
• Draggable Interface: Move the control panel anywhere on screen

Screenshots

Collapsed View - Compact interface for daily use

Expanded View - Full numpad for numeric input

Installation

Prerequisites

# Ubuntu/Debian
sudo apt-get install qt6-base-dev libx11-dev cmake build-essential

# Fedora/RHEL  
sudo dnf install qt6-qtbase-devel libX11-devel cmake gcc-c++

Build from Source

# Clone the repository
git clone https://github.com/fivethreeo/blender_accessibility.git
cd blender_accessibility

# Create build directory
mkdir build
cd build

# Configure and build
cmake ..
make

Permissions Setup

For accessing input devices without sudo:

# Add your user to the input group
sudo usermod -a -G input $USER

# You may need to logout/login for changes to take effect

Usage

1. Run the application:

   ./ControlPanel  # or sudo ./ControlPanel if permissions not set

2. Select Target:

   • Choose the target window (e.g., Blender)
   • Select your keyboard device from the list
   • Click "Start Control"

3. Button Functions:

Button Function Behavior Shift/Ctrl/Alt Three-state toggle Off -> Active (Green) -> Locked (Red) -> Off X, Y, Z Axis keys Common transform axes G, S, E, F Grab, Scale, Extrude Essential modeling tools
B, Tab, Del Box Select, Mode Selection and editing

•        Numpad Toggle        Expand/collapse numeric keypad
  

× Close Application Exit ControlPanel ≡ Drag Panel Reposition control panel

4. Modifier Key Behavior:

   • First Click: Activates modifier (green) - turns off with other keys
   • Second Click: Locks modifier (red) - stays active permanently
   • Third Click: Turns off modifier

5. Smart Mouse Features:

   • Tracks mouse position for 3 seconds with 25px fuzzy tolerance
   • Moves to your most frequent work area when buttons are clicked
   • Numpad keys return mouse to original position

Technical Details

Architecture

• Frontend: Qt6 Widgets application with expandable layout
• Backend: X11 window management + Linux input subsystem
• Input: Raw keyboard event injection via /dev/input/ devices
• Mouse Tracking: Continuous position monitoring with frequency analysis

Smart Mouse Algorithm

• Records mouse position every 50ms (3-second history)
• Groups positions within 25px tolerance for area detection
• Finds most frequent work area using FIFO queue
• Stores position when entering control panel

Window Detection

Uses multiple methods for robust window enumeration:

1. _NET_CLIENT_LIST (modern window managers)
2. XQueryTree (fallback method)
3. _NET_CLIENT_LIST_STACKING (alternative property)
4. Filters system windows (desktop, panels, docks)

Supported Systems

• Linux with X11 window system
• Qt6 compatible distributions
• Kernel 4.4+ with input subsystem support

Troubleshooting

Common Issues

1. "No keyboard devices found":

   # Check available devices
   ls /dev/input/by-id/
   
   # Ensure you have permissions
   ls -l /dev/input/by-id/

2. "Failed to open keyboard device":

   # Run with sudo or set permissions
   sudo ./ControlPanel

3. Windows not detected:

   • Use the Refresh button in the setup dialog
   • Ensure target applications have visible windows
   • Some applications may use non-standard windowing

4. Mouse positioning issues:

   • Move mouse to desired area before using buttons
   • The system learns your work area over 3 seconds

Debug Mode

Run with debug output:

./ControlPanel 2>&1 | tee debug.log

Building for Development

# Debug build with symbols
cmake -DCMAKE_BUILD_TYPE=Debug ..
make

# Release build
cmake -DCMAKE_BUILD_TYPE=Release ..
make

Blender Workflow Tips

1. Modeling Workflow:

   • Lock Shift for precise movement
   • Use G, S, E for grab, scale, extrude
   • X, Y, Z for axis constraints
   • Expand numpad for numeric input

2. Navigation:

   • Use locked modifiers for extended operations
   • Smart mouse positioning keeps you in your work area
   • Numpad for precise numeric transformations

3. Efficiency:

   • Keep common modifiers locked during complex operations
   • Use the compact view for daily work
   • Expand numpad only when needed for numbers

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Qt Framework for the excellent cross-platform GUI library
• X11 developers for window management capabilities
• Blender community for inspiration and workflow optimization

Support

If you encounter any issues or have questions:

1. Check the Troubleshooting section
2. Search existing Issues
3. Create a new issue with detailed information

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Note: This application requires appropriate permissions to access input devices.