i3 Smart Floating - ulises-jeremias/dotfiles GitHub Wiki

🪟 i3: Smart Floating Windows

The Smart Floating system provides intelligent window management that automatically optimizes floating window size and positioning for better user experience.

[!TIP] Instead of manually resizing and centering floating windows every time, smart floating does it automatically with perfect sizing based on your screen dimensions.

📋 Overview

What Smart Floating Solves

Traditional i3 floating mode often results in:

  • Poor window sizing: Windows float at their original tiled size
  • Manual repositioning: Need to manually center and resize each time
  • Inconsistent experience: No standardized floating window behavior
  • Workflow interruption: Breaking focus to adjust window layout

Smart floating automatically solves these issues by:

  • Intelligent sizing: Automatically calculates optimal window dimensions
  • Perfect centering: Windows are automatically positioned in screen center
  • Screen-aware: Adapts to different screen sizes and resolutions
  • Consistent behavior: Same experience across all applications

🎯 Key Features

🚀 Smart Toggle ($Mod+Shift+F)

A single keybind that intelligently handles floating mode:

From Tiled → Floating:

  • ✨ Converts window to floating mode
  • 📏 Automatically resizes to comfortable dimensions (70% width, 65% height)
  • 🎯 Centers window perfectly on screen
  • ✅ Respects minimum/maximum size limits

From Floating → Tiled:

  • 🔄 Simply returns window to tiled mode
  • 🎨 Maintains i3's default tiling behavior

📐 Intelligent Sizing Algorithm

# Calculates optimal size based on screen dimensions
width = screen_width × 70%
height = screen_height × 65%

# With safety constraints
minimum: 600×400 pixels
maximum: 1400×900 pixels

🎛️ Default Floating Constraints

All floating windows respect global size limits:

floating_minimum_size 400 x 300
floating_maximum_size 1400 x 900

⌨️ Keybindings

Keybind Action Description
$Mod+Space Standard Toggle Original i3 floating toggle (no auto-sizing)
$Mod+Shift+F 🆕 Smart Toggle Intelligent toggle with auto-resize and centering
$Mod+Shift+Space Focus Toggle Switch focus between tiling/floating areas

Usage Examples

# Toggle floating with smart sizing
Super + Shift + F

# Standard floating toggle (no smart features)
Super + Space

# Move floating window manually
Super + Mouse drag

# Resize floating window manually
Super + Right-click drag

🔧 Technical Implementation

Smart Floating Script

The system uses an intelligent script (~/.config/i3/smart-float.sh) that:

  1. Detects current window state using i3's JSON API
  2. Calculates optimal dimensions based on screen resolution
  3. Applies size constraints to ensure usability
  4. Centers window using i3's positioning commands

Screen Adaptation

Multiple Monitor Support:

  • Automatically detects current monitor dimensions
  • Calculates optimal size for each screen independently
  • Maintains consistent proportions across different resolutions

Resolution Examples:

Screen Resolution Smart Window Size Percentage
1920×1080 1344×702 70% × 65%
2560×1440 1400×900 Limited by max constraints
1366×768 956×499 70% × 65%

🎨 Configuration

Window Manager Settings

Smart floating works with existing i3 configuration:

# Smart floating: toggle floating + center + resize to comfortable size
bindsym $Mod+Shift+f exec --no-startup-id ~/.config/i3/smart-float.sh

# Default floating window size constraints
floating_minimum_size 400 x 300
floating_maximum_size 1400 x 900

# Use Mouse+$mod to drag floating windows
floating_modifier $mod

Size Customization

To modify the default sizing behavior, edit the smart-float script:

# Custom sizing percentages
width=$((WIDTH * 80 / 100))    # 80% instead of 70%
height=$((HEIGHT * 70 / 100))  # 70% instead of 65%

# Custom size limits
[ $width -lt 800 ](/ulises-jeremias/dotfiles/wiki/-$width--lt-800-) && width=800     # Larger minimum
[ $width -gt 1600 ](/ulises-jeremias/dotfiles/wiki/-$width--gt-1600-) && width=1600   # Larger maximum

🔄 Workflow Integration

Common Usage Patterns

Quick Application Focus:

1. Launch application (Super+Return for terminal)
2. Use Smart Float (Super+Shift+F) for focused work
3. Application automatically sized and centered
4. Return to tiling (Super+Shift+F) when done

Multi-Window Setup:

1. Keep main work in tiling mode
2. Float secondary applications (calculator, notes)
3. Smart sizing ensures consistent overlay experience
4. Easy switching between modes

Presentation Mode:

1. Float presentation application
2. Automatic centering for optimal viewing
3. Consistent sizing across different projectors
4. Quick return to desktop layout

🎯 Best Practices

When to Use Smart Floating

✅ Ideal Use Cases:

  • Calculator applications: Perfect for quick calculations
  • Note-taking apps: Overlay notes while reading
  • Media players: Video players and music controls
  • System utilities: Settings panels and configuration tools
  • Terminal sessions: Quick command execution

⚠️ Consider Standard Tiling For:

  • Primary work applications: Code editors, browsers
  • Document editing: Full-screen writing and editing
  • Multitasking workflows: Multiple applications side-by-side

Window Management Tips

Maximize Efficiency:

  • Use smart floating for temporary/utility applications
  • Reserve tiling for primary productivity applications
  • Combine with scratchpad for frequently accessed tools
  • Use focus toggle to quickly switch context

Avoid Common Pitfalls:

  • Don't float too many windows simultaneously
  • Remember smart sizing works best for utility applications
  • Use manual resize when specific dimensions are needed

🛠️ Troubleshooting

Common Issues

Smart float not working:

# Check if script exists and is executable
ls -la ~/.config/i3/smart-float.sh

# Test script manually
bash ~/.config/i3/smart-float.sh

# Reload i3 configuration
i3-msg reload

Wrong window dimensions:

# Check screen detection
xdotool getdisplaygeometry

# Verify i3 can resize windows
i3-msg "resize set 800 600"

# Test manual positioning
i3-msg "move position center"

Script errors:

# Check dependencies
command -v xdotool
command -v jq

# Check i3 API access
i3-msg -t get_tree | jq '.. | select(.focused? == true)'

Performance Optimization

Reduce Script Execution Time:

  • Cache screen dimensions for better performance
  • Use faster JSON parsing if available
  • Optimize i3-msg command sequence

System Integration:

  • Ensure xdotool is installed for screen detection
  • Verify jq is available for JSON parsing
  • Test with different window managers if needed

✅ Integration

Works With

  • ✅ All window managers: Primarily designed for i3
  • ✅ Multi-monitor setups: Automatic per-monitor optimization
  • ✅ All application types: Universal window management
  • ✅ Rice switching: Maintains behavior across themes

Pairs Well With

  • Scratchpad functionality: Quick access to floating utilities
  • i3 layouts: Complement existing workspace management
  • Application-specific rules: Custom floating behaviors per app

🚀 Future Enhancements

Planned Features

  • Application-specific sizing: Custom dimensions per application type
  • Saved positions: Remember window positions for specific apps
  • Smart tiling return: Intelligent placement when returning to tiled mode
  • Animation support: Smooth transitions between states

Customization Opportunities

  • Profile-based sizing: Different size profiles for different workflows
  • Hot corners: Screen edge triggers for floating mode
  • Gesture support: Touch/trackpad gestures for window management

Enjoy effortless floating window management that adapts to your screen and workflow! 🚀

[!TIP] Try using Super+Shift+F instead of Super+Space for a week - you'll never go back to manual window positioning!