Corner tile snap zone too small (1-2px) — make configurable

[rkristelijn]

Problem

The corner tile snap zones (quarter tiling) are extremely small — only 1-2 pixels wide. This makes it very difficult to drag a window into a corner to trigger quarter tiling, especially on multi-monitor setups where you easily overshoot onto the adjacent monitor.

The constants are hardcoded in src/core/window.c:

#define ORIGIN_CONSTANT 1
#define EXTREME_CONSTANT 2
#define COMMON_EDGE_PADDING 5

For corner tiling, the user must hit both edge zones simultaneously (e.g. ZONE_LEFT | ZONE_TOP), making the effective target area approximately 2×2 pixels. This is nearly impossible to hit consistently with a mouse or trackpad.

For comparison:

• KDE Plasma: configurable snap zone (default ~25px)
• Windows 11: generous corner zones (~50px+)
• macOS (Rectangle): configurable zones

Proposal

Add a new org.cinnamon.muffin gsetting tile-edge-zone-width (integer, default 25, range 2–100) that controls the snap zone width for edge and corner tiling.

This would:

1. Replace the hardcoded ORIGIN_CONSTANT and EXTREME_CONSTANT with the setting value
2. Make corner tiling usable without requiring pixel-perfect mouse placement
3. Allow users who prefer the current behavior to keep it

Environment

• Linux Mint 22.3 (Cinnamon)
• Multi-monitor setup (MacBook + external)
• tile-maximize enabled

Steps to reproduce

1. Enable corner tiling: gsettings set org.cinnamon.muffin tile-maximize true
2. Drag a window toward a screen corner
3. Observe how precisely you need to position the cursor (1-2px from edge) to trigger quarter tiling
4. On multi-monitor: cursor often overshoots onto adjacent display before hitting the zone