✨ Improved snapping on left, right, and bottom edges

[jvanderen1]

Description

Adds Rectangle-style vertical snapping to WindowDirection+Snapping.swift. When dragging a window to the left, right, or bottom screen edge, snap zones now include corners, halves, thirds, center thirds, and two-thirds cycling — providing full coverage of all tiling options via drag-to-snap.

Fixes #1066

Changes

• Left/Right edges now have 7 vertical zones (by mouse Y position): corner quarters (~1%), top/bottom half (~1–6.3%), top/bottom vertical third (6.3–33%), and a center zone that defaults to verticalCenterThird with topTwoThirds/bottomTwoThirds cycling
• Bottom edge now has the same 7-zone layout applied horizontally: corner quarters, left/right half, left/right third, and horizontalCenterThird with leftTwoThirds/rightTwoThirds cycling
• Consolidated processLeftSnap, processRightSnap, and processBottomSnap into a single generic processEdgeSnap function with an EdgeZoneDirections configuration struct, eliminating code duplication
• Zone thresholds for corners (1/95) and halves (6/95) are derived from measurements of Rectangle's snapping behavior

How has this been tested?

macOS (Sequoia 15.3.2)

Tested drag-to-snap on all three edges (left, right, bottom), verifying each of the 7 zones returns the correct WindowDirection:

• Verified two-thirds cycling works when dragging from a third zone into the center zone
• Left edge: corner quarters, topHalf, topThird, verticalCenterThird, bottomThird, bottomHalf zones
• Right edge: corner quarters, topHalf, topThird, verticalCenterThird, bottomThird, bottomHalf zones
• Bottom edge: corner quarters, leftHalf, leftThird, horizontalCenterThird, rightThird, rightHalf zones
• Center zone two-thirds cycling (e.g. topThird → drag to center → topTwoThirds)
• Top edge behavior unchanged (topHalf at edges, maximize in center)

Video Demos

Snapping.Left.and.Right.mp4

Snapping.Bottom.mp4

Checklist

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation if applicable
• I have no unrelated changes in this PR.

Please describe to which degree, if any, an LLM was used in creating this pull request.

I used Claude Opus 4.6 (Thinking) to help develop the snapping zone logic, zone thresholds, EdgeZoneDirections consolidation pattern, and code structure. All changes were reviewed and tested manually.

[MrKai77]

Otherwise great work! This is totally a great start on adding more actions to window snapping! Just want to make sure we don't introduce any significant breaking changes for existing users, such as the halves I mentioned above.

[jvanderen1]

@MrKai77 I appreciate the feedback provided! I agree that minimizing breaking changes would minimize risk for our current users. I don't know if this application has ever put proposed changes behind an experiment, but that may be helpful (or a separate configuration).

I think it would also be helpful for you or other users to try this out before submitting. I am able to build and run this myself, but if possible, I would like user feedback from folks actually trying it out.

Happy to take further feedback!

P.S. another side comment, I do notice that dragging against the top edge takes a really long time to compute compared to other edges. You can see my cursor struggling on the top edge in the new video snippets. Any known reason for this?

[MrKai77]

This is working really well actually!

On the experiment point: we sometimes tuck more advanced features behind the Advanced tab or a defaults write flag to keep them out of reach for most users, but I don’t think that’s necessary here.

I’ve tested this locally and it feels very smooth. I’ll also tag @SenpaiHunters to give it a try if possible. Once merged, this will roll into Loop’s development build, where a few hundred beta testers can provide additional feedback before it reaches stable.

Regarding your side note: the issue is likely caused by this line:

Loop/Loop/Core/WindowDragManager.swift

Line 111 in c274356

CGWarpMouseCursorPosition(newOrigin)

You can also mitigate it by disabling “Suppress Mission Control” in Loop’s settings.

Overall, this is looking fantastic, really appreciate the work here :)