[Cocoa] Remove code only relevant for macOS < 11.0

[HeikoKlare]

Summary

This PR removes code from the macOS/Cocoa-specific SWT classes that was only needed for macOS versions older than 11.0 (Big Sur).

Important

This PR must not be merged before #3185, which bumps the minimum supported macOS version for SWT to 11.0 and is the prerequisite for this cleanup.

Motivation

Once the minimum supported macOS version is raised to 11.0, all conditional code paths guarded by version checks like OS.VERSION < OS.VERSION(10, x, 0) or OS.isBigSurOrLater() become either dead code (always-false branches) or unconditional code (always-true branches). This PR cleans up all such cases to simplify the codebase.

How the Changes Were Found

The cocoa-specific Java source directories were scanned for:

• OS.VERSION comparisons (e.g., OS.VERSION < OS.VERSION(10, 13, 0), OS.VERSION >= OS.VERSION(10, 14, 0))
• OS.isBigSurOrLater() calls

For each occurrence, the logic was evaluated assuming macOS >= 11.0 is always true:

• Always-false branches (e.g., if (OS.VERSION < OS.VERSION(10, x, 0)) for any x ≤ 16) — the entire conditional block was removed.
• Always-true branches (e.g., if (OS.VERSION >= OS.VERSION(10, x, 0)) for any x ≤ 16, or if (OS.isBigSurOrLater())) — the condition was removed and the body was kept unconditionally.
• Ternary expressions — simplified to the always-true value.

Cascading removals were also applied: after simplifying call sites, methods and constants that became unused (e.g., OS.isBigSurOrLater(), kAlertNoteIcon, kAlertCautionIcon, SHADOWED_IBEAM_SOURCE) were deleted as well.

Changes per File

File	Change
Control.java	Removed macOS 10.13 (High Sierra) graphics context save/restore workaround in print(); kept only the modern rendering path
FileDialog.java	overwrite field is now always true; removed 10.11 version check around setAccessoryViewDisclosed; simplified setOverwrite() to always set true
Spinner.java	Removed findCursor() override that only existed to work around a nearly-invisible I-Beam cursor on dark backgrounds before macOS 10.14
Text.java	Same I-Beam cursor workaround removed
Combo.java	Same I-Beam cursor workaround removed
Cursor.java	Removed SHADOWED_IBEAM_SOURCE pixel data constant and the pre-10.14 I-Beam cursor workaround; SWT.CURSOR_IBEAM now always uses NSCursor.IBeamCursor()
Tree.java	Removed pre-10.11 header rect adjustment; removed >= 10.11 guards on header offset code (now always applied); removed >= 10.15 guard on scrollRowToVisible fix; removed isBigSurOrLater guards on setStyle and highlight rendering
Table.java	Same pattern as Tree.java
Shell.java	Removed >= 10.12 guard on automatic window tabbing disable; removed isBigSurOrLater guard on cancelRootMenuTracking; changed else if (>= 10.11) to unconditional else for child window z-order workaround
Display.java	Updated minimum version check from 10.10 to 11.0; simplified shadow/background color getters (removed >= 10.14 conditionals); removed >= 10.14 early returns in setAppAppearance/setWindowsAppearance; removed !isBigSurOrLater guard on layer backing; simplified icon loading to always use modern NSImageName* APIs
OS.java	Removed if (>= 10.14) guards in isAppDarkAppearance() and isSystemDarkAppearance(); removed now-unused isBigSurOrLater() method; removed unused kAlertNoteIcon and kAlertCautionIcon constants
TextLayout.java	Removed >= 10.11 guard on sel_attachment method registration
MessageBox.java	Removed isBigSurOrLater conditionals; always uses modern NSImageNameInfo/NSImageNameCaution
List.java	Removed isBigSurOrLater guard on NSTableViewStylePlain style setting
TabItem.java	Always uses selectedControlTextColor (was a ternary on isBigSurOrLater)
TreeItem.java	Always adds TEXT_GAP for text width calculation (was guarded by isBigSurOrLater)

Notes

• No behavior change is intended for any macOS version >= 11.0 — this is a pure cleanup.
• The OS.VERSION field and OS.VERSION(major, minor, bugfix) helper remain, as they may still be useful for future version-specific code.

---

🤖 Generated with Claude Code

[github-actions]

Test Results (macos)

   54 files  +   27     54 suites  +27   7m 7s ⏱️ + 4m 7s
4 531 tests ±    0  4 287 ✅ ±    0  244 💤 ± 0  0 ❌ ±0 
2 130 runs  +1 065  2 068 ✅ +1 034   62 💤 +31  0 ❌ ±0 

Results for commit 0925dc8. ± Comparison against base commit 596bef6.

♻️ This comment has been updated with latest results.

[vogella]

Nice one. Good to see that Claude is useful to you and our Eclipse project to improve the code base.

[HannesWell]

That's a nice clean-up.
After a quick-search it seems like the removal affects all version checks and now API introduced in macOS 11 or later is used.