[tobiasmelcher]

Fixes #2942

When "Show Whitespace Characters" is enabled, the unified-diff deletion and addition code minings now render whitespace as visible glyphs at the configured alpha, matching the editor text drawn by WhitespaceCharacterPainter:

• spaces as ·, the ideographic space (U+3000) as °
• tabs as a single » on the first column of the expanded tab run
• ¤/¶ line delimiters at the end of filled lines

The leading/enclosed/trailing (and ideographic) visibility flags are honored as the editor does, including on all-whitespace lines where any of the three flags shows the run.

Because the label is kept tab-expanded for layout, the glyph substitution learns from the raw line which expanded columns originate from a tab. The click-through overlay opened on a mining keeps the original tabs in its document and lets the real WhitespaceCharacterPainter render them.

The global whitespace settings are read once and cached, invalidated by a preference-store listener, instead of being re-read on every paint of every mining.

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Developed with assistance from Claude Code.

[github-actions]

Test Results

    54 files  ± 0      54 suites  ±0   37m 49s ⏱️ + 3m 25s
 4 909 tests +21   4 887 ✅ +21   22 💤 ±0  0 ❌ ±0 
12 618 runs  +63  12 464 ✅ +63  154 💤 ±0  0 ❌ ±0 

Results for commit 975422e. ± Comparison against base commit 0717ca6.

This pull request removes 1 and adds 22 tests. Note that renamed tests count towards both.

org.eclipse.team.tests.ui.UnifiedDiffTextTest ‑ testDetailedDiffRunningIntoTrailingSpacesIsTrimmedNotDropped

org.eclipse.team.tests.ui.UnifiedDiffCodeMiningProviderTest ‑ testClickOverlayUsesWhitespaceCharacterPainter
org.eclipse.team.tests.ui.UnifiedDiffCodeMiningProviderTest ‑ testFooterMiningRendersLineFeedCharacters
org.eclipse.team.tests.ui.UnifiedDiffCodeMiningProviderTest ‑ testFooterMiningRendersTrailingBlankLineDelimiters
org.eclipse.team.tests.ui.UnifiedDiffCodeMiningProviderTest ‑ testFooterMiningRendersWhitespaceWithoutMovingDetailedDiff
org.eclipse.team.tests.ui.UnifiedDiffCodeMiningProviderTest ‑ testHeaderMiningCachesWhitespaceWithoutMovingDetailedDiff
org.eclipse.team.tests.ui.UnifiedDiffCodeMiningProviderTest ‑ testHeaderMiningRendersTrailingBlankLineDelimiters
org.eclipse.team.tests.ui.UnifiedDiffManagerTest ‑ testDelimiterCharactersUseTheirOwnDetailedRange
org.eclipse.team.tests.ui.UnifiedDiffManagerTest ‑ testRevertModePaintsTrailingEmptyCrLfLine
org.eclipse.team.tests.ui.UnifiedDiffTextTest ‑ testApplySegmentAllWhitespaceLineHonoursEachFlag
org.eclipse.team.tests.ui.UnifiedDiffTextTest ‑ testApplySegmentAllWhitespaceLineHonoursEachTabFlag
…

♻️ This comment has been updated with latest results.

[tobiasmelcher]

@HannesWell it would be great if you could review and test this change by end of next week. I'll be on vacation then and plan to merge once I'm back.

[tobiasmelcher]

Hi @HannesWell, just a friendly reminder: unless I hear any objections, I plan to merge this tomorrow. Thanks!

[HannesWell]

Thank you for working on this Tobias and sorry for the delayed reply. The last one/two weeks were very busy for me with tasks outside the Eclipse realm.

In general this looks good but it seems that whitespace diffs are not handled correctly.
Given the following two files:

The unified Diff misses the differences in the 'blank' line and it misses the line break at the end of the 'removed' line:

Maybe it's related that I'm on Windows (as the line break markers indicate)?

Furthermore I'm surprised that this change requires that much code. And without being familiar with this part of the code, I wonder if this could be done simpler?
Or if this really requires so much effort, then I wonder if it would be better to implement this in general for code-minings/'ghost-text' so that eventually the unified diff would (in my simplified understanding) just have to pass an option like 'show withe space characters'.

[tobiasmelcher]

Hi @HannesWell,
thanks for catching this. I’ve fixed the handling of whitespace-only differences, final blank lines, and the trailing CR/LF markers, including their detailed-diff highlighting.

Here is the corrected result:

Whitespace differences and trailing line delimiters are rendered in the unified diff

For the broader question about simplifying this and potentially making whitespace rendering a general code-mining/ghost-text capability: I agree that deserves a separate discussion. I propose tracking it in a separate issue in eclipse.platform.ui, where we can evaluate a reusable solution rather than expanding this PR further.