Show pinned editors first on editor tabs and in chevron drop-down list

[deepika-u]

This PR adds an option under Preferences > General > Editors: "Show pinned editors first then followed by others".

When working with many open editors, developers frequently pin important files to keep them easily accessible and protected from automatic eviction. This PR allows pinned editors to be prioritized at the top of both the chevron overflow list (>>) and the Quick Switch (Ctrl+E) dropdown, aligning with modern IDE navigation paradigms.

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Behavior

When Enabled (true):

1. Chevron Dropdown (>>): Pinned editors appear at the top of the dropdown in screen tab order, followed by unpinned editors in screen tab order.
2. Quick Switch (Ctrl+E): Pinned editors appear at the top in MRU (Most Recently Used) order, followed by unpinned editors in MRU order (or tab order if MRU is disabled).
3. Dynamic Application: Toggling the preference in Preferences > General > Editors immediately updates the lists without requiring an IDE restart.

When Disabled (false - Default):

• Standard Eclipse behavior is preserved without regressions:
  • Physical tabs remain in their natural opened/dragged order.
  • Chevron dropdown displays tabs in standard tab-index order.
  • Ctrl+E displays editors in standard MRU order.

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Verification & Testing

• Chevron dropdown (>>) shows pinned editors at the top when the preference is enabled.
• Ctrl+E Quick Switch shows pinned editors at the top (in MRU order) followed by unpinned editors.
• Disabling the preference restores default Eclipse behavior (Chevron = tab order, Ctrl+E = standard MRU order).
• Automated unit tests in WorkbookEditorsHandlerTest covering MRU and non-MRU modes under enabled and disabled states.

Before the pr ->

Ctrl+E ->

After the pr ->

Ctrl+E ->

Why This Feature is Needed

1. Hierarchy & Priority Awareness: Pinning moves priority files to the leftmost side of the tab bar and to the top of all drop-down lists (Ctrl+E and Chevron).
2. Instant Muscle-Memory Access: Pinned files are always at the far left (easy to click) and at the top of Ctrl+E/Chevron (accessible with Down-Arrow → Enter).
3. Workflow Continuity in High-Volume Workspaces: Temporary files opened during development appear to the right of pinned files, leaving anchor files untouched at the front.

Why It Matters

1. Zero Disruption / Configurable by Default: SHOW_PINNED_EDITORS_FIRST defaults to false. When off, Eclipse functions 100% identically to stock behavior (Chevron = tab order, Ctrl+E = MRU history).
2. Preserves Relative Order: Order among pinned files (and among unpinned files) is strictly preserved.
3. Unified UX Across Entry Points: The physical tab strip, the chevron overflow dropdown (>>), and the Quick Switch dialog (Ctrl+E) are all aligned in the same order.
4. Visual Clarity: Pin icons and placement make pinned items distinct across all navigation surfaces.

[SougandhS]

Cool feature, something many users have wanted for a long time.

[github-actions]

Test Results

   864 files  ±0     864 suites  ±0   53m 55s ⏱️ + 6m 47s
 8 405 tests +2   8 162 ✅ +1  242 💤 ±0  1 ❌ +1 
21 084 runs  +6  20 404 ✅ +3  677 💤 ±0  3 ❌ +3 

For more details on these failures, see this check.

Results for commit 1af0ec4. ± Comparison against base commit 0074e63.

♻️ This comment has been updated with latest results.

[iloveeclipse]

While reading the description I assumed it will be applied to the editor tabs, not just the editor drop down list. Now tabs and drop-down list order will be inconsistent, which is not nice.

Would it make sense to apply same preference to the tab ordering? E.g. if user pins an editor, it will be moved to the left most place in the tab folder, if a second editor pinned, it will be moved next to the already pinned one?

[deepika-u]

Would it make sense to apply same preference to the tab ordering? E.g. if user pins an editor, it will be moved to the left most place in the tab folder, if a second editor pinned, it will be moved next to the already pinned one?

Sounds cool, let me check on it.

[deepika-u]

@iloveeclipse - Thank you for the thoughtful feedback and suggestion!

I completely agree that keeping the physical editor tabs in sync with the drop-down lists provides a much more cohesive and intuitive user experience.

The PR and description have been updated accordingly. Please feel free to review the latest changes and let me know if you have any further suggestions!

[iloveeclipse]

OK, I believe I was not clear enough: shouldn't then the pinned editors also move to the left most place int the editor tabs list shown for the editor area?

[deepika-u]

OK, I believe I was not clear enough: shouldn't then the pinned editors also move to the left most place int the editor tabs list shown for the editor area?

Let me check on it. Looks like something got missed out.

[deepika-u]

I have checked further and i could see

Can you check now when you get some time please?