galaxy/specs/APP-3632/TECH.md

APP-3632: Code Review Header UI Refactor

Problem

The updated Figma designs for the code review panel introduce git operation buttons (commit, push, create PR) in the inner header. The existing header layout doesn't have room for these — it already contains the branch name, diff stats, discard button, add-context button, and diff mode dropdown. This PR clears space by relocating contextual info upward and consolidating actions into the overflow menu.

Feature Flag

All UI changes are gated behind FeatureFlag::GitOperationsInCodeReview. The flag is not in DOGFOOD_FLAGS — it is off everywhere by default. Both the inner header (code_review_header.rs) and the right panel header (right_panel.rs) maintain legacy render paths that match master when the flag is off.

To test locally: cargo run --features git_operations_in_code_review

Overview of Changes

When the flag is on, this PR restructures the code review header into two layers:

1. Right panel header (top-level): shows repo context — repo path, branch name, and diff stats
2. Inner code review header: simplified to just the diff mode selector, file nav button, and an overflow menu

Actions that were previously standalone buttons (discard all, add diff set as context) are consolidated into the overflow menu. The file navigation toggle button is now an ActionButton with PaneHeaderTheme that appears in both wide and compact layouts.

When the flag is off, both headers render identically to master.

File-by-File Changes

app/src/workspace/view/right_panel.rs

Purpose: Redesign the panel header to show contextual git info (flag-gated).

• Call site dispatches to render_header (flag on) or render_header_legacy (flag off)
• New layout replaces the static "Code review" title with:
  • Repo path — tilde-shortened (e.g. ~/Repos/warp-internal:), rendered in semibold sub-text color
  • Branch name — read from DiffStateModel via get_diff_state_model()
  • Diff stats — read from CodeReviewView::loaded_diff_stats()
• Uses shared CONTENT_LEFT_MARGIN / CONTENT_RIGHT_MARGIN constants so the header aligns with the content area below
• Legacy layout preserves the "Code review" title with PANE_HEADER_HEIGHT and HEADER_EDGE_PADDING

app/src/code_review/code_review_header.rs

Purpose: Simplify the inner header to only layout concerns, with legacy fallback.

• Master's code (render, render_wide_layout, render_compact_layout, and all helpers) is untouched — zero deletions from master's version aside from adding FilterableDropdown to imports.
• New path (render_new): added at the bottom of the file. Renders diff mode dropdown (left) + git operations button + file nav button + overflow menu (right). Compact layout is a single row.
• render_header in CodeReviewView checks the flag and calls render_new or render

app/src/code_review/code_review_view.rs

Purpose: Restyle the dropdown, relocate buttons, consolidate menu items.

• File navigation button: ViewHandle<ActionButton> with PaneHeaderTheme, created once in new(). Passed to the header via CodeReviewHeaderFields.file_nav_button so both wide and compact layouts can render it. Tooltip updates dynamically when sidebar state changes.
• Diff mode dropdown: flag-gated styling in new(). Flag on: ButtonVariant::Text with semibold larger font. Flag off: master's bordered outline/accent style.
• header_menu_items(): dispatches to header_menu_items_new (flag on) or header_menu_items_legacy (flag off, matches master). New version adds "Discard all" and AISettings check.
• loaded_diff_stats(): new public accessor for the right panel header
• Shared margin constants: CONTENT_LEFT_MARGIN (16px) and CONTENT_RIGHT_MARGIN (4px) exported as pub(crate)
• render_header: takes state and app params, dispatches to render_new or render based on flag
• render_file_navigation_button: public function retained from master (used by legacy right panel header)

app/src/pane_group/working_directories.rs

Purpose: Expose diff state for the panel header to read.

• Adds get_diff_state_model(&self, repo_path: &Path) -> Option<ModelHandle<DiffStateModel>>

app/src/lib.rs

• Wired git_operations_in_code_review cargo feature to FeatureFlag::GitOperationsInCodeReview runtime flag

crates/warp_features/src/lib.rs

• GitOperationsInCodeReview removed from DOGFOOD_FLAGS (flag is off everywhere by default)

Design Decisions

• Dual render paths behind feature flag: the header restructuring is a prerequisite for git operation buttons (added in child branches). Since this PR may merge before the rest of the stack, both old and new rendering coexist. The legacy code is clearly marked and will be deleted when the flag is promoted.
• File nav button as ActionButton: uses PaneHeaderTheme to match the three-dots and maximize buttons. Created as a ViewHandle in new() (not inline during render) so it can appear in both wide and compact layouts via ChildView.
• Branch name reads from DiffStateModel directly rather than being passed through CodeReviewView, because the panel header renders independently of whether diffs have loaded.
• Diff stats still read from CodeReviewView::loaded_diff_stats() because they depend on the loaded diff state, which only CodeReviewView owns.
• Overflow menu is always rendered (no longer gated on FileAndDiffSetComments). Individual items are independently gated, so the menu gracefully degrades to empty when all flags are off.