refactoring + bugfixes (#34)

* Extract shared helpers from diff/merge views and consolidate file watchers

Move duplicated code into common.rs:
- build_find_bar(): find/replace bar + goto-line + 5 GActions (~220 lines x2)
- build_nav_button_group(): prev/next navigation buttons
- build_undo_redo_box(): undo/redo buttons wired to active view
- build_filter_toggles(): blank-line and whitespace toggle buttons
- start_file_watcher(): generic file watcher with on_tick callback
- build_app_window(): shared window builder with notebook and actions

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Split common.rs (4,419 lines) into 12 focused submodules

Convert the monolithic common.rs into a common/ directory module with
dedicated files for each responsibility area: editor, gutter, helpers,
tabs, find_bar, scroll_sync, navigation, toolbar, search, chunk_map,
file_watcher, and tests. Pure code motion with no logic changes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Refactor FileTab into Diff/Merge enum with PaneInfo

Replace flat FileTab struct with a Diff/Merge enum. Introduce PaneInfo
to hold per-pane (path, buffer, save button) state. Accessor methods
(saveable_panes, is_reloadable) eliminate dummy save buttons and
empty-path guards.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Extract shared editor action helpers (refresh, save-as, save-all)

Move duplicated refresh/save-as/save-all logic from diff_view and
merge_view into shared helpers in common/helpers.rs. Each view still
wires its own actions but calls the shared functions for the actual
save/reload/dialog logic.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Deduplicate dir_window button handlers via action group

Replace ~140 lines of duplicated copy-left/copy-right/delete button
click handlers with one-liner activate_action calls. The action group
definitions (already used for keyboard shortcuts) now serve both
buttons and keys.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix merge Save As stale tab path and remove duplicate action group insert

- Pass middle_tab_path through MergeViewResult so FileTab::Merge shares
  the same Rc as the save-as action, keeping close/unsaved dialogs in
  sync after Save As.
- Remove duplicate vcs_tab.insert_action_group call in vcs_window.rs.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix merge tab close prompt showing stale path after Save As

Read the live middle_tab_path Rc instead of capturing a static String
from second_path at construction time. The confirm_unsaved_dialog now
shows the current file name after Save As.

The merge watcher intentionally tracks original source paths (not the
Save As target) since the watcher monitors source files being merged,
matching Meld's behavior.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Update TESTING.md with missing test cases

Add 42 test cases for features not previously covered: Save As, Save
All, Open Externally, Refresh, tab navigation (Ctrl+1..9), New
Comparison (Ctrl+N), blank comparison, wrap-around navigation, chunk
map viewport indicator, and keyboard shortcuts dialog.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix error message for non-existent single path argument

`path.is_dir()` returns false for non-existent paths, causing a
misleading "single file argument not supported" error. Add an explicit
existence check before the is_dir/is_file branches.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Support -L/--label flags for directory comparison

Wire labels through build_dir_window → build_dir_tab to override
pane header text. Labels swap correctly with the swap-panes button.
Tooltips still show the actual directory path.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix CLI help: show <LABEL> instead of <LABELS> for -L flag

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Repaint chunk borders when clicking inside a chunk

Cursor tracking updated current_chunk index but never triggered a
redraw, so bold borders only appeared after keyboard navigation or
scrolling. Now queue_draw on filler overlays and gutters when the
current chunk changes. Fixed in both diff and merge views.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Scroll to cursor after toolbar undo/redo

The toolbar undo/redo buttons called buf.undo()/redo() without
scrolling the view, causing the viewport to jump away from the
edit location. Now calls scroll_mark_onscreen after each operation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Update TESTING.md: vertical scroll is synced by chunk

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix find/replace: cross-pane navigation, Escape, macOS shortcut, undo

- Find next/prev now cycles across panes when no match in current pane
- Escape closes find bar from widget level (not just text views)
- Use Cmd+Shift+H for Find & Replace on macOS (Cmd+H is system Hide)
- Replace All uses delete+insert in a user action group so undo works

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix find next/prev cycling across panes

find_next_match wrapped within the same buffer, so cross-pane search
was never reached. Split into find_next_match_no_wrap with a
skip_current flag: current pane skips the cursor position, other
panes search from start/end without skipping.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Clarify TESTING.md wording for Alt+Left/Right in dir file diff tab

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Update TESTING.md: directory tab shows dir names, not "Directory"

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Show full absolute path in pane header tooltip

Canonicalize file_path so the tooltip always shows the full path
instead of a relative one when launched with relative arguments.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Prevent duplicate file tabs in directory comparison

open_file_diff now checks if a tab with the same rel_path is already
open and switches to it instead of opening a duplicate.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix TESTING.md: tab switching is Alt+1..9, not Ctrl+1..9

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Use native trash command on macOS instead of GIO

GIO's File::trash() silently deletes directories permanently on macOS
instead of moving them to Finder's Trash. Use the native macOS trash
command which works correctly. GIO is still used on Linux.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix merge view chunk highlighting, conflict drawing, and navigation

- Add conflict-aware cursor detection: clicking conflict regions on
  left/right panes now highlights the conflict band via fallback to
  merged_gutter_chunks when chunk_at_cursor returns None
- Separate conflict drawing from regular chunk drawing: skip conflict
  chunks in draw_chunk_backgrounds via is_conflict flags, draw them
  with dedicated conflict stroke functions at full alpha
- Add bold border support for conflict regions (current chunk highlight)
- Fix navigation guard: prevent cursor_position_notify from overriding
  current_chunk during Alt+Up/Down navigation
- Collapse conflict bands into single navigation targets on side panes
  so Alt+Up/Down skips entire conflict band in one step
- Fix chunk map viewport indicators for merge view by redrawing on all
  three scroll adjustments
- Focus middle pane on 3-way merge open (CLI and new-comparison tab)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix scroll sync skipping Equal regions in line mapping

map_line_through_chunks advanced past Equal chunks without checking if
the source line fell inside them, causing the mapped position to jump
to the next non-equal chunk boundary. This made the left pane "stick"
in 3-way merge when left and middle had few differences. Now returns
the correct 1:1 mapped position when source line is within an Equal
region.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Track Save As directory changes in file watcher for diff and merge views

FileWatcher now supports dynamically adding watched paths via watch().
Both file_window and merge_view monitor save paths for directory changes
and tell the watcher to pick up new directories after Save As.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Show conflicting files in VCS window and open them in 3-way merge view

Add VcsStatus::Conflict for unmerged files (UU, AA, DD, DU, UD, AU, UA).
Conflict files display with red "Conflict" label in the VCS file list.
Opening a conflict launches a 3-way merge: ours (:2:) on left, working
copy in middle, theirs (:3:) on right.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* bump to 0.7.0

* Fix flaky UI tests by retrying keystrokes and polling for label changes

Centralize xdotool key-sending in conftest.py with a 200ms delay after
focus to let GTK process the event. Add send_keys_until() that retries
keystrokes up to 3 times if the expected label change doesn't appear
within the timeout (default 1s per attempt, 5s max).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* focus left pane on window show

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: joske

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "mergers"
-version = "0.6.1"
+version = "0.7.0"
 edition = "2024"
 description = "A visual diff and merge tool for files and directories"
 license = "GPL-2.0"

Cargo.toml

@@ -21,6 +21,7 @@
 - [ ] "3-way Merge" button: three file dialogs, then opens merge; welcome closes
 - [ ] Preferences button / Ctrl+,: opens Preferences dialog
 - [ ] Ctrl+W: closes welcome window
+- [ ] Ctrl+N: opens a new welcome window
 - [ ] Cancel any file dialog: nothing happens
 
 ## File Diff (2-way)
@@ -32,6 +33,7 @@
 - [ ] Filler lines: thin colored lines where the other side has more content
 - [ ] Gutter: curved connecting bands between panes
 - [ ] Chunk map strips: minimap of changes at far edges; clickable to jump
+- [ ] Chunk map viewport indicator: visible rectangle showing current scroll position
 - [ ] Syntax highlighting: detected from filename
 - [ ] Line numbers: shown/hidden per settings
 
@@ -55,7 +57,7 @@
 
 ### Scroll Sync
 - [ ] Horizontal scroll synced between panes
-- [ ] Vertical scroll independent per pane
+- [ ] Vertical scroll synced by chunk between panes
 
 ### Find / Replace
 - [ ] Ctrl+F: opens find bar; Ctrl+H: opens find + replace
@@ -68,11 +70,19 @@
 - [ ] Close (X / Escape): hides bar, clears highlights
 
 ### Save
+- [ ] Ctrl+S: saves focused pane; button goes insensitive
 - [ ] Save button insensitive until buffer changes
 - [ ] Save writes correct file; button goes insensitive; error dialog on failure
 - [ ] Save path tracks swaps: after swap, save writes to correct original file
 - [ ] Save after swap: pane contents and labels remain consistent (no un-swap)
 - [ ] Save after swap in dir file tab: watcher reload preserves swapped state
+- [ ] Ctrl+Shift+S (Save As): file dialog; writes to chosen path; updates pane label and tooltip
+- [ ] Save As updates tab-tracked path (close/unsaved dialog shows new name)
+- [ ] Ctrl+Shift+L (Save All): saves all dirty panes in current view
+- [ ] Ctrl+Shift+O: opens focused file in system default app
+- [ ] Ctrl+R / F5 (Refresh): reloads both files from disk
+- [ ] Refresh with unsaved changes: confirm dialog before reloading
+- [ ] Refresh on blank comparison pane: no-op (doesn't crash)
 
 ### File Watcher
 - [ ] External file change: auto-reloads if no unsaved changes
@@ -91,7 +101,7 @@
 - [ ] Alt+Right on a diff chunk: copies left chunk content to right (no file copy dialog)
 - [ ] Alt+Left on a diff chunk: copies right chunk content to left (no file copy dialog)
 - [ ] Alt+Left/Right with no current chunk: nothing happens
-- [ ] In dir window file tab: Alt+Left/Right copies chunks, does NOT trigger dir file copy
+- [ ] In file diff tab opened from dir window: Alt+Left/Right copies chunks, does NOT trigger dir file copy
 
 ### Edge Cases
 - [ ] Identical files: "Files are identical" info bar; edit one side -> bar disappears; undo -> reappears
@@ -110,6 +120,8 @@
 - [ ] Click in pane, then Alt+Down: navigates from cursor position, not from top
 - [ ] Navigate chunks with cursor in different positions: cursor-aware seeking
 - [ ] Alt+Up/Down intercepted: sourceview move-lines action does not fire
+- [ ] Wrap-around navigation: Alt+Down past last chunk wraps to first (if enabled in prefs)
+- [ ] Wrap-around off: Alt+Down on last chunk stays; Alt+Up on first chunk stays
 
 ## Directory Comparison
 
@@ -143,13 +155,19 @@
 - [ ] "Delete": always available
 
 ### Notebook Tabs
-- [ ] Directory tab labeled "Directory"
+- [ ] Directory tab labeled with "dir1 — dir2"
 - [ ] File tabs labeled with dir-relative names
 - [ ] Opening file diff tab: left pane has focus, cursor at line 1
 - [ ] Tab close (X): prompts for unsaved changes
 - [ ] Ctrl+W on Directory tab: closes entire window
 - [ ] Ctrl+W on file tab: closes that tab
 - [ ] Same file not opened twice: switches to existing tab
+- [ ] Alt+1..9: switches to tab by index
+- [ ] Ctrl+N: opens New Comparison tab
+- [ ] New Comparison tab: "Compare Files" and "3-Way Merge" buttons with file choosers
+- [ ] New Comparison → Compare Files: opens diff tab, removes new-comparison tab
+- [ ] New Comparison → 3-Way Merge: opens merge tab, removes new-comparison tab
+- [ ] Blank comparison (Ctrl+T or from New Comparison): opens editable blank diff tab
 
 ### File Watcher
 - [ ] Directory rescans on FS changes (500ms poll)
@@ -196,13 +214,23 @@
 
 ### Scroll Sync
 - [ ] Horizontal sync across all three panes
-- [ ] Vertical independent per pane
+- [ ] Vertical scroll synced by chunk across all three panes
 
 ### Find / Replace
 - [ ] Ctrl+F/H: find bar highlights matches across all three buffers
 - [ ] Match count sums all three buffers
 - [ ] Replace All replaces in all three buffers
 
+### Save
+- [ ] Ctrl+S: saves middle pane
+- [ ] Ctrl+Shift+S (Save As): saves middle to a new path; updates pane label
+- [ ] Save As updates tab-tracked path (close/unsaved dialog shows new name)
+- [ ] Ctrl+Shift+L (Save All): saves middle if dirty
+- [ ] Ctrl+Shift+O: opens focused file externally (works for all 3 panes)
+- [ ] Ctrl+R / F5 (Refresh): reloads all 3 files from disk
+- [ ] Refresh with unsaved middle: confirm dialog before reloading
+- [ ] After Save As, watcher reloads from new path (left/right still watch originals)
+
 ### Edge Cases
 - [ ] Binary files: all panes show info bar; all read-only; middle save hidden
 - [ ] All three identical: no changes, no chunks
@@ -242,6 +270,8 @@
 - [ ] Ctrl+W on file tab: closes tab with unsaved check
 - [ ] Window close: checks all tabs for unsaved changes
 - [ ] Temp directory cleaned up on window destroy
+- [ ] Alt+1..9: switches to tab by index
+- [ ] Ctrl+N: opens New Comparison tab
 
 ### Security
 - [ ] Paths with `..` components refused
@@ -255,6 +285,7 @@
 - [ ] Word wrap (None/Word/Character): dropdown; live-apply
 - [ ] Tab width (1-16): spin button; live-apply
 - [ ] Hide hidden files: toggle; default on; saved to settings
+- [ ] Wrap-around navigation: toggle; saved to settings
 - [ ] File filters: add/remove entries; saved on dialog close
 - [ ] Settings persisted to `~/.config/mergers/settings.toml`
 - [ ] Changes applied to all views in the parent window
@@ -281,14 +312,25 @@
 | Ctrl+J | Previous conflict (merge only) |
 | Ctrl+K | Next conflict (merge only) |
 | Ctrl+F | Find |
-| Ctrl+H | Find + Replace |
+| Ctrl+H (Cmd+Shift+H on macOS) | Find + Replace |
 | F3 | Find next |
 | Shift+F3 | Find previous |
 | Ctrl+L | Go to line |
 | Ctrl+Shift+P | Export patch (file diff only) |
 | Alt+Left | Copy chunk right→left (file diff) / Copy file to left (dir) |
 | Alt+Right | Copy chunk left→right (file diff) / Copy file to right (dir) |
 | Ctrl+S | Save active pane |
+| Ctrl+Shift+S | Save As (file diff / merge) |
+| Ctrl+Shift+L | Save All dirty panes |
+| Ctrl+Shift+O | Open focused file externally |
+| Ctrl+R / F5 | Refresh (reload from disk) |
+| Ctrl+N | New Comparison tab (dir/VCS windows) |
+| Alt+1..9 | Switch to tab by index (notebook windows) |
 | Delete | Delete selected (dir only) |
 | Enter | Open selected file / expand-collapse dir (dir/VCS) |
 | Escape | Close find bar / go-to-line / preferences dialog |
+
+## Preferences — Keyboard Shortcuts
+
+- [ ] "Keyboard Shortcuts" button in Preferences: opens shortcuts dialog
+- [ ] Dialog lists all shortcuts grouped by category

TESTING.md

@@ -15,7 +15,7 @@ struct Cli {
     paths: Vec<PathBuf>,
 
     /// Custom labels for panes (one per pane)
-    #[arg(short = 'L', long = "label")]
+    #[arg(short = 'L', long = "label", value_name = "LABEL")]
     labels: Vec<String>,
 }
 
@@ -68,7 +68,10 @@ fn main() -> glib::ExitCode {
         }
     } else if cli.paths.len() == 1 {
         let path = &cli.paths[0];
-        if path.is_dir() && vcs::is_git_repo(path) {
+        if !path.exists() {
+            eprintln!("Error: '{}' does not exist", path.display());
+            std::process::exit(1);
+        } else if path.is_dir() && vcs::is_git_repo(path) {
             CompareMode::Vcs { dir: path.clone() }
         } else if path.is_dir() {
             eprintln!("Error: '{}' is not inside a git repository", path.display());