walkdir: navigator, shortcuts, window wiring, drop target, tests (ht0)

M2 (task ht0): walk the directory.

- src/navigator.{c,h}: GObject (no GtkWidget) holding the folder listing —
  image-MIME filter + extension fallback, hide-RAW-sidecars (decision #33),
  sort name/time/size, cursor + prev/next/wrap, path-based marks (survive
  re-sort, pruned on rescan/monitor, cleared on remove), nearest-fallback,
  GFileMonitor debounced 250ms (decision #28), 'changed' signal. 92% gcov.
- src/shortcuts.{c,h}: GtkShortcutController (MANAGED) binding h/l/Left/Right/
  g/G/o/q to win.* actions; one table all milestones add to.
- src/window.{c,h}: open file->parent+current / folder->first; h/l/g/G actions
  -> nav -> load -> viewer; single GCancellable last-write-wins (g_file_equal
  guard for M3 async); header title 'filename · n/total'; GtkDropTarget
  (GDK_TYPE_FILE_LIST, many->first, decision Z); GtkFileDialog open.
- data/gschema: add hide-raw-sidecars key.
- tests: unit test_navigator (12 subtests), integration test_walk_folder
  (temp fixtures walk + ./sample-images skip-if-absent). 8/8 green; ASan clean
  (GIO_USE_VFS=local in fixtures_env).

Fixed during this milestone: a UAF (borrowed c_name used after unref), a
cancellable double-ref leak, time::modified UINT64 vs INT64, and several
test-harness leaks. Sub-agent review issues addressed (mark pruning on
rescan/monitor, remove-before-cursor test, recursive temp-dir cleanup,
callback _cb naming, connect-before-mutate).

1 files changed, 99 insertions, 0 deletions

diff --git a/src/navigator.h b/src/navigator.h
new file mode 100644
index 0000000..b672480
--- /dev/null
+++ b/src/navigator.h
@@ -0,0 +1,99 @@
+#ifndef GGAZE_NAVIGATOR_H
+#define GGAZE_NAVIGATOR_H
+
+/*:*
+ * ggaze — directory navigator
+ *
+ * Navigator is a GObject (no GtkWidget) that owns the current directory
+ * listing: it filters to image MIME types, sorts (name/time/size), keeps a
+ * cursor and a path-based mark set, watches the directory with GFileMonitor
+ * (debounced) and emits "changed" on structural changes so the views stay in
+ * sync. If the current file disappears (external delete, or trash/move) it
+ * falls back to the nearest. Owns no GTK state; unit-testable without a
+ * display. See docs/architecture.md "Responsibilities / navigator".
+ *
+ * Copyright (c) 2026 ggaze contributors
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *:*/
+
+#include <gio/gio.h>
+#include <glib-object.h>
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+#define GGAZE_TYPE_NAVIGATOR (navigator_get_type())
+G_DECLARE_FINAL_TYPE(Navigator, navigator, GGAZE, NAVIGATOR, GObject)
+
+typedef enum {
+   GGAZE_SORT_NAME = 0,
+   GGAZE_SORT_TIME,
+   GGAZE_SORT_SIZE
+} GgazeSort;
+
+/* Construct a navigator over p_dir (file or folder; a file's parent is used by
+ * the caller). Refs p_dir. Lists immediately. e_sort is the initial sort;
+ * b_wrap controls prev/next wrap; b_hide_raw hides RAW sidecars when a JPEG
+ * with the same stem exists (decision #33). The current cursor is the first
+ * file. */
+Navigator *navigator_new(GFile *p_dir, GgazeSort e_sort, gboolean b_wrap,
+                         gboolean b_hide_raw);
+
+/* g_object_unref wrapper for the _new/_delete convention. */
+void navigator_delete(Navigator *p_nav);
+
+/* --- listing ------------------------------------------------------------- */
+GFile *navigator_get_dir(Navigator *p_nav); /* (transfer none) */
+guint  navigator_get_count(Navigator *p_nav);
+GFile *navigator_get_file(Navigator *p_nav,
+                          guint      u_index);        /* (transfer none) */
+gint   navigator_get_current_index(Navigator *p_nav); /* -1 if empty */
+GFile *navigator_get_current(Navigator *p_nav);       /* (transfer none) */
+guint
+navigator_get_remaining(Navigator *p_nav); /* count; M7 excludes trashed */
+gboolean navigator_set_current(Navigator *p_nav, guint u_index);
+gboolean navigator_set_current_file(Navigator *p_nav,
+                                    GFile     *p_file); /* by path */
+
+/* --- navigation (honour wrap) ------------------------------------------- */
+gboolean navigator_prev(Navigator *p_nav);
+gboolean navigator_next(Navigator *p_nav);
+gboolean navigator_first(Navigator *p_nav);
+gboolean navigator_last(Navigator *p_nav);
+
+/* --- sort/filter --------------------------------------------------------- */
+GgazeSort navigator_get_sort(Navigator *p_nav);
+void      navigator_set_sort(Navigator *p_nav, GgazeSort e_sort);
+gboolean  navigator_get_wrap(Navigator *p_nav);
+void      navigator_set_wrap(Navigator *p_nav, gboolean b_wrap);
+gboolean  navigator_get_hide_raw(Navigator *p_nav);
+void      navigator_set_hide_raw(Navigator *p_nav, gboolean b_hide_raw);
+
+/* --- marks (path-based; survive re-sort; cleared on remove) ------------- */
+gboolean navigator_is_marked(Navigator *p_nav, GFile *p_file);
+void     navigator_toggle_mark(Navigator *p_nav, GFile *p_file);
+void     navigator_mark_range(Navigator *p_nav, GFile *p_from, GFile *p_to);
+void     navigator_mark_all(Navigator *p_nav);
+void     navigator_clear_marks(Navigator *p_nav);
+guint    navigator_get_mark_count(Navigator *p_nav);
+GList *navigator_get_marks(Navigator *p_nav); /* (transfer full) GFile* refs */
+
+/* --- mutations ---------------------------------------------------------- */
+/* Re-read the directory; if the current file is gone, fall back to nearest;
+ * emit "changed". */
+void navigator_rescan(Navigator *p_nav);
+/* Remove p_file from the listing (used by trash/move); clear its mark; if it
+ * was current, fall back to nearest; emit "changed". Returns TRUE if removed.
+ */
+gboolean navigator_remove(Navigator *p_nav, GFile *p_file);
+
+/* GFileMonitor debounce in ms (default 250; decision #28). Tests may lower it.
+ */
+void navigator_set_debounce_ms(Navigator *p_nav, guint u_ms);
+
+/* "changed" signal: emitted on sort/filter/rescan/remove/monitor event. */
+void navigator_emit_changed(Navigator *p_nav);
+
+G_END_DECLS
+
+#endif /* GGAZE_NAVIGATOR_H */
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