Fix Next/Prev enable state (#407) and unbind Cyan shortcut by default…

negpy/desktop/view/canvas/toolbar.py

@@ -316,6 +316,7 @@ def _connect_signals(self) -> None:
         self.controller.zoom_changed.connect(self._on_zoom_changed)
 
         self.session.state_changed.connect(self._update_ui_state)
+        self.session.asset_model.layoutChanged.connect(self._update_ui_state)
 
         # Overflow menu action connections
         self._ov_hq_action.triggered.connect(self.controller.toggle_hq_preview)
@@ -415,8 +416,10 @@ def _show_shortcuts(self) -> None:
 
     def _update_ui_state(self) -> None:
         state = self.session.state
-        self.btn_prev.setEnabled(state.selected_file_idx > 0)
-        self.btn_next.setEnabled(state.selected_file_idx < len(state.uploaded_files) - 1)
+        model = self.session.asset_model
+        display_idx = model.actual_to_display(state.selected_file_idx)
+        self.btn_prev.setEnabled(display_idx > 0)
+        self.btn_next.setEnabled(0 <= display_idx < model.rowCount() - 1)
         self.btn_hq.setChecked(state.hq_preview)
         self._ov_hq_action.setChecked(state.hq_preview)
 

negpy/desktop/view/shortcut_registry.py

@@ -26,8 +26,8 @@ class ShortcutEntry:
     "auto_crop": ShortcutEntry("Shift+A", "Toggle autocrop", "Geometry"),
     "pick_dust": ShortcutEntry("Shift+D", "Toggle heal tool", "Tools"),
     "cancel_tool": ShortcutEntry("Esc", "Cancel active tool", "Tools"),
-    "cyan_dec": ShortcutEntry("Alt+Shift+C", "Cyan down", "Exposure"),
-    "cyan_inc": ShortcutEntry("Alt+C", "Cyan up", "Exposure"),
+    "cyan_dec": ShortcutEntry("", "Cyan down", "Exposure"),
+    "cyan_inc": ShortcutEntry("", "Cyan up", "Exposure"),
     "magenta_down": ShortcutEntry("D", "Magenta down", "Exposure"),
     "magenta_up": ShortcutEntry("E", "Magenta up", "Exposure"),
     "yellow_down": ShortcutEntry("F", "Yellow down", "Exposure"),

tests/test_desktop_session.py

@@ -494,5 +494,46 @@ def test_clearing_filter_restores_full_list(self):
         self.assertEqual(len(self.model._sorted_indices), 5)
 
 
+class TestNavButtonBoundaries(unittest.TestCase):
+    """Regression for #407: Next/Prev enable must be computed in display space
+    (sorted/filtered order), matching session.next_file/prev_file — not raw
+    uploaded_files (load-order) index space."""
+
+    def setUp(self):
+        self.state = AppState()
+        # Loaded reverse-alphabetically; default sort is name-ascending, so
+        # display order is the reverse of load order.
+        self.state.uploaded_files = [
+            {"name": "c.dng", "path": "/tmp/c.dng", "hash": "h1"},
+            {"name": "b.dng", "path": "/tmp/b.dng", "hash": "h2"},
+            {"name": "a.dng", "path": "/tmp/a.dng", "hash": "h3"},
+        ]
+        self.model = AssetListModel(self.state)
+
+    def _enabled(self, actual_idx):
+        display_idx = self.model.actual_to_display(actual_idx)
+        prev_enabled = display_idx > 0
+        next_enabled = 0 <= display_idx < self.model.rowCount() - 1
+        return prev_enabled, next_enabled
+
+    def test_first_display_file_is_last_loaded(self):
+        # a.dng (actual 2) is the last-loaded but first in display order.
+        prev_enabled, next_enabled = self._enabled(2)
+        self.assertFalse(prev_enabled)
+        self.assertTrue(next_enabled)
+
+    def test_last_display_file_is_first_loaded(self):
+        # c.dng (actual 0) is the first-loaded but last in display order.
+        prev_enabled, next_enabled = self._enabled(0)
+        self.assertTrue(prev_enabled)
+        self.assertFalse(next_enabled)
+
+    def test_filtered_out_selection_disables_both(self):
+        self.model.set_filter("a.dng", regex=False)
+        prev_enabled, next_enabled = self._enabled(0)  # c.dng no longer visible
+        self.assertFalse(prev_enabled)
+        self.assertFalse(next_enabled)
+
+
 if __name__ == "__main__":
     unittest.main()

tests/test_shortcut_registry.py

@@ -39,6 +39,17 @@ def test_load_bindings_merges_saved_overrides():
     assert bindings["grade_up"] == default_bindings()["grade_up"]
 
 
+def test_cyan_defaults_empty_but_bindable():
+    # #406: Cyan ships with no default binding, yet stays assignable via the editor.
+    defaults = default_bindings()
+    assert defaults["cyan_inc"] == ""
+    assert defaults["cyan_dec"] == ""
+
+    bindings = merge_bindings({"cyan_inc": "Alt+C", "cyan_dec": "Alt+Shift+C"})
+    assert bindings["cyan_inc"] == "Alt+C"
+    assert bindings["cyan_dec"] == "Alt+Shift+C"
+
+
 def test_tooltip_with_multiple_shortcuts_renders_all_keys():
     tooltip = tooltip_with_shortcut("Density", ["density_up", "density_down"], {"density_up": "Q", "density_down": "A"})