view: fix some inconsistencies in view_ functions

... especially regarding whether a (view *) parameter may be NULL. It's
confusing when some functions accept NULL and others don't, and could
trip someone up.

I'm partly to blame for the inconsistency, since (if memory serves) I
added view_is_tiled() and view_is_floating(), which do accept NULL.

In detail:

- Make view_is_tiled() and view_is_floating() no longer accept NULL.

- Rename view_isfocusable -> view_is_focusable for consistency with
  other view_is_ functions.

- Eliminate view_inhibits_keybinds() as it only existed to safely accept
  NULL and check a single flag, which can be checked directly.

- Add assert(view) to remaining public view_ functions to catch
  accidentally passing NULL.

- Inline inhibit_keybinds() into view_toggle_keybinds(). It is closely
  related and not called from anywhere else; inlining it allows
  eliminating an extra assert() which is now impossible.

include/view.h

@@ -271,7 +271,7 @@ void view_array_append(struct server *server, struct wl_array *views,
 	enum lab_view_criteria criteria);
 
 /**
- * view_isfocusable() - Check whether or not a view can be focused
+ * view_is_focusable() - Check whether or not a view can be focused
  * @view: view to be checked
  *
  * The purpose of this test is to filter out views (generally Xwayland) which
@@ -282,9 +282,8 @@ void view_array_append(struct server *server, struct wl_array *views,
  * The only views that are allowed to be focusd are those that have a surface
  * and have been mapped at some point since creation.
  */
-bool view_isfocusable(struct view *view);
+bool view_is_focusable(struct view *view);
 
-bool view_inhibits_keybinds(struct view *view);
 void view_toggle_keybinds(struct view *view);
 
 void view_set_activated(struct view *view, bool activated);

src/desktop.c

@@ -114,7 +114,7 @@ first_view(struct server *server)
 			continue;
 		}
 		struct view *view = node_view_from_node(node);
-		if (view_isfocusable(view)) {
+		if (view_is_focusable(view)) {
 			return view;
 		}
 	}
@@ -186,7 +186,7 @@ desktop_cycle_view(struct server *server, struct view *start_view,
 		view = node_view_from_node(node);
 
 		enum property skip = window_rules_get_property(view, "skipWindowSwitcher");
-		if (view_isfocusable(view) && skip != LAB_PROP_TRUE) {
+		if (view_is_focusable(view) && skip != LAB_PROP_TRUE) {
 			return view;
 		}
 	} while (view != start_view);
@@ -208,7 +208,7 @@ desktop_topmost_focusable_view(struct server *server)
 			continue;
 		}
 		view = node_view_from_node(node);
-		if (view->mapped && view_isfocusable(view)) {
+		if (view->mapped && view_is_focusable(view)) {
 			return view;
 		}
 	}
@@ -247,7 +247,7 @@ desktop_focus_output(struct output *output)
 			continue;
 		}
 		view = node_view_from_node(node);
-		if (!view_isfocusable(view)) {
+		if (!view_is_focusable(view)) {
 			continue;
 		}
 		if (wlr_output_layout_intersects(layout,

src/keyboard.c

@@ -94,7 +94,8 @@ handle_keybinding(struct server *server, uint32_t modifiers, xkb_keysym_t sym, x
 			continue;
 		}
 		if (server->seat.nr_inhibited_keybind_views
-				&& view_inhibits_keybinds(server->focused_view)
+				&& server->focused_view
+				&& server->focused_view->inhibits_keybinds
 				&& !actions_contain_toggle_keybinds(&keybind->actions)) {
 			continue;
 		}

src/osd.c

@@ -479,7 +479,7 @@ osd_update(struct server *server)
 
 	/* Outline current window */
 	if (rc.window_switcher.outlines) {
-		if (view_isfocusable(server->osd_state.cycle_view)) {
+		if (view_is_focusable(server->osd_state.cycle_view)) {
 			osd_update_preview_outlines(server->osd_state.cycle_view);
 		}
 	}

src/view.c

@@ -85,7 +85,7 @@ view_matches_query(struct view *view, struct view_query *query)
 static bool
 matches_criteria(struct view *view, enum lab_view_criteria criteria)
 {
-	if (!view_isfocusable(view)) {
+	if (!view_is_focusable(view)) {
 		return false;
 	}
 	if (criteria & LAB_VIEW_CRITERIA_CURRENT_WORKSPACE) {
@@ -144,8 +144,9 @@ view_array_append(struct server *server, struct wl_array *views,
 }
 
 bool
-view_isfocusable(struct view *view)
+view_is_focusable(struct view *view)
 {
+	assert(view);
 	if (!view->surface) {
 		return false;
 	}
@@ -322,6 +323,7 @@ view_move_resize(struct view *view, struct wlr_box geo)
 void
 view_resize_relative(struct view *view, int left, int right, int top, int bottom)
 {
+	assert(view);
 	if (view->fullscreen || view->maximized) {
 		return;
 	}
@@ -337,6 +339,7 @@ view_resize_relative(struct view *view, int left, int right, int top, int bottom
 void
 view_move_relative(struct view *view, int x, int y)
 {
+	assert(view);
 	if (view->fullscreen) {
 		return;
 	}
@@ -351,6 +354,7 @@ view_move_relative(struct view *view, int x, int y)
 struct view_size_hints
 view_get_size_hints(struct view *view)
 {
+	assert(view);
 	if (view->impl->get_size_hints) {
 		return view->impl->get_size_hints(view);
 	}
@@ -458,6 +462,7 @@ minimize_sub_views(struct view *view, bool minimized)
 void
 view_minimize(struct view *view, bool minimized)
 {
+	assert(view);
 	/*
 	 * Minimize the root window first because some xwayland clients send a
 	 * request-unmap to sub-windows at this point (for example gimp and its
@@ -765,14 +770,16 @@ view_restore_to(struct view *view, struct wlr_box geometry)
 bool
 view_is_tiled(struct view *view)
 {
-	return view && (view->tiled || view->tiled_region
+	assert(view);
+	return (view->tiled || view->tiled_region
 		|| view->tiled_region_evacuate);
 }
 
 bool
 view_is_floating(struct view *view)
 {
-	return view && !(view->fullscreen || view->maximized || view->tiled
+	assert(view);
+	return !(view->fullscreen || view->maximized || view->tiled
 		|| view->tiled_region || view->tiled_region_evacuate);
 }
 
@@ -1323,36 +1330,23 @@ view_reload_ssd(struct view *view)
 	}
 }
 
-static void
-inhibit_keybinds(struct view *view, bool inhibit)
+void
+view_toggle_keybinds(struct view *view)
 {
-	assert(view->inhibits_keybinds != inhibit);
-
-	view->inhibits_keybinds = inhibit;
-	if (inhibit) {
+	assert(view);
+	view->inhibits_keybinds = !view->inhibits_keybinds;
+	if (view->inhibits_keybinds) {
 		view->server->seat.nr_inhibited_keybind_views++;
 	} else {
 		view->server->seat.nr_inhibited_keybind_views--;
 	}
 
 	if (view->ssd_enabled) {
-		ssd_enable_keybind_inhibit_indicator(view->ssd, inhibit);
+		ssd_enable_keybind_inhibit_indicator(view->ssd,
+			view->inhibits_keybinds);
 	}
 }
 
-bool
-view_inhibits_keybinds(struct view *view)
-{
-	return view && view->inhibits_keybinds;
-}
-
-void
-view_toggle_keybinds(struct view *view)
-{
-	assert(view);
-	inhibit_keybinds(view, !view->inhibits_keybinds);
-}
-
 void
 view_destroy(struct view *view)
 {