Remove anyhow and adapt paginator

Cargo.lock

@@ -382,7 +382,6 @@ dependencies = [
 name = "gnome-tour"
 version = "3.38.0"
 dependencies = [
- "anyhow",
  "gdk",
  "gettext-rs",
  "gio",

Cargo.toml

@@ -16,7 +16,6 @@ log = "0.4"
 gettext-rs = { version = "0.4", features = ["gettext-system"] }
 libhandy = "0.7"
 pretty_env_logger = "0.4"
-anyhow = "1.0"
 
 [dependencies.gst_player]
 version = "0.16"

src/application.rs

@@ -61,7 +61,7 @@ impl Application {
             "next-page",
             clone!(@strong application => move |_, _| {
                 if let Some(window) = &*application.window.borrow().clone() {
-                    if window.paginator.borrow_mut().next().is_err() {
+                    if window.paginator.borrow_mut().try_next().is_none() {
                         window.widget.close();
                     }
                 }
@@ -73,7 +73,7 @@ impl Application {
             "previous-page",
             clone!(@strong application => move |_, _| {
                 if let Some(window) = &*application.window.borrow().clone() {
-                    if window.paginator.borrow_mut().previous().is_err() {
+                    if window.paginator.borrow_mut().try_previous().is_none() {
                         window.reset_tour();
                     }
                 }

src/widgets/paginator.rs

-use anyhow::Result;
 use gettextrs::gettext;
 use glib::clone;
 use gtk::prelude::*;
@@ -38,22 +37,22 @@ impl PaginatorWidget {
         paginator
     }
 
-    pub fn next(&self) -> Result<()> {
+    pub fn try_next(&self) -> Option<()> {
         let p = *self.current_page.borrow() + 1;
         if p == self.carousel.get_n_pages() {
-            anyhow::bail!("Already at the latest page");
+            return None;
         }
         self.set_page(p);
-        Ok(())
+        Some(())
     }
 
-    pub fn previous(&self) -> Result<()> {
+    pub fn try_previous(&self) -> Option<()> {
         let p = *self.current_page.borrow();
         if p == 0 {
-            anyhow::bail!("Already at the first page");
+            return None;
         }
         self.set_page(p - 1);
-        Ok(())
+        Some(())
     }
 
     pub fn add_page(&self, page: gtk::Widget) {