imageView: Merge set_image_from_file with set_images_from_files

Also changing behavior when opening with multiple command line
arguments or when multiple images were selected from other
applications.

Old behavior: Spawn an instance of Loupe for each argument.
New behavior: One Loupe instance containing all arguments.

Closes #195

src/application.rs

@@ -71,10 +71,8 @@ mod imp {
         // Handles opening files from the command line or other applications
         fn open(&self, files: &[gio::File], _hint: &str) {
             let application = self.obj();
-            for file in files {
+            let win = LpWindow::new(&*application);
-                let win = LpWindow::new(&*application);
+            win.image_view().set_images_from_files(files.to_vec());
-                win.image_view().set_image_from_file(file.clone());
-            }
         }
     }
 

src/widgets/image_view.rs

@@ -241,20 +241,19 @@ glib::wrapper! {
 
 #[gtk::template_callbacks]
 impl LpImageView {
-    pub fn set_image_from_file(&self, file: gio::File) {
+    pub fn set_images_from_files(&self, files: Vec<gio::File>) {
         // Add image to recently used file. Does not work in Flatpaks:
         // <https://github.com/flatpak/xdg-desktop-portal/issues/215>
-        gtk::RecentManager::default().add_item(&file.uri());
-
-        self.load_file(file);
-    }
-
-    pub fn set_images_from_files(&self, files: Vec<gio::File>) {
         let recent_manager = gtk::RecentManager::default();
         for file in files.iter() {
             recent_manager.add_item(&file.uri());
         }
-        self.load_files(files);
+
+        if files.len() == 1 {
+            self.load_file(files[0].clone());
+        } else {
+            self.load_files(files);
+        }
     }
 
     fn load_files(&self, files: Vec<gio::File>) {

src/window.rs

@@ -388,7 +388,7 @@ mod imp {
                     // We've added type annotations here, and written it as `let list: gdk::FileList = ...`,
                     // but you might also see places where type arguments are used.
                     // This line could have been written as `let list = value.get::<gdk::FileList>().unwrap()`.
-                    let mut files = match value.get::<gdk::FileList>() {
+                    let files = match value.get::<gdk::FileList>() {
                         Ok(list) => list.files(),
                         Err(err) => {
                             log::error!("Issue with drop value: {err}");
@@ -396,10 +396,8 @@ mod imp {
                         }
                     };
 
-                    if files.len() > 1 {
+                    if !files.is_empty() {
                         obj.image_view().set_images_from_files(files);
-                    } else if let Some(file) = files.pop() {
-                        obj.image_view().set_image_from_file(file);
                     } else {
                         log::error!("Dropped FileList was empty");
                         return false;
@@ -566,7 +564,7 @@ impl LpWindow {
                     spawn(async move {
                         let result = crate::util::untrash(&path).await;
                         match result {
-                            Ok(()) => win.image_view().set_image_from_file(gio::File::for_path(&path)),
+                            Ok(()) => win.image_view().set_images_from_files(vec![gio::File::for_path(&path)]),
                             Err(err) => {
                                 log::error!("Failed to untrash {path:?}: {err}");
                                 win.show_toast(