Save-Dialog: Added a Save Dialog for Ctrl+Q Unsaved Changes

Changed the logic of app.quit accelerator, introduced a dialog in it.
Also made functions such is_save_senstive() and save_overwrite()
publicly accessible for logic building.

Fixes: #537
Part-of: <https://gitlab.gnome.org/GNOME/loupe/-/merge_requests/576>

src/application.rs

@@ -20,6 +20,7 @@
 //
 // SPDX-License-Identifier: GPL-3.0-or-later
 
+use crate::util::gettext::*;
 use adw::prelude::*;
 use adw::subclass::prelude::*;
 
@@ -133,7 +134,55 @@ impl LpApplication {
                 .activate(|app: &Self, _, _| app.show_help())
                 .build(),
             gio::ActionEntryBuilder::new("quit")
-                .activate(|app: &Self, _, _| app.quit())
+                .activate(|app: &Self, _, _| {
+                    if let Some(win) = app.active_window() {
+                        if let Some(lp_window) = win.downcast_ref::<LpWindow>() {
+                            if let Some(edit_window) = lp_window.edit_window() {
+                                if edit_window.has_unsaved_changes() {
+                                    let dialog = adw::AlertDialog::new(
+                                        Some(&gettext("Unsaved Changes")),
+                                        Some(&gettext(
+                                            "Changes which are not lost will be permanently lost",
+                                        )),
+                                    );
+
+                                    dialog.add_response("cancel", &gettext("Cancel"));
+                                    dialog.add_response("discard", &gettext("Discard"));
+                                    dialog.add_response("save", &gettext("Save"));
+
+                                    let app_clone = app.clone();
+                                    let win_clone = win.clone();
+                                    let edit_window_clone = edit_window.clone();
+                                    let dialog_clone = dialog.clone();
+
+                                    dialog.set_response_appearance(
+                                        "discard",
+                                        adw::ResponseAppearance::Destructive,
+                                    );
+
+                                    glib::MainContext::default().spawn_local(async move {
+                                        let res = dialog_clone.choose_future(&win_clone).await;
+                                        println!("User response: {}", res);
+                                        match res.as_str() {
+                                            "cancel" => {}
+                                            "discard" => {
+                                                app_clone.quit();
+                                            }
+                                            "save" => {
+                                                edit_window_clone.save_as();
+                                            }
+                                            _ => {}
+                                        }
+                                    });
+
+                                    dialog.present(Some(&win));
+                                    return;
+                                }
+                            }
+                        }
+                        app.quit();
+                    }
+                })
                 .build(),
             gio::ActionEntryBuilder::new("new-window")
                 .activate(|app: &Self, _, _| {

src/widgets/edit_window.rs

@@ -244,7 +244,7 @@ mod imp {
             }
         }
 
-        async fn save_overwrite(&self) {
+        pub(super) async fn save_overwrite(&self) {
             let obj = self.obj();
             self.save.popdown();
 
@@ -434,7 +434,7 @@ mod imp {
             }
         }
 
-        fn is_save_sensitive(&self) -> bool {
+        pub(super) fn is_save_sensitive(&self) -> bool {
             let obj = self.obj();
 
             self.operations
@@ -485,6 +485,20 @@ impl LpEditWindow {
         imp.update_save_state(false);
     }
 
+    pub fn has_unsaved_changes(&self) -> bool {
+        self.imp().is_save_sensitive()
+    }
+
+    pub fn save_as(&self) {
+        glib::spawn_future_local(glib::clone!(
+            #[weak(rename_to=win)]
+            self,
+            async move {
+                win.imp().save_overwrite().await;
+            }
+        ));
+    }
+
     pub fn add_operation(&self, operation: glycin::Operation) {
         let imp = self.imp();
 

src/widgets/window.rs

@@ -268,6 +268,13 @@ impl LpWindow {
         }
     }
 
+    pub fn edit_window(&self) -> Option<LpEditWindow> {
+        self.imp()
+            .edit_window_child
+            .child()
+            .and_then(|w| w.downcast::<LpEditWindow>().ok())
+    }
+
     pub fn image_view(&self) -> LpImageView {
         self.imp().image_window.image_view()
     }