feat(linux): switch to a recently shown tab with Ctrl+E

linux/changelog.d/3883.added.1.md

@@ -0,0 +1 @@
+Ctrl+Shift+O opens the overview of the window's tabs, where typing searches them.

linux/changelog.d/3883.added.md

@@ -0,0 +1 @@
+Ctrl+E goes back to the tab shown before; hold Ctrl and press E again to go further back.

linux/crates/app/src/application/accelerators.rs

@@ -83,6 +83,10 @@ pub const ACCELERATORS: &[Accelerator] = &[
     application("win.new-editor-tab", &["<Primary>t"], Tabs),
     application("win.close-current", &["<Primary>w"], Tabs),
     application("win.reopen-closed-tab", &["<Primary><Shift>t"], Tabs),
+    // Ctrl+Tab stays the tab view's next tab, as across GNOME.
+    application("win.switch-recent-tab", &["<Primary>e"], Tabs),
+    // As in GNOME Web and Console.
+    application("win.show-tabs", &["<Primary><Shift>o"], Tabs),
     // AdwTabView's own controller, which runs in the capture phase. The
     // workspace removes its Ctrl+Home and Ctrl+End pairs, so the lists
     // and the editor inside the tabs keep those keys.

linux/crates/app/src/test_support/key_injector.rs

@@ -72,6 +72,23 @@ impl KeyInjector {
         Ok(())
     }
 
+    /// Keep `keyval` down until the guard drops, so a failed test does
+    /// not leave it held for the next one.
+    pub(crate) fn hold(&self, keyval: gdk::Key) -> Result<Held<'_>, KeyInjectionError> {
+        let keycode = self.keycode(keyval)?;
+        self.fake(KEY_PRESS_EVENT, keycode)?;
+        self.connection.flush()?;
+        self.connection.get_input_focus()?.reply()?;
+        Ok(Held { keys: self, keycode })
+    }
+
+    fn let_go(&self, keycode: u8) -> Result<(), KeyInjectionError> {
+        self.fake(KEY_RELEASE_EVENT, keycode)?;
+        self.connection.flush()?;
+        self.connection.get_input_focus()?.reply()?;
+        Ok(())
+    }
+
     /// Click the primary button `count` times at `at` in `widget`'s own
     /// coordinates, in the window that has the keyboard. A widget not laid
     /// out yet sits at the window's corner, so it is refused.
@@ -141,6 +158,19 @@ impl KeyInjector {
     }
 }
 
+pub(crate) struct Held<'a> {
+    keys: &'a KeyInjector,
+    keycode: u8,
+}
+
+impl Drop for Held<'_> {
+    fn drop(&mut self) {
+        if let Err(error) = self.keys.let_go(self.keycode) {
+            tracing::error!(%error, "a held key was not let go");
+        }
+    }
+}
+
 fn require_x11(display_type: &str) -> Result<(), KeyInjectionError> {
     if display_type == X11_DISPLAY {
         Ok(())

linux/crates/app/src/ui/workspace/mod.rs

@@ -14,6 +14,7 @@ mod health_banner;
 mod imp;
 mod import;
 mod import_ledger;
+mod recent_tabs;
 mod references;
 mod saves;
 mod session_watches;