improv(app-list): only send screencopy requests as needed

cosmic-app-list/src/app.rs

@@ -658,6 +658,12 @@ impl cosmic::Application for CosmicAppList {
                     .chain(self.favorite_list.iter())
                     .find(|t| t.desktop_info.id == id)
                 {
+                    for (ref handle, _, _) in &toplevel_group.toplevels {
+                        if let Some(tx) = self.wayland_sender.as_ref() {
+                            let _ = tx.send(WaylandRequest::Screencopy(handle.clone()));
+                        }
+                    }
+
                     let rectangle = match self.rectangles.get(&toplevel_group.id) {
                         Some(r) => r,
                         None => return Command::none(),

cosmic-app-list/src/wayland_handler.rs

@@ -220,15 +220,13 @@ impl ToplevelInfoHandler for AppData {
         toplevel: &zcosmic_toplevel_handle_v1::ZcosmicToplevelHandleV1,
     ) {
         if let Some(info) = self.toplevel_info_state.info(toplevel) {
-            // spawn thread for sending the image
-            self.send_image(toplevel.clone());
-
             let _ = self
                 .tx
                 .unbounded_send(WaylandUpdate::Toplevel(ToplevelUpdate::Add(
                     toplevel.clone(),
                     info.clone(),
                 )));
+            self.send_image(toplevel.clone());
         }
     }
 
@@ -239,8 +237,6 @@ impl ToplevelInfoHandler for AppData {
         toplevel: &zcosmic_toplevel_handle_v1::ZcosmicToplevelHandleV1,
     ) {
         if let Some(info) = self.toplevel_info_state.info(toplevel) {
-            // spawn thread for sending the image
-            self.send_image(toplevel.clone());
             let _ = self
                 .tx
                 .unbounded_send(WaylandUpdate::Toplevel(ToplevelUpdate::Update(
@@ -615,6 +611,9 @@ pub(crate) fn wayland_handler(
     if handle
         .insert_source(rx, |event, _, state| match event {
             calloop::channel::Event::Msg(req) => match req {
+                WaylandRequest::Screencopy(handle) => {
+                    state.send_image(handle.clone());
+                }
                 WaylandRequest::Toplevel(req) => match req {
                     ToplevelRequest::Activate(handle) => {
                         if let Some(seat) = state.seat_state.seats().next() {

cosmic-app-list/src/wayland_subscription.rs

@@ -128,6 +128,7 @@ pub enum WaylandRequest {
         exec: String,
         gpu_idx: Option<usize>,
     },
+    Screencopy(ZcosmicToplevelHandleV1),
 }
 
 #[derive(Debug, Clone)]