App: Fix more refference cycles

podcasts-gtk/src/utils.rs

@@ -1,8 +1,8 @@
 #![cfg_attr(feature = "cargo-clippy", allow(type_complexity))]
 
 use gdk::FrameClockExt;
-use gdk_pixbuf::Pixbuf;
-use glib;
+use gdk_pixbuf::{Object, Pixbuf};
+use glib::{self, object::WeakRef};
 use gtk;
 use gtk::prelude::*;
 use gtk::{IsA, Widget};
@@ -64,16 +64,26 @@ use i18n::i18n;
 /// let list = gtk::ListBox::new();
 /// lazy_load(widgets, list, |w| w, || {});
 /// ```
-pub(crate) fn lazy_load<T, C, F, W, U>(data: T, container: C, mut contructor: F, callback: U)
-where
+pub(crate) fn lazy_load<T, C, F, W, U>(
+    data: T,
+    container: WeakRef<C>,
+    mut contructor: F,
+    callback: U,
+) where
     T: IntoIterator + 'static,
     T::Item: 'static,
-    C: ContainerExt + 'static,
+    // FIXME: leaking a strong refference here
+    C: IsA<Object> + ContainerExt + 'static,
     F: FnMut(T::Item) -> W + 'static,
     W: IsA<Widget> + WidgetExt,
     U: Fn() + 'static,
 {
     let func = move |x| {
+        let container = match container.upgrade() {
+            Some(c) => c,
+            None => return,
+        };
+
         let widget = contructor(x);
         container.add(&widget);
         widget.show();

podcasts-gtk/src/widgets/show.rs

@@ -1,7 +1,7 @@
 use glib;
 use gtk::{self, prelude::*, Adjustment};
 
-use crossbeam_channel::Sender;
+use crossbeam_channel::{bounded, Sender};
 use failure::Error;
 use fragile::Fragile;
 use html2text;
@@ -103,14 +103,11 @@ impl ShowWidget {
 
 /// Populate the listbox with the shows episodes.
 fn populate_listbox(
-    // FIXME: we are leaking strong refs here
     show: &Rc<ShowWidget>,
     pd: Arc<Show>,
     sender: Sender<Action>,
     vadj: Option<Adjustment>,
 ) -> Result<(), Error> {
-    use crossbeam_channel::bounded;
-
     let count = dbqueries::get_pd_episodes_count(&pd)?;
 
     let (sender_, receiver) = bounded(1);
@@ -128,7 +125,8 @@ fn populate_listbox(
         return Ok(());
     }
 
-    let show_ = show.clone();
+    let show_weak = Rc::downgrade(&show);
+    let list_weak = show.episodes.downgrade();
     gtk::idle_add(move || {
         let episodes = match receiver.try_recv() {
             Some(e) => e,
@@ -136,18 +134,18 @@ fn populate_listbox(
         };
         debug_assert!(episodes.len() as i64 == count);
 
-        let list = show_.episodes.clone();
         let constructor = clone!(sender => move |ep| {
             EpisodeWidget::new(ep, &sender).container.clone()
         });
 
-        let callback = clone!(show_, vadj => move || {
-            if let Some(ref v) = vadj {
-                show_.view.set_adjutments(None, Some(v))
+        let callback = clone!(show_weak, vadj => move || {
+            match (show_weak.upgrade(), &vadj) {
+                (Some(ref shows), Some(ref v)) => shows.view.set_adjutments(None, Some(v)),
+                _ => (),
             };
         });
 
-        lazy_load(episodes, list.clone(), constructor, callback);
+        lazy_load(episodes, list_weak.clone(), constructor, callback);
 
         glib::Continue(false)
     });

podcasts-gtk/src/widgets/shows_view.rs

@@ -64,17 +64,18 @@ impl ShowsView {
 fn populate_flowbox(shows: &Rc<ShowsView>, vadj: Option<Adjustment>) -> Result<(), Error> {
     let ignore = get_ignored_shows()?;
     let podcasts = dbqueries::get_podcasts_filter(&ignore)?;
+    let show_weak = Rc::downgrade(&shows);
+    let flowbox_weak = shows.flowbox.downgrade();
 
     let constructor = move |parent| ShowsChild::new(&parent).child;
-    // FIXME: We are, possibly,leaking the strong ref here
-    let callback = clone!(shows => move || {
-        if let Some(ref v) = vadj {
-            shows.view.set_adjutments(None, Some(v))
+    let callback = move || {
+        match (show_weak.upgrade(), &vadj) {
+            (Some(ref shows), Some(ref v)) => shows.view.set_adjutments(None, Some(v)),
+            _ => (),
         };
-     });
+    };
 
-    let flowbox = shows.flowbox.clone();
-    lazy_load(podcasts, flowbox, constructor, callback);
+    lazy_load(podcasts, flowbox_weak, constructor, callback);
     Ok(())
 }