h-gtk:utils Add a more flexible implementation of lazy_load.

lazy_load_full is meant for siturations that you don't need
the constraisn of passing a single container parent and adding
a sigle widget to it.

Reimplemnted lazy_load on top of lazy_load_full.

hammond-gtk/src/utils.rs

@@ -70,11 +70,26 @@ where
     C: ContainerExt + 'static,
     F: FnMut(T::Item) -> W + 'static,
     W: IsA<Widget>,
+{
+    let func = move |x| container.add(&contructor(x));
+    lazy_load_full(data, func);
+}
+
+/// Iterate over `data` and execute `func` using a `glib::idle_add()`.
+///
+/// This is a more flexible version of `lazy_load` with less constrains.
+/// If you just want to lazy add `widgets` to a `container` check if
+/// `lazy_load` fits your needs first.
+pub fn lazy_load_full<T, F>(data: T, mut func: F)
+where
+    T: IntoIterator + 'static,
+    T::Item: 'static,
+    F: FnMut(T::Item) + 'static,
 {
     let mut data = data.into_iter();
     gtk::idle_add(move || {
         data.next()
-            .map(|x| container.add(&contructor(x)))
+            .map(|x| func(x))
             .map(|_| glib::Continue(true))
             .unwrap_or(glib::Continue(false))
     });