From 955da784da5ba70e493aa9652fcda72403a5bc6f Mon Sep 17 00:00:00 2001
From: Schmiddiii <github@schmiddi.anonaddy.com>
Date: Fri, 9 Jun 2023 11:19:11 +0200
Subject: [PATCH] :sparkles: Autoload feed list (#138)

---
 data/resources/ui/feed_list.ui | 55 ++++++++++------------------------
 src/gui/feed/feed_list.rs      | 36 ++++++++++++++++++++--
 2 files changed, 50 insertions(+), 41 deletions(-)

diff --git a/data/resources/ui/feed_list.ui b/data/resources/ui/feed_list.ui
index 381aa36..a9b3830 100644
--- a/data/resources/ui/feed_list.ui
+++ b/data/resources/ui/feed_list.ui
@@ -9,51 +9,28 @@
     <property name="hexpand">True</property>
     <property name="halign">GTK_ALIGN_FILL</property>
     <child>
-      <object class="GtkScrolledWindow">
+      <object class="GtkScrolledWindow" id="scrolled_window">
         <property name="hscrollbar-policy">GTK_POLICY_NEVER</property>
+        <signal name="edge-reached" handler="edge_reached" swapped="true"/>
+
         <child>
-          <object class="AdwClamp">
+          <object class="AdwClampScrollable">
             <child>
-              <object class="GtkBox">
-                <property name="orientation">vertical</property>
+              <object class="GtkListView" id="feed_list">
+                <style>
+                  <class name="card"/>
+                  <class name="separators"/>
+                  <class name="feed-list"/>
+                </style>
+                <property name="margin-start">5</property>
+                <property name="margin-end">5</property>
+                <property name="margin-top">5</property>
+                <property name="margin-bottom">5</property>
+
                 <property name="vexpand">True</property>
-                <property name="valign">GTK_ALIGN_FILL</property>
+                <property name="valign">GTK_ALIGN_START</property>
                 <property name="hexpand">True</property>
                 <property name="halign">GTK_ALIGN_FILL</property>
-                <child>
-                  <object class="GtkListView" id="feed_list">
-                    <style>
-                      <class name="card"/>
-                      <class name="separators"/>
-                      <class name="feed-list"/>
-                    </style>
-                    <property name="margin-start">5</property>
-                    <property name="margin-end">5</property>
-                    <property name="margin-top">5</property>
-                    <property name="margin-bottom">5</property>
-
-                    <property name="vexpand">True</property>
-                    <property name="valign">GTK_ALIGN_START</property>
-                    <property name="hexpand">True</property>
-                    <property name="halign">GTK_ALIGN_FILL</property>
-                    <!-- Fix issue where highlighting the first/last item in the list would cut off the highlighting -->
-                    <property name="overflow">visible</property>
-                  </object>
-                </child>
-                <child>
-                  <object class="GtkButton" id="load_more">
-                    <binding name="visible">
-                      <lookup name="more-available" type="TFFeedList">
-                      </lookup>
-                    </binding>
-                    <property name="label" translatable="yes">Load more</property>
-                    <property name="vexpand">False</property>
-                    <property name="valign">GTK_ALIGN_FILL</property>
-                    <property name="hexpand">True</property>
-                    <property name="halign">GTK_ALIGN_FILL</property>
-                    <property name="action-name">feed.more</property>
-                  </object>
-                </child>
               </object>
             </child>
           </object>
diff --git a/src/gui/feed/feed_list.rs b/src/gui/feed/feed_list.rs
index e29fde8..9dee48e 100644
--- a/src/gui/feed/feed_list.rs
+++ b/src/gui/feed/feed_list.rs
@@ -22,11 +22,15 @@ use std::cmp::min;
 
 use gdk::{
     gio::{SimpleAction, SimpleActionGroup},
+    glib,
     glib::clone,
     prelude::{ActionMapExt, ListModelExt, ObjectExt, ToValue},
     subclass::prelude::ObjectSubclassIsExt,
 };
-use gtk::traits::WidgetExt;
+use gtk::{
+    traits::{AdjustmentExt, WidgetExt},
+    Adjustment,
+};
 use tf_join::AnyVideo;
 use tf_playlist::PlaylistManager;
 
@@ -64,6 +68,20 @@ impl FeedList {
         actions.add_action(&action_more);
     }
 
+    fn setup_autoload(&self) {
+        let adj = self.imp().scrolled_window.vadjustment();
+        adj.connect_changed(clone!(@weak self as s => move |adj| {
+            s.load_if_screen_not_filled(adj);
+        }));
+    }
+
+    fn load_if_screen_not_filled(&self, adj: &Adjustment) {
+        if self.property("more-available") && adj.upper() <= adj.page_size() {
+            // The screen is not yet filled.
+            let _ = self.activate_action("feed.more", None);
+        }
+    }
+
     pub fn set_items(&self, new_items: Vec<VideoObject>) {
         let imp = self.imp();
         let items = &imp.items;
@@ -142,6 +160,7 @@ pub mod imp {
     use gtk::glib;
     use gtk::prelude::*;
     use gtk::subclass::prelude::*;
+    use gtk::PositionType;
     use gtk::SignalListItemFactory;
     use gtk::Widget;
 
@@ -159,7 +178,7 @@ pub mod imp {
         #[template_child]
         pub(super) feed_list: TemplateChild<gtk::ListView>,
         #[template_child]
-        load_more: TemplateChild<gtk::Button>,
+        pub(super) scrolled_window: TemplateChild<gtk::ScrolledWindow>,
 
         pub(super) items: RefCell<Vec<VideoObject>>,
         pub(super) model: RefCell<ListStore>,
@@ -205,6 +224,18 @@ pub mod imp {
 
                 video_object.play();
             });
+
+            self.instance().setup_autoload();
+        }
+    }
+
+    #[gtk::template_callbacks]
+    impl FeedList {
+        #[template_callback]
+        fn edge_reached(&self, pos: PositionType) {
+            if pos == PositionType::Bottom {
+                let _ = WidgetExt::activate_action(&self.instance(), "feed.more", None);
+            }
         }
     }
 
@@ -216,6 +247,7 @@ pub mod imp {
 
         fn class_init(klass: &mut Self::Class) {
             Self::bind_template(klass);
+            Self::bind_template_callbacks(klass);
         }
 
         fn instance_init(obj: &InitializingObject<Self>) {