fix button always showing

Author: extrawurst

src/logging.rs

@@ -136,18 +136,20 @@ impl Plugin for LogViewerPlugin {
         // Running update_log_ui in PreUpdate to prevent data races between updating the UI and filtering log lines.
         // `handle_level_filter_chip_toggle`` can modify the `{level}_visible` fields in `LogViewerState`
         // while `update_log_ui` is adding new loglines to the viewer in parallel based on older values.
-        app.add_systems(
-            PreUpdate,
-            (manage_scroll_ui_state, receive_logs, update_log_counts).chain(),
-        );
+        app.add_systems(PreUpdate, (receive_logs, update_log_counts).chain());
 
         app.add_systems(
             Update,
             (
                 on_traffic_light_button,
                 on_auto_open_check,
                 on_level_filter_chip,
-                (handle_listcontainer_overflow, handle_scroll_update).chain(),
+                (
+                    manage_scroll_ui_state,
+                    handle_listcontainer_overflow,
+                    handle_scroll_update,
+                )
+                    .chain(),
             ),
         );
     }
@@ -546,39 +548,30 @@ fn handle_listcontainer_overflow(
 }
 
 fn manage_scroll_ui_state(
-    mut log_viewer: ResMut<LogViewerState>,
+    log_viewer: Res<LogViewerState>,
     mut border_color_q: Query<&mut BorderColor, With<LogViewerMarker>>,
     mut scroll_to_bottom_btn_q: Query<&mut Node, With<GoDownBtnMarker>>,
     mut scroll_query: Query<(&ScrollPosition, &ComputedNode, &Children), With<ListContainerMarker>>,
     child_comp_node_query: Query<&ComputedNode, With<ListMarker>>,
 ) {
-    if let Ok((scroll_position, parent_comp_node, children)) = scroll_query.get_single_mut() {
-        if let Ok(child_comp_node) = child_comp_node_query.get(children[0]) {
-            // The list is at bottom if the sum of the parent's height and the scroll offset is equal to the child's height.
-            // We subtract the font size to account for the last log line being partially visible and still count that as being at the bottom.
-            let is_at_bottom = parent_comp_node.size().y + scroll_position.offset_y
-                >= child_comp_node.size().y - LOG_LINE_FONT_SIZE;
+    if let Ok((_scroll_position, _parent_comp_node, children)) = scroll_query.single_mut() {
+        if let Ok(_child_comp_node) = child_comp_node_query.get(children[0]) {
+            let hide_button = log_viewer.scroll_state != ScrollState::Manual;
 
-            if let Ok(mut border_color) = border_color_q.get_single_mut() {
-                *border_color = if is_at_bottom {
+            if let Ok(mut border_color) = border_color_q.single_mut() {
+                *border_color = if hide_button {
                     Color::NONE.into()
                 } else {
                     css::WHITE.with_alpha(0.25).into()
                 };
             }
-            if let Ok(mut scroll_to_bottom_btn) = scroll_to_bottom_btn_q.get_single_mut() {
-                scroll_to_bottom_btn.display = if is_at_bottom {
+            if let Ok(mut scroll_to_bottom_btn) = scroll_to_bottom_btn_q.single_mut() {
+                scroll_to_bottom_btn.display = if hide_button {
                     Display::None
                 } else {
                     Display::Flex
                 };
             }
-
-            log_viewer.scroll_state = if is_at_bottom {
-                ScrollState::Auto
-            } else {
-                ScrollState::Manual
-            };
         }
     }
 }
@@ -590,7 +583,7 @@ fn handle_scroll_to_bottom(
     computed_node_query: Query<&ComputedNode, With<ListMarker>>,
 ) {
     // ListContainerMarker -> ListMarker have a Parent -> Child relationship.
-    if let Ok((mut scroll_position, children)) = scroll_query.get_single_mut() {
+    if let Ok((mut scroll_position, children)) = scroll_query.single_mut() {
         if let Ok(computed_node) = computed_node_query.get(children[0]) {
             scroll_position.offset_y = computed_node.size().y;
             log_viewer.scroll_state = ScrollState::Auto;
@@ -645,7 +638,7 @@ fn spawn_logline(commands: &mut Commands, parent: Entity, event: &LogEvent) -> E
             TextFont::from_font_size(LOG_LINE_FONT_SIZE),
             TextColor(css::WHITE.into()),
         ))
-        .set_parent(parent)
+        .insert(ChildOf { parent })
         .id()
 }