Return early in MenuPopup::on_event if self.menu.children is empty

gyscos · Jun 20, 2024 · cb42dc1 · cb42dc1
1 parent 9333a54
commit cb42dc1
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Showing 3 changed files with 34 additions and 11 deletions.
diff --git a/cursive-core/src/theme/style.rs b/cursive-core/src/theme/style.rs
@@ -394,17 +394,17 @@ impl AsRef<Style> for Style {
     }
 }
 
-fn combine_styles<S: AsRef<Style>>(styles: impl IntoIterator<Item=S>) -> Style {
-        let mut color = ColorStyle::inherit_parent();
-        let mut effects = Effects::empty();
+fn combine_styles<S: AsRef<Style>>(styles: impl IntoIterator<Item = S>) -> Style {
+    let mut color = ColorStyle::inherit_parent();
+    let mut effects = Effects::empty();
 
-        for style in styles {
-            let style = style.as_ref();
-            color = ColorStyle::merge(color, style.color);
-            effects = Effects::merge(effects, style.effects);
-        }
+    for style in styles {
+        let style = style.as_ref();
+        color = ColorStyle::merge(color, style.color);
+        effects = Effects::merge(effects, style.effects);
+    }
 
-        Style { effects, color }
+    Style { effects, color }
 }
 
 /// Creates a new `Style` by merging all given styles.

diff --git a/cursive-core/src/utils/markup/cursup.rs b/cursive-core/src/utils/markup/cursup.rs
@@ -226,7 +226,8 @@ mod tests {
                 Span {
                     content: "bar",
                     width: 3,
-                    attr: &Style::from_color_style(BaseColor::Red.dark().into()).combine(Effect::Bold)
+                    attr: &Style::from_color_style(BaseColor::Red.dark().into())
+                        .combine(Effect::Bold)
                 },
                 Span {
                     content: " baz",

diff --git a/cursive-core/src/views/menu_popup.rs b/cursive-core/src/views/menu_popup.rs
@@ -35,6 +35,8 @@ impl_scroller!(MenuPopup::scroll_core);
 
 impl MenuPopup {
     /// Creates a new `MenuPopup` using the given menu tree.
+    ///
+    /// The menu tree cannot be modified after this view has been created.
     pub fn new(menu: Arc<menu::Tree>) -> Self {
         MenuPopup {
             menu,
@@ -123,6 +125,11 @@ impl MenuPopup {
         self.on_action = Some(Callback::from_fn(f));
     }
 
+    // Scroll up by `n` rows.
+    //
+    // # Panics
+    //
+    // If `self.menu.children.is_empty()`.
     fn scroll_up(&mut self, mut n: usize, mut cycle: bool) {
         while n > 0 {
             if self.focus > 0 {
@@ -141,6 +148,11 @@ impl MenuPopup {
         }
     }
 
+    // Scroll down by `n` rows.
+    //
+    // # Panics
+    //
+    // If `self.menu.children.is_empty()`.
     fn scroll_down(&mut self, mut n: usize, mut cycle: bool) {
         while n > 0 {
             if self.focus + 1 < self.menu.children.len() {
@@ -160,6 +172,11 @@ impl MenuPopup {
         }
     }
 
+    // Prepare the callback for when an item has been picked.
+    //
+    // # Panics
+    //
+    // If `self.menu.children.is_empty()`.
     fn submit(&mut self) -> EventResult {
         match self.menu.children[self.focus] {
             menu::Item::Leaf { ref cb, .. } => {
@@ -227,6 +244,11 @@ impl MenuPopup {
     ///
     /// Here the event has already been relativized. This means `y=0` points to the first item.
     fn inner_on_event(&mut self, event: Event) -> EventResult {
+        // If there is no item, nothing can be done.
+        if self.menu.children.is_empty() {
+            return EventResult::Ignored;
+        }
+
         match event {
             Event::Key(Key::Up) => self.scroll_up(1, true),
             Event::Key(Key::PageUp) => self.scroll_up(5, false),
@@ -320,7 +342,7 @@ impl View for MenuPopup {
         scroll::draw_box_frame(
             self,
             printer,
-            |s, y| s.menu.children[y].is_delimiter(),
+            |s, y| s.menu.children.get(y).map_or(false, |c| c.is_delimiter()),
             |_s, _x| false,
         );