feat: zoom items on ctrl+scroll

src/lib.rs

@@ -20,6 +20,7 @@ mod mime_app;
 pub mod mime_icon;
 mod mounter;
 mod mouse_area;
+mod scroll_area;
 mod operation;
 mod spawn_detached;
 use tab::Location;

src/scroll_area.rs

@@ -0,0 +1,218 @@
+//! A container for capturing mouse wheel events.
+
+use cosmic::{
+    iced_core::{
+        event::{self, Event},
+        layout,
+        mouse::{self},
+        overlay,
+        renderer::{self},
+        widget::{Operation, OperationOutputWrapper, Tree},
+        Clipboard, Layout, Length, Rectangle, Shell, Size, Widget,
+    },
+    widget::Id,
+    Element, Renderer, Theme,
+};
+
+/// Emit messages on mouse wheel events.
+#[allow(missing_debug_implementations)]
+pub struct ScrollArea<'a, Message> {
+    id: Id,
+    content: Element<'a, Message>,
+    on_scroll: Option<Box<dyn Fn(Option<mouse::ScrollDelta>) -> Option<Message> + 'a>>,
+    should_propogate_events: bool,
+}
+
+impl<'a, Message> ScrollArea<'a, Message> {
+    /// The message to emit on a forward button release.
+    #[must_use]
+    pub fn on_scroll(
+        mut self,
+        message: impl Fn(Option<mouse::ScrollDelta>) -> Option<Message> + 'a,
+    ) -> Self {
+        self.on_scroll = Some(Box::new(message));
+        self
+    }
+
+    /// Sets the widget's unique identifier.
+    #[must_use]
+    pub fn with_id(mut self, id: Id) -> Self {
+        self.id = id;
+        self
+    }
+}
+
+impl<'a, Message> ScrollArea<'a, Message> {
+    /// Creates a [`ScrollArea`] with the given content.
+    pub fn new(content: impl Into<Element<'a, Message>>, should_propogate_events: bool) -> Self {
+        ScrollArea {
+            id: Id::unique(),
+            content: content.into(),
+            on_scroll: None,
+            should_propogate_events,
+        }
+    }
+}
+
+impl<'a, Message> Widget<Message, Theme, Renderer> for ScrollArea<'a, Message>
+where
+    Message: Clone,
+{
+    fn children(&self) -> Vec<Tree> {
+        vec![Tree::new(&self.content)]
+    }
+
+    fn diff(&mut self, tree: &mut Tree) {
+        tree.diff_children(std::slice::from_mut(&mut self.content));
+    }
+
+    fn size(&self) -> Size<Length> {
+        self.content.as_widget().size()
+    }
+
+    fn layout(
+        &self,
+        tree: &mut Tree,
+        renderer: &Renderer,
+        limits: &layout::Limits,
+    ) -> layout::Node {
+        self.content
+            .as_widget()
+            .layout(&mut tree.children[0], renderer, limits)
+    }
+
+    fn operate(
+        &self,
+        tree: &mut Tree,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+        operation: &mut dyn Operation<OperationOutputWrapper<Message>>,
+    ) {
+        self.content
+            .as_widget()
+            .operate(&mut tree.children[0], layout, renderer, operation);
+    }
+
+    fn on_event(
+        &mut self,
+        tree: &mut Tree,
+        event: Event,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        renderer: &Renderer,
+        clipboard: &mut dyn Clipboard,
+        shell: &mut Shell<'_, Message>,
+        viewport: &Rectangle,
+    ) -> event::Status {
+        if let event::Status::Captured = self.content.as_widget_mut().on_event(
+            &mut tree.children[0],
+            event.clone(),
+            layout,
+            cursor,
+            renderer,
+            clipboard,
+            shell,
+            viewport,
+        ) {
+            return event::Status::Captured;
+        }
+
+        update(self, &event, layout, cursor, shell)
+    }
+
+    fn mouse_interaction(
+        &self,
+        tree: &Tree,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        viewport: &Rectangle,
+        renderer: &Renderer,
+    ) -> mouse::Interaction {
+        self.content.as_widget().mouse_interaction(
+            &tree.children[0],
+            layout,
+            cursor,
+            viewport,
+            renderer,
+        )
+    }
+
+    fn draw(
+        &self,
+        tree: &Tree,
+        renderer: &mut Renderer,
+        theme: &Theme,
+        renderer_style: &renderer::Style,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        viewport: &Rectangle,
+    ) {
+        self.content.as_widget().draw(
+            &tree.children[0],
+            renderer,
+            theme,
+            renderer_style,
+            layout,
+            cursor,
+            viewport,
+        );
+    }
+
+    fn overlay<'b>(
+        &'b mut self,
+        tree: &'b mut Tree,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+    ) -> Option<overlay::Element<'b, Message, Theme, Renderer>> {
+        self.content
+            .as_widget_mut()
+            .overlay(&mut tree.children[0], layout, renderer)
+    }
+
+    fn id(&self) -> Option<Id> {
+        Some(self.id.clone())
+    }
+
+    fn set_id(&mut self, id: Id) {
+        self.id = id;
+    }
+}
+
+impl<'a, Message> From<ScrollArea<'a, Message>> for Element<'a, Message>
+where
+    Message: 'a + Clone,
+    Renderer: 'a + renderer::Renderer,
+    Theme: 'a,
+{
+    fn from(area: ScrollArea<'a, Message>) -> Element<'a, Message> {
+        Element::new(area)
+    }
+}
+
+/// Processes the given [`Event`] and updates the [`State`] of a [`ScrollArea`]
+/// accordingly.
+fn update<Message: Clone>(
+    widget: &mut ScrollArea<'_, Message>,
+    event: &Event,
+    layout: Layout<'_>,
+    cursor: mouse::Cursor,
+    shell: &mut Shell<'_, Message>,
+) -> event::Status {
+    let layout_bounds = layout.bounds();
+    if !cursor.is_over(layout_bounds) {
+        return event::Status::Ignored;
+    }
+
+    if let Event::Mouse(mouse::Event::WheelScrolled { delta }) = event {
+        if let Some(message) = widget.on_scroll.as_ref() {
+            if let Some(msg) = message(Some(delta.clone())) {
+                shell.publish(msg);
+                if !widget.should_propogate_events {
+                    return event::Status::Captured;
+                }
+            }
+        }
+    }
+
+    event::Status::Ignored
+}

src/tab.rs

@@ -63,7 +63,7 @@ use crate::{
     menu,
     mime_app::{mime_apps, MimeApp},
     mime_icon::{mime_for_path, mime_icon},
-    mouse_area,
+    mouse_area, scroll_area::ScrollArea,
 };
 use unix_permissions_ext::UNIXPermissionsExt;
 use uzers::{get_group_by_gid, get_user_by_uid};
@@ -3372,6 +3372,9 @@ impl Tab {
             mouse_area = mouse_area.on_right_press(Message::ContextMenu);
         }
 
+        let mouse_area = ScrollArea::new(mouse_area, true)
+            .on_scroll(respond_to_scroll_direction);
+
         let mut popover = widget::popover(mouse_area);
 
         if let Some(point) = self.context_menu {
@@ -3577,6 +3580,24 @@ impl Tab {
     }
 }
 
+fn respond_to_scroll_direction(delta: Option<cosmic::iced_core::mouse::ScrollDelta>) -> Option<Message> {
+    let delta_y = match delta {
+        Some(cosmic::iced_core::mouse::ScrollDelta::Lines { y, .. }) => y,
+        Some(cosmic::iced_core::mouse::ScrollDelta::Pixels { y, .. }) => y,
+        None => 0.0,
+    };
+
+    if delta_y > 0.0 {
+        return Some(Message::ScrollUp);
+    }
+
+    if delta_y < 0.0 {
+        return Some(Message::ScrollDown);
+    }
+
+    None
+}
+
 #[cfg(test)]
 mod tests {
     use std::{fs, io, path::PathBuf};
@@ -3589,8 +3610,9 @@ mod tests {
     use super::{scan_path, Location, Message, Tab};
     use crate::{
         app::test_utils::{
-            assert_eq_tab_path, empty_fs, eq_path_item, filter_dirs, read_dir_sorted, simple_fs,
+            assert_eq_tab_path, assert_scroll_affects_item_zoom, empty_fs, eq_path_item,
-            tab_click_new, NAME_LEN, NUM_DIRS, NUM_FILES, NUM_HIDDEN, NUM_NESTED,
+            filter_dirs, read_dir_sorted, simple_fs, tab_click_new, NAME_LEN, NUM_DIRS,
+            NUM_FILES, NUM_HIDDEN, NUM_NESTED,
         },
         config::{IconSizes, TabConfig},
     };
@@ -3823,6 +3845,54 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn tab_scroll_up_with_ctrl_modifier_zooms() -> io::Result<()> {
+        let fs = simple_fs(0, NUM_NESTED, NUM_DIRS, 0, NAME_LEN)?;
+        let path = fs.path();
+
+        let mut tab = Tab::new(Location::Path(path.into()), TabConfig::default());
+        
+        let should_zoom = true;
+        assert_scroll_affects_item_zoom(&mut tab, Message::ScrollUp, Modifiers::CTRL, should_zoom);
+
+        Ok(())
+    }
+
+    #[test]
+    fn tab_scroll_up_without_ctrl_modifier_does_not_zoom() -> io::Result<()> {
+        let fs = simple_fs(0, NUM_NESTED, NUM_DIRS, 0, NAME_LEN)?;
+        let path = fs.path();
+
+        let mut tab = Tab::new(Location::Path(path.into()), TabConfig::default());
+        let should_not_zoom = false;
+        assert_scroll_affects_item_zoom(&mut tab, Message::ScrollUp, Modifiers::empty(), should_not_zoom);
+
+        Ok(())
+    }
+
+    #[test]
+    fn tab_scroll_down_with_ctrl_modifier_zooms() -> io::Result<()> {
+        let fs = simple_fs(0, NUM_NESTED, NUM_DIRS, 0, NAME_LEN)?;
+        let path = fs.path();
+        
+        let mut tab = Tab::new(Location::Path(path.into()), TabConfig::default());
+        let should_zoom = true;
+        assert_scroll_affects_item_zoom(&mut tab, Message::ScrollDown, Modifiers::CTRL, should_zoom);
+
+        Ok(())
+    }
+
+    #[test]
+    fn tab_scroll_down_without_ctrl_modifier_does_not_zoom() -> io::Result<()> {
+        let fs = simple_fs(0, NUM_NESTED, NUM_DIRS, 0, NAME_LEN)?;
+        let path = fs.path();
+        
+        let mut tab = Tab::new(Location::Path(path.into()), TabConfig::default());
+        let should_not_zoom = false;
+        assert_scroll_affects_item_zoom(&mut tab, Message::ScrollDown, Modifiers::empty(), should_not_zoom);
+
+        Ok(())
+    }
     #[test]
     fn tab_empty_history_does_nothing_on_prev_next() -> io::Result<()> {
         let fs = simple_fs(0, NUM_NESTED, NUM_DIRS, 0, NAME_LEN)?;