Refactored `view` node into `View!` widget.

TODO/_current.md

@@ -34,12 +34,6 @@
         - Is a different event from Winit.
         - The next version of Winit will fix this: https://github.com/rust-windowing/winit/issues/753
 
-# View!
-
-* `view` really needs to be a widget.
-    - In the icon example the view is not centered in the stack because
-      stack align does not work with non-widget nodes.
-
 # Align
 
 * Review align in window background.

examples/icon.rs

@@ -113,33 +113,37 @@ fn icons() -> impl UiNode {
                     select_font("two_tone"),
                 ]
             },
-            Container!(view(merge_var!(selected_font, search, |f, s| (*f, s.clone())), hn!(|a: &ViewArgs<(&'static str, Txt)>| {
-                if let Some((f, s)) = a.get_new() {
-                    let mut icons = match f {
-                        "filled" => icons::filled::all(),
-                        "outlined" => icons::outlined::all(),
-                        "rounded" => icons::rounded::all(),
-                        "sharp" => icons::sharp::all(),
-                        "two_tone" => icons::two_tone::all(),
-                        _ => unreachable!(),
-                    };
-                    if !s.is_empty() {
-                        let s = s.to_uppercase();
-                        icons.retain(|f| {
-                            f.name.contains(&s) ||
-                            f.display_name().to_uppercase().contains(&s)
-                        });
+            View!(
+                ::<(&'static str, Txt)>,
+                merge_var!(selected_font, search, |f, s| (*f, s.clone())),
+                hn!(|a: &ViewArgs<(&'static str, Txt)>| {
+                    if let Some((f, s)) = a.get_new() {
+                        let mut icons = match f {
+                            "filled" => icons::filled::all(),
+                            "outlined" => icons::outlined::all(),
+                            "rounded" => icons::rounded::all(),
+                            "sharp" => icons::sharp::all(),
+                            "two_tone" => icons::two_tone::all(),
+                            _ => unreachable!(),
+                        };
+                        if !s.is_empty() {
+                            let s = s.to_uppercase();
+                            icons.retain(|f| {
+                                f.name.contains(&s) ||
+                                f.display_name().to_uppercase().contains(&s)
+                            });
+                        }
+                        if icons.is_empty() {
+                            a.set_view(Text! {
+                                txt = formatx!("no icons found for '{s}'");
+                                margin = (10, 0, 0, 0);
+                            })
+                        } else {
+                            a.set_view(show_font(icons, f));
+                        }
                     }
-                    if icons.is_empty() {
-                        a.set_view(Text! {
-                            txt = formatx!("no icons found for '{s}'");
-                            margin = (10, 0, 0, 0);
-                        })
-                    } else {
-                        a.set_view(show_font(icons, f));
-                    }
-                }
-            }))),
+                }),
+            ),
         ]
     }
 }

tests/focus.rs

@@ -1088,7 +1088,7 @@ pub fn focused_removed_by_deleting() {
 
     let buttons = ui_vec! {
         Button! { child = Text!("Button 0") },
-        view(exist.clone(), hn!(|a: &ViewArgs<bool>| {
+        View!(::<bool>, exist.clone(), hn!(|a: &ViewArgs<bool>| {
             if a.data().get() {
                 a.set_view(Button! { id = button1_id; child = Text!("Button 1") });
             } else {
@@ -1183,7 +1183,8 @@ pub fn focus_continued_after_widget_id_move() {
 
     let do_move_id = var(false);
 
-    let mut app = app.run(view(
+    let mut app = app.run(View!(
+        ::<bool>,
         do_move_id.clone(),
         hn!(|a: &ViewArgs<bool>| {
             if a.data().get() {

zero-ui/src/widgets/view.rs

@@ -239,7 +239,9 @@ pub fn presenter_opt<D: VarValue>(data: impl IntoVar<Option<D>>, update: impl In
     })
 }
 
-/// Arguments for the [`view`] widget function.
+/// Arguments for the [`View!`] widget function.
+/// 
+/// [`View!`]: struct@View
 #[derive(Clone)]
 pub struct ViewArgs<D: VarValue> {
     data: BoxedVar<D>,
@@ -297,11 +299,13 @@ impl<D: VarValue> ViewArgs<D> {
 ///
 /// # Examples
 ///
+/// View using the shorthand syntax:
+/// 
 /// ```
 /// use zero_ui::prelude::*;
 ///
 /// fn countdown(n: impl IntoVar<usize>) -> impl UiNode {
-///     Container!(view(n, hn!(|a: &ViewArgs<usize>| {
+///     View!(::<usize>, n, hn!(|a: &ViewArgs<usize>| {
 ///         // we generate a new view on the first call or when the data has changed to zero.
 ///         if a.is_nil() || a.data().get_new() == Some(0) {
 ///             a.set_view(if a.data().get() > 0 {
@@ -320,15 +324,59 @@ impl<D: VarValue> ViewArgs<D> {
 ///                 }
 ///             });
 ///         }
-///     })))
+///     }))
 /// }
 /// ```
-pub fn view<D: VarValue>(data: impl IntoVar<D>, update: impl WidgetHandler<ViewArgs<D>>) -> impl UiNode {
+/// 
+/// You can also use the normal widget syntax and set the `view` property.
+/// 
+/// ```
+/// use zero_ui::prelude::*;
+///
+/// fn countdown(n: impl IntoVar<usize>) -> impl UiNode {
+///     View! {
+///         view::<usize> = {
+///             data: n,
+///             update: hn!(|a: &ViewArgs<usize>| { }),
+///         };
+///         background_color = colors::GRAY;
+///     }
+/// }
+/// ```
+#[widget($crate::widgets::View {
+    (::<$T:ty>, $data:expr, $update:expr $(,)?) => {
+        view::<$T> = {
+            data: $data, 
+            update: $update,
+        };
+    }
+})]
+pub struct View(WidgetBase);
+impl View {
+    widget_impl! {
+        /// Spacing around content, inside the border.
+        pub crate::properties::padding(padding: impl IntoVar<SideOffsets>);
+
+        /// Content alignment.
+        pub crate::properties::child_align(align: impl IntoVar<Align>);
+
+        /// Content overflow clipping.
+        pub crate::properties::clip_to_bounds(clip: impl IntoVar<bool>);
+    }
+}
+
+/// The view generator.
+/// 
+/// See [`View!`] for more details.
+/// 
+/// [`View!`]: struct@View
+#[property(CHILD, widget_impl(View))]
+pub fn view<D: VarValue>(child: impl UiNode, data: impl IntoVar<D>, update: impl WidgetHandler<ViewArgs<D>>) -> impl UiNode {
     let data = data.into_var().boxed();
     let mut update = update.cfg_boxed();
     let replace = Arc::new(Mutex::new(None));
 
-    match_node(NilUiNode.boxed(), move |c, op| match op {
+    match_node(child, move |c, op| match op {
         UiNodeOp::Init => {
             WIDGET.sub_var(&data);
             update.event(&ViewArgs {