Create switch view

src/view/mod.rs

@@ -21,6 +21,7 @@ mod text;
 // mod use_state;
 mod linear_layout;
 mod list;
+mod switch;
 #[allow(clippy::module_inception)]
 mod view;
 
@@ -29,4 +30,5 @@ pub use xilem_core::{Id, IdPath, VecSplice};
 pub use button::button;
 pub use linear_layout::{h_stack, v_stack, LinearLayout};
 pub use list::{list, List};
+pub use switch::switch;
 pub use view::{Adapt, AdaptState, Cx, Memoize, View, ViewMarker, ViewSequence};

src/view/switch.rs

@@ -0,0 +1,81 @@
+// Copyright 2022 The Druid Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::any::Any;
+
+use crate::view::ViewMarker;
+use crate::{view::Id, widget::ChangeFlags, MessageResult};
+
+use super::{Cx, View};
+
+pub struct Switch<T, A> {
+    is_on: bool,
+    #[allow(clippy::type_complexity)]
+    callback: Box<dyn Fn(&mut T, bool) -> A + Send>,
+}
+
+pub fn switch<T, A>(
+    is_on: bool,
+    clicked: impl Fn(&mut T, bool) -> A + Send + 'static,
+) -> Switch<T, A> {
+    Switch::new(is_on, clicked)
+}
+
+impl<T, A> Switch<T, A> {
+    pub fn new(is_on: bool, clicked: impl Fn(&mut T, bool) -> A + Send + 'static) -> Self {
+        Switch {
+            is_on,
+            callback: Box::new(clicked),
+        }
+    }
+}
+
+impl<T, A> ViewMarker for Switch<T, A> {}
+
+impl<T, A> View<T, A> for Switch<T, A> {
+    type State = ();
+
+    type Element = crate::widget::Switch;
+
+    fn build(&self, cx: &mut Cx) -> (crate::view::Id, Self::State, Self::Element) {
+        let (id, element) =
+            cx.with_new_id(|cx| crate::widget::Switch::new(cx.id_path(), self.is_on));
+        (id, (), element)
+    }
+
+    fn rebuild(
+        &self,
+        _cx: &mut Cx,
+        prev: &Self,
+        _id: &mut Id,
+        _state: &mut Self::State,
+        element: &mut Self::Element,
+    ) -> ChangeFlags {
+        if prev.is_on != self.is_on {
+            element.set_is_on(self.is_on)
+        } else {
+            ChangeFlags::default()
+        }
+    }
+
+    fn message(
+        &self,
+        _id_path: &[Id],
+        _state: &mut Self::State,
+        _message: Box<dyn Any>,
+        app_state: &mut T,
+    ) -> MessageResult<A> {
+        MessageResult::Action((self.callback)(app_state, !self.is_on))
+    }
+}