xilem_core: return element in View::rebuild

Otherwise it's not possible to modify the element anymore after child `View` has used the element in `View::rebuild`
DJMcNab · Jun 1, 2024 · 7f4faff · 7f4faff
1 parent 824112c
commit 7f4faff
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Showing 11 changed files with 92 additions and 81 deletions.
diff --git a/xilem/src/view/button.rs b/xilem/src/view/button.rs
@@ -2,10 +2,8 @@
 // SPDX-License-Identifier: Apache-2.0
 
 use crate::{core::View, Pod};
-use masonry::{
-    widget::{self, WidgetMut},
-    ArcStr, WidgetPod,
-};
+use masonry::{widget, ArcStr, WidgetPod};
+use xilem_core::ViewElement;
 
 use crate::{MessageResult, ViewCtx, ViewId};
 
@@ -37,17 +35,18 @@ where
         })
     }
 
-    fn rebuild(
+    fn rebuild<'a>(
         &self,
         prev: &Self,
         _: &mut Self::ViewState,
         ctx: &mut ViewCtx,
-        mut element: WidgetMut<widget::Button>,
-    ) {
+        mut element: <Self::Element as ViewElement>::Mut<'a>,
+    ) -> <Self::Element as ViewElement>::Mut<'a> {
         if prev.label != self.label {
             element.set_text(self.label.clone());
             ctx.mark_changed();
         }
+        element
     }
 
     fn teardown(

diff --git a/xilem/src/view/checkbox.rs b/xilem/src/view/checkbox.rs
@@ -5,6 +5,7 @@ use masonry::{
     widget::{self, WidgetMut},
     ArcStr, WidgetPod,
 };
+use xilem_core::ViewElement;
 
 use crate::{MessageResult, Pod, View, ViewCtx, ViewId};
 
@@ -46,13 +47,13 @@ where
         })
     }
 
-    fn rebuild(
+    fn rebuild<'a>(
         &self,
         prev: &Self,
         (): &mut Self::ViewState,
         ctx: &mut ViewCtx,
-        mut element: WidgetMut<'_, widget::Checkbox>,
-    ) {
+        mut element: <Self::Element as ViewElement>::Mut<'a>,
+    ) -> <Self::Element as ViewElement>::Mut<'a> {
         if prev.label != self.label {
             element.set_text(self.label.clone());
             ctx.mark_changed();
@@ -61,6 +62,7 @@ where
             element.set_checked(self.checked);
             ctx.mark_changed();
         }
+        element
     }
 
     fn teardown(

diff --git a/xilem/src/view/flex.rs b/xilem/src/view/flex.rs
@@ -7,7 +7,7 @@ use masonry::{
     widget::{self, Axis, CrossAxisAlignment, MainAxisAlignment, WidgetMut},
     Widget, WidgetPod,
 };
-use xilem_core::{AppendVec, ElementSplice, View, ViewSequence};
+use xilem_core::{AppendVec, ElementSplice, View, ViewElement, ViewSequence};
 
 use crate::{Pod, ViewCtx};
 
@@ -75,13 +75,13 @@ where
         (WidgetPod::new(widget).into(), seq_state)
     }
 
-    fn rebuild(
+    fn rebuild<'a>(
         &self,
         prev: &Self,
         view_state: &mut Self::ViewState,
         ctx: &mut ViewCtx,
-        mut element: WidgetMut<widget::Flex>,
-    ) {
+        mut element: <Self::Element as ViewElement>::Mut<'a>,
+    ) -> <Self::Element as ViewElement>::Mut<'a> {
         if prev.axis != self.axis {
             element.set_direction(self.axis);
             ctx.mark_changed();
@@ -102,24 +102,25 @@ where
         let mut splice = FlexSplice {
             // Skip the initial spacer which is always present
             ix: 1,
-            element,
+            element: &mut element,
             scratch: AppendVec::default(),
         };
         self.sequence
             .seq_rebuild(&prev.sequence, view_state, ctx, &mut splice);
         debug_assert!(splice.scratch.into_inner().is_empty());
+        element
     }
 
     fn teardown(
         &self,
         view_state: &mut Self::ViewState,
         ctx: &mut ViewCtx,
-        element: <Self::Element as xilem_core::ViewElement>::Mut<'_>,
+        mut element: <Self::Element as xilem_core::ViewElement>::Mut<'_>,
     ) {
         let mut splice = FlexSplice {
             // Skip the initial spacer which is always present
             ix: 1,
-            element,
+            element: &mut element,
             scratch: AppendVec::default(),
         };
         self.sequence.seq_teardown(view_state, ctx, &mut splice);
@@ -138,13 +139,13 @@ where
     }
 }
 
-struct FlexSplice<'w> {
+struct FlexSplice<'f, 'w> {
     ix: usize,
-    element: WidgetMut<'w, widget::Flex>,
+    element: &'f mut WidgetMut<'w, widget::Flex>,
     scratch: AppendVec<Pod<Box<dyn Widget>>>,
 }
 
-impl ElementSplice<Pod<Box<dyn Widget>>> for FlexSplice<'_> {
+impl<'f> ElementSplice<Pod<Box<dyn Widget>>> for FlexSplice<'f, '_> {
     fn push(&mut self, element: Pod<Box<dyn masonry::Widget>>) {
         self.element.insert_child_pod(self.ix, element.inner);
         // Insert a spacer after the child

diff --git a/xilem/src/view/label.rs b/xilem/src/view/label.rs
@@ -5,6 +5,7 @@ use masonry::{
     widget::{self, WidgetMut},
     ArcStr, WidgetPod,
 };
+use xilem_core::ViewElement;
 
 use crate::{Color, MessageResult, Pod, TextAlignment, View, ViewCtx, ViewId};
 
@@ -55,13 +56,13 @@ impl<State, Action> View<State, Action, ViewCtx> for Label {
         (widget_pod.into(), ())
     }
 
-    fn rebuild(
+    fn rebuild<'a>(
         &self,
         prev: &Self,
         (): &mut Self::ViewState,
         ctx: &mut ViewCtx,
-        mut element: WidgetMut<'_, widget::Label>,
-    ) {
+        mut element: <Self::Element as ViewElement>::Mut<'a>,
+    ) -> <Self::Element as ViewElement>::Mut<'a> {
         if prev.label != self.label {
             element.set_text(self.label.clone());
             ctx.mark_changed();
@@ -78,6 +79,7 @@ impl<State, Action> View<State, Action, ViewCtx> for Label {
             element.set_alignment(self.alignment);
             ctx.mark_changed();
         }
+        element
     }
 
     fn teardown(&self, (): &mut Self::ViewState, _: &mut ViewCtx, _: WidgetMut<'_, widget::Label>) {

diff --git a/xilem/src/view/prose.rs b/xilem/src/view/prose.rs
@@ -6,6 +6,7 @@ use masonry::{
     widget::{self, WidgetMut},
     ArcStr, WidgetPod,
 };
+use xilem_core::ViewElement;
 
 use crate::{Color, MessageResult, Pod, TextAlignment, View, ViewCtx, ViewId};
 
@@ -57,13 +58,13 @@ impl<State, Action> View<State, Action, ViewCtx> for Prose {
         (widget_pod.into(), ())
     }
 
-    fn rebuild(
+    fn rebuild<'a>(
         &self,
         prev: &Self,
         (): &mut Self::ViewState,
         ctx: &mut ViewCtx,
-        mut element: WidgetMut<'_, widget::Prose>,
-    ) {
+        mut element: <Self::Element as ViewElement>::Mut<'a>,
+    ) -> <Self::Element as ViewElement>::Mut<'a> {
         if prev.label != self.label {
             element.set_text(self.label.clone());
             ctx.mark_changed();
@@ -76,6 +77,7 @@ impl<State, Action> View<State, Action, ViewCtx> for Prose {
             element.set_alignment(self.alignment);
             ctx.mark_changed();
         }
+        element
     }
 
     fn teardown(&self, (): &mut Self::ViewState, _: &mut ViewCtx, _: WidgetMut<'_, widget::Prose>) {

diff --git a/xilem/src/view/textbox.rs b/xilem/src/view/textbox.rs
@@ -1,12 +1,8 @@
 // Copyright 2024 the Xilem Authors
 // SPDX-License-Identifier: Apache-2.0
 
-use masonry::{
-    text2::TextBrush,
-    widget::{self, WidgetMut},
-    WidgetPod,
-};
-use xilem_core::View;
+use masonry::{text2::TextBrush, widget, WidgetPod};
+use xilem_core::{View, ViewElement};
 
 use crate::{Color, MessageResult, Pod, TextAlignment, ViewCtx, ViewId};
 
@@ -82,13 +78,13 @@ impl<State: 'static, Action: 'static> View<State, Action, ViewCtx> for Textbox<S
         })
     }
 
-    fn rebuild(
+    fn rebuild<'a>(
         &self,
         prev: &Self,
         _: &mut Self::ViewState,
         ctx: &mut ViewCtx,
-        mut element: WidgetMut<widget::Textbox>,
-    ) {
+        mut element: <Self::Element as ViewElement>::Mut<'a>,
+    ) -> <Self::Element as ViewElement>::Mut<'a> {
         // Unlike the other properties, we don't compare to the previous value;
         // instead, we compare directly to the element's text. This is to handle
         // cases like "Previous data says contents is 'fooba', user presses 'r',
@@ -109,6 +105,7 @@ impl<State: 'static, Action: 'static> View<State, Action, ViewCtx> for Textbox<S
             element.set_alignment(self.alignment);
             ctx.mark_changed();
         }
+        element
     }
 
     fn teardown(

diff --git a/xilem_core/examples/filesystem.rs b/xilem_core/examples/filesystem.rs
@@ -163,21 +163,22 @@ impl<State, Action> View<State, Action, ViewCtx> for File {
         (path.into(), ())
     }
 
-    fn rebuild(
+    fn rebuild<'a>(
         &self,
         prev: &Self,
         _view_state: &mut Self::ViewState,
         ctx: &mut ViewCtx,
-        element: <Self::Element as xilem_core::ViewElement>::Mut<'_>,
-    ) {
+        element: <Self::Element as ViewElement>::Mut<'a>,
+    ) -> <Self::Element as ViewElement>::Mut<'a> {
         if prev.name != self.name {
             let new_path = ctx.current_folder_path.join(&*self.name);
             let _ = std::fs::rename(&element, &new_path);
             *element = new_path;
         }
         if self.contents != prev.contents {
-            let _ = std::fs::write(element, self.contents.as_bytes());
+            let _ = std::fs::write(&element, self.contents.as_bytes());
         }
+        element
     }
 
     fn teardown(

diff --git a/xilem_core/examples/user_interface.rs b/xilem_core/examples/user_interface.rs
@@ -68,14 +68,15 @@ impl<State, Action> View<State, Action, ViewCtx> for Button {
         )
     }
 
-    fn rebuild(
+    fn rebuild<'a>(
         &self,
         _prev: &Self,
         _view_state: &mut Self::ViewState,
         _ctx: &mut ViewCtx,
-        _element: <Self::Element as ViewElement>::Mut<'_>,
-    ) {
+        element: <Self::Element as ViewElement>::Mut<'a>,
+    ) -> <Self::Element as ViewElement>::Mut<'a> {
         // Nothing to do
+        element
     }
 
     fn teardown(