Implement From<Option<T>> for Element

core/src/element.rs

@@ -532,3 +532,49 @@ where
         )
     }
 }
+
+impl<'a, T, Message, Theme, Renderer> From<Option<T>>
+    for Element<'a, Message, Theme, Renderer>
+where
+    T: Into<Self>,
+    Renderer: crate::Renderer,
+{
+    fn from(element: Option<T>) -> Self {
+        struct Void;
+
+        impl<Message, Theme, Renderer> Widget<Message, Theme, Renderer> for Void
+        where
+            Renderer: crate::Renderer,
+        {
+            fn size(&self) -> Size<Length> {
+                Size {
+                    width: Length::Fixed(0.0),
+                    height: Length::Fixed(0.0),
+                }
+            }
+
+            fn layout(
+                &self,
+                _tree: &mut Tree,
+                _renderer: &Renderer,
+                _limits: &layout::Limits,
+            ) -> layout::Node {
+                layout::Node::new(Size::ZERO)
+            }
+
+            fn draw(
+                &self,
+                _tree: &Tree,
+                _renderer: &mut Renderer,
+                _theme: &Theme,
+                _style: &renderer::Style,
+                _layout: Layout<'_>,
+                _cursor: mouse::Cursor,
+                _viewport: &Rectangle,
+            ) {
+            }
+        }
+
+        element.map(T::into).unwrap_or_else(|| Element::new(Void))
+    }
+}

core/src/length.rs

@@ -57,6 +57,7 @@ impl Length {
 
     /// Adapts the [`Length`] so it can contain the other [`Length`] and
     /// match its fluidity.
+    #[inline]
     pub fn enclose(self, other: Length) -> Self {
         match (self, other) {
             (Length::Shrink, Length::Fill | Length::FillPortion(_)) => other,

core/src/size.rs

@@ -1,4 +1,4 @@
-use crate::{Radians, Vector};
+use crate::{Length, Radians, Vector};
 
 /// An amount of space in 2 dimensions.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Default)]
@@ -66,6 +66,15 @@ impl Size {
     }
 }
 
+impl Size<Length> {
+    /// Returns true if either `width` or `height` are 0-sized.
+    #[inline]
+    pub fn is_void(&self) -> bool {
+        matches!(self.width, Length::Fixed(0.0))
+            || matches!(self.height, Length::Fixed(0.0))
+    }
+}
+
 impl<T> From<[T; 2]> for Size<T> {
     fn from([width, height]: [T; 2]) -> Self {
         Size { width, height }

examples/pane_grid/src/main.rs

@@ -276,13 +276,13 @@ fn view_content<'a>(
         button(
             "Split vertically",
             Message::Split(pane_grid::Axis::Vertical, pane),
-        )
+        ),
+        if total_panes > 1 && !is_pinned {
+            Some(button("Close", Message::Close(pane)).style(button::danger))
+        } else {
+            None
+        }
     ]
-    .push_maybe(if total_panes > 1 && !is_pinned {
-        Some(button("Close", Message::Close(pane)).style(button::danger))
-    } else {
-        None
-    })
     .spacing(5)
     .max_width(160);
 
@@ -300,7 +300,7 @@ fn view_controls<'a>(
     is_pinned: bool,
     is_maximized: bool,
 ) -> Element<'a, Message> {
-    let row = row![].spacing(5).push_maybe(if total_panes > 1 {
+    let maximize = if total_panes > 1 {
         let (content, message) = if is_maximized {
             ("Restore", Message::Restore)
         } else {
@@ -315,7 +315,7 @@ fn view_controls<'a>(
         )
     } else {
         None
-    });
+    };
 
     let close = button(text("Close").size(14))
         .style(button::danger)
@@ -326,7 +326,7 @@ fn view_controls<'a>(
             None
         });
 
-    row.push(close).into()
+    row![maximize, close].spacing(5).into()
 }
 
 mod style {

examples/qr_code/src/main.rs

@@ -88,18 +88,18 @@ impl QRGenerator {
             input,
             row![toggle_total_size, choose_theme]
                 .spacing(20)
-                .align_y(Center)
+                .align_y(Center),
+            self.total_size.map(|total_size| {
+                slider(Self::SIZE_RANGE, total_size, Message::TotalSizeChanged)
+            }),
+            self.qr_code.as_ref().map(|data| {
+                if let Some(total_size) = self.total_size {
+                    qr_code(data).total_size(total_size)
+                } else {
+                    qr_code(data).cell_size(10.0)
+                }
+            })
         ]
-        .push_maybe(self.total_size.map(|total_size| {
-            slider(Self::SIZE_RANGE, total_size, Message::TotalSizeChanged)
-        }))
-        .push_maybe(self.qr_code.as_ref().map(|data| {
-            if let Some(total_size) = self.total_size {
-                qr_code(data).total_size(total_size)
-            } else {
-                qr_code(data).cell_size(10.0)
-            }
-        }))
         .width(700)
         .spacing(20)
         .align_x(Center);

examples/screenshot/src/main.rs

@@ -158,15 +158,15 @@ impl Example {
         .spacing(10)
         .align_y(Center);
 
-        let crop_controls =
+        let crop_controls = column![
-            column![crop_origin_controls, crop_dimension_controls]
+            crop_origin_controls,
-                .push_maybe(
+            crop_dimension_controls,
-                    self.crop_error
+            self.crop_error
-                        .as_ref()
+                .as_ref()
-                        .map(|error| text!("Crop error! \n{error}")),
+                .map(|error| text!("Crop error! \n{error}")),
-                )
+        ]
-                .spacing(10)
+        .spacing(10)
-                .align_x(Center);
+        .align_x(Center);
 
         let controls = {
             let save_result =
@@ -208,8 +208,8 @@ impl Example {
                 ]
                 .spacing(10)
                 .align_x(Center),
+                save_result.map(text)
             ]
-            .push_maybe(save_result.map(text))
             .spacing(40)
         };
 

examples/tour/src/main.rs

@@ -142,17 +142,17 @@ impl Tour {
     }
 
     fn view(&self) -> Element<'_, Message> {
-        let controls =
+        let controls = row![
-            row![]
+            self.screen.previous().is_some().then(|| {
-                .push_maybe(self.screen.previous().is_some().then(|| {
+                padded_button("Back")
-                    padded_button("Back")
+                    .on_press(Message::BackPressed)
-                        .on_press(Message::BackPressed)
+                    .style(button::secondary)
-                        .style(button::secondary)
+            }),
-                }))
+            horizontal_space(),
-                .push(horizontal_space())
+            self.can_continue().then(|| {
-                .push_maybe(self.can_continue().then(|| {
+                padded_button("Next").on_press(Message::NextPressed)
-                    padded_button("Next").on_press(Message::NextPressed)
+            })
-                }));
+        ];
 
         let screen = match self.screen {
             Screen::Welcome => self.welcome(),

widget/src/column.rs

@@ -145,23 +145,13 @@ where
         let child = child.into();
         let child_size = child.as_widget().size_hint();
 
-        self.width = self.width.enclose(child_size.width);
+        if !child_size.is_void() {
-        self.height = self.height.enclose(child_size.height);
+            self.width = self.width.enclose(child_size.width);
-
+            self.height = self.height.enclose(child_size.height);
-        self.children.push(child);
+            self.children.push(child);
-        self
-    }
-
-    /// Adds an element to the [`Column`], if `Some`.
-    pub fn push_maybe(
-        self,
-        child: Option<impl Into<Element<'a, Message, Theme, Renderer>>>,
-    ) -> Self {
-        if let Some(child) = child {
-            self.push(child)
-        } else {
-            self
         }
+
+        self
     }
 
     /// Extends the [`Column`] with the given children.

widget/src/row.rs

@@ -136,23 +136,13 @@ where
         let child = child.into();
         let child_size = child.as_widget().size_hint();
 
-        self.width = self.width.enclose(child_size.width);
+        if !child_size.is_void() {
-        self.height = self.height.enclose(child_size.height);
+            self.width = self.width.enclose(child_size.width);
-
+            self.height = self.height.enclose(child_size.height);
-        self.children.push(child);
+            self.children.push(child);
-        self
-    }
-
-    /// Adds an element to the [`Row`], if `Some`.
-    pub fn push_maybe(
-        self,
-        child: Option<impl Into<Element<'a, Message, Theme, Renderer>>>,
-    ) -> Self {
-        if let Some(child) = child {
-            self.push(child)
-        } else {
-            self
         }
+
+        self
     }
 
     /// Extends the [`Row`] with the given children.