Introduce `Shell` type in `iced_native`

Widgets now can invalidate the current layout of the application on demand.

16 files changed, 77 insertions, 79 deletions

diff --git a/native/src/widget/button.rs b/native/src/widget/button.rs
index 1d785f35..686289e4 100644
--- a/native/src/widget/button.rs
+++ b/native/src/widget/button.rs
@@ -9,7 +9,7 @@ use crate::renderer;
 use crate::touch;
 use crate::{
     Background, Clipboard, Color, Element, Hasher, Layout, Length, Padding,
-    Point, Rectangle, Vector, Widget,
+    Point, Rectangle, Shell, Vector, Widget,
 };
 
 use std::hash::Hash;
@@ -197,7 +197,7 @@ where
         cursor_position: Point,
         renderer: &Renderer,
         clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         if let event::Status::Captured = self.content.on_event(
             event.clone(),
@@ -205,7 +205,7 @@ where
             cursor_position,
             renderer,
             clipboard,
-            messages,
+            shell,
         ) {
             return event::Status::Captured;
         }
@@ -232,7 +232,7 @@ where
                         self.state.is_pressed = false;
 
                         if bounds.contains(cursor_position) {
-                            messages.push(on_press);
+                            shell.publish(on_press);
                         }
 
                         return event::Status::Captured;
diff --git a/native/src/widget/checkbox.rs b/native/src/widget/checkbox.rs
index 81611426..2af2d60c 100644
--- a/native/src/widget/checkbox.rs
+++ b/native/src/widget/checkbox.rs
@@ -11,7 +11,7 @@ use crate::touch;
 use crate::widget::{self, Row, Text};
 use crate::{
     Alignment, Clipboard, Color, Element, Hasher, Layout, Length, Point,
-    Rectangle, Widget,
+    Rectangle, Shell, Widget,
 };
 
 pub use iced_style::checkbox::{Style, StyleSheet};
@@ -171,7 +171,7 @@ where
         cursor_position: Point,
         _renderer: &Renderer,
         _clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         match event {
             Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
@@ -179,7 +179,7 @@ where
                 let mouse_over = layout.bounds().contains(cursor_position);
 
                 if mouse_over {
-                    messages.push((self.on_toggle)(!self.is_checked));
+                    shell.publish((self.on_toggle)(!self.is_checked));
 
                     return event::Status::Captured;
                 }
diff --git a/native/src/widget/column.rs b/native/src/widget/column.rs
index 0d4d6fa7..4c43c8c8 100644
--- a/native/src/widget/column.rs
+++ b/native/src/widget/column.rs
@@ -8,7 +8,7 @@ use crate::overlay;
 use crate::renderer;
 use crate::{
     Alignment, Clipboard, Element, Hasher, Layout, Length, Padding, Point,
-    Rectangle, Widget,
+    Rectangle, Shell, Widget,
 };
 
 use std::u32;
@@ -146,7 +146,7 @@ where
         cursor_position: Point,
         renderer: &Renderer,
         clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         self.children
             .iter_mut()
@@ -158,7 +158,7 @@ where
                     cursor_position,
                     renderer,
                     clipboard,
-                    messages,
+                    shell,
                 )
             })
             .fold(event::Status::Ignored, event::Status::merge)
diff --git a/native/src/widget/container.rs b/native/src/widget/container.rs
index 596af7fd..756d9d1b 100644
--- a/native/src/widget/container.rs
+++ b/native/src/widget/container.rs
@@ -9,7 +9,7 @@ use crate::overlay;
 use crate::renderer;
 use crate::{
     Background, Clipboard, Color, Element, Hasher, Layout, Length, Padding,
-    Point, Rectangle, Widget,
+    Point, Rectangle, Shell, Widget,
 };
 
 use std::u32;
@@ -167,7 +167,7 @@ where
         cursor_position: Point,
         renderer: &Renderer,
         clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         self.content.widget.on_event(
             event,
@@ -175,7 +175,7 @@ where
             cursor_position,
             renderer,
             clipboard,
-            messages,
+            shell,
         )
     }
 
diff --git a/native/src/widget/image/viewer.rs b/native/src/widget/image/viewer.rs
index 95e5c6e4..0fc766c3 100644
--- a/native/src/widget/image/viewer.rs
+++ b/native/src/widget/image/viewer.rs
@@ -5,8 +5,8 @@ use crate::layout;
 use crate::mouse;
 use crate::renderer;
 use crate::{
-    Clipboard, Element, Hasher, Layout, Length, Point, Rectangle, Size, Vector,
-    Widget,
+    Clipboard, Element, Hasher, Layout, Length, Point, Rectangle, Shell, Size,
+    Vector, Widget,
 };
 
 use std::hash::Hash;
@@ -169,7 +169,7 @@ where
         cursor_position: Point,
         renderer: &Renderer,
         _clipboard: &mut dyn Clipboard,
-        _messages: &mut Vec<Message>,
+        _shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         let bounds = layout.bounds();
         let is_mouse_over = bounds.contains(cursor_position);
diff --git a/native/src/widget/pane_grid.rs b/native/src/widget/pane_grid.rs
index 3637822b..24b87eed 100644
--- a/native/src/widget/pane_grid.rs
+++ b/native/src/widget/pane_grid.rs
@@ -34,8 +34,8 @@ use crate::overlay;
 use crate::renderer;
 use crate::touch;
 use crate::{
-    Clipboard, Color, Element, Hasher, Layout, Length, Point, Rectangle, Size,
-    Vector, Widget,
+    Clipboard, Color, Element, Hasher, Layout, Length, Point, Rectangle, Shell,
+    Size, Vector, Widget,
 };
 
 pub use iced_style::pane_grid::{Line, StyleSheet};
@@ -205,7 +205,7 @@ where
         &mut self,
         layout: Layout<'_>,
         cursor_position: Point,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) {
         let mut clicked_region =
             self.elements.iter().zip(layout.children()).filter(
@@ -214,7 +214,7 @@ where
 
         if let Some(((pane, content), layout)) = clicked_region.next() {
             if let Some(on_click) = &self.on_click {
-                messages.push(on_click(*pane));
+                shell.publish(on_click(*pane));
             }
 
             if let Some(on_drag) = &self.on_drag {
@@ -226,7 +226,7 @@ where
 
                     self.state.pick_pane(pane, origin);
 
-                    messages.push(on_drag(DragEvent::Picked { pane: *pane }));
+                    shell.publish(on_drag(DragEvent::Picked { pane: *pane }));
                 }
             }
         }
@@ -236,7 +236,7 @@ where
         &mut self,
         layout: Layout<'_>,
         cursor_position: Point,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         if let Some((_, on_resize)) = &self.on_resize {
             if let Some((split, _)) = self.state.picked_split() {
@@ -263,7 +263,7 @@ where
                         }
                     };
 
-                    messages.push(on_resize(ResizeEvent { split, ratio }));
+                    shell.publish(on_resize(ResizeEvent { split, ratio }));
 
                     return event::Status::Captured;
                 }
@@ -362,7 +362,7 @@ where
         cursor_position: Point,
         renderer: &Renderer,
         clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         let mut event_status = event::Status::Ignored;
 
@@ -395,15 +395,11 @@ where
                             if let Some((split, axis, _)) = clicked_split {
                                 self.state.pick_split(&split, axis);
                             } else {
-                                self.click_pane(
-                                    layout,
-                                    cursor_position,
-                                    messages,
-                                );
+                                self.click_pane(layout, cursor_position, shell);
                             }
                         }
                         None => {
-                            self.click_pane(layout, cursor_position, messages);
+                            self.click_pane(layout, cursor_position, shell);
                         }
                     }
                 }
@@ -430,7 +426,7 @@ where
                             _ => DragEvent::Canceled { pane },
                         };
 
-                        messages.push(on_drag(event));
+                        shell.publish(on_drag(event));
                     }
 
                     self.state.idle();
@@ -445,7 +441,7 @@ where
             Event::Mouse(mouse::Event::CursorMoved { .. })
             | Event::Touch(touch::Event::FingerMoved { .. }) => {
                 event_status =
-                    self.trigger_resize(layout, cursor_position, messages);
+                    self.trigger_resize(layout, cursor_position, shell);
             }
             _ => {}
         }
@@ -464,7 +460,7 @@ where
                     cursor_position,
                     renderer,
                     clipboard,
-                    messages,
+                    shell,
                     is_picked,
                 )
             })
diff --git a/native/src/widget/pane_grid/content.rs b/native/src/widget/pane_grid/content.rs
index c44506dd..533827b7 100644
--- a/native/src/widget/pane_grid/content.rs
+++ b/native/src/widget/pane_grid/content.rs
@@ -5,7 +5,9 @@ use crate::overlay;
 use crate::renderer;
 use crate::widget::container;
 use crate::widget::pane_grid::TitleBar;
-use crate::{Clipboard, Element, Hasher, Layout, Point, Rectangle, Size};
+use crate::{
+    Clipboard, Element, Hasher, Layout, Point, Rectangle, Shell, Size,
+};
 
 /// The content of a [`Pane`].
 ///
@@ -160,7 +162,7 @@ where
         cursor_position: Point,
         renderer: &Renderer,
         clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
         is_picked: bool,
     ) -> event::Status {
         let mut event_status = event::Status::Ignored;
@@ -174,7 +176,7 @@ where
                 cursor_position,
                 renderer,
                 clipboard,
-                messages,
+                shell,
             );
 
             children.next().unwrap()
@@ -191,7 +193,7 @@ where
                 cursor_position,
                 renderer,
                 clipboard,
-                messages,
+                shell,
             )
         };
 
diff --git a/native/src/widget/pane_grid/title_bar.rs b/native/src/widget/pane_grid/title_bar.rs
index 070cf404..353e1ce9 100644
--- a/native/src/widget/pane_grid/title_bar.rs
+++ b/native/src/widget/pane_grid/title_bar.rs
@@ -5,7 +5,7 @@ use crate::overlay;
 use crate::renderer;
 use crate::widget::container;
 use crate::{
-    Clipboard, Element, Hasher, Layout, Padding, Point, Rectangle, Size,
+    Clipboard, Element, Hasher, Layout, Padding, Point, Rectangle, Shell, Size,
 };
 
 /// The title bar of a [`Pane`].
@@ -218,7 +218,7 @@ where
         cursor_position: Point,
         renderer: &Renderer,
         clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         let mut children = layout.children();
         let padded = children.next().unwrap();
@@ -235,7 +235,7 @@ where
                 cursor_position,
                 renderer,
                 clipboard,
-                messages,
+                shell,
             )
         } else {
             event::Status::Ignored
@@ -247,7 +247,7 @@ where
             cursor_position,
             renderer,
             clipboard,
-            messages,
+            shell,
         );
 
         control_status.merge(title_status)
diff --git a/native/src/widget/pick_list.rs b/native/src/widget/pick_list.rs
index 9d1a86ec..cb781a89 100644
--- a/native/src/widget/pick_list.rs
+++ b/native/src/widget/pick_list.rs
@@ -11,7 +11,7 @@ use crate::text::{self, Text};
 use crate::touch;
 use crate::{
     Clipboard, Element, Hasher, Layout, Length, Padding, Point, Rectangle,
-    Size, Widget,
+    Shell, Size, Widget,
 };
 use std::borrow::Cow;
 
@@ -245,7 +245,7 @@ where
         cursor_position: Point,
         _renderer: &Renderer,
         _clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         match event {
             Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
@@ -271,7 +271,7 @@ where
                 };
 
                 if let Some(last_selection) = self.last_selection.take() {
-                    messages.push((self.on_selected)(last_selection));
+                    shell.publish((self.on_selected)(last_selection));
 
                     *self.is_open = false;
 
@@ -312,7 +312,7 @@ where
                 };
 
                 if let Some(next_option) = next_option {
-                    messages.push((self.on_selected)(next_option.clone()));
+                    shell.publish((self.on_selected)(next_option.clone()));
                 }
 
                 event::Status::Captured
diff --git a/native/src/widget/radio.rs b/native/src/widget/radio.rs
index 86ad4c4e..523773bd 100644
--- a/native/src/widget/radio.rs
+++ b/native/src/widget/radio.rs
@@ -11,7 +11,7 @@ use crate::touch;
 use crate::widget::{self, Row, Text};
 use crate::{
     Alignment, Clipboard, Color, Element, Hasher, Layout, Length, Point,
-    Rectangle, Widget,
+    Rectangle, Shell, Widget,
 };
 
 pub use iced_style::radio::{Style, StyleSheet};
@@ -187,13 +187,13 @@ where
         cursor_position: Point,
         _renderer: &Renderer,
         _clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         match event {
             Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
             | Event::Touch(touch::Event::FingerPressed { .. }) => {
                 if layout.bounds().contains(cursor_position) {
-                    messages.push(self.on_click.clone());
+                    shell.publish(self.on_click.clone());
 
                     return event::Status::Captured;
                 }
diff --git a/native/src/widget/row.rs b/native/src/widget/row.rs
index 6fe3284b..a0174f79 100644
--- a/native/src/widget/row.rs
+++ b/native/src/widget/row.rs
@@ -6,7 +6,7 @@ use crate::overlay;
 use crate::renderer;
 use crate::{
     Alignment, Clipboard, Element, Hasher, Layout, Length, Padding, Point,
-    Rectangle, Widget,
+    Rectangle, Shell, Widget,
 };
 
 use std::hash::Hash;
@@ -145,7 +145,7 @@ where
         cursor_position: Point,
         renderer: &Renderer,
         clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         self.children
             .iter_mut()
@@ -157,7 +157,7 @@ where
                     cursor_position,
                     renderer,
                     clipboard,
-                    messages,
+                    shell,
                 )
             })
             .fold(event::Status::Ignored, event::Status::merge)
diff --git a/native/src/widget/scrollable.rs b/native/src/widget/scrollable.rs
index 2bf2ea5e..fac8af9e 100644
--- a/native/src/widget/scrollable.rs
+++ b/native/src/widget/scrollable.rs
@@ -8,7 +8,7 @@ use crate::touch;
 use crate::widget::Column;
 use crate::{
     Alignment, Background, Clipboard, Color, Element, Hasher, Layout, Length,
-    Padding, Point, Rectangle, Size, Vector, Widget,
+    Padding, Point, Rectangle, Shell, Size, Vector, Widget,
 };
 
 use std::{f32, hash::Hash, u32};
@@ -144,14 +144,14 @@ impl<'a, Message, Renderer: crate::Renderer> Scrollable<'a, Message, Renderer> {
         &self,
         bounds: Rectangle,
         content_bounds: Rectangle,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) {
         if content_bounds.height <= bounds.height {
             return;
         }
 
         if let Some(on_scroll) = &self.on_scroll {
-            messages.push(on_scroll(
+            shell.publish(on_scroll(
                 self.state.offset.absolute(bounds, content_bounds)
                     / (content_bounds.height - bounds.height),
             ));
@@ -251,7 +251,7 @@ where
         cursor_position: Point,
         renderer: &Renderer,
         clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         let bounds = layout.bounds();
         let is_mouse_over = bounds.contains(cursor_position);
@@ -286,7 +286,7 @@ where
                 cursor_position,
                 renderer,
                 clipboard,
-                messages,
+                shell,
             )
         };
 
@@ -307,7 +307,7 @@ where
                         }
                     }
 
-                    self.notify_on_scroll(bounds, content_bounds, messages);
+                    self.notify_on_scroll(bounds, content_bounds, shell);
 
                     return event::Status::Captured;
                 }
@@ -336,7 +336,7 @@ where
                                 self.notify_on_scroll(
                                     bounds,
                                     content_bounds,
-                                    messages,
+                                    shell,
                                 );
                             }
                         }
@@ -377,7 +377,7 @@ where
                             content_bounds,
                         );
 
-                        self.notify_on_scroll(bounds, content_bounds, messages);
+                        self.notify_on_scroll(bounds, content_bounds, shell);
 
                         return event::Status::Captured;
                     }
@@ -409,7 +409,7 @@ where
                             self.notify_on_scroll(
                                 bounds,
                                 content_bounds,
-                                messages,
+                                shell,
                             );
 
                             return event::Status::Captured;
diff --git a/native/src/widget/slider.rs b/native/src/widget/slider.rs
index 3ce53f6c..65632a5c 100644
--- a/native/src/widget/slider.rs
+++ b/native/src/widget/slider.rs
@@ -8,7 +8,7 @@ use crate::renderer;
 use crate::touch;
 use crate::{
     Background, Clipboard, Color, Element, Hasher, Layout, Length, Point,
-    Rectangle, Size, Widget,
+    Rectangle, Shell, Size, Widget,
 };
 
 use std::hash::Hash;
@@ -191,7 +191,7 @@ where
         cursor_position: Point,
         _renderer: &Renderer,
         _clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         let is_dragging = self.state.is_dragging;
 
@@ -220,7 +220,7 @@ where
             };
 
             if (self.value.into() - new_value.into()).abs() > f64::EPSILON {
-                messages.push((self.on_change)(new_value));
+                shell.publish((self.on_change)(new_value));
 
                 self.value = new_value;
             }
@@ -241,7 +241,7 @@ where
             | Event::Touch(touch::Event::FingerLost { .. }) => {
                 if is_dragging {
                     if let Some(on_release) = self.on_release.clone() {
-                        messages.push(on_release);
+                        shell.publish(on_release);
                     }
                     self.state.is_dragging = false;
 
diff --git a/native/src/widget/text_input.rs b/native/src/widget/text_input.rs
index 40c6c573..5e1726db 100644
--- a/native/src/widget/text_input.rs
+++ b/native/src/widget/text_input.rs
@@ -21,7 +21,7 @@ use crate::text::{self, Text};
 use crate::touch;
 use crate::{
     Clipboard, Color, Element, Hasher, Layout, Length, Padding, Point,
-    Rectangle, Size, Vector, Widget,
+    Rectangle, Shell, Size, Vector, Widget,
 };
 
 use std::u32;
@@ -384,7 +384,7 @@ where
         cursor_position: Point,
         renderer: &Renderer,
         clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         match event {
             Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
@@ -509,7 +509,7 @@ where
                 editor.insert(c);
 
                 let message = (self.on_change)(editor.contents());
-                messages.push(message);
+                shell.publish(message);
 
                 return event::Status::Captured;
             }
@@ -521,7 +521,7 @@ where
                 match key_code {
                     keyboard::KeyCode::Enter => {
                         if let Some(on_submit) = self.on_submit.clone() {
-                            messages.push(on_submit);
+                            shell.publish(on_submit);
                         }
                     }
                     keyboard::KeyCode::Backspace => {
@@ -551,7 +551,7 @@ where
                         editor.backspace();
 
                         let message = (self.on_change)(editor.contents());
-                        messages.push(message);
+                        shell.publish(message);
                     }
                     keyboard::KeyCode::Delete => {
                         if platform::is_jump_modifier_pressed(modifiers)
@@ -582,7 +582,7 @@ where
                         editor.delete();
 
                         let message = (self.on_change)(editor.contents());
-                        messages.push(message);
+                        shell.publish(message);
                     }
                     keyboard::KeyCode::Left => {
                         if platform::is_jump_modifier_pressed(modifiers)
@@ -674,7 +674,7 @@ where
                         editor.delete();
 
                         let message = (self.on_change)(editor.contents());
-                        messages.push(message);
+                        shell.publish(message);
                     }
                     keyboard::KeyCode::V => {
                         if self.state.keyboard_modifiers.command() {
@@ -700,7 +700,7 @@ where
                             editor.paste(content.clone());
 
                             let message = (self.on_change)(editor.contents());
-                            messages.push(message);
+                            shell.publish(message);
 
                             self.state.is_pasting = Some(content);
                         } else {
diff --git a/native/src/widget/toggler.rs b/native/src/widget/toggler.rs
index 2dcc3ffe..6cecc7e1 100644
--- a/native/src/widget/toggler.rs
+++ b/native/src/widget/toggler.rs
@@ -10,7 +10,7 @@ use crate::text;
 use crate::widget::{Row, Text};
 use crate::{
     Alignment, Clipboard, Element, Event, Hasher, Layout, Length, Point,
-    Rectangle, Widget,
+    Rectangle, Shell, Widget,
 };
 
 pub use iced_style::toggler::{Style, StyleSheet};
@@ -173,14 +173,14 @@ where
         cursor_position: Point,
         _renderer: &Renderer,
         _clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         match event {
             Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left)) => {
                 let mouse_over = layout.bounds().contains(cursor_position);
 
                 if mouse_over {
-                    messages.push((self.on_toggle)(!self.is_active));
+                    shell.publish((self.on_toggle)(!self.is_active));
 
                     event::Status::Captured
                 } else {
diff --git a/native/src/widget/tooltip.rs b/native/src/widget/tooltip.rs
index c35005e0..79a57824 100644
--- a/native/src/widget/tooltip.rs
+++ b/native/src/widget/tooltip.rs
@@ -11,8 +11,8 @@ use crate::text;
 use crate::widget::container;
 use crate::widget::text::Text;
 use crate::{
-    Clipboard, Element, Event, Hasher, Layout, Length, Padding, Point, Size,
-    Vector, Widget,
+    Clipboard, Element, Event, Hasher, Layout, Length, Padding, Point, Shell,
+    Size, Vector, Widget,
 };
 
 /// An element to display a widget over another.
@@ -130,7 +130,7 @@ where
         cursor_position: Point,
         renderer: &Renderer,
         clipboard: &mut dyn Clipboard,
-        messages: &mut Vec<Message>,
+        shell: &mut Shell<'_, Message>,
     ) -> event::Status {
         self.content.widget.on_event(
             event,
@@ -138,7 +138,7 @@ where
             cursor_position,
             renderer,
             clipboard,
-            messages,
+            shell,
         )
     }