Add command to retrieve window size

runtime/src/window/action.rs

@@ -1,3 +1,7 @@
+
+
+use iced_core::window::SizeType;
+
 use crate::core::window::{Icon, Level, Mode, UserAttention};
 use crate::futures::MaybeSend;
 
@@ -20,6 +24,13 @@ pub enum Action<T> {
         /// The new logical height of the window
         height: u32,
     },
+    /// Fetch the current size of the window.
+    FetchSize {
+        /// Which size to fetch
+        size_type: SizeType,
+        /// Callback function
+        callback: Box<dyn FnOnce((u32, u32)) -> T + 'static>,
+    },
     /// Set the window to maximized or back
     Maximize(bool),
     /// Set the window to minimized or back
@@ -104,6 +115,10 @@ impl<T> Action<T> {
             Self::Close => Action::Close,
             Self::Drag => Action::Drag,
             Self::Resize { width, height } => Action::Resize { width, height },
+            Self::FetchSize { size_type, callback } => Action::FetchSize {
+                size_type: size_type,
+                callback: Box::new(move |s| f(callback(s))),
+            },
             Self::Maximize(maximized) => Action::Maximize(maximized),
             Self::Minimize(minimized) => Action::Minimize(minimized),
             Self::Move { x, y } => Action::Move { x, y },
@@ -131,6 +146,7 @@ impl<T> fmt::Debug for Action<T> {
                 f,
                 "Action::Resize {{ widget: {width}, height: {height} }}"
             ),
+            Self::FetchSize { size_type, .. } => write!(f, "Action::FetchSize {{ size_type: {size_type:?} }}"),
             Self::Maximize(maximized) => {
                 write!(f, "Action::Maximize({maximized})")
             }