Add resize service

src/services/mod.rs

@@ -9,6 +9,7 @@ pub mod fetch;
 pub mod interval;
 pub mod reader;
 pub mod render;
+pub mod resize;
 pub mod storage;
 pub mod timeout;
 pub mod websocket;
@@ -19,6 +20,7 @@ pub use self::fetch::FetchService;
 pub use self::interval::IntervalService;
 pub use self::reader::ReaderService;
 pub use self::render::RenderService;
+pub use self::resize::ResizeService;
 pub use self::storage::StorageService;
 pub use self::timeout::TimeoutService;
 pub use self::websocket::WebSocketService;

src/services/resize.rs

@@ -0,0 +1,66 @@
+//! This module contains the implementation of a service that listens for browser window resize events.
+use stdweb::Value;
+use yew::callback::Callback;
+use stdweb::{js, web::{window, Window}};
+
+
+/// A service that fires events when the browser window resizes.
+#[derive(Default)]
+pub struct ResizeService {}
+
+/// A handle to the event listener for resize events.
+#[must_use]
+pub struct ResizeTask(Option<Value>);
+
+/// Dimensions of the window.
+pub struct WindowDimensions {
+    /// The width of the viewport of the browser window.
+    pub width: i32,
+    /// The height of the viewport of the browser window.
+    pub height: i32,
+}
+
+impl WindowDimensions {
+    /// Gets the dimensions of the browser window.
+    pub fn get_dimensions(window: &Window) -> Self {
+        WindowDimensions {
+            width: window.inner_width(),
+            height: window.inner_height(),
+        }
+    }
+}
+
+impl ResizeService {
+    /// Creates a new ResizeService.
+    pub fn new() -> ResizeService {
+        ResizeService {}
+    }
+
+    /// Register a callback that will be called when the browser window resizes.
+    pub fn register(&mut self, callback: Callback<WindowDimensions>) -> ResizeTask {
+        let callback = move || {
+            let window = window();
+            let dimensions = WindowDimensions::get_dimensions(&window);
+            callback.emit(dimensions);
+        };
+        let handle = js! {
+            var callback = @{callback};
+            var action = function() {
+                callback();
+            };
+            return window.addEventListener("resize", action);
+        };
+        ResizeTask(Some(handle))
+    }
+}
+
+impl Drop for ResizeTask {
+    fn drop(&mut self) {
+        let handle = self.0.take().expect("Resize task already empty.");
+        js! {
+            @(no_return)
+            var handle = @{handle};
+            handle.callback.drop();
+        }
+    }
+}