Send status messages to the compositor

src/components/main/compositing/mod.rs

@@ -9,6 +9,8 @@ use windowing::{ApplicationMethods, WindowMethods, WindowMouseEvent, WindowClick
 use windowing::{WindowMouseDownEvent, WindowMouseUpEvent};
 
 use script::dom::event::{Event, ClickEvent, MouseDownEvent, MouseUpEvent};
+use script::compositor_interface::{ReadyState, CompositorInterface};
+use script::compositor_interface;
 
 use azure::azure_hl::{DataSourceSurface, DrawTarget, SourceSurfaceMethods};
 use core::cell::Cell;
@@ -36,6 +38,13 @@ pub struct CompositorTask {
     chan: SharedChan<Msg>,
 }
 
+impl CompositorInterface for CompositorTask {
+    fn send_compositor_msg(&self, msg: ReadyState) {
+        let msg = ChangeReadyState(msg);
+        self.chan.send(msg);
+    }
+}
+
 impl CompositorTask {
     /// Starts the compositor. Returns an interface that can be used to communicate with the
     /// compositor and a port which allows notification when the compositor shuts down.
@@ -63,10 +72,12 @@ impl CompositorTask {
 
 /// Messages to the compositor.
 pub enum Msg {
-    /// Requests that the compositor paint the given layer buffer set for the given page size.
-    Paint(LayerBufferSet, Size2D<uint>),
     /// Requests that the compositor shut down.
     Exit,
+    /// Requests that the compositor paint the given layer buffer set for the given page size.
+    Paint(LayerBufferSet, Size2D<uint>),
+    /// Alerts the compositor to the current status of page loading
+    ChangeReadyState(ReadyState),
 }
 
 /// Azure surface wrapping to work with the layers infrastructure.
@@ -134,12 +145,19 @@ fn run_main_loop(port: Port<Msg>,
     let check_for_messages: @fn() = || {
         // Periodically check if the script task responded to our last resize event
         resize_rate_limiter.check_resize_response();
-
         // Handle messages
         while port.peek() {
             match port.recv() {
                 Exit => *done = true,
 
+                ChangeReadyState(ready_state) => {
+                    let window_title = match ready_state {
+                        compositor_interface::FinishedLoading => ~"Servo",
+                        _ => fmt!("%? — Servo", ready_state),
+                    };
+                    window.set_title(window_title);
+                }
+
                 Paint(new_layer_buffer_set, new_size) => {
                     debug!("osmain: received new frame");
 

src/components/main/engine.rs

@@ -10,6 +10,7 @@ use core::comm::{Port, SharedChan};
 use gfx::opts::Opts;
 use gfx::render_task::RenderTask;
 use gfx::render_task;
+use script::compositor_interface::{CompositorInterface, ReadyState};
 use script::engine_interface::{EngineTask, ExitMsg, LoadUrlMsg, Msg};
 use script::layout_interface::LayoutTask;
 use script::layout_interface;
@@ -48,13 +49,15 @@ impl Engine {
                  profiler_chan: ProfilerChan)
                  -> EngineTask {
         let (script_port, script_chan) = (Cell(script_port), Cell(script_chan));
-        let (request_port, request_chan) = comm::stream();
+        let (engine_port, engine_chan) = comm::stream();
-        let (request_port, request_chan) = (Cell(request_port), SharedChan::new(request_chan));
+        let (engine_port, engine_chan) = (Cell(engine_port), SharedChan::new(engine_chan));
-        let request_chan_clone = request_chan.clone();
+        let engine_chan_clone = engine_chan.clone();
+        let compositor = Cell(compositor);
         let profiler_port = Cell(profiler_port);
         let opts = Cell(copy *opts);
 
         do task::spawn {
+            let compositor = compositor.take();
             let render_task = RenderTask::new(compositor.clone(),
                                               opts.with_ref(|o| copy *o),
                                               profiler_chan.clone());
@@ -70,16 +73,20 @@ impl Engine {
                                                               opts,
                                                               profiler_task.chan.clone());
 
+            let compositor_clone = compositor.clone();
             let script_task = ScriptTask::new(script_port.take(),
                                               script_chan.take(),
-                                              request_chan_clone.clone(),
+                                              engine_chan_clone.clone(),
+                                              |msg: ReadyState| {
+                                                  compositor_clone.send_compositor_msg(msg)
+                                              },
                                               layout_task.clone(),
                                               resource_task.clone(),
                                               image_cache_task.clone());
 
 
             Engine {
-                request_port: request_port.take(),
+                request_port: engine_port.take(),
                 compositor: compositor.clone(),
                 render_task: render_task,
                 resource_task: resource_task.clone(),
@@ -89,7 +96,7 @@ impl Engine {
                 profiler_task: profiler_task,
             }.run();
         }
-        request_chan.clone()
+        engine_chan.clone()
     }
 
     fn run(&self) {

src/components/main/platform/common/glut_windowing.rs

@@ -162,6 +162,10 @@ impl WindowMethods<Application> for Window {
     pub fn set_needs_display(@mut self) {
         glut::post_redisplay()
     }
+
+    pub fn set_title(@mut self, title: &str) {
+        glut::set_window_title(self.glut_window, title);
+    }
 }
 
 impl Window {

src/components/main/windowing.rs

@@ -61,5 +61,7 @@ pub trait WindowMethods<A> {
     pub fn check_loop(@mut self);
     /// Schedules a redisplay at the next turn of the event loop.
     pub fn set_needs_display(@mut self);
+    /// Sets the title of the window
+    pub fn set_title(@mut self, title: &str);
 }
 

src/components/script/compositor_interface.rs

@@ -0,0 +1,19 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! The high-level interface from script to compositor. Using this abstract interface helps reduce
+/// coupling between these two components
+
+pub enum ReadyState {
+    /// Informs the compositor that a page is loading. Used for setting status
+    Loading,
+    /// Informs the compositor that a page is rendering. Used for setting status
+    Rendering,
+    /// Informs the compositor that a page is finished loading. Used for setting status
+    FinishedLoading,
+}
+
+pub trait CompositorInterface: Clone {
+    fn send_compositor_msg(&self, ReadyState);
+}

src/components/script/dom/window.rs

@@ -4,6 +4,7 @@
 
 use dom::bindings::utils::WrapperCache;
 use dom::bindings::window;
+
 use layout_interface::ReflowForScriptQuery;
 use script_task::{ExitMsg, FireTimerMsg, ScriptMsg, ScriptContext};
 

src/components/script/script.rc

@@ -64,7 +64,8 @@ pub mod html {
     pub mod hubbub_html_parser;
 }
 
-pub mod layout_interface;
+pub mod compositor_interface;
 pub mod engine_interface;
+pub mod layout_interface;
 pub mod script_task;
 

src/components/script/script_task.rs

@@ -5,6 +5,7 @@
 /// The script task is the task that owns the DOM in memory, runs JavaScript, and spawns parsing
 /// and layout tasks.
 
+use compositor_interface::{ReadyState, Loading, Rendering, FinishedLoading};
 use dom::bindings::utils::GlobalStaticData;
 use dom::document::Document;
 use dom::element::Element;
@@ -68,12 +69,14 @@ impl ScriptTask {
     pub fn new(script_port: Port<ScriptMsg>,
                script_chan: SharedChan<ScriptMsg>,
                engine_task: EngineTask,
+               //FIXME(rust #5192): workaround for lack of working ~Trait
+               compositor_task: ~fn(ReadyState),
                layout_task: LayoutTask,
                resource_task: ResourceTask,
                image_cache_task: ImageCacheTask)
                -> ScriptTask {
         let (script_chan_copy, script_port) = (script_chan.clone(), Cell(script_port));
-
+        let compositor_task = Cell(compositor_task);
         // FIXME: rust#6399
         let mut the_task = task();
         the_task.sched_mode(SingleThreaded);
@@ -82,6 +85,7 @@ impl ScriptTask {
                                                     script_port.take(),
                                                     script_chan_copy.clone(),
                                                     engine_task.clone(),
+                                                    compositor_task.take(),
                                                     resource_task.clone(),
                                                     image_cache_task.clone());
             script_context.start();
@@ -123,6 +127,8 @@ pub struct ScriptContext {
 
     /// For communicating load url messages to the engine
     engine_task: EngineTask,
+    /// For communicating loading messages to the compositor
+    compositor_task: ~fn(ReadyState),
 
     /// The JavaScript runtime.
     js_runtime: js::rust::rt,
@@ -176,6 +182,7 @@ impl ScriptContext {
                script_port: Port<ScriptMsg>,
                script_chan: SharedChan<ScriptMsg>,
                engine_task: EngineTask,
+               compositor_task: ~fn(ReadyState),
                resource_task: ResourceTask,
                img_cache_task: ImageCacheTask)
                -> @mut ScriptContext {
@@ -200,6 +207,7 @@ impl ScriptContext {
             script_chan: script_chan,
 
             engine_task: engine_task,
+            compositor_task: compositor_task,
 
             js_runtime: js_runtime,
             js_context: js_context,
@@ -308,6 +316,12 @@ impl ScriptContext {
         self.layout_task.chan.send(layout_interface::ExitMsg)
     }
 
+    // tells the compositor when loading starts and finishes
+    // FIXME ~compositor_interface doesn't work right now, which is why this is necessary
+    fn send_compositor_msg(&self, msg: ReadyState) {
+        (self.compositor_task)(msg);
+    }
+
     /// The entry point to document loading. Defines bindings, sets up the window and document
     /// objects, parses HTML and CSS, and kicks off initial layout.
     fn load(&mut self, url: Url) {
@@ -319,6 +333,7 @@ impl ScriptContext {
             self.bindings_initialized = true
         }
 
+        self.send_compositor_msg(Loading);
         // Parse HTML.
         //
         // Note: We can parse the next document in parallel with any previous documents.
@@ -359,6 +374,7 @@ impl ScriptContext {
             url: url
         });
 
+        self.send_compositor_msg(Rendering);
         // Perform the initial reflow.
         self.damage = Some(DocumentDamage {
             root: root_node,
@@ -376,6 +392,7 @@ impl ScriptContext {
                                                     ~"???",
                                                     1);
         }
+        self.send_compositor_msg(FinishedLoading);
     }
 
     /// Sends a ping to layout and waits for the response. The response will arrive when the