Remove the servo- prefix from core components.

src/components/main/scripting/script_task.rs

@@ -0,0 +1,465 @@
+/* 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 script task is the task that owns the DOM in memory, runs JavaScript, and spawns parsing
+/// and layout tasks.
+
+use dom::bindings::utils::GlobalStaticData;
+use dom::document::Document;
+use dom::event::{Event, ResizeEvent, ReflowEvent};
+use dom::node::define_bindings;
+use dom::window::Window;
+use layout::layout_task::{AddStylesheet, BuildData, BuildMsg, Damage, LayoutQuery};
+use layout::layout_task::{LayoutQueryResponse, LayoutTask, MatchSelectorsDamage, NoDamage};
+use layout::layout_task::{QueryMsg, ReflowDamage};
+use layout::layout_task;
+
+use core::cast::transmute;
+use core::cell::Cell;
+use core::comm::{Port, SharedChan};
+use core::io::read_whole_file;
+use core::local_data;
+use core::ptr::null;
+use core::task::{SingleThreaded, task};
+use core::util::replace;
+use dom::window::TimerData;
+use geom::size::Size2D;
+use html::hubbub_html_parser;
+use js::JSVAL_NULL;
+use js::global::{global_class, debug_fns};
+use js::glue::bindgen::RUST_JSVAL_TO_OBJECT;
+use js::jsapi::JSContext;
+use js::jsapi::bindgen::{JS_CallFunctionValue, JS_GetContextPrivate};
+use js::rust::{Compartment, Cx};
+use js;
+use servo_net::image_cache_task::ImageCacheTask;
+use servo_net::resource_task::ResourceTask;
+use servo_util::tree::TreeNodeRef;
+use std::net::url::Url;
+use std::net::url;
+
+/// Messages used to control the script task.
+pub enum ScriptMsg {
+    /// Loads a new URL.
+    LoadMsg(Url),
+    /// Executes a standalone script.
+    ExecuteMsg(Url),
+    /// Sends a DOM event.
+    SendEventMsg(Event),
+    /// Fires a JavaScript timeout.
+    FireTimerMsg(~TimerData),
+    /// Exits the engine.
+    ExitMsg,
+}
+
+/// Encapsulates external communication with the script task.
+pub struct ScriptTask {
+    /// The channel used to send messages to the script task.
+    chan: SharedChan<ScriptMsg>,
+}
+
+impl ScriptTask {
+    /// Creates a new script task.
+    pub fn new(script_port: Port<ScriptMsg>,
+               script_chan: SharedChan<ScriptMsg>,
+               layout_task: LayoutTask,
+               resource_task: ResourceTask,
+               image_cache_task: ImageCacheTask)
+               -> ScriptTask {
+        let (script_chan_copy, script_port) = (script_chan.clone(), Cell(script_port));
+
+        // FIXME: rust#6399
+        let mut the_task = task();
+        the_task.sched_mode(SingleThreaded);
+        do the_task.spawn {
+            let script_context = ScriptContext::new(layout_task.clone(),
+                                                    script_port.take(),
+                                                    script_chan_copy.clone(),
+                                                    resource_task.clone(),
+                                                    image_cache_task.clone());
+            script_context.start();
+        }
+
+        ScriptTask {
+            chan: script_chan
+        }
+    }
+}
+
+/// Information for one frame in the browsing context.
+pub struct Frame {
+    document: @mut Document,
+    window: @mut Window,
+    url: Url,
+}
+
+/// Information for an entire page. Pages are top-level browsing contexts and can contain multiple
+/// frames.
+///
+/// FIXME: Rename to `Page`, following WebKit?
+pub struct ScriptContext {
+    /// A handle to the layout task.
+    layout_task: LayoutTask,
+    /// A handle to the image cache task.
+    image_cache_task: ImageCacheTask,
+    /// A handle to the resource task.
+    resource_task: ResourceTask,
+
+    /// The port that we will use to join layout. If this is `None`, then layout is not currently
+    /// running.
+    layout_join_port: Option<Port<()>>,
+    /// The port on which we receive messages (load URL, exit, etc.)
+    script_port: Port<ScriptMsg>,
+    /// A channel for us to hand out when we want some other task to be able to send us script
+    /// messages.
+    script_chan: SharedChan<ScriptMsg>,
+
+    /// The JavaScript runtime.
+    js_runtime: js::rust::rt,
+    /// The JavaScript context.
+    js_context: @Cx,
+    /// The JavaScript compartment.
+    js_compartment: @mut Compartment,
+
+    /// Global static data related to the DOM.
+    dom_static: GlobalStaticData,
+    /// Whether the JS bindings have been initialized.
+    bindings_initialized: bool,
+
+    /// The outermost frame. This frame contains the document, window, and page URL.
+    root_frame: Option<Frame>,
+
+    /// The current size of the window, in pixels.
+    window_size: Size2D<uint>,
+    /// What parts of layout are dirty.
+    damage: Damage,
+}
+
+fn global_script_context_key(_: @ScriptContext) {}
+
+/// Returns this task's script context singleton.
+pub fn global_script_context() -> @ScriptContext {
+    unsafe {
+        local_data::local_data_get(global_script_context_key).get()
+    }
+}
+
+/// Returns the script context from the JS Context.
+///
+/// FIXME: Rename to `script_context_from_js_context`.
+pub fn task_from_context(js_context: *JSContext) -> *mut ScriptContext {
+    JS_GetContextPrivate(js_context) as *mut ScriptContext
+}
+
+#[unsafe_destructor]
+impl Drop for ScriptContext {
+    fn finalize(&self) {
+        unsafe {
+            let _ = local_data::local_data_pop(global_script_context_key);
+        }
+    }
+}
+
+impl ScriptContext {
+    /// Creates a new script context.
+    pub fn new(layout_task: LayoutTask,
+               script_port: Port<ScriptMsg>,
+               script_chan: SharedChan<ScriptMsg>,
+               resource_task: ResourceTask,
+               img_cache_task: ImageCacheTask)
+               -> @mut ScriptContext {
+        let js_runtime = js::rust::rt();
+        let js_context = js_runtime.cx();
+
+        js_context.set_default_options_and_version();
+        js_context.set_logging_error_reporter();
+
+        let compartment = match js_context.new_compartment(global_class) {
+              Ok(c) => c,
+              Err(()) => fail!("Failed to create a compartment"),
+        };
+
+        let script_context = @mut ScriptContext {
+            layout_task: layout_task,
+            image_cache_task: img_cache_task,
+            resource_task: resource_task,
+
+            layout_join_port: None,
+            script_port: script_port,
+            script_chan: script_chan,
+
+            js_runtime: js_runtime,
+            js_context: js_context,
+            js_compartment: compartment,
+
+            dom_static: GlobalStaticData(),
+            bindings_initialized: false,
+
+            root_frame: None,
+
+            window_size: Size2D(800, 600),
+            damage: MatchSelectorsDamage,
+        };
+        // Indirection for Rust Issue #6248, dynamic freeze scope artifically extended
+        let script_context_ptr = {
+            let borrowed_ctx= &mut *script_context;
+            borrowed_ctx as *mut ScriptContext
+        };
+        js_context.set_cx_private(script_context_ptr as *());
+
+        unsafe {
+            local_data::local_data_set(global_script_context_key, transmute(script_context))
+        }
+
+        script_context
+    }
+
+    /// Starts the script task. After calling this method, the script task will loop receiving
+    /// messages on its port.
+    pub fn start(&mut self) {
+        while self.handle_msg() {
+            // Go on...
+        }
+    }
+
+    /// Handles an incoming control message.
+    fn handle_msg(&mut self) -> bool {
+        match self.script_port.recv() {
+            LoadMsg(url) => {
+                self.load(url);
+                true
+            }
+            ExecuteMsg(url) => {
+                self.handle_execute_msg(url);
+                true
+            }
+            SendEventMsg(event) => {
+                self.handle_event(event);
+                true
+            }
+            FireTimerMsg(timer_data) => {
+                self.handle_fire_timer_msg(timer_data);
+                true
+            }
+            ExitMsg => {
+                self.handle_exit_msg();
+                false
+            }
+        }
+    }
+
+    /// Handles a request to execute a script.
+    fn handle_execute_msg(&self, url: Url) {
+        debug!("script: Received url `%s` to execute", url::to_str(&url));
+
+        match read_whole_file(&Path(url.path)) {
+            Err(msg) => println(fmt!("Error opening %s: %s", url::to_str(&url), msg)),
+
+            Ok(bytes) => {
+                self.js_compartment.define_functions(debug_fns);
+                let _ = self.js_context.evaluate_script(self.js_compartment.global_obj,
+                                                        bytes,
+                                                        copy url.path,
+                                                        1);
+            }
+        }
+    }
+
+    /// Handles a timer that fired.
+    fn handle_fire_timer_msg(&mut self, timer_data: ~TimerData) {
+        let this_value = if timer_data.args.len() > 0 {
+            RUST_JSVAL_TO_OBJECT(timer_data.args[0])
+        } else {
+            self.js_compartment.global_obj.ptr
+        };
+
+        // TODO: Support extra arguments. This requires passing a `*JSVal` array as `argv`.
+        let rval = JSVAL_NULL;
+        JS_CallFunctionValue(self.js_context.ptr,
+                             this_value,
+                             timer_data.funval,
+                             0,
+                             null(),
+                             &rval);
+
+        self.relayout()
+    }
+
+    /// Handles a request to exit the script task and shut down layout.
+    fn handle_exit_msg(&mut self) {
+        self.join_layout();
+        for self.root_frame.each |frame| {
+            frame.document.teardown();
+        }
+        self.layout_task.send(layout_task::ExitMsg)
+    }
+
+    /// 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) {
+        // Define the script DOM bindings.
+        //
+        // FIXME: Can this be done earlier, to save the flag?
+        if !self.bindings_initialized {
+            define_bindings(self.js_compartment);
+            self.bindings_initialized = true
+        }
+
+        // Parse HTML.
+        //
+        // Note: We can parse the next document in parallel with any previous documents.
+        let html_parsing_result = hubbub_html_parser::parse_html(copy url,
+                                                                 self.resource_task.clone(),
+                                                                 self.image_cache_task.clone());
+
+        let root_node = html_parsing_result.root;
+
+        // Send style sheets over to layout.
+        //
+        // FIXME: These should be streamed to layout as they're parsed. We don't need to stop here
+        // in the script task.
+        loop {
+              match html_parsing_result.style_port.recv() {
+                  Some(sheet) => self.layout_task.send(AddStylesheet(sheet)),
+                  None => break,
+              }
+        }
+
+        // Receive the JavaScript scripts.
+        let js_scripts = html_parsing_result.js_port.recv();
+        debug!("js_scripts: %?", js_scripts);
+
+        // Create the window and document objects.
+        let window = Window::new(self.script_chan.clone(), &mut *self);
+        let document = Document(root_node, Some(window));
+
+        // Tie the root into the document.
+        do root_node.with_mut_base |base| {
+            base.add_to_doc(document)
+        }
+
+        // Create the root frame.
+        self.root_frame = Some(Frame {
+            document: document,
+            window: window,
+            url: url
+        });
+
+        // Perform the initial reflow.
+        self.damage.add(MatchSelectorsDamage);
+        self.relayout();
+
+        // Define debug functions.
+        self.js_compartment.define_functions(debug_fns);
+
+        // Evaluate every script in the document.
+        do vec::consume(js_scripts) |_, bytes| {
+            let _ = self.js_context.evaluate_script(self.js_compartment.global_obj,
+                                                    bytes,
+                                                    ~"???",
+                                                    1);
+        }
+    }
+
+    /// Sends a ping to layout and waits for the response. The response will arrive when the
+    /// layout task has finished any pending request messages.
+    fn join_layout(&mut self) {
+        if self.layout_join_port.is_some() {
+            let join_port = replace(&mut self.layout_join_port, None);
+            match join_port {
+                Some(ref join_port) => {
+                    if !join_port.peek() {
+                        info!("script: waiting on layout");
+                    }
+
+                    join_port.recv();
+
+                    debug!("script: layout joined")
+                }
+                None => fail!(~"reader forked but no join port?"),
+            }
+        }
+    }
+
+    /// Initiate an asynchronous relayout operation
+    pub fn trigger_relayout(&mut self, damage: Damage) {
+        self.damage.add(damage);
+        self.relayout();
+    }
+
+    /// This method will wait until the layout task has completed its current action, join the
+    /// layout task, and then request a new layout run. It won't wait for the new layout
+    /// computation to finish.
+    ///
+    /// This function fails if there is no root frame.
+    fn relayout(&mut self) {
+        debug!("script: performing relayout");
+
+        // Now, join the layout so that they will see the latest changes we have made.
+        self.join_layout();
+
+        // Layout will let us know when it's done.
+        let (join_port, join_chan) = comm::stream();
+        self.layout_join_port = Some(join_port);
+
+        match self.root_frame {
+            None => fail!(~"Tried to relayout with no root frame!"),
+            Some(ref root_frame) => {
+                // Send new document and relevant styles to layout.
+                let data = ~BuildData {
+                    node: root_frame.document.root,
+                    url: copy root_frame.url,
+                    script_chan: self.script_chan.clone(),
+                    window_size: self.window_size,
+                    script_join_chan: join_chan,
+                    damage: replace(&mut self.damage, NoDamage),
+                };
+
+                self.layout_task.send(BuildMsg(data))
+            }
+        }
+
+        debug!("script: layout forked")
+    }
+
+    /// Sends the given query to layout.
+    pub fn query_layout(&mut self, query: LayoutQuery) -> LayoutQueryResponse {
+         self.join_layout();
+
+         let (response_port, response_chan) = comm::stream();
+         self.layout_task.send(QueryMsg(query, response_chan));
+         response_port.recv()
+    }
+
+    /// This is the main entry point for receiving and dispatching DOM events.
+    ///
+    /// TODO: Actually perform DOM event dispatch.
+    fn handle_event(&mut self, event: Event) {
+        match event {
+            ResizeEvent(new_width, new_height, response_chan) => {
+                debug!("script got resize event: %u, %u", new_width, new_height);
+
+                self.damage.add(ReflowDamage);
+                self.window_size = Size2D(new_width, new_height);
+
+                if self.root_frame.is_some() {
+                    self.relayout()
+                }
+
+                response_chan.send(())
+            }
+
+            ReflowEvent => {
+                debug!("script got reflow event");
+
+                self.damage.add(MatchSelectorsDamage);
+
+                if self.root_frame.is_some() {
+                    self.relayout()
+                }
+            }
+        }
+    }
+}
+