servo/components/servo/lib.rs

/* 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/. */

/// Servo, the mighty web browser engine from the future.
///
/// This is a very simple library that wires all of Servo's components
/// together as type `Browser`, along with a generic client
/// implementing the `WindowMethods` trait, to create a working web
/// browser.
///
/// The `Browser` type is responsible for configuring a
/// `Constellation`, which does the heavy lifting of coordinating all
/// of Servo's internal subsystems, including the `ScriptTask` and the
/// `LayoutTask`, as well maintains the navigation context.
///
/// The `Browser` is fed events from a generic type that implements the
/// `WindowMethods` trait.

extern crate gaol;
extern crate libc;
#[macro_use]
extern crate util as _util;

mod export {
    extern crate canvas;
    extern crate canvas_traits;
    extern crate compositing;
    extern crate devtools;
    extern crate devtools_traits;
    extern crate euclid;
    extern crate gfx;
    extern crate gleam;
    extern crate ipc_channel;
    extern crate layers;
    extern crate layout;
    extern crate msg;
    extern crate net;
    extern crate net_traits;
    extern crate profile;
    extern crate profile_traits;
    extern crate script;
    extern crate script_traits;
    extern crate style;
    extern crate url;
}

#[cfg(feature = "webdriver")]
extern crate webdriver_server;

#[cfg(feature = "webdriver")]
fn webdriver(port: u16, constellation: Sender<ConstellationMsg>) {
    webdriver_server::start_server(port, constellation);
}

#[cfg(not(feature = "webdriver"))]
fn webdriver(_port: u16, _constellation: Sender<ConstellationMsg>) { }

use compositing::CompositorEventListener;
use compositing::compositor_task::InitialCompositorState;
use compositing::constellation::InitialConstellationState;
use compositing::pipeline::UnprivilegedPipelineContent;
use compositing::sandboxing;
use compositing::windowing::WindowEvent;
use compositing::windowing::WindowMethods;
use compositing::{CompositorProxy, CompositorTask, Constellation};
use gaol::sandbox::{ChildSandbox, ChildSandboxMethods};
use gfx::font_cache_task::FontCacheTask;
use ipc_channel::ipc::{self, IpcSender};
use msg::constellation_msg::CompositorMsg as ConstellationMsg;
use net::image_cache_task::new_image_cache_task;
use net::resource_task::new_resource_task;
use net::storage_task::StorageTaskFactory;
use net_traits::storage_task::StorageTask;
use profile::mem as profile_mem;
use profile::time as profile_time;
use profile_traits::mem;
use profile_traits::time;
use std::borrow::Borrow;
use std::rc::Rc;
use std::sync::mpsc::Sender;
use util::opts;

pub use _util as util;
pub use export::canvas;
pub use export::canvas_traits;
pub use export::compositing;
pub use export::devtools;
pub use export::devtools_traits;
pub use export::euclid;
pub use export::gfx;
pub use export::gleam::gl;
pub use export::ipc_channel;
pub use export::layers;
pub use export::layout;
pub use export::msg;
pub use export::net;
pub use export::net_traits;
pub use export::profile;
pub use export::profile_traits;
pub use export::script;
pub use export::script_traits;
pub use export::style;
pub use export::url;

/// The in-process interface to Servo.
///
/// It does everything necessary to render the web, primarily
/// orchestrating the interaction between JavaScript, CSS layout,
/// rendering, and the client window.
///
/// Clients create a `Browser` for a given reference-counted type
/// implementing `WindowMethods`, which is the bridge to whatever
/// application Servo is embedded in. Clients then create an event
/// loop to pump messages between the embedding application and
/// various browser components.

pub struct Browser {
    compositor: Box<CompositorEventListener + 'static>,
}

impl Browser {
    pub fn new<Window>(window: Option<Rc<Window>>) -> Browser
                       where Window: WindowMethods + 'static {
        // Global configuration options, parsed from the command line.
        let opts = opts::get();

        script::init();

        // Get both endpoints of a special channel for communication between
        // the client window and the compositor. This channel is unique because
        // messages to client may need to pump a platform-specific event loop
        // to deliver the message.
        let (compositor_proxy, compositor_receiver) =
            WindowMethods::create_compositor_channel(&window);
        let supports_clipboard = match window {
            Some(ref win_rc) => {
                let win: &Window = win_rc.borrow();
                win.supports_clipboard()
            }
            None => false
        };
        let time_profiler_chan = profile_time::Profiler::create(opts.time_profiler_period);
        let mem_profiler_chan = profile_mem::Profiler::create(opts.mem_profiler_period);
        let devtools_chan = opts.devtools_port.map(|port| {
            devtools::start_server(port)
        });

        // Create the constellation, which maintains the engine
        // pipelines, including the script and layout threads, as well
        // as the navigation context.
        let constellation_chan = create_constellation(opts.clone(),
                                                      compositor_proxy.clone_compositor_proxy(),
                                                      time_profiler_chan.clone(),
                                                      mem_profiler_chan.clone(),
                                                      devtools_chan,
                                                      supports_clipboard);

        if cfg!(feature = "webdriver") {
            if let Some(port) = opts.webdriver_port {
                webdriver(port, constellation_chan.clone());
            }
        }

        // The compositor coordinates with the client window to create the final
        // rendered page and display it somewhere.
        let compositor = CompositorTask::create(window, InitialCompositorState {
            sender: compositor_proxy,
            receiver: compositor_receiver,
            constellation_chan: constellation_chan,
            time_profiler_chan: time_profiler_chan,
            mem_profiler_chan: mem_profiler_chan,
        });

        Browser {
            compositor: compositor,
        }
    }

    pub fn handle_events(&mut self, events: Vec<WindowEvent>) -> bool {
        self.compositor.handle_events(events)
    }

    pub fn repaint_synchronously(&mut self) {
        self.compositor.repaint_synchronously()
    }

    pub fn pinch_zoom_level(&self) -> f32 {
        self.compositor.pinch_zoom_level()
    }

    pub fn request_title_for_main_frame(&self) {
        self.compositor.title_for_main_frame()
    }
}

fn create_constellation(opts: opts::Opts,
                        compositor_proxy: Box<CompositorProxy + Send>,
                        time_profiler_chan: time::ProfilerChan,
                        mem_profiler_chan: mem::ProfilerChan,
                        devtools_chan: Option<Sender<devtools_traits::DevtoolsControlMsg>>,
                        supports_clipboard: bool) -> Sender<ConstellationMsg> {
    let resource_task = new_resource_task(opts.user_agent.clone(), devtools_chan.clone());

    let image_cache_task = new_image_cache_task(resource_task.clone());
    let font_cache_task = FontCacheTask::new(resource_task.clone());
    let storage_task: StorageTask = StorageTaskFactory::new();

    let initial_state = InitialConstellationState {
        compositor_proxy: compositor_proxy,
        devtools_chan: devtools_chan,
        image_cache_task: image_cache_task,
        font_cache_task: font_cache_task,
        resource_task: resource_task,
        storage_task: storage_task,
        time_profiler_chan: time_profiler_chan,
        mem_profiler_chan: mem_profiler_chan,
        supports_clipboard: supports_clipboard,
    };
    let constellation_chan =
        Constellation::<layout::layout_task::LayoutTask,
                        script::script_task::ScriptTask>::start(initial_state);

    // Send the URL command to the constellation.
    match opts.url {
        Some(url) => {
            constellation_chan.send(ConstellationMsg::InitLoadUrl(url)).unwrap();
        },
        None => ()
    };

    constellation_chan
}

/// Content process entry point.
pub fn run_content_process(token: String) {
    let (unprivileged_content_sender, unprivileged_content_receiver) =
        ipc::channel::<UnprivilegedPipelineContent>().unwrap();
    let connection_bootstrap: IpcSender<IpcSender<UnprivilegedPipelineContent>> =
        IpcSender::connect(token).unwrap();
    connection_bootstrap.send(unprivileged_content_sender).unwrap();

    let unprivileged_content = unprivileged_content_receiver.recv().unwrap();
    opts::set_defaults(unprivileged_content.opts());

    // Enter the sandbox if necessary.
    if opts::get().sandbox {
        ChildSandbox::new(sandboxing::content_process_sandbox_profile()).activate().unwrap();
    }

    script::init();

    unprivileged_content.start_all::<layout::layout_task::LayoutTask,
                                     script::script_task::ScriptTask>(true);
}