servo/components/compositing/windowing.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/. */

//! Abstract windowing methods. The concrete implementations of these can be found in `platform/`.

use compositor_task::{CompositorProxy, CompositorReceiver};

use geom::point::TypedPoint2D;
use geom::scale_factor::ScaleFactor;
use geom::size::TypedSize2D;
use layers::geometry::DevicePixel;
use layers::platform::surface::NativeGraphicsMetadata;
use msg::constellation_msg::{Key, KeyState, KeyModifiers};
use script_traits::MouseButton;
use url::Url;
use util::cursor::Cursor;
use util::geometry::ScreenPx;
use std::fmt::{Error, Formatter, Debug};
use std::rc::Rc;

#[derive(Clone)]
pub enum MouseWindowEvent {
    Click(MouseButton, TypedPoint2D<DevicePixel, f32>),
    MouseDown(MouseButton, TypedPoint2D<DevicePixel, f32>),
    MouseUp(MouseButton, TypedPoint2D<DevicePixel, f32>),
}

#[derive(Clone)]
pub enum WindowNavigateMsg {
    Forward,
    Back,
}

/// Events that the windowing system sends to Servo.
#[derive(Clone)]
pub enum WindowEvent {
    /// Sent when no message has arrived, but the event loop was kicked for some reason (perhaps
    /// by another Servo subsystem).
    ///
    /// FIXME(pcwalton): This is kind of ugly and may not work well with multiprocess Servo.
    /// It's possible that this should be something like
    /// `CompositorMessageWindowEvent(compositor_task::Msg)` instead.
    Idle,
    /// Sent when part of the window is marked dirty and needs to be redrawn. Before sending this
    /// message, the window must make the same GL context as in `PrepareRenderingEvent` current.
    Refresh,
    /// Sent to initialize the GL context. The windowing system must have a valid, current GL
    /// context when this message is sent.
    InitializeCompositing,
    /// Sent when the window is resized.
    Resize(TypedSize2D<DevicePixel, u32>),
    /// Sent when a new URL is to be loaded.
    LoadUrl(String),
    /// Sent when a mouse hit test is to be performed.
    MouseWindowEventClass(MouseWindowEvent),
    /// Sent when a mouse move.
    MouseWindowMoveEventClass(TypedPoint2D<DevicePixel, f32>),
    /// Sent when the user scrolls. The first point is the delta and the second point is the
    /// origin.
    Scroll(TypedPoint2D<DevicePixel, f32>, TypedPoint2D<DevicePixel, i32>),
    /// Sent when the user zooms.
    Zoom(f32),
    /// Simulated "pinch zoom" gesture for non-touch platforms (e.g. ctrl-scrollwheel).
    PinchZoom(f32),
    /// Sent when the user uses chrome navigation (i.e. backspace or shift-backspace).
    Navigation(WindowNavigateMsg),
    /// Sent when the user quits the application
    Quit,
    /// Sent when a key input state changes
    KeyEvent(Key, KeyState, KeyModifiers),
}

impl Debug for WindowEvent {
    fn fmt(&self, f: &mut Formatter) -> Result<(),Error> {
        match *self {
            WindowEvent::Idle => write!(f, "Idle"),
            WindowEvent::Refresh => write!(f, "Refresh"),
            WindowEvent::InitializeCompositing => write!(f, "InitializeCompositing"),
            WindowEvent::Resize(..) => write!(f, "Resize"),
            WindowEvent::KeyEvent(..) => write!(f, "Key"),
            WindowEvent::LoadUrl(..) => write!(f, "LoadUrl"),
            WindowEvent::MouseWindowEventClass(..) => write!(f, "Mouse"),
            WindowEvent::MouseWindowMoveEventClass(..) => write!(f, "MouseMove"),
            WindowEvent::Scroll(..) => write!(f, "Scroll"),
            WindowEvent::Zoom(..) => write!(f, "Zoom"),
            WindowEvent::PinchZoom(..) => write!(f, "PinchZoom"),
            WindowEvent::Navigation(..) => write!(f, "Navigation"),
            WindowEvent::Quit => write!(f, "Quit"),
        }
    }
}

pub trait WindowMethods {
    /// Returns the size of the window in hardware pixels.
    fn framebuffer_size(&self) -> TypedSize2D<DevicePixel, u32>;
    /// Returns the size of the window in density-independent "px" units.
    fn size(&self) -> TypedSize2D<ScreenPx, f32>;
    /// Presents the window to the screen (perhaps by page flipping).
    fn present(&self);

    /// Sets the page title for the current page.
    fn set_page_title(&self, title: Option<String>);
    /// Sets the load data for the current page.
    fn set_page_url(&self, url: Url);
    /// Called when the browser is done loading a frame.
    fn load_end(&self);

    /// Returns the hidpi factor of the monitor.
    fn hidpi_factor(&self) -> ScaleFactor<ScreenPx, DevicePixel, f32>;

    /// Gets the OS native graphics information for this window.
    fn native_metadata(&self) -> NativeGraphicsMetadata;

    /// Creates a channel to the compositor. The dummy parameter is needed because we don't have
    /// UFCS in Rust yet.
    ///
    /// This is part of the windowing system because its implementation often involves OS-specific
    /// magic to wake the up window's event loop.
    fn create_compositor_channel(_: &Option<Rc<Self>>)
                                 -> (Box<CompositorProxy+Send>, Box<CompositorReceiver>);

    /// Requests that the window system prepare a composite. Typically this will involve making
    /// some type of platform-specific graphics context current. Returns true if the composite may
    /// proceed and false if it should not.
    fn prepare_for_composite(&self) -> bool;

    /// Sets the cursor to be used in the window.
    fn set_cursor(&self, cursor: Cursor);

    /// Process a key event.
    fn handle_key(&self, key: Key, mods: KeyModifiers);
}