Cleaning up main; Added window module

Adds a wrapper for the glutin::Window which provides strongly typed
APIs and more convenient interfaces. Moves some gl calls into the
opengl-based renderer.

The point of most of the changes here is to clean up main().

1 files changed, 299 insertions, 0 deletions

diff --git a/src/window.rs b/src/window.rs
new file mode 100644
index 00000000..c1790bb6
--- /dev/null
+++ b/src/window.rs
@@ -0,0 +1,299 @@
+// Copyright 2016 Joe Wilm, The Alacritty Project Contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+use std::convert::From;
+use std::fmt::{self, Display};
+use std::ops::Deref;
+
+use gl;
+use glutin;
+
+/// Default title for the window
+const DEFAULT_TITLE: &'static str = "Alacritty";
+
+/// Resize handling for Mac and maybe other platforms
+///
+/// This delegates to a statically referenced closure for convenience. The
+/// C-style callback doesn't receive a pointer or anything, so we are forced to
+/// use static storage.
+///
+/// This will fail horribly if more than one window is created. Don't do that :)
+fn window_resize_handler(width: u32, height: u32) {
+    unsafe {
+        RESIZE_CALLBACK.as_ref().map(|func| func(width, height));
+    }
+}
+
+/// The resize callback invoked by `window_resize_handler`
+static mut RESIZE_CALLBACK: Option<Box<Fn(u32, u32)>> = None;
+
+/// Window errors
+#[derive(Debug)]
+pub enum Error {
+    /// Error creating the window
+    Creation(glutin::CreationError),
+
+    /// Error manipulating the rendering context
+    Context(glutin::ContextError),
+}
+
+/// Result of fallible operations concerning a Window.
+type Result<T> = ::std::result::Result<T, Error>;
+
+/// A window which can be used for displaying the terminal
+///
+/// Wraps the underlying windowing library to provide a stable API in Alacritty
+pub struct Window {
+    glutin_window: glutin::Window,
+}
+
+/// Threadsafe APIs for the window
+pub struct Proxy(glutin::WindowProxy);
+
+/// Information about where the window is being displayed
+///
+/// Useful for subsystems like the font rasterized which depend on DPI and scale
+/// factor.
+pub struct DeviceProperties {
+    /// Scale factor for pixels <-> points.
+    ///
+    /// This will be 1. on standard displays and may have a different value on
+    /// hidpi displays.
+    pub scale_factor: f32,
+}
+
+/// Size of the window
+#[derive(Debug, Copy, Clone)]
+pub struct Size<T> {
+    pub width: T,
+    pub height: T,
+}
+
+/// Strongly typed Pixels unit
+#[derive(Debug, Copy, Clone)]
+pub struct Pixels<T>(pub T);
+
+/// Strongly typed Points unit
+///
+/// Points are like pixels but adjusted for DPI.
+#[derive(Debug, Copy, Clone)]
+pub struct Points<T>(pub T);
+
+pub trait ToPoints {
+    fn to_points(&self, scale: f32) -> Size<Points<u32>>;
+}
+
+impl ToPoints for Size<Points<u32>> {
+    #[inline]
+    fn to_points(&self, _scale: f32) -> Size<Points<u32>> {
+        *self
+    }
+}
+
+impl ToPoints for Size<Pixels<u32>> {
+    fn to_points(&self, scale: f32) -> Size<Points<u32>> {
+        let width_pts = (*self.width as f32 / scale) as u32;
+        let height_pts = (*self.height as f32 / scale) as u32;
+
+        Size {
+            width: Points(width_pts),
+            height: Points(height_pts)
+        }
+    }
+}
+
+impl<T: Display> Display for Size<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{} × {}", self.width, self.height)
+    }
+}
+
+macro_rules! deref_newtype {
+    ($($src:ty),+) => {
+        $(
+        impl<T> Deref for $src {
+            type Target = T;
+
+            #[inline]
+            fn deref(&self) -> &Self::Target {
+                &self.0
+            }
+        }
+        )+
+    }
+}
+
+deref_newtype! { Points<T>, Pixels<T> }
+
+
+impl<T: Display> Display for Pixels<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}px", self.0)
+    }
+}
+
+impl ::std::error::Error for Error {
+    fn cause(&self) -> Option<&::std::error::Error> {
+        match *self {
+            Error::Creation(ref err) => Some(err),
+            Error::Context(ref err) => Some(err),
+        }
+    }
+
+    fn description(&self) -> &str {
+        match *self {
+            Error::Creation(ref _err) => "Error creating glutin Window",
+            Error::Context(ref _err) => "Error operating on render context",
+        }
+    }
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        match *self {
+            Error::Creation(ref err) => {
+                write!(f, "Error creating glutin::Window; {}", err)
+            },
+            Error::Context(ref err) => {
+                write!(f, "Error operating on render context; {}", err)
+            },
+        }
+    }
+}
+
+impl From<glutin::CreationError> for Error {
+    fn from(val: glutin::CreationError) -> Error {
+        Error::Creation(val)
+    }
+}
+
+impl From<glutin::ContextError> for Error {
+    fn from(val: glutin::ContextError) -> Error {
+        Error::Context(val)
+    }
+}
+
+impl Window {
+    /// Create a new window
+    ///
+    /// This creates a window and fully initializes a window.
+    pub fn new() -> Result<Window> {
+        /// Create a glutin::Window
+        let mut window = glutin::WindowBuilder::new()
+            .with_vsync()
+            .with_title(DEFAULT_TITLE)
+            .build()?;
+
+        /// Set the glutin window resize callback for *this* window. The
+        /// function pointer must be a C-style callback. This sets such a
+        /// callback which simply delegates to a statically referenced Rust
+        /// closure.
+        window.set_window_resize_callback(Some(window_resize_handler as fn(u32, u32)));
+
+        /// Set OpenGL symbol loader
+        gl::load_with(|symbol| window.get_proc_address(symbol) as *const _);
+
+        /// Make the window's context current so OpenGL operations can run
+        unsafe {
+            window.make_current()?;
+        }
+
+        Ok(Window {
+            glutin_window: window,
+        })
+    }
+
+    /// Get some properties about the device
+    ///
+    /// Some window properties are provided since subsystems like font
+    /// rasterization depend on DPI and scale factor.
+    pub fn device_properties(&self) -> DeviceProperties {
+        DeviceProperties {
+            scale_factor: self.glutin_window.hidpi_factor(),
+        }
+    }
+
+    /// Set the window resize callback
+    ///
+    /// Pass a `move` closure which will be called with the new width and height
+    /// when the window is resized. According to the glutin docs, this can be
+    /// used to draw during resizing.
+    ///
+    /// This method takes self mutably to ensure there's no race condition
+    /// setting the callback.
+    pub fn set_resize_callback<F: Fn(u32, u32) + 'static>(&mut self, func: F) {
+        unsafe {
+            RESIZE_CALLBACK = Some(Box::new(func));
+        }
+    }
+
+    pub fn inner_size_pixels(&self) -> Option<Size<Pixels<u32>>> {
+        self.glutin_window
+            .get_inner_size_pixels()
+            .map(|(w, h)| Size { width: Pixels(w), height: Pixels(h) })
+    }
+
+    #[inline]
+    pub fn hidpi_factor(&self) -> f32 {
+        self.glutin_window.hidpi_factor()
+    }
+
+    #[inline]
+    pub fn create_window_proxy(&self) -> Proxy {
+        Proxy(self.glutin_window.create_window_proxy())
+    }
+
+    #[inline]
+    pub fn swap_buffers(&self) -> Result<()> {
+        self.glutin_window
+            .swap_buffers()
+            .map_err(From::from)
+    }
+
+    /// Block waiting for events
+    ///
+    /// FIXME should return our own type
+    #[inline]
+    pub fn wait_events(&self) -> glutin::WaitEventsIterator {
+        self.glutin_window.wait_events()
+    }
+
+    /// Block waiting for events
+    ///
+    /// FIXME should return our own type
+    #[inline]
+    pub fn poll_events(&self) -> glutin::PollEventsIterator {
+        self.glutin_window.poll_events()
+    }
+}
+
+impl Proxy {
+    /// Wakes up the event loop of the window
+    ///
+    /// This is useful for triggering a draw when the renderer would otherwise
+    /// be waiting on user input.
+    pub fn wakeup_event_loop(&self) {
+        self.0.wakeup_event_loop();
+    }
+}
+
+pub trait SetInnerSize<T> {
+    fn set_inner_size<S: ToPoints>(&mut self, size: S);
+}
+
+impl SetInnerSize<Pixels<u32>> for Window {
+    fn set_inner_size<T: ToPoints>(&mut self, size: T) {
+        let size = size.to_points(self.hidpi_factor());
+        self.glutin_window.set_inner_size(*size.width as _, *size.height as _);
+    }
+}