Sans UIApplication & UIApplicationDelegate

mod.rs

//! iOS support
//!
//! # Building app
//! To build ios app you will need rustc built for this targets:
//!
//!  - armv7-apple-ios
//!  - armv7s-apple-ios
//!  - i386-apple-ios
//!  - aarch64-apple-ios
//!  - x86_64-apple-ios
//!
//! Then
//!
//! ```
//! cargo build --target=...
//! ```
//! The simplest way to integrate your app into xcode environment is to build it
//! as a static library. Wrap your main function and export it.
//!
//! ```rust, ignore
//! #[no_mangle]
//! pub extern fn start_winit_app() {
//!     start_inner()
//! }
//!
//! fn start_inner() {
//!    ...
//! }
//!
//! ```
//!
//! Compile project and then drag resulting .a into Xcode project. Add winit.h to xcode.
//!
//! ```ignore
//! void start_winit_app();
//! ```
//!
//! Use start_winit_app inside your xcode's main function.
//!
//!
//! # App lifecycle and events
//!
//! iOS environment is very different from other platforms and you must be very
//! careful with it's events. Familiarize yourself with
//! [app lifecycle](https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIApplicationDelegate_Protocol/).
//!
//!
//! This is how those event are represented in winit:
//!
//!  - applicationDidBecomeActive is Focused(true)
//!  - applicationWillResignActive is Focused(false)
//!  - applicationDidEnterBackground is Suspended(true)
//!  - applicationWillEnterForeground is Suspended(false)
//!  - applicationWillTerminate is Destroyed
//!
//! Keep in mind that after Destroyed event is received every attempt to draw with
//! opengl will result in segfault.
//!
//! Also note that app will not receive Destroyed event if suspended, it will be SIGKILL'ed

#![cfg(target_os = "ios")]

use std::cell::RefCell;
use std::collections::VecDeque;
use std::os::raw::*;
use std::sync::Arc;
use std::{fmt, mem, ptr};

use objc::declare::ClassDecl;
use objc::runtime::{Class, Object, Sel, BOOL, YES};

use events::{Touch, TouchPhase};
use window::MonitorId as RootMonitorId;
use {
    CreationError, Event, LogicalPosition, LogicalSize, MouseCursor, PhysicalPosition,
    PhysicalSize, WindowAttributes, WindowEvent, WindowId as RootEventId,
};

mod ffi;
use self::ffi::{
    id, kCFRunLoopDefaultMode, kCFRunLoopRunHandledSource, longjmp, nil, setjmp,
    CFRunLoopRunInMode, CFTimeInterval, CGFloat, CGPoint, CGRect, JmpBuf, NSString,
    UIApplicationMain, JBLEN,
};

static mut JMPBUF: Option<Box<JmpBuf>> = None;

pub struct Window {
    _events_queue: Arc<RefCell<VecDeque<Event>>>,
    delegate_state: Box<DelegateState>,
}

unsafe impl Send for Window {}
unsafe impl Sync for Window {}

#[derive(Debug)]
struct DelegateState {
    window: id,
    size: LogicalSize,
    scale: f64,
}

impl DelegateState {
    fn new(window: id, size: LogicalSize, scale: f64) -> DelegateState {
        DelegateState {
            window,
            size,
            scale,
        }
    }
}

impl Drop for DelegateState {
    fn drop(&mut self) {
        unsafe {
            let _: () = msg_send![self.window, release];
        }
    }
}

#[derive(Clone)]
pub struct MonitorId;

impl fmt::Debug for MonitorId {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        #[derive(Debug)]
        struct MonitorId {
            name: Option<String>,
            dimensions: PhysicalSize,
            position: PhysicalPosition,
            hidpi_factor: f64,
        }

        let monitor_id_proxy = MonitorId {
            name: self.get_name(),
            dimensions: self.get_dimensions(),
            position: self.get_position(),
            hidpi_factor: self.get_hidpi_factor(),
        };

        monitor_id_proxy.fmt(f)
    }
}

impl MonitorId {
    #[inline]
    pub fn get_uiscreen(&self) -> id {
        let class = class!(UIScreen);
        unsafe { msg_send![class, mainScreen] }
    }

    #[inline]
    pub fn get_name(&self) -> Option<String> {
        Some("Primary".to_string())
    }

    #[inline]
    pub fn get_dimensions(&self) -> PhysicalSize {
        let bounds: CGRect = unsafe { msg_send![self.get_uiscreen(), nativeBounds] };
        (bounds.size.width as f64, bounds.size.height as f64).into()
    }

    #[inline]
    pub fn get_position(&self) -> PhysicalPosition {
        // iOS assumes single screen
        (0, 0).into()
    }

    #[inline]
    pub fn get_hidpi_factor(&self) -> f64 {
        let scale: CGFloat = unsafe { msg_send![self.get_uiscreen(), nativeScale] };
        scale as f64
    }
}

pub struct EventsLoop {
    events_queue: Arc<RefCell<VecDeque<Event>>>,
}

#[derive(Clone)]
pub struct EventsLoopProxy;

impl EventsLoop {
    pub fn new() -> EventsLoop {
        unsafe {
            if !msg_send![class!(NSThread), isMainThread] {
                panic!("`EventsLoop` can only be created on the main thread on iOS");
            }
        }
        EventsLoop {
            events_queue: Default::default(),
        }
    }

    #[inline]
    pub fn get_available_monitors(&self) -> VecDeque<MonitorId> {
        let mut rb = VecDeque::with_capacity(1);
        rb.push_back(MonitorId);
        rb
    }

    #[inline]
    pub fn get_primary_monitor(&self) -> MonitorId {
        MonitorId
    }

    pub fn poll_events<F>(&mut self, mut callback: F)
    where
        F: FnMut(::Event),
    {
        if let Some(event) = self.events_queue.borrow_mut().pop_front() {
            callback(event);
            return;
        }

        unsafe {
            // jump hack, so we won't quit on willTerminate event before processing it
            assert!(
                JMPBUF.is_some(),
                "`EventsLoop::poll_events` must be called after window creation on iOS"
            );
            if setjmp(mem::transmute_copy(&mut JMPBUF)) != 0 {
                if let Some(event) = self.events_queue.borrow_mut().pop_front() {
                    callback(event);
                    return;
                }
            }
        }

        unsafe {
            // run runloop
            let seconds: CFTimeInterval = 0.000002;
            while CFRunLoopRunInMode(kCFRunLoopDefaultMode, seconds, 1)
                == kCFRunLoopRunHandledSource
            {}
        }

        if let Some(event) = self.events_queue.borrow_mut().pop_front() {
            callback(event)
        }
    }

    pub fn run_forever<F>(&mut self, mut callback: F)
    where
        F: FnMut(::Event) -> ::ControlFlow,
    {
        // Yeah that's a very bad implementation.
        loop {
            let mut control_flow = ::ControlFlow::Continue;
            self.poll_events(|e| {
                if let ::ControlFlow::Break = callback(e) {
                    control_flow = ::ControlFlow::Break;
                }
            });
            if let ::ControlFlow::Break = control_flow {
                break;
            }
            ::std::thread::sleep(::std::time::Duration::from_millis(5));
        }
    }

    pub fn create_proxy(&self) -> EventsLoopProxy {
        EventsLoopProxy
    }
}

impl EventsLoopProxy {
    pub fn wakeup(&self) -> Result<(), ::EventsLoopClosed> {
        unimplemented!()
    }
}

#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct WindowId;

#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct DeviceId;

#[derive(Clone)]
pub struct PlatformSpecificWindowBuilderAttributes {
    pub root_view_class: &'static Class,
}

impl Default for PlatformSpecificWindowBuilderAttributes {
    fn default() -> Self {
        PlatformSpecificWindowBuilderAttributes {
            root_view_class: class!(UIView),
        }
    }
}

// TODO: AFAIK transparency is enabled by default on iOS,
// so to be consistent with other platforms we have to change that.
impl Window {
    pub fn new(
        ev: &EventsLoop,
        _attributes: WindowAttributes,
        pl_attributes: PlatformSpecificWindowBuilderAttributes,
    ) -> Result<Window, CreationError> {
        unsafe {
            // debug_assert!(mem::size_of_val(&JMPBUF) == mem::size_of::<Box<JmpBuf>>());
            // assert!(
            //     mem::replace(&mut JMPBUF, Some(Box::new([0; JBLEN]))).is_none(),
            //     "Only one `Window` is supported on iOS"
            // );

            let screen_class = class!(UIScreen);
            let window_class = class!(UIWindow);
            let controller_class = class!(UIViewController);
            let color_class = class!(UIColor);
            let green_color: id = msg_send![color_class, greenColor];
            let main_screen: id = msg_send![screen_class, mainScreen];
            let bounds: CGRect = msg_send![main_screen, bounds];
            let scale: CGFloat = msg_send![main_screen, nativeScale];
            let window: id = msg_send![window_class, alloc];
            let window: id = msg_send![window, initWithFrame:bounds.clone()];


            let view_controller: id = msg_send![controller_class, alloc];
            let view_controller: id = msg_send![view_controller, init];

            let _: () = msg_send![window, setRootViewController: view_controller];

            let _: () = msg_send![window, makeKeyAndVisible];
            let _: () = msg_send![window, setBackgroundColor: green_color];
            let size = (bounds.size.width as f64, bounds.size.height as f64).into();
            let delegate_state = Box::new(DelegateState::new(window, size, scale as f64));
            let app_class = class!(UIApplication);
            let app: id = msg_send![app_class, sharedApplication];
            println!("{:?}", app);
            // unsafe {
            //     if setjmp(mem::transmute_copy(&mut JMPBUF)) != 0 {
            //         let app_class = class!(UIApplication);
            //         let app: id = msg_send![app_class, sharedApplication];
            //         let delegate: id = msg_send![app, delegate];
            //         let state: *mut c_void = *(&*delegate).get_ivar("winitState");
            //         let mut delegate_state = Box::from_raw(state as *mut DelegateState);
            //         let events_queue = &*ev.events_queue;
            //         (&mut *delegate).set_ivar("eventsQueue", mem::transmute::<_, *mut c_void>(events_queue));

            //         // easiest? way to get access to PlatformSpecificWindowBuilderAttributes to configure the view
            //         let rect: CGRect = msg_send![MonitorId.get_uiscreen(), bounds];

            //         let uiview_class = class!(UIView);
            //         let root_view_class = pl_attributes.root_view_class;
            //         let is_uiview: BOOL = msg_send![root_view_class, isSubclassOfClass:uiview_class];
            //         assert!(is_uiview == YES, "`root_view_class` must inherit from `UIView`");

            //         delegate_state.view = msg_send![root_view_class, alloc];
            //         assert!(!delegate_state.view.is_null(), "Failed to create `UIView` instance");
            //         delegate_state.view = msg_send![delegate_state.view, initWithFrame:rect];
            //         assert!(!delegate_state.view.is_null(), "Failed to initialize `UIView` instance");

            //         let _: () = msg_send![delegate_state.controller, setView:delegate_state.view];
            //         let _: () = msg_send![delegate_state.window, makeKeyAndVisible];

            return Ok(Window {
                _events_queue: ev.events_queue.clone(),
                delegate_state,
            });
        }
        //     }
        // }

        // // create_delegate_class();
        // // start_app();

        // panic!("Couldn't create `UIApplication`!")
    }

    #[inline]
    pub fn get_uiwindow(&self) -> id {
        self.delegate_state.window
    }

    #[inline]
    pub fn get_uiview(&self) -> id {
        self.delegate_state.window
    }

    #[inline]
    pub fn set_title(&self, _title: &str) {
        // N/A
    }

    #[inline]
    pub fn show(&self) {
        // N/A
    }

    #[inline]
    pub fn hide(&self) {
        // N/A
    }

    #[inline]
    pub fn get_position(&self) -> Option<LogicalPosition> {
        // N/A
        None
    }

    #[inline]
    pub fn get_inner_position(&self) -> Option<LogicalPosition> {
        // N/A
        None
    }

    #[inline]
    pub fn set_position(&self, _position: LogicalPosition) {
        // N/A
    }

    #[inline]
    pub fn get_inner_size(&self) -> Option<LogicalSize> {
        Some(self.delegate_state.size)
    }

    #[inline]
    pub fn get_outer_size(&self) -> Option<LogicalSize> {
        self.get_inner_size()
    }

    #[inline]
    pub fn set_inner_size(&self, _size: LogicalSize) {
        // N/A
    }

    #[inline]
    pub fn set_min_dimensions(&self, _dimensions: Option<LogicalSize>) {
        // N/A
    }

    #[inline]
    pub fn set_max_dimensions(&self, _dimensions: Option<LogicalSize>) {
        // N/A
    }

    #[inline]
    pub fn set_resizable(&self, _resizable: bool) {
        // N/A
    }

    #[inline]
    pub fn set_cursor(&self, _cursor: MouseCursor) {
        // N/A
    }

    #[inline]
    pub fn grab_cursor(&self, _grab: bool) -> Result<(), String> {
        Err("Cursor grabbing is not possible on iOS.".to_owned())
    }

    #[inline]
    pub fn hide_cursor(&self, _hide: bool) {
        // N/A
    }

    #[inline]
    pub fn get_hidpi_factor(&self) -> f64 {
        self.delegate_state.scale
    }

    #[inline]
    pub fn set_cursor_position(&self, _position: LogicalPosition) -> Result<(), String> {
        Err("Setting cursor position is not possible on iOS.".to_owned())
    }

    #[inline]
    pub fn set_maximized(&self, _maximized: bool) {
        // N/A
        // iOS has single screen maximized apps so nothing to do
    }

    #[inline]
    pub fn set_fullscreen(&self, _monitor: Option<RootMonitorId>) {
        // N/A
        // iOS has single screen maximized apps so nothing to do
    }

    #[inline]
    pub fn set_decorations(&self, _decorations: bool) {
        // N/A
    }

    #[inline]
    pub fn set_always_on_top(&self, _always_on_top: bool) {
        // N/A
    }

    #[inline]
    pub fn set_window_icon(&self, _icon: Option<::Icon>) {
        // N/A
    }

    #[inline]
    pub fn set_ime_spot(&self, _logical_spot: LogicalPosition) {
        // N/A
    }

    #[inline]
    pub fn get_current_monitor(&self) -> RootMonitorId {
        RootMonitorId { inner: MonitorId }
    }

    #[inline]
    pub fn get_available_monitors(&self) -> VecDeque<MonitorId> {
        let mut rb = VecDeque::with_capacity(1);
        rb.push_back(MonitorId);
        rb
    }

    #[inline]
    pub fn get_primary_monitor(&self) -> MonitorId {
        MonitorId
    }

    #[inline]
    pub fn id(&self) -> WindowId {
        WindowId
    }
}

// Constant device ID, to be removed when this backend is updated to report real device IDs.
const DEVICE_ID: ::DeviceId = ::DeviceId(DeviceId);