1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94

use crate::{event::InternalEvent, *};

use std::ops::Deref;

/// The platform system context provided to the application main thread.

///

/// It is used to allow the application to deal with platform events, and

/// perform actions which must be done on the main thread (eg. creating windows).

///

/// To acquire a context when using `riddle` (the **recommended** approach):

///

/// * ` RiddleLib::context()` returns a `RiddleContext` which implements `Borrow<PlatformContext>`.

/// * ` RiddleLib::run()` passes a `RiddleContext` to the application callback.

///

/// To acquire a context when using this crate directly:

///

/// * [`PlatformMainThreadState::borrow_context()`]

/// * [`PlatformMainThreadState::run`] passes it to application callback

///

/// # Example

///

/// ```no_run

/// use riddle::{*, platform::*};

///

/// fn main() -> Result<(), RiddleError> {

///     let rdl =  RiddleLib::new()?;

///

///     // Get a context before the application starts the main event loop.

///     let window_a: WindowHandle = WindowBuilder::new().build(rdl.context())?;

///     let mut window_b: Option<WindowHandle> = None;

///

///     rdl.run(move |rdl| {

///         if window_b.is_none() {

///             // rdl: RiddleContext, is used to build the second window.

///             window_b = Some(WindowBuilder::new().build(rdl).unwrap());

///         } else {

///             rdl.quit();

///         }

/// #       std::thread::sleep(std::time::Duration::from_secs(1));

///     })

/// }

/// ```

pub struct PlatformContext<'a> {
    pub(crate) main_thread_state: &'a PlatformMainThreadState,
    pub(crate) event_loop: Option<&'a winit::event_loop::EventLoopWindowTarget<InternalEvent>>,
    pub(crate) triggering_event: PlatformEvent,
}

impl<'a> PlatformContext<'a> {
    pub(crate) fn with_event_loop<T, F>(&self, f: F) -> Result<T>
    where
        F: FnOnce(&winit::event_loop::EventLoopWindowTarget<InternalEvent>) -> Result<T>,
    {
        match self.event_loop {
            Some(el) => f(el),
            None => {
                let el_ref = self.main_thread_state.event_loop.borrow();
                let el = el_ref.deref();
                match el {
                    Some(el) => f(el),
                    None => Err(PlatformError::InvalidContextState),
                }
            }
        }
    }

    /// Issue a quit request to the underlying platform system.

    ///

    /// The application will quit when that message is processed by the

    /// main event loop.

    pub fn quit(&self) -> Result<()> {
        self.main_thread_state
            .system
            .event_proxy
            .lock()
            .unwrap()
            .send_event(InternalEvent::QuitRequested)
            .map_err(|_| PlatformError::MessageDispatchError)
    }

    /// Get the event associated with the context.

    ///

    /// This will be the platform event that triggered the application closure, or

    /// [`PlatformEvent::Unknown`] if the context was created before the main event loop

    /// has started.

    pub fn event(&self) -> &PlatformEvent {
        &self.triggering_event
    }

    /// The platform system associated with this context.

    pub fn system(&self) -> &PlatformSystem {
        &self.main_thread_state.system
    }
}