cursor state on w32

src/win32/callback.rs

@@ -1,30 +1,41 @@
 use std::mem;
+use std::ptr;
 use std::rc::Rc;
 use std::cell::RefCell;
 use std::sync::mpsc::Sender;
+use std::sync::{
+    Arc,
+    Mutex
+};
 
+use CursorState;
 use Event;
 use super::event;
 
 use user32;
 use winapi;
 
-/// Stores the current window and its events dispatcher.
-/// 
-/// We only have one window per thread. We still store the HWND in case where we
-///  receive an event for another window.
-thread_local!(pub static WINDOW: Rc<RefCell<Option<(winapi::HWND, Sender<Event>)>>> = Rc::new(RefCell::new(None)));
+/// There's no parameters passed to the callback function, so it needs to get
+/// its context (the HWND, the Sender for events, etc.) stashed in
+/// a thread-local variable.
+thread_local!(pub static CONTEXT_STASH: RefCell<Option<ThreadLocalData>> = RefCell::new(None));
+
+pub struct ThreadLocalData {
+    pub win: winapi::HWND,
+    pub sender: Sender<Event>,
+    pub cursor_state: Arc<Mutex<CursorState>>
+}
 
 /// Checks that the window is the good one, and if so send the event to it.
 fn send_event(input_window: winapi::HWND, event: Event) {
-    WINDOW.with(|window| {
-        let window = window.borrow();
-        let stored = match *window {
+    CONTEXT_STASH.with(|context_stash| {
+        let context_stash = context_stash.borrow();
+        let stored = match *context_stash {
             None => return,
             Some(ref v) => v
         };
 
-        let &(ref win, ref sender) = stored;
+        let &ThreadLocalData { ref win, ref sender, .. } = stored;
 
         if win != &input_window {
             return;
@@ -45,13 +56,15 @@ pub unsafe extern "system" fn callback(window: winapi::HWND, msg: winapi::UINT,
         winapi::WM_DESTROY => {
             use events::Event::Closed;
 
-            WINDOW.with(|w| {
-                let w = w.borrow();
-                let &(ref win, _) = match *w {
+            CONTEXT_STASH.with(|context_stash| {
+                let context_stash = context_stash.borrow();
+                let stored = match *context_stash {
                     None => return,
                     Some(ref v) => v
                 };
 
+                let &ThreadLocalData { ref win, .. } = stored;
+
                 if win == &window {
                     user32::PostQuitMessage(0);
                 }
@@ -209,6 +222,38 @@ pub unsafe extern "system" fn callback(window: winapi::HWND, msg: winapi::UINT,
             0
         },
 
+        winapi::WM_SETCURSOR => {
+            CONTEXT_STASH.with(|context_stash| {
+                let cstash = context_stash.borrow();
+                let cstash = cstash.as_ref();
+                // there's a very bizarre borrow checker bug
+                // possibly related to rust-lang/rust/#23338
+                let cursor_state = if let Some(cstash) = cstash { 
+                    if let Ok(cursor_state) = cstash.cursor_state.lock() {
+                        match *cursor_state {
+                            CursorState::Normal => {
+                                unsafe {
+                                    user32::SetCursor(user32::LoadCursorW(
+                                            ptr::null_mut(),
+                                            winapi::IDC_ARROW));
+                                }
+                            },
+                            CursorState::Grab | CursorState::Hide => {
+                                unsafe {
+                                    user32::SetCursor(ptr::null_mut());
+                                }
+                            }
+                        }
+                    }
+                } else {
+                    return
+                };
+
+//                let &ThreadLocalData { ref cursor_state, .. } = stored;
+            });
+            0
+        },
+
         _ => {
             user32::DefWindowProcW(window, msg, wparam, lparam)
         }

src/win32/init.rs

@@ -1,4 +1,8 @@
 use std::sync::atomic::AtomicBool;
+use std::sync::{
+    Arc,
+    Mutex
+};
 use std::ptr;
 use std::mem;
 use std::os;
@@ -21,7 +25,6 @@ use PixelFormat;
 
 use std::ffi::CString;
 use std::sync::mpsc::channel;
-use std::sync::Mutex;
 
 use libc;
 use super::gl;
@@ -221,12 +224,20 @@ unsafe fn init(title: Vec<u16>, builder: BuilderAttribs<'static>,
         user32::SetForegroundWindow(real_window.0);
     }
 
-    // filling the WINDOW task-local storage so that we can start receiving events
+    // Creating a mutex to track the current cursor state
+    let cursor_state = Arc::new(Mutex::new(CursorState::Normal));
+
+    // filling the CONTEXT_STASH task-local storage so that we can start receiving events
     let events_receiver = {
         let (tx, rx) = channel();
         let mut tx = Some(tx);
-        callback::WINDOW.with(|window| {
-            (*window.borrow_mut()) = Some((real_window.0, tx.take().unwrap()));
+        callback::CONTEXT_STASH.with(|context_stash| {
+            let data = callback::ThreadLocalData {
+                win: real_window.0,
+                sender: tx.take().unwrap(),
+                cursor_state: cursor_state.clone()
+            };
+            (*context_stash.borrow_mut()) = Some(data);
         });
         rx
     };
@@ -252,7 +263,7 @@ unsafe fn init(title: Vec<u16>, builder: BuilderAttribs<'static>,
         gl_library: gl_library,
         events_receiver: events_receiver,
         is_closed: AtomicBool::new(false),
-        cursor_state: Mutex::new(CursorState::Normal),
+        cursor_state: cursor_state,
     })
 }
 

src/win32/mod.rs

@@ -2,7 +2,10 @@ use std::sync::atomic::AtomicBool;
 use std::mem;
 use std::ptr;
 use std::ffi::CString;
-use std::sync::Mutex;
+use std::sync::{
+    Arc,
+    Mutex
+};
 use std::sync::mpsc::Receiver;
 use libc;
 use {CreationError, Event, MouseCursor};
@@ -47,7 +50,7 @@ pub struct Window {
     is_closed: AtomicBool,
 
     /// The current cursor state.
-    cursor_state: Mutex<CursorState>,
+    cursor_state: Arc<Mutex<CursorState>>,
 }
 
 unsafe impl Send for Window {}