Merge pull request #328 from tomaka/grab

Cursor grabbing

3 files changed, 92 insertions, 4 deletions

diff --git a/src/win32/callback.rs b/src/win32/callback.rs
index bbf5b55..1cfb640 100644
--- a/src/win32/callback.rs
+++ b/src/win32/callback.rs
@@ -1,3 +1,4 @@
+use std::mem;
 use std::rc::Rc;
 use std::cell::RefCell;
 use std::sync::mpsc::Sender;
@@ -176,6 +177,26 @@ pub unsafe extern "system" fn callback(window: winapi::HWND, msg: winapi::UINT,
             0
         },
 
+        winapi::WM_INPUT => {
+            let mut data: winapi::RAWINPUT = mem::uninitialized();
+            let mut data_size = mem::size_of::<winapi::RAWINPUT>() as winapi::UINT;
+            user32::GetRawInputData(mem::transmute(lparam), winapi::RID_INPUT,
+                                    mem::transmute(&mut data), &mut data_size,
+                                    mem::size_of::<winapi::RAWINPUTHEADER>() as winapi::UINT);
+
+            if data.header.dwType == winapi::RIM_TYPEMOUSE {
+                let _x = data.mouse.lLastX;  // FIXME: this is not always the relative movement
+                let _y = data.mouse.lLastY;
+                // TODO: 
+                //send_event(window, Event::MouseRawMovement { x: x, y: y });
+
+                0
+
+            } else {
+                user32::DefWindowProcW(window, msg, wparam, lparam)
+            }
+        },
+
         winapi::WM_SETFOCUS => {
             use events::Event::Focused;
             send_event(window, Focused(true));
diff --git a/src/win32/init.rs b/src/win32/init.rs
index 08d54c0..c5e18cc 100644
--- a/src/win32/init.rs
+++ b/src/win32/init.rs
@@ -15,11 +15,13 @@ use Api;
 use BuilderAttribs;
 use CreationError;
 use CreationError::OsError;
+use CursorState;
 use GlRequest;
 use PixelFormat;
 
 use std::ffi::CString;
 use std::sync::mpsc::channel;
+use std::sync::Mutex;
 
 use libc;
 use super::gl;
@@ -250,6 +252,7 @@ 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),
     })
 }
 
@@ -265,7 +268,7 @@ unsafe fn register_window_class() -> Vec<u16> {
         cbWndExtra: 0,
         hInstance: kernel32::GetModuleHandleW(ptr::null()),
         hIcon: ptr::null_mut(),
-        hCursor: ptr::null_mut(),
+        hCursor: ptr::null_mut(),       // must be null in order for cursor state to work properly
         hbrBackground: ptr::null_mut(),
         lpszMenuName: ptr::null(),
         lpszClassName: class_name.as_ptr(),
diff --git a/src/win32/mod.rs b/src/win32/mod.rs
index 41004b3..e20d8b7 100644
--- a/src/win32/mod.rs
+++ b/src/win32/mod.rs
@@ -1,6 +1,8 @@
 use std::sync::atomic::AtomicBool;
+use std::mem;
 use std::ptr;
 use std::ffi::CString;
+use std::sync::Mutex;
 use std::sync::mpsc::Receiver;
 use libc;
 use {CreationError, Event, MouseCursor};
@@ -43,6 +45,9 @@ pub struct Window {
 
     /// True if a `Closed` event has been received.
     is_closed: AtomicBool,
+
+    /// The current cursor state.
+    cursor_state: Mutex<CursorState>,
 }
 
 unsafe impl Send for Window {}
@@ -148,7 +153,6 @@ impl Window {
 
     /// See the docs in the crate root file.
     pub fn get_inner_size(&self) -> Option<(u32, u32)> {
-        use std::mem;
         let mut rect: winapi::RECT = unsafe { mem::uninitialized() };
 
         if unsafe { user32::GetClientRect(self.window.0, &mut rect) } == 0 {
@@ -163,7 +167,6 @@ impl Window {
 
     /// See the docs in the crate root file.
     pub fn get_outer_size(&self) -> Option<(u32, u32)> {
-        use std::mem;
         let mut rect: winapi::RECT = unsafe { mem::uninitialized() };
 
         if unsafe { user32::GetWindowRect(self.window.0, &mut rect) } == 0 {
@@ -257,7 +260,68 @@ impl Window {
     }
 
     pub fn set_cursor_state(&self, state: CursorState) -> Result<(), String> {
-        unimplemented!();
+        let mut current_state = self.cursor_state.lock().unwrap();
+
+        let foreground_thread_id = unsafe { user32::GetWindowThreadProcessId(self.window.0, ptr::null_mut()) };
+        let current_thread_id = unsafe { kernel32::GetCurrentThreadId() };
+
+        unsafe { user32::AttachThreadInput(foreground_thread_id, current_thread_id, 1) };
+
+        let res = match (state, *current_state) {
+            (CursorState::Normal, CursorState::Normal) => Ok(()),
+            (CursorState::Hide, CursorState::Hide) => Ok(()),
+            (CursorState::Grab, CursorState::Grab) => Ok(()),
+
+            (CursorState::Hide, CursorState::Normal) => {
+                unsafe {
+                    user32::SetCursor(ptr::null_mut());
+                    *current_state = CursorState::Hide;
+                    Ok(())
+                }
+            },
+
+            (CursorState::Normal, CursorState::Hide) => {
+                unsafe {
+                    user32::SetCursor(user32::LoadCursorW(ptr::null_mut(), winapi::IDC_ARROW));
+                    *current_state = CursorState::Normal;
+                    Ok(())
+                }
+            },
+
+            (CursorState::Grab, CursorState::Normal) => {
+                unsafe {
+                    user32::SetCursor(ptr::null_mut());
+                    let mut rect = mem::uninitialized();
+                    if user32::GetClientRect(self.window.0, &mut rect) == 0 {
+                        return Err(format!("GetWindowRect failed"));
+                    }
+                    user32::ClientToScreen(self.window.0, mem::transmute(&mut rect.left));
+                    user32::ClientToScreen(self.window.0, mem::transmute(&mut rect.right));
+                    if user32::ClipCursor(&rect) == 0 {
+                        return Err(format!("ClipCursor failed"));
+                    }
+                    *current_state = CursorState::Grab;
+                    Ok(())
+                }
+            },
+
+            (CursorState::Normal, CursorState::Grab) => {
+                unsafe {
+                    user32::SetCursor(user32::LoadCursorW(ptr::null_mut(), winapi::IDC_ARROW));
+                    if user32::ClipCursor(ptr::null()) == 0 {
+                        return Err(format!("ClipCursor failed"));
+                    }
+                    *current_state = CursorState::Normal;
+                    Ok(())
+                }
+            },
+
+            _ => unimplemented!(),
+        };
+
+        unsafe { user32::AttachThreadInput(foreground_thread_id, current_thread_id, 0) };
+
+        res
     }
 
     pub fn hidpi_factor(&self) -> f32 {