Minimum/maximum dimensions for windows in win32 api

src/api/win32/callback.rs

@@ -6,6 +6,7 @@ use std::sync::{Arc, Mutex};
 use std::ffi::OsString;
 use std::os::windows::ffi::OsStringExt;
 
+use WindowAttributes;
 use CursorState;
 use Event;
 use super::event;
@@ -19,10 +20,26 @@ use winapi;
 /// a thread-local variable.
 thread_local!(pub static CONTEXT_STASH: RefCell<Option<ThreadLocalData>> = RefCell::new(None));
 
+/// Contains information about states and the window for the callback.
+#[derive(Clone)]
+pub struct WindowState {
+    pub cursor_state: CursorState,
+    pub attributes: WindowAttributes
+}
+
 pub struct ThreadLocalData {
     pub win: winapi::HWND,
     pub sender: Sender<Event>,
-    pub cursor_state: Arc<Mutex<CursorState>>
+    pub window_state: Arc<Mutex<WindowState>>
+    //pub cursor_state: Arc<Mutex<CursorState>>
+}
+
+struct MinMaxInfo {
+    reserved: winapi::POINT, // Do not use/change
+    max_size: winapi::POINT,
+    max_position: winapi::POINT,
+    min_track: winapi::POINT,
+    max_track: winapi::POINT
 }
 
 /// Checks that the window is the good one, and if so send the event to it.
@@ -240,9 +257,9 @@ pub unsafe extern "system" fn callback(window: winapi::HWND, msg: winapi::UINT,
                 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 {
+                let _window_state = if let Some(cstash) = cstash {
-                    if let Ok(cursor_state) = cstash.cursor_state.lock() {
+                    if let Ok(window_state) = cstash.window_state.lock() {
-                        match *cursor_state {
+                        match window_state.cursor_state {
                             CursorState::Normal => {
                                 user32::SetCursor(user32::LoadCursorW(
                                         ptr::null_mut(),
@@ -281,6 +298,40 @@ pub unsafe extern "system" fn callback(window: winapi::HWND, msg: winapi::UINT,
             0
         },
 
+        winapi::WM_GETMINMAXINFO => {
+            let mut mmi = lparam as *mut MinMaxInfo;
+            //(*mmi).max_position = winapi::POINT { x: -8, y: -8 }; // The upper left corner of the window if it were maximized on the primary monitor.
+            //(*mmi).max_size = winapi::POINT { x: 200, y: 200 }; // The dimensions of the primary monitor.
+
+            CONTEXT_STASH.with(|context_stash| {
+                let cstash = context_stash.borrow();
+                let cstash = cstash.as_ref();
+
+                let _window_state = if let Some(cstash) = cstash {
+                    if let Ok(window_state) = cstash.window_state.lock() {
+                        match window_state.attributes.min_dimensions {
+                            Some((width, height)) => {
+                                (*mmi).min_track = winapi::POINT { x: width as i32, y: height as i32 };
+                            },
+                            None => {
+                                (*mmi).min_track = winapi::POINT { x: 800, y: 600 };
+                            }
+                        }
+
+                        match window_state.attributes.max_dimensions {
+                            Some((width, height)) => {
+                                (*mmi).max_track = winapi::POINT { x: width as i32, y: height as i32 };
+                            },
+                            None => { }
+                        }
+                    }
+                } else {
+                    return
+                };
+            });
+            0
+        },
+
         x if x == *super::WAKEUP_MSG_ID => {
             use events::Event::Awakened;
             send_event(window, Awakened);

src/api/win32/init.rs

@@ -5,6 +5,7 @@ use std::mem;
 use std::thread;
 
 use super::callback;
+use super::callback::WindowState;
 use super::Window;
 use super::MonitorId;
 use super::WindowWrapper;
@@ -215,7 +216,7 @@ unsafe fn init(title: Vec<u16>, window: &WindowAttributes, pf_reqs: &PixelFormat
     }
 
     // Creating a mutex to track the current cursor state
-    let cursor_state = Arc::new(Mutex::new(CursorState::Normal));
+    let cursor_state = CursorState::Normal;
 
     // filling the CONTEXT_STASH task-local storage so that we can start receiving events
     let events_receiver = {
@@ -225,7 +226,10 @@ unsafe fn init(title: Vec<u16>, window: &WindowAttributes, pf_reqs: &PixelFormat
             let data = callback::ThreadLocalData {
                 win: real_window.0,
                 sender: tx.take().unwrap(),
-                cursor_state: cursor_state.clone()
+                window_state: Arc::new(Mutex::new(WindowState {
+                    cursor_state: cursor_state.clone(),
+                    attributes: window.clone()
+                }))
             };
             (*context_stash.borrow_mut()) = Some(data);
         });

src/api/win32/mod.rs

@@ -54,7 +54,7 @@ pub struct Window {
     events_receiver: Receiver<Event>,
 
     /// The current cursor state.
-    cursor_state: Arc<Mutex<CursorState>>,
+    cursor_state: CursorState,
 }
 
 unsafe impl Send for Window {}
@@ -258,14 +258,14 @@ impl Window {
     }
 
     pub fn set_cursor_state(&self, state: CursorState) -> Result<(), String> {
-        let mut current_state = self.cursor_state.lock().unwrap();
+        let mut current_state = self.cursor_state;
 
         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) {
+        let res = match (state, current_state) {
             (CursorState::Normal, CursorState::Normal) => Ok(()),
             (CursorState::Hide, CursorState::Hide) => Ok(()),
             (CursorState::Grab, CursorState::Grab) => Ok(()),
@@ -273,7 +273,7 @@ impl Window {
             (CursorState::Hide, CursorState::Normal) => {
                 unsafe {
                     user32::SetCursor(ptr::null_mut());
-                    *current_state = CursorState::Hide;
+                    current_state = CursorState::Hide;
                     Ok(())
                 }
             },
@@ -281,7 +281,7 @@ impl Window {
             (CursorState::Normal, CursorState::Hide) => {
                 unsafe {
                     user32::SetCursor(user32::LoadCursorW(ptr::null_mut(), winapi::IDC_ARROW));
-                    *current_state = CursorState::Normal;
+                    current_state = CursorState::Normal;
                     Ok(())
                 }
             },
@@ -298,7 +298,7 @@ impl Window {
                     if user32::ClipCursor(&rect) == 0 {
                         return Err(format!("ClipCursor failed"));
                     }
-                    *current_state = CursorState::Grab;
+                    current_state = CursorState::Grab;
                     Ok(())
                 }
             },
@@ -309,7 +309,7 @@ impl Window {
                     if user32::ClipCursor(ptr::null()) == 0 {
                         return Err(format!("ClipCursor failed"));
                     }
-                    *current_state = CursorState::Normal;
+                    current_state = CursorState::Normal;
                     Ok(())
                 }
             },

src/lib.rs

@@ -527,6 +527,16 @@ pub struct WindowAttributes {
     /// The default is `None`.
     pub dimensions: Option<(u32, u32)>,
 
+    /// The minimum dimensions a window can be, If this is `None`, the minimum will be set to 800x600.
+    ///
+    /// The default is `None`.
+    pub min_dimensions: Option<(u32, u32)>,
+
+    /// The maximum dimensions a window can be, If this is `None`, the maximum will be the dimensions of the primary monitor.
+    ///
+    /// The default is `None`.
+    pub max_dimensions: Option<(u32, u32)>,
+
     /// If `Some`, the window will be in fullscreen mode with the given monitor.
     ///
     /// The default is `None`.
@@ -563,6 +573,8 @@ impl Default for WindowAttributes {
     fn default() -> WindowAttributes {
         WindowAttributes {
             dimensions: None,
+            min_dimensions: None,
+            max_dimensions: None,
             monitor: None,
             title: "glutin window".to_owned(),
             visible: true,

src/window.rs

@@ -52,6 +52,24 @@ impl<'a> WindowBuilder<'a> {
         self.window.dimensions = Some((width, height));
         self
     }
+    
+    /// Sets a minimum dimension size for the window
+    ///
+    /// Width and height are in pixels.
+    #[inline]
+    pub fn with_min_dimensions(mut self, width: u32, height: u32) -> WindowBuilder<'a> {
+        self.window.min_dimensions = Some((width, height));
+        self
+    }
+
+    /// Sets a maximum dimension size for the window
+    ///
+    /// Width and height are in pixels.
+    #[inline]
+    pub fn with_max_dimensions(mut self, width: u32, height: u32) -> WindowBuilder<'a> {
+        self.window.max_dimensions = Some((width, height));
+        self
+    }
 
     /// Requests a specific title for the window.
     #[inline]