[Windows] Adjust min_dimensions and max_dimensions using AdjustWindowRectEx.

CHANGELOG.md

@@ -16,6 +16,7 @@
 - Fixed thread safety issues with input methods on X11.
 - Add support for `Touch` for win32 backend.
 - Fixed `Window::get_inner_size` and friends to return the size in pixels instead of points when using HIDPI displays on OSX.
+- Properly calculate the minimum and maximum window size on Windows, including window decorations.
 
 # Version 0.11.3 (2018-03-28)
 

src/platform/windows/events_loop.rs

@@ -33,6 +33,7 @@ use winapi::um::{winuser, shellapi, processthreadsapi};
 use winapi::um::winnt::LONG;
 
 use platform::platform::event;
+use platform::platform::window::adjust_size;
 use platform::platform::Cursor;
 use platform::platform::WindowId;
 use platform::platform::DEVICE_ID;
@@ -898,18 +899,20 @@ pub unsafe extern "system" fn callback(window: HWND, msg: UINT,
                     if let Some(wstash) = cstash.windows.get(&window) {
                         let window_state = wstash.lock().unwrap();
 
-                        match window_state.attributes.min_dimensions {
-                            Some((width, height)) => {
-                                (*mmi).ptMinTrackSize = POINT { x: width as i32, y: height as i32 };
-                            },
-                            None => { }
-                        }
+                        if window_state.attributes.min_dimensions.is_some() ||
+                           window_state.attributes.max_dimensions.is_some() {
+
+                            let style = winuser::GetWindowLongA(window, winuser::GWL_STYLE) as DWORD;
+                            let ex_style = winuser::GetWindowLongA(window, winuser::GWL_EXSTYLE) as DWORD;
 
-                        match window_state.attributes.max_dimensions {
-                            Some((width, height)) => {
+                            if let Some(min_dimensions) = window_state.attributes.min_dimensions {
+                                let (width, height) = adjust_size(min_dimensions, style, ex_style);
+                                (*mmi).ptMinTrackSize = POINT { x: width as i32, y: height as i32 };
+                            }
+                            if let Some(max_dimensions) = window_state.attributes.max_dimensions {
+                                let (width, height) = adjust_size(max_dimensions, style, ex_style);
                                 (*mmi).ptMaxTrackSize = POINT { x: width as i32, y: height as i32 };
-                            },
-                            None => { }
+                            }
                         }
                     }
                 }

src/platform/windows/window.rs

@@ -622,6 +622,14 @@ pub struct WindowWrapper(HWND, HDC);
 // https://github.com/retep998/winapi-rs/issues/396
 unsafe impl Send for WindowWrapper {}
 
+pub unsafe fn adjust_size(
+    (x, y): (u32, u32), style: DWORD, ex_style: DWORD,
+) -> (LONG, LONG) {
+    let mut rect = RECT { left: 0, right: x as LONG, top: 0, bottom: y as LONG };
+    winuser::AdjustWindowRectEx(&mut rect, style, 0, ex_style);
+    (rect.right - rect.left, rect.bottom - rect.top)
+}
+
 unsafe fn init(window: WindowAttributes, pl_attribs: PlatformSpecificWindowBuilderAttributes,
                inserter: events_loop::Inserter, events_loop_proxy: events_loop::EventsLoopProxy) -> Result<Window, CreationError> {
     let title = OsStr::new(&window.title).encode_wide().chain(Some(0).into_iter())
@@ -659,10 +667,10 @@ unsafe fn init(window: WindowAttributes, pl_attribs: PlatformSpecificWindowBuild
     let real_window = {
         let (width, height) = if window.dimensions.is_some() {
             let min_dimensions = window.min_dimensions
-                .map(|d| (d.0 as raw::c_int, d.1 as raw::c_int))
+                .map(|d| adjust_size(d, style, ex_style))
                 .unwrap_or((0, 0));
             let max_dimensions = window.max_dimensions
-                .map(|d| (d.0 as raw::c_int, d.1 as raw::c_int))
+                .map(|d| adjust_size(d, style, ex_style))
                 .unwrap_or((raw::c_int::max_value(), raw::c_int::max_value()));
 
             (