Fix Window.set_inner_size() on Win32

Previously, the function would actually set the outer size of the window
instead of the inner size.
We fix this by first letting windows calculate the outer size based upon
the specified inner size.

1 files changed, 11 insertions, 2 deletions

diff --git a/src/api/win32/mod.rs b/src/api/win32/mod.rs
index f580950..59fdf5d 100644
--- a/src/api/win32/mod.rs
+++ b/src/api/win32/mod.rs
@@ -182,8 +182,17 @@ impl Window {
         use libc;
 
         unsafe {
-            user32::SetWindowPos(self.window.0, ptr::null_mut(), 0, 0, x as libc::c_int,
-                y as libc::c_int, winapi::SWP_NOZORDER | winapi::SWP_NOREPOSITION | winapi::SWP_NOMOVE);
+            // Calculate the outer size based upon the specified inner size
+            let mut rect = winapi::RECT { top: 0, left: 0, bottom: y as winapi::LONG, right: x as winapi::LONG };
+            let dw_style = user32::GetWindowLongA(self.window.0, winapi::GWL_STYLE) as winapi::DWORD;
+            let b_menu = !user32::GetMenu(self.window.0).is_null() as winapi::BOOL;
+            let dw_style_ex = user32::GetWindowLongA(self.window.0, winapi::GWL_EXSTYLE) as winapi::DWORD;
+            user32::AdjustWindowRectEx(&mut rect, dw_style, b_menu, dw_style_ex);
+            let outer_x = (rect.right - rect.left).abs() as libc::c_int;
+            let outer_y = (rect.top - rect.bottom).abs() as libc::c_int;
+
+            user32::SetWindowPos(self.window.0, ptr::null_mut(), 0, 0, outer_x, outer_y,
+                winapi::SWP_NOZORDER | winapi::SWP_NOREPOSITION | winapi::SWP_NOMOVE);
             user32::UpdateWindow(self.window.0);
         }
     }