winit-sonoma-fix/src/platform/windows/util.rs
Francesca Frangipane 2f7321a076
X11+Windows: Guess initial DPI factor (#583)
* X11: Guess initial DPI factor

* Windows: Guess initial DPI factor
2018-07-01 11:01:46 -04:00

105 lines
2.9 KiB
Rust

use std::{self, mem, ptr, slice};
use std::ops::BitAnd;
use winapi::ctypes::wchar_t;
use winapi::shared::minwindef::{BOOL, DWORD};
use winapi::shared::windef::{HWND, POINT, RECT};
use winapi::um::errhandlingapi::GetLastError;
use winapi::um::winbase::{
FormatMessageW,
FORMAT_MESSAGE_ALLOCATE_BUFFER,
FORMAT_MESSAGE_FROM_SYSTEM,
FORMAT_MESSAGE_IGNORE_INSERTS,
lstrlenW,
LocalFree,
};
use winapi::um::winnt::{
LPCWSTR,
MAKELANGID,
LANG_NEUTRAL,
SUBLANG_DEFAULT,
};
use winapi::um::winuser;
pub fn has_flag<T>(bitset: T, flag: T) -> bool
where T:
Copy + PartialEq + BitAnd<T, Output = T>
{
bitset & flag == flag
}
pub fn wchar_to_string(wchar: &[wchar_t]) -> String {
String::from_utf16_lossy(wchar).to_string()
}
pub fn wchar_ptr_to_string(wchar: *const wchar_t) -> String {
let len = unsafe { lstrlenW(wchar) } as usize;
let wchar_slice = unsafe { slice::from_raw_parts(wchar, len) };
wchar_to_string(wchar_slice)
}
pub unsafe fn status_map<T, F: FnMut(&mut T) -> BOOL>(mut fun: F) -> Option<T> {
let mut data: T = mem::uninitialized();
if fun(&mut data) != 0 {
Some(data)
} else {
None
}
}
pub fn get_cursor_pos() -> Option<POINT> {
unsafe { status_map(|cursor_pos| winuser::GetCursorPos(cursor_pos)) }
}
pub fn get_window_rect(hwnd: HWND) -> Option<RECT> {
unsafe { status_map(|rect| winuser::GetWindowRect(hwnd, rect)) }
}
// This won't be needed anymore if we just add a derive to winapi.
pub fn rect_eq(a: &RECT, b: &RECT) -> bool {
let left_eq = a.left == b.left;
let right_eq = a.right == b.right;
let top_eq = a.top == b.top;
let bottom_eq = a.bottom == b.bottom;
left_eq && right_eq && top_eq && bottom_eq
}
#[derive(Debug, Default, Clone, PartialEq, Eq)]
pub struct WinError(Option<String>);
impl WinError {
pub fn from_last_error() -> Self {
WinError(unsafe { get_last_error() })
}
}
pub unsafe fn get_last_error() -> Option<String> {
let err = GetLastError();
if err != 0 {
let buf_addr: LPCWSTR = {
let mut buf_addr: LPCWSTR = mem::uninitialized();
FormatMessageW(
FORMAT_MESSAGE_ALLOCATE_BUFFER
| FORMAT_MESSAGE_FROM_SYSTEM
| FORMAT_MESSAGE_IGNORE_INSERTS,
ptr::null(),
err,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT) as DWORD,
// This is a pointer to a pointer
&mut buf_addr as *mut LPCWSTR as *mut _,
0,
ptr::null_mut(),
);
buf_addr
};
if !buf_addr.is_null() {
let buf_len = lstrlenW(buf_addr) as usize;
let buf_slice = std::slice::from_raw_parts(buf_addr, buf_len);
let string = wchar_to_string(buf_slice);
LocalFree(buf_addr as *mut _);
return Some(string);
}
}
None
}